| RaceComp Engineering | 05-12-2005 09:17 AM |
The official Late Brakers thread as applied to slow in fast out, or vise versa...
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Ok, so the previous thread got out of control and we needed this thread for the track goers who know the basics.
My preference in driving/racing is fast in fast out, with minimal drama and yes, some risk. BUT , this isnt everyones way to do it, and I know we teach beginners slow in fast out, but that doesnt always happen or work when racing. I know alot of the open wheel guys are very fast in and very fast out. So there is the question. TO BE OR NOT TO BE?...lol..
So whatta you do?..I know alot of AWD cars dont turn well, and that makes alot of people slow in etc........
Then the question of this same theory but when passing, etc.......
Give your feedback.
Myles Williams
[url]www.racecompengineering.com[/url]
[email][email�protected][/email]
Racecomp Engineering LLC.
9123 Old Annapolis Rd Suite 103w
Columbia, Maryland 21044
410-730-RACE
410-730-5503 FAX
410-707-0108 mobile
My preference in driving/racing is fast in fast out, with minimal drama and yes, some risk. BUT , this isnt everyones way to do it, and I know we teach beginners slow in fast out, but that doesnt always happen or work when racing. I know alot of the open wheel guys are very fast in and very fast out. So there is the question. TO BE OR NOT TO BE?...lol..
So whatta you do?..I know alot of AWD cars dont turn well, and that makes alot of people slow in etc........
Then the question of this same theory but when passing, etc.......
Give your feedback.
Myles Williams
[url]www.racecompengineering.com[/url]
[email][email�protected][/email]
Racecomp Engineering LLC.
9123 Old Annapolis Rd Suite 103w
Columbia, Maryland 21044
410-730-RACE
410-730-5503 FAX
410-707-0108 mobile
| adeliciouspizza | 05-12-2005 09:20 AM |
slow in is ALWAYS faster than too fast in. i am somewhat of a noob so i tend to drive 8-9/10's but never push it beyond my or the car's ability.
| slowscooby | 05-12-2005 09:55 AM |
Im with ya on the "slow in fast out" mantra....and i try and think of all the stuff you read and hear about when your driving hard....but i just kinda go with my natural feelings when "Racing/Driving".....and that usually ends up with, fast in fast out......but since the re92's were created from old seashells i usually understeer a lot and just hope they grip....then they usually catch at the last second and i go.....and that means fast in...uncertainty...slow out.
So all in all i think with a good setup in these cars a happy medium between slow and fast can be acheived on the turn in....We'll say, quick in fast out....and maybe i dont know what the hell im talking about and im gonna hurt myself.
So all in all i think with a good setup in these cars a happy medium between slow and fast can be acheived on the turn in....We'll say, quick in fast out....and maybe i dont know what the hell im talking about and im gonna hurt myself.
| Scooby Freak | 05-12-2005 10:09 AM |
Well, the first few laps are slow in, fast out. Then I gently increase the entry speed on each lap until I reach too fast in, slow out. Then I take a deep breath & go back to slow in, fast out.
Myles, you have to let me ride along for a couple hot laps around summit point sometime this summer.
-jeff
Myles, you have to let me ride along for a couple hot laps around summit point sometime this summer.
-jeff
| ITWRX4ME | 05-12-2005 10:13 AM |
Doesn't it depend on what follows the turn in question, not to mention whether you're dueling with another car?
| RaceComp Engineering | 05-12-2005 10:27 AM |
[QUOTE=Scooby Freak]Well, the first few laps are slow in, fast out. Then I gently increase the entry speed on each lap until I reach too fast in, slow out. Then I take a deep breath & go back to slow in, fast out.
Myles, you have to let me ride along for a couple hot laps around summit point sometime this summer.
-jeff[/QUOTE]
no problem. In my street car( which is all I have now, since I sold the Porsche)..I tend to go out, do 1 warmup and then 2 hot laps and then come in. We can do that no problem.
mw
Myles, you have to let me ride along for a couple hot laps around summit point sometime this summer.
-jeff[/QUOTE]
no problem. In my street car( which is all I have now, since I sold the Porsche)..I tend to go out, do 1 warmup and then 2 hot laps and then come in. We can do that no problem.
mw
| kfoote | 05-12-2005 10:28 AM |
One thing to remember with "slow in, fast out"... "slow" is relative, and I think of "slow in" as slow enough to not compromise exit speed. As an example, at NHIS using the South Oval in my Miata, I use slow in, fast out, but don't back off the throttle until after turn-in. In a car that inherently understeers (AWD), slow in means slow enough to get the car to turn in, but getting it to turn in at as high of a speed as possible.
| turboICE | 05-12-2005 10:33 AM |
It all depends, slow in fast out doesn't work as well at say a LRP as it does at say a SP or VIR. LRP is all momementum and fast lap times require big ones. Big bend is the quintessential trail brake turn, just take a look at the turn in dots that Skippy uses every year they black out the prior year's dot and move the turn in farther and father back. This year it is just on the 3 side of the 2 brake marker, threshhold, early turn in with increasing input and trail braking all the way to apex.
Of course there is never a benefit to overcooking into a turn. So maybe the real issue is sure slow in, fast out always works but the definition for slow in is much more flexible than some would believe - it is not set in stone what slow in means for all turns.
Racing (someone is with you or trying to pass you) into a turn is never going to be a definitive answer - the answer then is you use the tack that will result with you in front of him again by the time you reach start/finish. If that means giving up turn 1 to him so you can take it back at turn 2, 5 ,9 or whatever then that is the tack you take.
Rookie Ed better at bench racing than actual. ;)
Of course there is never a benefit to overcooking into a turn. So maybe the real issue is sure slow in, fast out always works but the definition for slow in is much more flexible than some would believe - it is not set in stone what slow in means for all turns.
Racing (someone is with you or trying to pass you) into a turn is never going to be a definitive answer - the answer then is you use the tack that will result with you in front of him again by the time you reach start/finish. If that means giving up turn 1 to him so you can take it back at turn 2, 5 ,9 or whatever then that is the tack you take.
Rookie Ed better at bench racing than actual. ;)
| CBRDSpeedfactory | 05-12-2005 10:52 AM |
the funniest part is, most driver's professional and the like need to overcook corners...thats when u go "oh ****....i can go that much faster"...especially in high speed corners..
i did that once in a formula mazda...when i went to left foot brake into turn 1 at mosport and over the bumps my foot didnt get there...what did i learn... i could gain almost 2 tenths not dragging my foot..
oh yeah... and then there was turn one at road atlanta...in the lmp...same sort of deal....i then realized i could go all but flat almost until i turned the car in, all i needed was a drag/downshift....and i was in 5th, as opposed to 4th....
anyway..... it's all analytical..and u have to learn the quickest way around the track the most essential way u can.....
i for one am VERY VERY particular about tire wear and bringing them up to temp...u wont see efficient use of a street tire at the track by astronomically high temp numbers....so, if u want just a fast lap...do a slow warm up, and dont heat the tires with constant radius fast corners, do the race car technique of accelerating and braking...u dont just want to heat the contact patch, u want to heat the sidewalls consistently also.... the weaving while braking and accelerating does that...
anyway...
listen to myles......i've only ridden with him in a car once or twice on the street, and i can tell he would be an accomplished driver on the track....
chad b
chadblock.com
i did that once in a formula mazda...when i went to left foot brake into turn 1 at mosport and over the bumps my foot didnt get there...what did i learn... i could gain almost 2 tenths not dragging my foot..
oh yeah... and then there was turn one at road atlanta...in the lmp...same sort of deal....i then realized i could go all but flat almost until i turned the car in, all i needed was a drag/downshift....and i was in 5th, as opposed to 4th....
anyway..... it's all analytical..and u have to learn the quickest way around the track the most essential way u can.....
i for one am VERY VERY particular about tire wear and bringing them up to temp...u wont see efficient use of a street tire at the track by astronomically high temp numbers....so, if u want just a fast lap...do a slow warm up, and dont heat the tires with constant radius fast corners, do the race car technique of accelerating and braking...u dont just want to heat the contact patch, u want to heat the sidewalls consistently also.... the weaving while braking and accelerating does that...
anyway...
listen to myles......i've only ridden with him in a car once or twice on the street, and i can tell he would be an accomplished driver on the track....
chad b
chadblock.com
| BriDrive | 05-12-2005 11:06 AM |
I theorize that the slow-in or fast -in will be dictated by the actual corner. For example, in one extreme: a tight hairpin for example, the fast-in approach will probably yield an overall faster time throught the sector. In another example, lets say turn 6 and 7 (backside of) Road Atlanta, an earlier intial brake point will allow one to "drive" through 6 into 7,carrying more speed ealier to apex and then on gas out to 7 for a repeat.
So, I'm suggesting braking procedure isn't fixed at all, but rather dictated by a circuits "flow".
BriDrive
So, I'm suggesting braking procedure isn't fixed at all, but rather dictated by a circuits "flow".
BriDrive
| CBRDSpeedfactory | 05-12-2005 11:13 AM |
well actually in turn 6 in 7...u want to carry as much speed as possible into turn 6's apex...
because u will gain more time continuing into 6 faast at high speed than you will gain slowing then trying to mash back on the gas...
fast into 6...carry momentum through/out of the apex...then brake EARLY EARLY for 7, and roll through the apex powering out.
Every person i've ever coached there has tried to rush 7 and dirtracked off the corner....
not saying this to you in particular, but to anyone that plays there....
We would be going almost 165mph into turn 6 in the lmp cars, brake hard real quick at about the 1.5 marker (carbon brakes) hard back to power...then off the throttle brake.... come off thebrake roll into 7 and power on nicely right past the apex....
the biggest thing in driving a car fast is this... "MINIMUM CORNER SPEED"...u always want to make sure u have the "highest" minimum corner speed.....the guys that are fast when we look at speed traces on data acquisition are the ones whose corners look like a "U" not a "V" ...if it looks like a "V" it means that they are overly slowing the middle of the corner....
chad b
chadblock.com
because u will gain more time continuing into 6 faast at high speed than you will gain slowing then trying to mash back on the gas...
fast into 6...carry momentum through/out of the apex...then brake EARLY EARLY for 7, and roll through the apex powering out.
Every person i've ever coached there has tried to rush 7 and dirtracked off the corner....
not saying this to you in particular, but to anyone that plays there....
We would be going almost 165mph into turn 6 in the lmp cars, brake hard real quick at about the 1.5 marker (carbon brakes) hard back to power...then off the throttle brake.... come off thebrake roll into 7 and power on nicely right past the apex....
the biggest thing in driving a car fast is this... "MINIMUM CORNER SPEED"...u always want to make sure u have the "highest" minimum corner speed.....the guys that are fast when we look at speed traces on data acquisition are the ones whose corners look like a "U" not a "V" ...if it looks like a "V" it means that they are overly slowing the middle of the corner....
chad b
chadblock.com
| BriDrive | 05-12-2005 11:14 AM |
And Chad, I presume in the Mazda, you had enough revs in fifth to get you up the hill after turn 1 (RA) faster than fourth.
In the FormulaFord Zetec's, just about everyone outside of J Bowles, J Howard found themselves doing a quick downshift after turn 1 was finished...granted the "new" formula mazda's have more power.
BriDrive
In the FormulaFord Zetec's, just about everyone outside of J Bowles, J Howard found themselves doing a quick downshift after turn 1 was finished...granted the "new" formula mazda's have more power.
BriDrive
| kfoote | 05-12-2005 11:17 AM |
One thing to remember about Chads' post above, is that in cars that produce significant amounts of downforce, that a car can be easier to drive through a high speed corner at a higher speed than at a lower speed. Downforce increases significantly with speed, so going through a corner at a higher speed can in some instances be a good thing, and slow in, fast out doesn't work as well.
Most production based cars don't produce enough downforce to make that big of a difference.
Most production based cars don't produce enough downforce to make that big of a difference.
| dave bruener | 05-12-2005 11:30 AM |
What I have concentrated on in the last couple of years is setting myself up to get on the gas as soon as possible. In watching the fast guys, I noticed that they are on the gas well before the apex and the really fast guys are full throttle before the apex. By focusing on the acceleration point, the brake zones sorted themselves out.
I have noted this in both autocross and wheel to wheel road racing and in front drive, rear drive or AWD.
I guess it doen't address the discussion directly but sometimes changing your frame of reference or your focus can yield better results.
I have noted this in both autocross and wheel to wheel road racing and in front drive, rear drive or AWD.
I guess it doen't address the discussion directly but sometimes changing your frame of reference or your focus can yield better results.
| RaceComp Engineering | 05-12-2005 11:34 AM |
I found it hard to take turn 12 FLAT.....but my first race there ( ATL) it rained and after 6 laps I had to commit to flat with a narrow dry line thru turn 12 with the WALL next to you on both sides.
Myles
Myles
| CBRDSpeedfactory | 05-12-2005 11:41 AM |
i was talking about a formula mazda at RA...but i havent driven various cars there...
even without downforce... my main point has been....maintaining high minimum corner speeds and momentum.....
a fastest lap is the fastest average speed, not the quickest line through certain sections..... which means high average/minimum speeds....
the actual application doesnt really change..but the degree and which u use the theories does... in my experience, most people under-use their brakes initially... and then slow too long into the corner...
almost any car is going towork if u maintain it's dynamic "platform", allowing it to roll unloaded onto one rear corner or front.... if u know what i mean...
trying to shed some light, and make people not "overthink" so much.... if u are thinking too hard, u are going slow and thinking ur going fast!
sincerely
cb
chadblock.com
even without downforce... my main point has been....maintaining high minimum corner speeds and momentum.....
a fastest lap is the fastest average speed, not the quickest line through certain sections..... which means high average/minimum speeds....
the actual application doesnt really change..but the degree and which u use the theories does... in my experience, most people under-use their brakes initially... and then slow too long into the corner...
almost any car is going towork if u maintain it's dynamic "platform", allowing it to roll unloaded onto one rear corner or front.... if u know what i mean...
trying to shed some light, and make people not "overthink" so much.... if u are thinking too hard, u are going slow and thinking ur going fast!
sincerely
cb
chadblock.com
| CBRDSpeedfactory | 05-12-2005 11:44 AM |
also...
if u are talking about being on throttle before the apex, that can be a neccesary evil....as generally, u have overslowed ur entry....
the fastest guys you will see, arent fast just on exit...that are fast from their turn-in point, to the apex. that is the point of the corner where u are balancing, weight, grip, and ur whole package...
have u guys heard of the idea of "traction circle" ? it's a good one to analyze.
chad b
if u are talking about being on throttle before the apex, that can be a neccesary evil....as generally, u have overslowed ur entry....
the fastest guys you will see, arent fast just on exit...that are fast from their turn-in point, to the apex. that is the point of the corner where u are balancing, weight, grip, and ur whole package...
have u guys heard of the idea of "traction circle" ? it's a good one to analyze.
chad b
| CBRDSpeedfactory | 05-12-2005 11:45 AM |
[QUOTE=BriDrive]And Chad, I presume in the Mazda, you had enough revs in fifth to get you up the hill after turn 1 (RA) faster than fourth.
In the FormulaFord Zetec's, just about everyone outside of J Bowles, J Howard found themselves doing a quick downshift after turn 1 was finished...granted the "new" formula mazda's have more power.
BriDrive[/QUOTE]
i actually am friends with jason bowles... i coached him at laguna in 2001 when he wanted to run formula mazda with us...at that time, he didnt seem like he liked the move from karts lol...but he is now doing real well, and he is an awesome kid.
chad b
In the FormulaFord Zetec's, just about everyone outside of J Bowles, J Howard found themselves doing a quick downshift after turn 1 was finished...granted the "new" formula mazda's have more power.
BriDrive[/QUOTE]
i actually am friends with jason bowles... i coached him at laguna in 2001 when he wanted to run formula mazda with us...at that time, he didnt seem like he liked the move from karts lol...but he is now doing real well, and he is an awesome kid.
chad b
| RaceComp Engineering | 05-12-2005 11:46 AM |
[QUOTE=CBRD]trying to shed some light, and make people not "overthink" so much.... if u are thinking too hard, u are going slow and thinking ur going fast!
sincerely
cb
chadblock.com[/QUOTE]
This is the statement of the decade that people on most forums should really think about............I am glad you said it. ITs true and THATS what people should think about.
mw
sincerely
cb
chadblock.com[/QUOTE]
This is the statement of the decade that people on most forums should really think about............I am glad you said it. ITs true and THATS what people should think about.
mw
| CBRDSpeedfactory | 05-12-2005 11:49 AM |
when ur comfortable... u find urself going down the backchute at road atlanta... going...hey..that chick in the grandstands down at the kink is kinda hot...
or going through turn 1 at mosport thinking "did they remove that blade of grass coming up from between the asphalt at the apex since last session?"
hee he....
chad b
or going through turn 1 at mosport thinking "did they remove that blade of grass coming up from between the asphalt at the apex since last session?"
hee he....
chad b
| RaceComp Engineering | 05-12-2005 11:50 AM |
[QUOTE=CBRD]when ur comfortable... u find urself going down the backchute at road atlanta... going...hey..that chick in the grandstands down at the kink is kinda hot...
or going through turn 1 at mosport thinking "did they remove that blade of grass coming up from between the asphalt at the apex since last session?"
hee he....
chad b[/QUOTE]
you sound like a go-karter..............LOL
mw
or going through turn 1 at mosport thinking "did they remove that blade of grass coming up from between the asphalt at the apex since last session?"
hee he....
chad b[/QUOTE]
you sound like a go-karter..............LOL
mw
| kfoote | 05-12-2005 12:01 PM |
First off, "If you are thinking too hard, you are going too slow" is 100% correct, and if you aren't familiar with the traction circle and theory behind it, study up.
As far as throttle on before the apex, generally the fastest way through the corner is to be full throttle at the geometric apex, which in some cases is not the piont where you are at the closest point to the inside of the corner. Also, things like camber and elevation changes can affect the ideal point where you want to get back on the throttle.
As a good example of this that has already been mentioned, at turn 1 at Mosport, generally you want to be full power about 30 ft before the apex at the end of the curbing, because though the radius tightens, there is more grip later in the corner due to the increased banking in the corner from the end of the curb to about 2/3 of the way to track out.
An example of the converse of this is turn 3 at NHIS, where the fastest lap will usually be produced by not being full power until after the rumble strips on the inside, as the transition bumps going across the oval and having the geometric apex be well after the curbing produce this result.
Thing to remember: every corner is different, and there are many exceptions to general rules of thumb.
As far as throttle on before the apex, generally the fastest way through the corner is to be full throttle at the geometric apex, which in some cases is not the piont where you are at the closest point to the inside of the corner. Also, things like camber and elevation changes can affect the ideal point where you want to get back on the throttle.
As a good example of this that has already been mentioned, at turn 1 at Mosport, generally you want to be full power about 30 ft before the apex at the end of the curbing, because though the radius tightens, there is more grip later in the corner due to the increased banking in the corner from the end of the curb to about 2/3 of the way to track out.
An example of the converse of this is turn 3 at NHIS, where the fastest lap will usually be produced by not being full power until after the rumble strips on the inside, as the transition bumps going across the oval and having the geometric apex be well after the curbing produce this result.
Thing to remember: every corner is different, and there are many exceptions to general rules of thumb.
| ChrisDP | 05-12-2005 12:30 PM |
Fading brakes are also an *exciting* way to increase corner entry speed :lol:
I was working fairly hard to catch a car under braking going into one turn for a few laps, then my brakes decided cried uncle. I shut down the gap by about 20 feet on the car in front and still made the corner on-line albeit with a bit more drama. At that point I realized "well crap I CAN go in hotter here!"
At least at VIR, I've found a number of corners where yes, you can come in "slow" and make the car turn by gently establishing front end grip... but sometimes it's quicker to come in fast and use a quick brake release to induce rotation. IE, turn 3 at VIR Full/North you can either ride the outside rim of the track on entry, gently brake for 3 and smoothly bring the car in. I take a bit more of a straight line which involves driving straight across the apex of the kink beforehand (which if you're in a roadrace shuts down the inside line for a competitor behind you as an added bonus) give the brakes a big squeeze to slow the car a bit, and come off the brakes fast to rotate the back end into the corner. The rotation itself gets the car aimed properly and scrubs off just enough speed to get the car on line for the apex. As soon as the car starts rotating, I can go back to full throttle quickly, nail the apex and have a TON of exit speed.
On the other hand, an ITC car has relatively no power, but much better handling so any speed scrubbing won't do you any favors because you just can't pull out of the corner fast.
I was working fairly hard to catch a car under braking going into one turn for a few laps, then my brakes decided cried uncle. I shut down the gap by about 20 feet on the car in front and still made the corner on-line albeit with a bit more drama. At that point I realized "well crap I CAN go in hotter here!"
At least at VIR, I've found a number of corners where yes, you can come in "slow" and make the car turn by gently establishing front end grip... but sometimes it's quicker to come in fast and use a quick brake release to induce rotation. IE, turn 3 at VIR Full/North you can either ride the outside rim of the track on entry, gently brake for 3 and smoothly bring the car in. I take a bit more of a straight line which involves driving straight across the apex of the kink beforehand (which if you're in a roadrace shuts down the inside line for a competitor behind you as an added bonus) give the brakes a big squeeze to slow the car a bit, and come off the brakes fast to rotate the back end into the corner. The rotation itself gets the car aimed properly and scrubs off just enough speed to get the car on line for the apex. As soon as the car starts rotating, I can go back to full throttle quickly, nail the apex and have a TON of exit speed.
On the other hand, an ITC car has relatively no power, but much better handling so any speed scrubbing won't do you any favors because you just can't pull out of the corner fast.
| elgorey | 05-12-2005 12:37 PM |
The distinction needs to be made between racing and driving/HPDE/Time Trial.
While racing, your position, not your laptimes is the most important. If you take wide, sweeping lines and late apexes, while it is the "textbook" slow in fast out line, you will be easy pickings for your opponents. Likewise, to pass your opponents, often times you will outbrake them in a braking zone, go into the corner hot, and apex slightly early in order to get in front of their bumper, which hurts your exit speed, but gains position in the race.
Then there are the pros, who can somehow defy physics, and not loose any time when they go offline and pass. Thats why they are pros :)
While racing, your position, not your laptimes is the most important. If you take wide, sweeping lines and late apexes, while it is the "textbook" slow in fast out line, you will be easy pickings for your opponents. Likewise, to pass your opponents, often times you will outbrake them in a braking zone, go into the corner hot, and apex slightly early in order to get in front of their bumper, which hurts your exit speed, but gains position in the race.
Then there are the pros, who can somehow defy physics, and not loose any time when they go offline and pass. Thats why they are pros :)
| nhluhr | 05-12-2005 06:04 PM |
Ross Bentley has some nice thoughts on late braking.
| turboICE | 05-12-2005 06:25 PM |
[QUOTE=elgorey]Likewise, to pass your opponents, often times you will outbrake them in a braking zone, go into the corner hot, and apex slightly early in order to get in front of their bumper, which hurts your exit speed, but gains position in the race.[/QUOTE]Done properly yes - not done properly you lose the position right back on exit - and at times you both lose position to the driver that used to be behind both of you.
| CBRDSpeedfactory | 05-12-2005 06:31 PM |
[QUOTE=nhluhr]Ross Bentley has some nice thoughts on late braking.[/QUOTE]
i did a classroom school with ross bentlet in 2001, he asked "what is the proper racing technique"...
the whole class said "in slow out fast..."
i said "in fast out fast..".... and he said "i agree with chad."
it was funny... ross is a good guy.... next thing i knew, i was passing him on track ;)
chad b
chadblock.com
i did a classroom school with ross bentlet in 2001, he asked "what is the proper racing technique"...
the whole class said "in slow out fast..."
i said "in fast out fast..".... and he said "i agree with chad."
it was funny... ross is a good guy.... next thing i knew, i was passing him on track ;)
chad b
chadblock.com
| goto_racing | 05-12-2005 06:46 PM |
if fast laps are what you are going for (ie qualifying)...
I have driven some "momentum" cars. In fact, every car is a momentum car, and I have to disagree about "fast in". By fast I am assuming you mean actual vehicle speed. Almost every corner is a late apex whether we percieve it or not.
If you are not on the threshold during turn in, you are loosing time, I agree. That is a given. But as pointed out earlier, the "apex" of the turn, is not the geometrical apex of your arc. In fact, your cars actual path is not even a constant radius. What you will find is that fast drivers have very strong(but smooth) turn initiations, which makes the radius of their turn sharper before corner entry than after, which they unwind as the track out. The reason cars are faster through corners like this is because of the traction "circle". In fact, it's not a circle at all, because the car is capable of different amounts of Force depending on which direction it is trying to exhert them. Typical sports cars can brake over 1G, corner at a little under that, but only accelarate at about .2 to .3G. What we get is a traction "ovoid", in which our car is much better at braking than turning, and MUCH better at turning than accelarating.
In order to mazimize our cars performance, we drive deep into the corner, brake hard, then turn in while still braking in order to utilize the cornering forces to rotate us. To get all this done allows us to do the "textbook" thing of getting on the throttle early. We didn't come into this corner "too slow" just because we are on the gas before the apex. We get on the gas at precisely the point where we no longer need to utilize cornering force to rotate the car, because since our car only accelarates at .2G, it will need need the extra space to get up to speed. To try to entry a corner "early" means more rotation must be accomplished after the apex. Rotation costs cornering force, which you must steal from accelaration, something our traction "ovoid" already lacks! It doesn't matter how much speed you carried past the apex if you must spend it all on finishing your rotation.
Because a mid apex line does not allow for hard braking and rotation, you may be faster at YOUR geometric apex, but I am faster at corner entry, turn apex, and track out.
In short, unequal forces make for unequal paths (think about the orbit of a comet), meaning the fastest way through a corner is to always be at the limit in everything a car is doing, not just turning.
For a good example of this. Watch some tapes of Senna. The only way I can describe his turn in is "BAM!!!!" :)
Of course, in a race, you only get as much road as your opponents give you. You're on your own then...
Chris Lock
I have driven some "momentum" cars. In fact, every car is a momentum car, and I have to disagree about "fast in". By fast I am assuming you mean actual vehicle speed. Almost every corner is a late apex whether we percieve it or not.
If you are not on the threshold during turn in, you are loosing time, I agree. That is a given. But as pointed out earlier, the "apex" of the turn, is not the geometrical apex of your arc. In fact, your cars actual path is not even a constant radius. What you will find is that fast drivers have very strong(but smooth) turn initiations, which makes the radius of their turn sharper before corner entry than after, which they unwind as the track out. The reason cars are faster through corners like this is because of the traction "circle". In fact, it's not a circle at all, because the car is capable of different amounts of Force depending on which direction it is trying to exhert them. Typical sports cars can brake over 1G, corner at a little under that, but only accelarate at about .2 to .3G. What we get is a traction "ovoid", in which our car is much better at braking than turning, and MUCH better at turning than accelarating.
In order to mazimize our cars performance, we drive deep into the corner, brake hard, then turn in while still braking in order to utilize the cornering forces to rotate us. To get all this done allows us to do the "textbook" thing of getting on the throttle early. We didn't come into this corner "too slow" just because we are on the gas before the apex. We get on the gas at precisely the point where we no longer need to utilize cornering force to rotate the car, because since our car only accelarates at .2G, it will need need the extra space to get up to speed. To try to entry a corner "early" means more rotation must be accomplished after the apex. Rotation costs cornering force, which you must steal from accelaration, something our traction "ovoid" already lacks! It doesn't matter how much speed you carried past the apex if you must spend it all on finishing your rotation.
Because a mid apex line does not allow for hard braking and rotation, you may be faster at YOUR geometric apex, but I am faster at corner entry, turn apex, and track out.
In short, unequal forces make for unequal paths (think about the orbit of a comet), meaning the fastest way through a corner is to always be at the limit in everything a car is doing, not just turning.
For a good example of this. Watch some tapes of Senna. The only way I can describe his turn in is "BAM!!!!" :)
Of course, in a race, you only get as much road as your opponents give you. You're on your own then...
Chris Lock
| trhoppe | 05-12-2005 07:10 PM |
[QUOTE=goto_racing]if fast laps are what you are going for (ie qualifying)...
I have driven some "momentum" cars. In fact, every car is a momentum car, and I have to disagree about "fast in". By fast I am assuming you mean actual vehicle speed. Almost every corner is a late apex whether we percieve it or not.
If you are not on the threshold during turn in, you are loosing time, I agree. That is a given. But as pointed out earlier, the "apex" of the turn, is not the geometrical apex of your arc. In fact, your cars actual path is not even a constant radius. What you will find is that fast drivers have very strong(but smooth) turn initiations, which makes the radius of their turn sharper before corner entry than after, which they unwind as the track out. The reason cars are faster through corners like this is because of the traction "circle". In fact, it's not a circle at all, because the car is capable of different amounts of Force depending on which direction it is trying to exhert them. Typical sports cars can brake over 1G, corner at a little under that, but only accelarate at about .2 to .3G. What we get is a traction "ovoid", in which our car is much better at braking than turning, and MUCH better at turning than accelarating.
In order to mazimize our cars performance, we drive deep into the corner, brake hard, then turn in while still braking in order to utilize the cornering forces to rotate us. To get all this done allows us to do the "textbook" thing of getting on the throttle early. We didn't come into this corner "too slow" just because we are on the gas before the apex. We get on the gas at precisely the point where we no longer need to utilize cornering force to rotate the car, because since our car only accelarates at .2G, it will need need the extra space to get up to speed. To try to entry a corner "early" means more rotation must be accomplished after the apex. Rotation costs cornering force, which you must steal from accelaration, something our traction "ovoid" already lacks! It doesn't matter how much speed you carried past the apex if you must spend it all on finishing your rotation.
Because a mid apex line does not allow for hard braking and rotation, you may be faster at YOUR geometric apex, but I am faster at corner entry, turn apex, and track out.
In short, unequal forces make for unequal paths (think about the orbit of a comet), meaning the fastest way through a corner is to always be at the limit in everything a car is doing, not just turning.
For a good example of this. Watch some tapes of Senna. The only way I can describe his turn in is "BAM!!!!" :)
Of course, in a race, you only get as much road as your opponents give you. You're on your own then...
Chris Lock[/QUOTE]
Best post ever!
-Tom
I have driven some "momentum" cars. In fact, every car is a momentum car, and I have to disagree about "fast in". By fast I am assuming you mean actual vehicle speed. Almost every corner is a late apex whether we percieve it or not.
If you are not on the threshold during turn in, you are loosing time, I agree. That is a given. But as pointed out earlier, the "apex" of the turn, is not the geometrical apex of your arc. In fact, your cars actual path is not even a constant radius. What you will find is that fast drivers have very strong(but smooth) turn initiations, which makes the radius of their turn sharper before corner entry than after, which they unwind as the track out. The reason cars are faster through corners like this is because of the traction "circle". In fact, it's not a circle at all, because the car is capable of different amounts of Force depending on which direction it is trying to exhert them. Typical sports cars can brake over 1G, corner at a little under that, but only accelarate at about .2 to .3G. What we get is a traction "ovoid", in which our car is much better at braking than turning, and MUCH better at turning than accelarating.
In order to mazimize our cars performance, we drive deep into the corner, brake hard, then turn in while still braking in order to utilize the cornering forces to rotate us. To get all this done allows us to do the "textbook" thing of getting on the throttle early. We didn't come into this corner "too slow" just because we are on the gas before the apex. We get on the gas at precisely the point where we no longer need to utilize cornering force to rotate the car, because since our car only accelarates at .2G, it will need need the extra space to get up to speed. To try to entry a corner "early" means more rotation must be accomplished after the apex. Rotation costs cornering force, which you must steal from accelaration, something our traction "ovoid" already lacks! It doesn't matter how much speed you carried past the apex if you must spend it all on finishing your rotation.
Because a mid apex line does not allow for hard braking and rotation, you may be faster at YOUR geometric apex, but I am faster at corner entry, turn apex, and track out.
In short, unequal forces make for unequal paths (think about the orbit of a comet), meaning the fastest way through a corner is to always be at the limit in everything a car is doing, not just turning.
For a good example of this. Watch some tapes of Senna. The only way I can describe his turn in is "BAM!!!!" :)
Of course, in a race, you only get as much road as your opponents give you. You're on your own then...
Chris Lock[/QUOTE]
Best post ever!
-Tom
| CBRDSpeedfactory | 05-12-2005 07:21 PM |
well what ur saying doesnt contradict anything that was already said...
it basically reinforces what i was saying...the fastest guys are good on entry... i always like a car to turn as much as possible initially, so im giving almost no steering input as i leave my apex point out...basically letting the cars initial rotation do the turning...
that means the car is "unwound" and exiting the corner.......
for instance... turns 6 and 7 again at road atlanta... you should be braking...turning in, and then basically straight with the wheel at the apex...so the car is coming off the corner in a widening motion, but in a relatively straight path.... then u brake early for 7..turn the car in, feed on power, and want to be using the added transition of the car from power to allow u to unwind the wheel...
i always teach "slow hands" in coaching.... and i teach guys to be aggressive...but smooth...
like i said...we didn't develop any new theories...
i think the point is, and what myles was trying to make is.... u need a good overall car...good brakes..good balance.. etc...
meaning excellent brakes...excellent dampers...and excellent alignment..and so forth.... but still.... dont overthink on the track...if u are soo busy worried about the corner u are in... then u are working to hard...ur mind should be smoothly and fluidly... a turn ahead.....
chad b
chadblock.com
it basically reinforces what i was saying...the fastest guys are good on entry... i always like a car to turn as much as possible initially, so im giving almost no steering input as i leave my apex point out...basically letting the cars initial rotation do the turning...
that means the car is "unwound" and exiting the corner.......
for instance... turns 6 and 7 again at road atlanta... you should be braking...turning in, and then basically straight with the wheel at the apex...so the car is coming off the corner in a widening motion, but in a relatively straight path.... then u brake early for 7..turn the car in, feed on power, and want to be using the added transition of the car from power to allow u to unwind the wheel...
i always teach "slow hands" in coaching.... and i teach guys to be aggressive...but smooth...
like i said...we didn't develop any new theories...
i think the point is, and what myles was trying to make is.... u need a good overall car...good brakes..good balance.. etc...
meaning excellent brakes...excellent dampers...and excellent alignment..and so forth.... but still.... dont overthink on the track...if u are soo busy worried about the corner u are in... then u are working to hard...ur mind should be smoothly and fluidly... a turn ahead.....
chad b
chadblock.com
| timmyb21 | 05-12-2005 07:22 PM |
[QUOTE=kfoote]One thing to remember with "slow in, fast out"... "slow" is relative, and I think of "slow in" as slow enough to not compromise exit speed. As an example, at NHIS using the South Oval in my Miata, I use slow in, fast out, but don't back off the throttle until after turn-in. In a car that inherently understeers (AWD), slow in means slow enough to get the car to turn in, but getting it to turn in at as high of a speed as possible.[/QUOTE]Exactly. Understeer is put in from the factory, so slow in, but not real slow. Is the car pushing? Too fast. You are trying to minimize the time spent in a corner so you can get to the next corner that much faster! This is especially important in low hp cars where the time spent accelerating down the straights will take considerably more time than something with buttloads of hp. I'll stop rambling now.
Tim
And for my amusement, dancing banana! :banana:
Tim
And for my amusement, dancing banana! :banana:
| CBRDSpeedfactory | 05-12-2005 07:23 PM |
and the other thing is...the quicker of a car u get into...youll be doing things faster.... obviously....especially corrections....
chad b
chadblock.com
chad b
chadblock.com
| goto_racing | 05-12-2005 08:37 PM |
[QUOTE=CBRD]well what ur saying doesnt contradict anything that was already said...
it basically reinforces what i was saying...the fastest guys are good on entry... i always like a car to turn as much as possible initially, so im giving almost no steering input as i leave my apex point out...basically letting the cars initial rotation do the turning...[/QUOTE]
I knew what you where saying, :) and I wasn't really disagreeing, but what it sounds like to people who are learning is different. I was just disagreeing with the terminology most people use to desribe this technique, which is very misleading. The difference between "hard" in(what you and I do) and "fast" in, is enormous. Yeah, getting the car rotated quickly is the right way to do it.
Even when we drive this way, our "slowest" point, or the point at which the car has the least velocity, depending on the turn, will occur at some distance between turn in and the apex of the corner. Not AT the apex(as in "brake all the way to the apex, son!"). Maybe this can be described as "slow in", but I think the instructional vocabulary could use some ironing out in this area.
Suggesstions anyone? It's your chance to coin the cornering phrase for the new millenium! :)
Chris Lock
it basically reinforces what i was saying...the fastest guys are good on entry... i always like a car to turn as much as possible initially, so im giving almost no steering input as i leave my apex point out...basically letting the cars initial rotation do the turning...[/QUOTE]
I knew what you where saying, :) and I wasn't really disagreeing, but what it sounds like to people who are learning is different. I was just disagreeing with the terminology most people use to desribe this technique, which is very misleading. The difference between "hard" in(what you and I do) and "fast" in, is enormous. Yeah, getting the car rotated quickly is the right way to do it.
Even when we drive this way, our "slowest" point, or the point at which the car has the least velocity, depending on the turn, will occur at some distance between turn in and the apex of the corner. Not AT the apex(as in "brake all the way to the apex, son!"). Maybe this can be described as "slow in", but I think the instructional vocabulary could use some ironing out in this area.
Suggesstions anyone? It's your chance to coin the cornering phrase for the new millenium! :)
Chris Lock
| CBRDSpeedfactory | 05-12-2005 08:43 PM |
Chris,
i will have to agree with u...mostly looking at data, our minimums are just before apexing just at the point of transition back to power...
i like how much the subie guys want to learn...i really got sick of the old euro crowd when i did euro stuff!!
two thumbs up guys!!
lets all hit the track some time..myles and i want to do our own subie days at the track!!
Chad b
chadblock.com
i will have to agree with u...mostly looking at data, our minimums are just before apexing just at the point of transition back to power...
i like how much the subie guys want to learn...i really got sick of the old euro crowd when i did euro stuff!!
two thumbs up guys!!
lets all hit the track some time..myles and i want to do our own subie days at the track!!
Chad b
chadblock.com
| goto_racing | 05-12-2005 09:10 PM |
[QUOTE=CBRD]Chris,
i will have to agree with u...mostly looking at data, our minimums are just before apexing just at the point of transition back to power...
[/QUOTE]
I almost suggested trying to find some data, you read my mind. Where did you get the data? What are you driving? Something fast I hope. :)
How about "Wide in, Easy out"? man that makes no sense....
Chris Lock
i will have to agree with u...mostly looking at data, our minimums are just before apexing just at the point of transition back to power...
[/QUOTE]
I almost suggested trying to find some data, you read my mind. Where did you get the data? What are you driving? Something fast I hope. :)
How about "Wide in, Easy out"? man that makes no sense....
Chris Lock
| Apex Rex | 05-12-2005 09:10 PM |
[QUOTE=CBRD]
lets all hit the track some time..myles and i want to do our own subie days at the track!!
Chad b
chadblock.com[/QUOTE]
No matter price nor track, I will find some way of getting out to that track day!
Lots of good info Im letting soak into my sponge of a brain in this thread. :p
lets all hit the track some time..myles and i want to do our own subie days at the track!!
Chad b
chadblock.com[/QUOTE]
No matter price nor track, I will find some way of getting out to that track day!
Lots of good info Im letting soak into my sponge of a brain in this thread. :p
| 360GT | 05-12-2005 09:16 PM |
deleted
| BriDrive | 05-12-2005 09:18 PM |
Hey Chris, If you appreciate the "Bam!" of the late Senna...you should REALLY appreciate the turn in of Fernando Alonso...
Chad, I wish you and Myles were a wee bit further south...
"...Suggesstions anyone? It's your chance to coin the cornering phrase for the new millenium!" Ummm, how 'bout: " Rotation Induction Point Braking"
BriDrive...sitting back to see if it sticks........
Chad, I wish you and Myles were a wee bit further south...
"...Suggesstions anyone? It's your chance to coin the cornering phrase for the new millenium!" Ummm, how 'bout: " Rotation Induction Point Braking"
BriDrive...sitting back to see if it sticks........
| CBRDSpeedfactory | 05-12-2005 10:32 PM |
LOL!
i love this forum
i was supposed to do a lamborghini day at Road atlanta..but im busy...go figure..
chad b
i love this forum
i was supposed to do a lamborghini day at Road atlanta..but im busy...go figure..
chad b
| CBRDSpeedfactory | 05-12-2005 10:36 PM |
by the way...senna was great...
his sports car version...James Weaver...the guy is insane...i looked at our data and was like...damn..
chad b
chadblock.com
his sports car version...James Weaver...the guy is insane...i looked at our data and was like...damn..
chad b
chadblock.com
| Scoobie Doogie | 05-12-2005 11:15 PM |
Hmmm... a Subie day at the track with Chad and Miles. Sounds priceless to me. As much as I like my Subie is it okay if I bring my ITR instead. It turns MUCH better.
Dave
Dave
| Mullin | 05-13-2005 09:29 AM |
At one of the tarmac rallies in last years WRC Nicky Grist did an interesting comparison between Seb & Marcus & their styles, Marcus was late break & Seb was early break (slow in) on the gas earlier (fast out), no need to explain which one is faster.
In the context of 4wd where you can get on the power earlier I'm with Seb on the slow in fast out approach. ;)
In the context of 4wd where you can get on the power earlier I'm with Seb on the slow in fast out approach. ;)
| CBRDSpeedfactory | 05-13-2005 09:51 AM |
rally is a-whole-nother realm..
ur not ebraking into the corner..
loeb is in a courage for le mans , and has been slower than all of his teeammates ;)
chad b
chadblock.com
ur not ebraking into the corner..
loeb is in a courage for le mans , and has been slower than all of his teeammates ;)
chad b
chadblock.com
| Joel Gat, 1.8L | 05-13-2005 01:15 PM |
Hello,
I don't think there's anything wrong with 'fast in, faster out.' As I alluded to yesterday in another thread, if 95% of the "track day" folks are trying to improve, they need to work on the most basic beginner technique. Learn to get on the brakes.
Brake deep into the corner, very hard. Whether it's racing or just a fun track day, I constantly see people getting on their brakes 50, 100, or more feet before they need to. They hold half as hard on the brake pedal for twice as long. In countless races, at almost any level of US national racing, you see passes where one person gets on the brakes too early, the next guy flies by and then gets on the brakes, and completes the pass effortlessly.
So the first "trick" that track day guys (and many racers) need to learn is "slow in, fast out." Not "slow on the straight leading to the corner and even slower on corner entry, geez I wish I was fast out." More like "fast on the straight, slow on entry, fast out." :p
Trail braking is a great technique that I would guess maybe 5% of the guys going to "track days" have ever even tried. Once you really know how to brake hard and late, then you can start moving that 'late' even later and maintain it through the entry. When you do that, compared to a straight-line braker, the trail braker is going faster at entry. When you can maintain that trail the entire time you're entering through the time you transition to power, then you've upped the speed through the corner significantly. Now you're really much faster at every point in the corner. Now you're going 'fast in, faster out,' relative to the straight-line braker.
How much faster are you going? I dunno. I've never datalogged Gary driving "the slow way." :p It's so hard to get drivers to waste time doing dumb things! Hahaha...
Joel
I don't think there's anything wrong with 'fast in, faster out.' As I alluded to yesterday in another thread, if 95% of the "track day" folks are trying to improve, they need to work on the most basic beginner technique. Learn to get on the brakes.
Brake deep into the corner, very hard. Whether it's racing or just a fun track day, I constantly see people getting on their brakes 50, 100, or more feet before they need to. They hold half as hard on the brake pedal for twice as long. In countless races, at almost any level of US national racing, you see passes where one person gets on the brakes too early, the next guy flies by and then gets on the brakes, and completes the pass effortlessly.
So the first "trick" that track day guys (and many racers) need to learn is "slow in, fast out." Not "slow on the straight leading to the corner and even slower on corner entry, geez I wish I was fast out." More like "fast on the straight, slow on entry, fast out." :p
Trail braking is a great technique that I would guess maybe 5% of the guys going to "track days" have ever even tried. Once you really know how to brake hard and late, then you can start moving that 'late' even later and maintain it through the entry. When you do that, compared to a straight-line braker, the trail braker is going faster at entry. When you can maintain that trail the entire time you're entering through the time you transition to power, then you've upped the speed through the corner significantly. Now you're really much faster at every point in the corner. Now you're going 'fast in, faster out,' relative to the straight-line braker.
How much faster are you going? I dunno. I've never datalogged Gary driving "the slow way." :p It's so hard to get drivers to waste time doing dumb things! Hahaha...
Joel
| ITWRX4ME | 06-10-2005 09:31 AM |
This month's Sports Car mag did an article on trail braking and it's effectiveness. But the way they set up the test and the way they gloss over the really important points makes the article basically worthless.
First, they set up the test on a flat oval, with short straightaways and performed the test in one gear (probably second, judging from the speeds attained). They focused solely on cornering speed, exit speed and lap time. The same driver drove all of the tests and they did about 12 to 15 laps using different lines; the slow in, fast out type of line, the trail braking line and the inside radius line.
The the trail braking laps yielded [i]faster lap times and faster cornering speeds[/i]. However, the slow in, fast out technique always yielded the [i]highest exit speed[/i].
Their conclusion was rather vague, basically saying you should give trailbraking a try. :rolleyes:
What they failed miserably to do was point out that, for this test, the [i]short straightaways gave the advantage to the trail braking technique[/i] simply because of its faster cornering speeds. If the straights had been longer, the faster exit speeds of the slow in, fast out technique would have prevailed because this allows the car to hit top speed sooner and sustain it longer.
I just did a track weekend at Shenandoah. I think I trail braked all but a very few corners. But my car does not have good lateral grip. So I know, in certain turns, I can't carry much speed. Using the trail braking line, I carry more speed early, decelerating all the way to mid corner, where I end up at the same speed, on the same part of the line that I would have used on a late apex. And the car is pointed at the exit because of the rotation gained during the trail braking phase.
I'd have to say the decision to use trail braking comes more from track layout and racing position than anything else.
Purely from a racing standpoint, you have to use trail braking if you're going to pass someone when all else is equal. But that's a double edged sword. Do it on the wrong corner, with the wrong timing and the wrong mid corner position and the guy you just passed will breeze by you on the next straight. Pwned!
First, they set up the test on a flat oval, with short straightaways and performed the test in one gear (probably second, judging from the speeds attained). They focused solely on cornering speed, exit speed and lap time. The same driver drove all of the tests and they did about 12 to 15 laps using different lines; the slow in, fast out type of line, the trail braking line and the inside radius line.
The the trail braking laps yielded [i]faster lap times and faster cornering speeds[/i]. However, the slow in, fast out technique always yielded the [i]highest exit speed[/i].
Their conclusion was rather vague, basically saying you should give trailbraking a try. :rolleyes:
What they failed miserably to do was point out that, for this test, the [i]short straightaways gave the advantage to the trail braking technique[/i] simply because of its faster cornering speeds. If the straights had been longer, the faster exit speeds of the slow in, fast out technique would have prevailed because this allows the car to hit top speed sooner and sustain it longer.
I just did a track weekend at Shenandoah. I think I trail braked all but a very few corners. But my car does not have good lateral grip. So I know, in certain turns, I can't carry much speed. Using the trail braking line, I carry more speed early, decelerating all the way to mid corner, where I end up at the same speed, on the same part of the line that I would have used on a late apex. And the car is pointed at the exit because of the rotation gained during the trail braking phase.
I'd have to say the decision to use trail braking comes more from track layout and racing position than anything else.
Purely from a racing standpoint, you have to use trail braking if you're going to pass someone when all else is equal. But that's a double edged sword. Do it on the wrong corner, with the wrong timing and the wrong mid corner position and the guy you just passed will breeze by you on the next straight. Pwned!
| BATSCUBIE | 06-10-2005 09:35 AM |
Drag racers go in fast and come out slow :devil:
| fliz | 06-10-2005 09:55 AM |
[QUOTE=ITWRX4ME]What they failed miserably to do was point out that, for this test, the [i]short straightaways gave the advantage to the trail braking technique[/i] simply because of its faster cornering speeds. If the straights had been longer, the faster exit speeds of the slow in, fast out technique would have prevailed because this allows the car to hit top speed sooner and sustain it longer.[/QUOTE]
I got the impression from that article that the trail braking line was faster largely because of the shorter distance travelled. Which is why the "inside line" was faster than both of them, once the driver got used to driving it.
They were claiming .2 sec / lap was just because the car travelled ~14 feet less on the trail braking line than the SIFO line.
I got the impression from that article that the trail braking line was faster largely because of the shorter distance travelled. Which is why the "inside line" was faster than both of them, once the driver got used to driving it.
They were claiming .2 sec / lap was just because the car travelled ~14 feet less on the trail braking line than the SIFO line.
| Roy Dietsch | 06-10-2005 10:11 AM |
It not a matter of should, its a matter of when and where, TRAIL BRAKING is FASTER in some turns 180's, carosels, turns that take time or where time beats out speed. I agree with alot that was said already. But I hope some people reading this don't go out to their second lap day and feel that can use this to gain time and end up in the tires. I've been racing for 5 years and Im just starting to learn, I probably dont have enough experiance for it to do me much good becuase I tend to over brake before turn in while LFBing. I moved my pedals and made a 6 inch wide brake so I can heel toe early and move both feet on the brake to help train the other and transistion smoothing onto the gas. I have only ridden with one person that trailbraked well enough to keep most of the exit speed but absolutly crush in the turns...Jeff Cashmore(multi time national champ ES, also races SM and Spec7) I think this is his 14th or so season...
Roy
Roy
| ITWRX4ME | 06-10-2005 10:30 AM |
[QUOTE=fliz]I got the impression from that article that the trail braking line was faster largely because of the shorter distance travelled. Which is why the "inside line" was faster than both of them, once the driver got used to driving it.
They were claiming .2 sec / lap was just because the car travelled ~14 feet less on the trail braking line than the SIFO line.[/QUOTE]
You're right, but again they miss the overall picture because the scope of the test gave the advantage to those techniques.
This test definitely lends credence to the autocrosser's technique of using the shortest distance possible. In that realm, the application of trail braking and the inside line are super important.
But what's the most important turn on a track? The turn leading onto the longest straight. Why is it most important? Because the exit speed on that turn determines how fast you reach top speed on the straightaway and how long you sustain it. The faster you can cover that straightaway, the shorter your lap times (duh).
If the straightaway is .25 mile long and the distance through the turn (from braking point to max throttle) is .1 mile, where do you have the most to gain from maximizing your sustained speed?
Let's say you can save .2 second to cover the .1 mile in that turn by trail braking, but your exit speed is 45 mph.
If you you give up that .2 second to use the traditional line and your exit speed is 50 mph, you may cover the .25 mile straight .5 second sooner (or better. I can't do the math).
Anyway, my point was that the article was just so useless. I expected more from Sports Car. They went so far into the traction circle numbers, which the average person has a hard time following, and left the really important, and practical, aspects completely unexplored.
They were claiming .2 sec / lap was just because the car travelled ~14 feet less on the trail braking line than the SIFO line.[/QUOTE]
You're right, but again they miss the overall picture because the scope of the test gave the advantage to those techniques.
This test definitely lends credence to the autocrosser's technique of using the shortest distance possible. In that realm, the application of trail braking and the inside line are super important.
But what's the most important turn on a track? The turn leading onto the longest straight. Why is it most important? Because the exit speed on that turn determines how fast you reach top speed on the straightaway and how long you sustain it. The faster you can cover that straightaway, the shorter your lap times (duh).
If the straightaway is .25 mile long and the distance through the turn (from braking point to max throttle) is .1 mile, where do you have the most to gain from maximizing your sustained speed?
Let's say you can save .2 second to cover the .1 mile in that turn by trail braking, but your exit speed is 45 mph.
If you you give up that .2 second to use the traditional line and your exit speed is 50 mph, you may cover the .25 mile straight .5 second sooner (or better. I can't do the math).
Anyway, my point was that the article was just so useless. I expected more from Sports Car. They went so far into the traction circle numbers, which the average person has a hard time following, and left the really important, and practical, aspects completely unexplored.
| goto_racing | 06-10-2005 12:28 PM |
I don't think this converstation was ever about "trail braking" per se. It was about what lines yield the fastest lap time. If the definition of "trail braking" is the driver continuing brake pressure after turn in, I think it is necessary for almost EVERY turn, whether you are slow in, fast in, whatever. If your race car is set up to put power down out of the turn, then it probably needs brake pressure to achieve a good turn in, no matter what your line or speed is.
Chris Lock
Chris Lock
| kfoote | 06-13-2005 12:52 PM |
In my Miata, I have to trail brake in just about every turn to help the car to rotate, so the amount of trail braking is more the issue rather than whether or not. For most standard corners, trail braking just enough to get the car turned in is all I need. In a stock suspension, low powered car like the Miata, it's all about getting on the power early, and being a left-foot braker, I am often back on the power before I have totally let off the brakes. From the time I have spent in Subarus, it seems to be the case with those as well; trail brake just enough to get the car to rotate, then back on the power as early as possible.
| ITWRX4ME | 06-13-2005 02:07 PM |
[QUOTE=kfoote]In my Miata, I have to trail brake in just about every turn to help the car to rotate, so the amount of trail braking is more the issue rather than whether or not. For most standard corners, trail braking just enough to get the car turned in is all I need. In a stock suspension, low powered car like the Miata, it's all about getting on the power early, and being a left-foot braker, I am often back on the power before I have totally let off the brakes. From the time I have spent in Subarus, it seems to be the case with those as well; trail brake just enough to get the car to rotate, then back on the power as early as possible.[/QUOTE]
I'll second that. Given the turbo lag in the WRX, there are many places I find my self in the same situation. My last track session, I started playing with left foot braking but I'm a long way off in having it be effective. Of course, I couldn't trail brake in the beginning either. ;)
I'll second that. Given the turbo lag in the WRX, there are many places I find my self in the same situation. My last track session, I started playing with left foot braking but I'm a long way off in having it be effective. Of course, I couldn't trail brake in the beginning either. ;)
| mnavarro | 06-14-2005 02:37 AM |
Maybe a stupid question, do ABS brakes have an affect on how deep into the turn you're breaking?
| subieworx | 06-14-2005 08:00 AM |
If they come on during breaking, of course. When the ABS system is activated it iwll increase your stopping distance.
| mnavarro | 06-14-2005 08:12 AM |
The only reason I say this is that SIFO means doing all your breaking before the turn-in and abs breaks allow you maintain better control even while turning in. So use your ABS to late break.
| ITWRX4ME | 06-14-2005 09:16 AM |
[QUOTE=mnavarro]Maybe a stupid question, do ABS brakes have an affect on how deep into the turn you're breaking?[/QUOTE]
The short answer is no. A person that can effectively threshold brake can stop quicker than ABS. That translates to less time spent decelerating.
However, threshold braking is another one of those advanced skills that has a very fine balancing point. You go past a certain point and you get flat spots on your $200 tires. Square tires == no good
The good news is that you can threshold brake on top of ABS and the ABS will save you from flat spots when you step over the threshold. So it's good to have it there when you need it.
The short answer is no. A person that can effectively threshold brake can stop quicker than ABS. That translates to less time spent decelerating.
However, threshold braking is another one of those advanced skills that has a very fine balancing point. You go past a certain point and you get flat spots on your $200 tires. Square tires == no good
The good news is that you can threshold brake on top of ABS and the ABS will save you from flat spots when you step over the threshold. So it's good to have it there when you need it.
| kfoote | 06-14-2005 10:22 AM |
I read the article this mornign, and there is very little info that can be applied to a real racing situation in there. The fastest line around a track will have corners using each of these different techniques. Running NHIS's South oval configuration, as described in Sportscar, I use all 3 different techniques in the first 4 real corners. I use the inslide line for the oval (not braking unil after turn-in in the Miata), I use their version of SIFO for turn 3, a slow tight left hand corner, where exit speed is critical, and I use their version of trail braking in turn 9, a goofy 3rd gear downhill left hander that is immediately followed by a fast right hander that leads on to a decent straight. Turn 6, the other corner in there is a hybrid of their versions of SIFO and trail braking, which is necessarry due to the strange banking profile of the corner.
Remember that all the conclusions that they came to are all based on a flat oval with only 300' straights, and I for one have never driven a totally flat 180* 50 MPH corner that entry speed and exit speed were equally important, and the only track that I can think of that had that setup was the street circuit in Washington DC that was used for one race.
Remember that all the conclusions that they came to are all based on a flat oval with only 300' straights, and I for one have never driven a totally flat 180* 50 MPH corner that entry speed and exit speed were equally important, and the only track that I can think of that had that setup was the street circuit in Washington DC that was used for one race.
| GarySheehan | 06-14-2005 11:04 AM |
[QUOTE=ITWRX4ME]The short answer is no. A person that can effectively threshold brake can stop quicker than ABS. That translates to less time spent decelerating.
However, threshold braking is another one of those advanced skills that has a very fine balancing point. You go past a certain point and you get flat spots on your $200 tires. Square tires == no good
The good news is that you can threshold brake on top of ABS and the ABS will save you from flat spots when you step over the threshold. So it's good to have it there when you need it.[/QUOTE]
Not quite correct. In a poor implementation of ABS this is true, but with a good ABS system there are some other things that need to be considered.
The best driver in the world can only modulate the brakes to the wheel with the least traction. If he goes over that, the wheel locks. An adequate ABS system allows the driver to brake EVERY tire at maximum adhesion. This optimizes the brake balance everywhere. Consider this when looking at a trailbraking situation where every tire is loaded differently.
Gary
Sheehan Motor Racing
[url]www.teamSMR.com[/url]
However, threshold braking is another one of those advanced skills that has a very fine balancing point. You go past a certain point and you get flat spots on your $200 tires. Square tires == no good
The good news is that you can threshold brake on top of ABS and the ABS will save you from flat spots when you step over the threshold. So it's good to have it there when you need it.[/QUOTE]
Not quite correct. In a poor implementation of ABS this is true, but with a good ABS system there are some other things that need to be considered.
The best driver in the world can only modulate the brakes to the wheel with the least traction. If he goes over that, the wheel locks. An adequate ABS system allows the driver to brake EVERY tire at maximum adhesion. This optimizes the brake balance everywhere. Consider this when looking at a trailbraking situation where every tire is loaded differently.
Gary
Sheehan Motor Racing
[url]www.teamSMR.com[/url]
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