| Rally Punx | 04-03-2003 10:13 PM |
Shift from 2nd to 1st on tight turn. How??
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I competed in my first autox a couple of weeks ago (after participating in a novice school) and was wondering how WRX guys are shifting from 2nd gear to 1st?? They had a pretty tight turn on the course and the car bogged coming out in 2nd gear. I tried to downshift into 1st, but it just spitted it right back out. I asked another scooby driver that was competing on the same heat and he said that the way to do it was to heel and toe. You'll have to excuse me, but I'm pretty new to all this and really don't know what heel and toe is. Can somebody just explain to me in simple terms how can I downshift from 2nd to 1st. I'll be competing again this weekend and would like to improve my times. I was 1.5 seconds behind the guy who won my class. I lost more than that just coming out of that particular turn. I will really appreciate it.
| supermarkus | 04-03-2003 10:17 PM |
maybe left foot brake in 2nd to keep the revs somewhat up?:confused: I haven't tried it in an autocross situation but, it works pretty well on tight on ramps and empty parking lots.
Also try rev matching and shifting before the turn instead of mid. Heel/toeing can be pretty hectic in the heat of battle, practice it lots before you release the hounds.
Do a search on the technique, there's lots of info on heel/toe shifting.
Also try rev matching and shifting before the turn instead of mid. Heel/toeing can be pretty hectic in the heat of battle, practice it lots before you release the hounds.
Do a search on the technique, there's lots of info on heel/toe shifting.
| MSG | 04-03-2003 10:48 PM |
Unless you have a large foot, heel & toe is pretty hard in the WRX. But the principle is very important to understand, and you can improvise.
The purpose is to match your engine rev's when you downshift. For example, if you want to downshift from 2nd to 1st at 20mph, you want to blip the throttle so that when you release the clutch in 1st gear, the RPM's are the same as if you were already going that speed in 1st gear. However, anytime you downshift to a very steep gear like 1st gear, you will find that the car is very touchy. It is such a torquey gear that it will be very hard to downshift, even if you match the rev's by blipping the throttle.
To experiment, try it on the street in a 3rd to 2nd downshift. See what 35mph is in 2nd gear on the tach (sorry, I don't remember offhand). So, be at 35 mph in 3rd gear. You will see you are at a far lower RPM. So, if you want to smoothly be in 2nd gear, and at a much sweeter spot in the RPM band, you need to blip the throttle when downshifting from 3rd to 2nd when downshifting, and get the engine rev's to match. Basically, you want to cause the revs to be what they should/would be when you release the clutch in 2nd gear. Not only will you get a much smoother downshift (imagine an egg sitting on the passenger floor) but you will be at the right spot in the rev band to accelerate in 2nd gear and get a quick blast. If you just downshift without the blip, the car will urch forward. I bet you know what I mean. Do the blip with your right foot for now. Understand the principle, and later learn heel & toe.
(FYI, heel & toe is using one foot (the right one) on both the brake & gas pedal simultaneously. There are different techniques, but basically you have the ball of the foot on the brake pedal when braking/slowing, and 'blip' the throttle with the heel of the foot. Your foot gets pretty sideways, but it is an important technique to learn. Every car is different due to the pedal setup, not just ther spacing but also their verticle 'height' differential. Personally, I think the WRX has bad pedals to heel & toe. I have bought new (larger) pedals, but have not yet installed them.)
Hope this made some sense. Just got back from a wine tasting, and am a little buzzed. But this is a VERY important thing to learn about driving a manual transmission car. It is much easier on the transmission (and smoother driving), but more importantly it allows you to maximize the car's power band when you want to.
MSG
The purpose is to match your engine rev's when you downshift. For example, if you want to downshift from 2nd to 1st at 20mph, you want to blip the throttle so that when you release the clutch in 1st gear, the RPM's are the same as if you were already going that speed in 1st gear. However, anytime you downshift to a very steep gear like 1st gear, you will find that the car is very touchy. It is such a torquey gear that it will be very hard to downshift, even if you match the rev's by blipping the throttle.
To experiment, try it on the street in a 3rd to 2nd downshift. See what 35mph is in 2nd gear on the tach (sorry, I don't remember offhand). So, be at 35 mph in 3rd gear. You will see you are at a far lower RPM. So, if you want to smoothly be in 2nd gear, and at a much sweeter spot in the RPM band, you need to blip the throttle when downshifting from 3rd to 2nd when downshifting, and get the engine rev's to match. Basically, you want to cause the revs to be what they should/would be when you release the clutch in 2nd gear. Not only will you get a much smoother downshift (imagine an egg sitting on the passenger floor) but you will be at the right spot in the rev band to accelerate in 2nd gear and get a quick blast. If you just downshift without the blip, the car will urch forward. I bet you know what I mean. Do the blip with your right foot for now. Understand the principle, and later learn heel & toe.
(FYI, heel & toe is using one foot (the right one) on both the brake & gas pedal simultaneously. There are different techniques, but basically you have the ball of the foot on the brake pedal when braking/slowing, and 'blip' the throttle with the heel of the foot. Your foot gets pretty sideways, but it is an important technique to learn. Every car is different due to the pedal setup, not just ther spacing but also their verticle 'height' differential. Personally, I think the WRX has bad pedals to heel & toe. I have bought new (larger) pedals, but have not yet installed them.)
Hope this made some sense. Just got back from a wine tasting, and am a little buzzed. But this is a VERY important thing to learn about driving a manual transmission car. It is much easier on the transmission (and smoother driving), but more importantly it allows you to maximize the car's power band when you want to.
MSG
| jmott | 04-04-2003 12:54 AM |
thought you can rev match and maybe get it in
the truth is youll probably eat up what little first gear synchro there is fast if you do this regularly.
just left foot brake to keep the boost up, or deal with the bogging.
if you must shift to first, prolly the best way to pull it off is MUSCLE it in there fast.
the truth is youll probably eat up what little first gear synchro there is fast if you do this regularly.
just left foot brake to keep the boost up, or deal with the bogging.
if you must shift to first, prolly the best way to pull it off is MUSCLE it in there fast.
| thechickencow | 04-04-2003 12:55 AM |
The way I've done it in rallyx'es locally which seem to have tighter turns that the autox'es I've done locally is this:
I generally brake for the turn early, then heel-toe (rev match) and try to get the shifter in 1st while still applying braking. At this point I'm usually at the apex of the turn and can get onto the gas as I'm letting the clutch out. Sometimes its faster to downshift, but sometimes it isn't.
Hope that helps.
I generally brake for the turn early, then heel-toe (rev match) and try to get the shifter in 1st while still applying braking. At this point I'm usually at the apex of the turn and can get onto the gas as I'm letting the clutch out. Sometimes its faster to downshift, but sometimes it isn't.
Hope that helps.
| fengshui-fu | 04-04-2003 01:05 AM |
left foot braking in 2nd is probably better off for your car's mechanics than forcing it into 1st (even with rev matching). brake pads and rotors are definitely cheaper to replace than transmissions if you are planning on racing in this fashion. Also, not everyone races their daily driver.
chris
chris
| MSG | 04-04-2003 01:08 AM |
JMott (hello) is right. You will probably need to slam it in there. I virtually never downshift to first, as it is pretty hard on the synchro's.
However, going back to my original post, practice the heel & toe for 3rd/2nd downshifts. It is much smoother, easier on the gearbox, and will keep you in the right place in the powerband.
However, going back to my original post, practice the heel & toe for 3rd/2nd downshifts. It is much smoother, easier on the gearbox, and will keep you in the right place in the powerband.
| ITWRX4ME | 04-04-2003 07:14 AM |
Can someone explain left foot braking. How does it keep you from bogging in a tight turn in second gear?
| spidey02wrx | 04-04-2003 07:21 AM |
Left-foot braking lets you stay on the gas to keep the revs up, and on the brake to slow the car down. Tough on the brakes, but sometimes its necessary for success. Many turbo cars use this technique to avoid the bog out of tight turns.
mark
mark
| ITWRX4ME | 04-04-2003 07:33 AM |
So, if you're on the gas and the brakes at the same time, something's got to slip. What is it? The clutch, the tires, the diff?
| AustinTX | 04-04-2003 07:36 AM |
You must get out of gear, let the clutch out, rev the motor to some RPM higher or equal to what it would be at in first, then push the clutch in and put it in first. It'll pop right in. The syncros don't seem to like spinning the clutch up, but they'll easily slow it down to match the speed it needs to be at.
| AustinTX | 04-04-2003 07:37 AM |
In other words, you'll have to double-clutch. It works like a charm.
| ellisnc | 04-04-2003 08:36 AM |
what I have done in the past for very slow corners is just slip the clutch in 2nd gear
1) brake for the corner
2) mid corner push the clutch in and slip the clutch with WOT coming out
works pretty well and done right not really that abusive to be honest
1) brake for the corner
2) mid corner push the clutch in and slip the clutch with WOT coming out
works pretty well and done right not really that abusive to be honest
| KC | 04-04-2003 09:06 AM |
As you can see, there's many differnet opinions... here's mine:
Don't downshift into 1st. Period.
Slow in - fast out.
Brake earlier with left foot (you're not shifting so you have a free foot doing nothing) but modulate the gas too (not too hard, not too soft)... it'll help keep boost up.
As soon as you're about 1/4 through the turn, use the brakes to balance the car (not on them hard) and gradually increase throttle, by the time you're near the apex, boost should be up and the car pointing where it needs to go.
You will lose more time shifting into 1st then back to second than you will just by keeping it in 2nd and modulating the throttle/brakes, not to mention unsettling the car in a turn when the weight transfers suddenly... BAD. It may SEEM like an eternity, but it really isn't. You just have to get used to it. :) Your tranny will thank you too.
I used to down shift on all tight turns until someone mentioned this to me after a 1st run and I FOUND a full second by doing this.
--kC
Don't downshift into 1st. Period.
Slow in - fast out.
Brake earlier with left foot (you're not shifting so you have a free foot doing nothing) but modulate the gas too (not too hard, not too soft)... it'll help keep boost up.
As soon as you're about 1/4 through the turn, use the brakes to balance the car (not on them hard) and gradually increase throttle, by the time you're near the apex, boost should be up and the car pointing where it needs to go.
You will lose more time shifting into 1st then back to second than you will just by keeping it in 2nd and modulating the throttle/brakes, not to mention unsettling the car in a turn when the weight transfers suddenly... BAD. It may SEEM like an eternity, but it really isn't. You just have to get used to it. :) Your tranny will thank you too.
I used to down shift on all tight turns until someone mentioned this to me after a 1st run and I FOUND a full second by doing this.
--kC
| thrdeye | 04-04-2003 09:13 AM |
haha I'm trying to left foot brake.....I nearly put my head through the windshield....it's touchy
| KC | 04-04-2003 09:21 AM |
[QUOTE][i]Originally posted by thrdeye [/i]
[B]haha I'm trying to left foot brake.....I nearly put my head through the windshield....it's touchy [/B][/QUOTE]UH huh. Takes practice. :D QUite a bit. But what better place to try it than in a safe environment where all you'll hit is cones and not cars or lamp posts. :D
You'll get the hang of it. Just don't give up. If you can do it with your right foot easily, it can be done with your left too.
[B]haha I'm trying to left foot brake.....I nearly put my head through the windshield....it's touchy [/B][/QUOTE]UH huh. Takes practice. :D QUite a bit. But what better place to try it than in a safe environment where all you'll hit is cones and not cars or lamp posts. :D
You'll get the hang of it. Just don't give up. If you can do it with your right foot easily, it can be done with your left too.
| TheWRX | 04-04-2003 09:21 AM |
[QUOTE][i]Originally posted by spidey02wrx [/i]
[B]Left-foot braking lets you stay on the gas to keep the revs up[/B][/QUOTE]
It's not going to change your revs, they are only determined by the gear ratio and speed. As others have said, it lets you keep the boost up.
Not that I'm an example of how to drive fast :o , but I never shift into 1st. After my first few events, I thought that it might be helpful. Then I took Evolution school, and watched John Thomas drive my car. That course had a couple of very tight corners right after the start. He threw it into 2nd almost out of the gate. When I asked him why he didn't stay in 1st through the first turns, he said something like "You don't need much power if you drive a smooth line." If it works for him, it can't be all wrong...
[B]Left-foot braking lets you stay on the gas to keep the revs up[/B][/QUOTE]
It's not going to change your revs, they are only determined by the gear ratio and speed. As others have said, it lets you keep the boost up.
Not that I'm an example of how to drive fast :o , but I never shift into 1st. After my first few events, I thought that it might be helpful. Then I took Evolution school, and watched John Thomas drive my car. That course had a couple of very tight corners right after the start. He threw it into 2nd almost out of the gate. When I asked him why he didn't stay in 1st through the first turns, he said something like "You don't need much power if you drive a smooth line." If it works for him, it can't be all wrong...
| Jaxx | 04-04-2003 10:27 AM |
i agree with KC .. don't shift into first
things to try
smaller diamater tires
reduced rotating mass lighter rims/uderdrive pully/fly wheel
catless uppipe
slip the clutch .. in second
things to try
smaller diamater tires
reduced rotating mass lighter rims/uderdrive pully/fly wheel
catless uppipe
slip the clutch .. in second
| ITWRX4ME | 04-04-2003 11:40 AM |
[QUOTE][i]Originally posted by ITWRX4ME [/i]
[B]So, if you're on the gas and the brakes at the same time, something's got to slip. What is it? The clutch, the tires, the diff? [/B][/QUOTE]
Still don't see an explanation for ^^^^ :confused:
[B]So, if you're on the gas and the brakes at the same time, something's got to slip. What is it? The clutch, the tires, the diff? [/B][/QUOTE]
Still don't see an explanation for ^^^^ :confused:
| akuhner | 04-04-2003 12:04 PM |
I have a similar problem at Rally-Cross, but being able to do it is important if you want to be competitive. I learned to heel toe rev match it into first at stop signs, but since I don't blow stop signs that only teachs you to get it into first. The sequence is this:
1) brake with foot sideways
2) clutch in
3) shift out of 2nd
4) clutch out
5) rev up to speed w/ side of foot (and keep it there!)
6) clutch in
7) shift into first
8) clutch out (still with revs at right level)
Do that all in a fraction of the time it took you to read it and you are all set. It works for me on the street every time, but for some reason it doesn't work as well in competition, especially in rally-x. When the speed of your wheels has no direct link to the speed of your car (spinning on a slippery surface, locked up in braking) it's really hard to rev match properly. Next time in dirt I'm going to try a new method - skip the rev matching in favor of full brake lock up! In theory that would be like shifting into first at a stand still - I hope!
I used the above double clutch / rev match sequence when driving a friends WRX at auto-x and it went in like butter (thank god!). But in my car I don't generally bother with getting back to first at Auto-X, KC is right about slow in fast out - fast in causes you to slow more which creates the bog when you are trying to get out.
Anyone have ideas on the rally-x shift to 1st?
Alex
PS. Left foot braking has nothing to do with this problem - LFB should only be used when you have to go from the brake to the gas a lot and need to save the fractions of a second where your right foot would usually be moving between pedals. NEVER brake and accelerate at the same time, it's completely pointless! :lol:
1) brake with foot sideways
2) clutch in
3) shift out of 2nd
4) clutch out
5) rev up to speed w/ side of foot (and keep it there!)
6) clutch in
7) shift into first
8) clutch out (still with revs at right level)
Do that all in a fraction of the time it took you to read it and you are all set. It works for me on the street every time, but for some reason it doesn't work as well in competition, especially in rally-x. When the speed of your wheels has no direct link to the speed of your car (spinning on a slippery surface, locked up in braking) it's really hard to rev match properly. Next time in dirt I'm going to try a new method - skip the rev matching in favor of full brake lock up! In theory that would be like shifting into first at a stand still - I hope!
I used the above double clutch / rev match sequence when driving a friends WRX at auto-x and it went in like butter (thank god!). But in my car I don't generally bother with getting back to first at Auto-X, KC is right about slow in fast out - fast in causes you to slow more which creates the bog when you are trying to get out.
Anyone have ideas on the rally-x shift to 1st?
Alex
PS. Left foot braking has nothing to do with this problem - LFB should only be used when you have to go from the brake to the gas a lot and need to save the fractions of a second where your right foot would usually be moving between pedals. NEVER brake and accelerate at the same time, it's completely pointless! :lol:
| Big C | 04-04-2003 12:15 PM |
I agree with KC....Last season I tried everything to get my WRX through the tight corners and the quickest way was always leave it in second and use LFBing. 1st feels faster, but the clock doesn't seem to take this into account :D
BTW- Car 187: LFBing might not help your RS as much, but does work when you have major turbo lag because it loads the engine and gives the turbo more energy to spool. If you do it correctly in a car that "needs" it you can drop times significantly...trust me.
BTW- Car 187: LFBing might not help your RS as much, but does work when you have major turbo lag because it loads the engine and gives the turbo more energy to spool. If you do it correctly in a car that "needs" it you can drop times significantly...trust me.
| Rebellion | 04-04-2003 12:24 PM |
[QUOTE][i]Originally posted by ITWRX4ME [/i]
[B]
Still don't see an explanation for ^^^^ :confused: [/B][/QUOTE]
nothing's slipping.. you're just burning brake pads. the gear is fully engaged so the clutch and the diff are out.
and you're still going the same speed so tires are out too.
The diff would be no more affected by LFB into a turn than not LFB. The wheel speed differences would still be the same.
edit- .. hmm I was thinking, and yeah maybe the diff would take some stress, but I don't think it's "damaging"
[B]
Still don't see an explanation for ^^^^ :confused: [/B][/QUOTE]
nothing's slipping.. you're just burning brake pads. the gear is fully engaged so the clutch and the diff are out.
and you're still going the same speed so tires are out too.
The diff would be no more affected by LFB into a turn than not LFB. The wheel speed differences would still be the same.
edit- .. hmm I was thinking, and yeah maybe the diff would take some stress, but I don't think it's "damaging"
| PaulC | 04-04-2003 12:42 PM |
Since you are a new autocrosser, I wouldn't worry about shifting into first or left foot braking to keep the boost up.
Focus on braking early and getting on the gas as soon as you can. On the tight turns it is easy to enter them too fast, forcing you to scrub off speed in the corner when you should be straightening the wheel and getting on the throttle.
I'm not saying that what has been said in this thread is [i]bad[/i] advice, but you need to walk before you can run, right? :)
I am a firm believer in the concept of spending your first couple seasons as an autocrosser working on the basics before you get fancy. It will pay off later.
Focus on braking early and getting on the gas as soon as you can. On the tight turns it is easy to enter them too fast, forcing you to scrub off speed in the corner when you should be straightening the wheel and getting on the throttle.
I'm not saying that what has been said in this thread is [i]bad[/i] advice, but you need to walk before you can run, right? :)
I am a firm believer in the concept of spending your first couple seasons as an autocrosser working on the basics before you get fancy. It will pay off later.
| supermarkus | 04-04-2003 12:48 PM |
[QUOTE][i]Originally posted by ITWRX4ME [/i]
[B]So, if you're on the gas and the brakes at the same time, something's got to slip. What is it? The clutch, the tires, the diff? [/B][/QUOTE]
You're not trying to lock up the brakes, just load the engine while you're slowing down. The biggest loser is your brake pads in this game.
[B]So, if you're on the gas and the brakes at the same time, something's got to slip. What is it? The clutch, the tires, the diff? [/B][/QUOTE]
You're not trying to lock up the brakes, just load the engine while you're slowing down. The biggest loser is your brake pads in this game.
| spidey02wrx | 04-04-2003 01:01 PM |
Here's a good thread over on honda-tech
[URL=http://www.honda-tech.com/zerothread?id=462385]LFB[/URL]
I learned alot from this thread and the one over there as well.
I had the (wrong) perception that this would help keep the 'revs up' . I just heard that LFB is good for turbo cars, and I planned on doing some of it this year.
mark
[URL=http://www.honda-tech.com/zerothread?id=462385]LFB[/URL]
I learned alot from this thread and the one over there as well.
I had the (wrong) perception that this would help keep the 'revs up' . I just heard that LFB is good for turbo cars, and I planned on doing some of it this year.
mark
| TheWRX | 04-04-2003 01:21 PM |
Now that we changed topics to LFB ;) , I have a question on how to apply it in practice: Do you guys do [I]all[/I] your braking with the left foot, or only in specific situations, like slow turns? Say you're approaching a tight turn after a high speed section. Do you do the braking before the turn with the left foot? Or is the main part of the braking still with the right foot, and you only get the left foot on the brake once you're in the turn, the way KC described?
| ITWRX4ME | 04-04-2003 02:06 PM |
Well, what I've read here and on that other thread still doesn't explain how left foot braking would help keep the 'turbo spooled up' or even keep the revs up for that matter. Mechanically, it just doesn't seem possible.
I can understand using it to rotate the car, but that has nothing to do with keeping the revs up.
So back to the original problem. If one is forced to slow down for a turn, to the extent that the speed would cause the engine to bog in second gear once the throttle is applied, how is left foot braking going to keep the engine from bogging, given the same speed?
Oh, Lucy! Ju got some 'splainin' to do!
I can understand using it to rotate the car, but that has nothing to do with keeping the revs up.
So back to the original problem. If one is forced to slow down for a turn, to the extent that the speed would cause the engine to bog in second gear once the throttle is applied, how is left foot braking going to keep the engine from bogging, given the same speed?
Oh, Lucy! Ju got some 'splainin' to do!
| Rebellion | 04-04-2003 02:28 PM |
because it's the difference between having no load on the engine and retaining load on the engine. You take your foot off the gas, your turbo stops spooling. Now leave your foot on the gas and put your foot on the brake and the engine is still under load therefore your turbo doesn't stop spooling.
| KC | 04-04-2003 02:31 PM |
Keeping boost up does just that. You're not in vaccuum. (Do you have a boost guage?). Remember, turbos don't only run in positive PSi (lbs), they also have a negative value. (Vaccuum)
Running 0 psi by LFB is better than taking your foot off the gas and having the boost drop into -psi (vaccuum). By keeping 0psi, boost is readily availble instead of waiting for the turbo to be fed exhaust gasses ("lag" or negative Psi) until you're under boost.
While LFB and keeping 'boost' at 0 PSi you still have pressure and exhaust gasses being sent towards the turbo and less time to get out of the negative. :) (More volume being moved through the headers and to the uppipe)
If you have a boost gauge.... in a straight line on your way home today or whatever at 30 mph, just let go of the go pedal and watch your boost go into the negative psi immediately. (Below 0)
Then do the same thing in the straight line but slow down gradually by LFB and keep modulating the go pedal so boost doesn't drop below 0.
You're not going to see 14psi, you may see only 2-3lbs... But to go from 0 to 14lbs is simply 14lbs of boost needed. To go from -7psi vaccuum to 14lbs positive is a longer time to wait for the turbo to spool.
Did that help?
Running 0 psi by LFB is better than taking your foot off the gas and having the boost drop into -psi (vaccuum). By keeping 0psi, boost is readily availble instead of waiting for the turbo to be fed exhaust gasses ("lag" or negative Psi) until you're under boost.
While LFB and keeping 'boost' at 0 PSi you still have pressure and exhaust gasses being sent towards the turbo and less time to get out of the negative. :) (More volume being moved through the headers and to the uppipe)
If you have a boost gauge.... in a straight line on your way home today or whatever at 30 mph, just let go of the go pedal and watch your boost go into the negative psi immediately. (Below 0)
Then do the same thing in the straight line but slow down gradually by LFB and keep modulating the go pedal so boost doesn't drop below 0.
You're not going to see 14psi, you may see only 2-3lbs... But to go from 0 to 14lbs is simply 14lbs of boost needed. To go from -7psi vaccuum to 14lbs positive is a longer time to wait for the turbo to spool.
Did that help?
| Big C | 04-04-2003 02:33 PM |
Simple explanation:
When the engine is under high load there is more exhaust energy to spin the turbo then when under light load. When you are pushing the brake and the gas you have a high load condition. By doing this you don't have to wait to get the motor back under load to spool the turbo up and therefore have more power available sooner. This is less pronounced in other turbo cars, but very helpful in a laggy car like a stock WRX.
FWIW- I'm only suggesting LFB as a technique that works very well to keep a stock/nearly stock WRX closer to boost in tight turns. There are many other reasons to use (or not use) LFB in other situations, I'm not addressing any of them.....
When the engine is under high load there is more exhaust energy to spin the turbo then when under light load. When you are pushing the brake and the gas you have a high load condition. By doing this you don't have to wait to get the motor back under load to spool the turbo up and therefore have more power available sooner. This is less pronounced in other turbo cars, but very helpful in a laggy car like a stock WRX.
FWIW- I'm only suggesting LFB as a technique that works very well to keep a stock/nearly stock WRX closer to boost in tight turns. There are many other reasons to use (or not use) LFB in other situations, I'm not addressing any of them.....
| Big C | 04-04-2003 02:47 PM |
Simple explanation:
When the engine is under high load there is more exhaust energy to spin the turbo then when under light load. When you are pushing the brake and the gas you have a high load condition. By doing this you don't have to wait to get the motor back under load to spool the turbo up and therefore have more power available sooner. This is less pronounced in other turbo cars, but very helpful in a laggy car like a stock WRX.
FWIW- I'm only suggesting LFB as a technique that works very well to keep a stock/nearly stock WRX closer to boost in tight turns. There are many other reasons to use (or not use) LFB in other situations, I'm not addressing any of them.....
When the engine is under high load there is more exhaust energy to spin the turbo then when under light load. When you are pushing the brake and the gas you have a high load condition. By doing this you don't have to wait to get the motor back under load to spool the turbo up and therefore have more power available sooner. This is less pronounced in other turbo cars, but very helpful in a laggy car like a stock WRX.
FWIW- I'm only suggesting LFB as a technique that works very well to keep a stock/nearly stock WRX closer to boost in tight turns. There are many other reasons to use (or not use) LFB in other situations, I'm not addressing any of them.....
| ITWRX4ME | 04-04-2003 02:54 PM |
I guess I'll have to try it and watch my boost gauge.
Not to be argumentative(just trying to understand) but if the engine's speed is not increased, how does load increase/maintain exhaust volume? Exhaust volume depends on engine speed, no?
Not to be argumentative(just trying to understand) but if the engine's speed is not increased, how does load increase/maintain exhaust volume? Exhaust volume depends on engine speed, no?
| Big C | 04-04-2003 03:18 PM |
Because your dumping fuel into it......The fuel is still burnt and the energy still goes out the exhaust. Even if its not as high of energy as if the rpms were higher its still better than the energy you have at zero throttle....
C
C
| KC | 04-04-2003 03:34 PM |
[QUOTE][i]Originally posted by Big C [/i]
[B]Because your dumping fuel into it......The fuel is still burnt and the energy still goes out the exhaust. Even if its not as high of energy as if the rpms were higher its still better than the energy you have at zero throttle....
C [/B][/QUOTE]*ding* :D
[B]Because your dumping fuel into it......The fuel is still burnt and the energy still goes out the exhaust. Even if its not as high of energy as if the rpms were higher its still better than the energy you have at zero throttle....
C [/B][/QUOTE]*ding* :D
| Dussander | 04-04-2003 04:12 PM |
Reto,
I basically shift to second and then leave my left foot hovering over the brake pedal for the rest of the course. I use the brake to help turn in, keep the turbo spooled, or straight line brake. I have a tendency to trail brake into a turn, letting off the pressure as I get into the turn. I don't (ok, rarely) use LFB on the street. Now if you need to down shift, which I still do, but very rarely, the LFB can throw you off. I've slammed in the brake expecting the clutch before and I've slammed in the clutch expecting the brake before. But, *cough*, I don't do those mistakes anymore. :)
I basically shift to second and then leave my left foot hovering over the brake pedal for the rest of the course. I use the brake to help turn in, keep the turbo spooled, or straight line brake. I have a tendency to trail brake into a turn, letting off the pressure as I get into the turn. I don't (ok, rarely) use LFB on the street. Now if you need to down shift, which I still do, but very rarely, the LFB can throw you off. I've slammed in the brake expecting the clutch before and I've slammed in the clutch expecting the brake before. But, *cough*, I don't do those mistakes anymore. :)
| EricB | 04-04-2003 04:33 PM |
> Exhaust volume depends on engine speed, no?
No. 3500 rpm's at full throttle has way more exhaust volume that 3500 rpm's off throttle. Why, because at full throttle you're burning lots more gas than when you're off throttle.
Eric
No. 3500 rpm's at full throttle has way more exhaust volume that 3500 rpm's off throttle. Why, because at full throttle you're burning lots more gas than when you're off throttle.
Eric
| TheWRX | 04-04-2003 05:04 PM |
[QUOTE][i]Originally posted by Dussander [/i]
[B]But, *cough*, I don't do those mistakes anymore. :) [/B][/QUOTE]
Famous last words! ;) I think we talked about this before. Doing all the braking with the left foot makes sense, it's probably easier on the brain to always do the same thing with the same foot. I was wondering if everybody was handling it this way, or if others (like KC) used different strategies.
[B]But, *cough*, I don't do those mistakes anymore. :) [/B][/QUOTE]
Famous last words! ;) I think we talked about this before. Doing all the braking with the left foot makes sense, it's probably easier on the brain to always do the same thing with the same foot. I was wondering if everybody was handling it this way, or if others (like KC) used different strategies.
| akuhner | 04-04-2003 09:46 PM |
That's interesting about keeping the turbo going, I hadn't thought of it that way, but I guess it makes sense. Personally, I still think it's a waste to gas and brake at the same time, and you don't see WRC guys doing it. But, the WRC cars have anti-lag systems that take care of the turbo problem for you, so maybe that's not a good comparison.
TheWRX - it's not possible to do all your braking with your left foot, you'll need to use the clutch and brake at the same time at some point!
TheWRX - it's not possible to do all your braking with your left foot, you'll need to use the clutch and brake at the same time at some point!
| thechickencow | 04-04-2003 10:13 PM |
[QUOTE][i]Originally posted by Car #187 [/i]
[B]... and you don't see WRC guys doing it. [/B][/QUOTE]
Uhh, yeah they do.
[B]... and you don't see WRC guys doing it. [/B][/QUOTE]
Uhh, yeah they do.
| AndyRoo | 04-05-2003 12:01 AM |
I have a question about double clutching.
I understand the concept and all and have done it before, but why do you have to put it into neutral to blip throttle? Can't you just blip the throttle with the clutch in between shifts?
I understand the concept and all and have done it before, but why do you have to put it into neutral to blip throttle? Can't you just blip the throttle with the clutch in between shifts?
| Rally Punx | 04-05-2003 12:27 AM |
Thanx for the inputs. I think I'm gonna give the LFB a try this weekend and see how I do. I have one day (tomorrow) to practice the technique, so I hope to be ready for Sunday.
| bohica | 04-05-2003 01:47 AM |
Left foot braking takes time to learn. ( to do it right) It's normal when learning, to
brake too hard, and if you have big feet how should I say
it can be even harder too learn. But it's practice practice practice.
brake too hard, and if you have big feet how should I say
it can be even harder too learn. But it's practice practice practice.
| ITWRX4ME | 04-05-2003 10:12 AM |
Interesting. I did try left foot braking while staying on the throttle and watched the boost guage. Sure enough, gauge read right around 0, as opposed to reading in the negative. Cool.
Now all that remains is to teach my left foot to modulate properly. It's so used to the on/off of clutching action.
Now all that remains is to teach my left foot to modulate properly. It's so used to the on/off of clutching action.
| STX_REX | 04-05-2003 11:15 AM |
Just remember,
You have to let the engine run to vaccum occasionaly or else you will empty the vaccum tank and you brakes will cease to function
You have to let the engine run to vaccum occasionaly or else you will empty the vaccum tank and you brakes will cease to function
| TheWRX | 04-05-2003 07:31 PM |
[QUOTE][i]Originally posted by Car #187 [/i]
[B]TheWRX - it's not possible to do all your braking with your left foot, you'll need to use the clutch and brake at the same time at some point! [/B][/QUOTE]
Well, yeah, I meant while you're driving an auto-x course. Not including stopping back in grid...
[B]TheWRX - it's not possible to do all your braking with your left foot, you'll need to use the clutch and brake at the same time at some point! [/B][/QUOTE]
Well, yeah, I meant while you're driving an auto-x course. Not including stopping back in grid...
| MattDell | 04-05-2003 11:20 PM |
Holy ****. I just went out for a drive, thought about this thread, then I decided to try and heel-toe into first.
*click*
It popped right into first! I let go of the clutch, and the car was going just as if I didn't just change gears. This is awesome, guys! :D
-Matt
*click*
It popped right into first! I let go of the clutch, and the car was going just as if I didn't just change gears. This is awesome, guys! :D
-Matt
| supermarkus | 04-06-2003 05:19 AM |
[QUOTE][i]Originally posted by Car #187 [/i]
[B]Personally, I still think it's a waste to gas and brake at the same time, and you don't see WRC guys doing it.[/B][/QUOTE]
You're dead wrong about this dude. You should pay closer attention before making a statement like that. Watch Burns drive some time on Speed Channel and wait until they show the footwell camera angle, he's left foot braking like it'll be illegal tomorrow. More specifically, watch him take medium turns that others set up with their hand brakes, quite often you'll see him keep his hands on the wheel during the turn... left foot braking baby! A good contrast in styles is watching Burns and Carlos Sainz, Burns sets up a lot of his turns with left foot braking, Sainz opts for hand brakes to adjust his line.
But you're right, they don't need to LFB to spool the turbo, but they all use it extensively to adjust their lines and weight transfer. Ah, the beauty of anti-lag.
[B]Personally, I still think it's a waste to gas and brake at the same time, and you don't see WRC guys doing it.[/B][/QUOTE]
You're dead wrong about this dude. You should pay closer attention before making a statement like that. Watch Burns drive some time on Speed Channel and wait until they show the footwell camera angle, he's left foot braking like it'll be illegal tomorrow. More specifically, watch him take medium turns that others set up with their hand brakes, quite often you'll see him keep his hands on the wheel during the turn... left foot braking baby! A good contrast in styles is watching Burns and Carlos Sainz, Burns sets up a lot of his turns with left foot braking, Sainz opts for hand brakes to adjust his line.
But you're right, they don't need to LFB to spool the turbo, but they all use it extensively to adjust their lines and weight transfer. Ah, the beauty of anti-lag.
| BIGSKYWRX | 04-06-2003 01:17 PM |
Left foot braking is the only real viable option, unless you have a turn so tight your almost stopping (we've had a few of those).
When Shiv discovered how to "quickly" get your computer to the agressive timing map in a matter of seconds after a ecu reset, he did it by putting a load on it (w/ left foot braking). I got to see this in real time w/ a logging run- left foot braking puts a good load on. Will your brake pads wear a little quicker- sure.
It really is amazing coming out of a turn when the brakes come off and the throttle is fully mashed- somewhat of a slingshot feeling.
I'm a slow learner (after many years of right foot braking) and it took many, many hours in town in day to day driving to get it (plenty of room for improvement still). It's especially hard in the heat of battle as old habits want to take over, but it is slowly coming.
Big Sky
When Shiv discovered how to "quickly" get your computer to the agressive timing map in a matter of seconds after a ecu reset, he did it by putting a load on it (w/ left foot braking). I got to see this in real time w/ a logging run- left foot braking puts a good load on. Will your brake pads wear a little quicker- sure.
It really is amazing coming out of a turn when the brakes come off and the throttle is fully mashed- somewhat of a slingshot feeling.
I'm a slow learner (after many years of right foot braking) and it took many, many hours in town in day to day driving to get it (plenty of room for improvement still). It's especially hard in the heat of battle as old habits want to take over, but it is slowly coming.
Big Sky
| ITWRX4ME | 04-07-2003 06:55 AM |
[QUOTE][i]Originally posted by Cobreth [/i]
[B]Holy ****. I just went out for a drive, thought about this thread, then I decided to try and heel-toe into first.
*click*
It popped right into first! I let go of the clutch, and the car was going just as if I didn't just change gears. This is awesome, guys! :D
-Matt [/B][/QUOTE]
I found the same thing, but, for me, it depends on my speed when I try it. At 10 mph, it's practically sucked into first. Above that, it gets harder and harder to push it into gear.
[B]Holy ****. I just went out for a drive, thought about this thread, then I decided to try and heel-toe into first.
*click*
It popped right into first! I let go of the clutch, and the car was going just as if I didn't just change gears. This is awesome, guys! :D
-Matt [/B][/QUOTE]
I found the same thing, but, for me, it depends on my speed when I try it. At 10 mph, it's practically sucked into first. Above that, it gets harder and harder to push it into gear.
| akuhner | 04-07-2003 09:41 PM |
[QUOTE]You're dead wrong about this dude. You should pay closer attention before making a statement like that[/QUOTE]
Why, because someone on nausia might call me on it? :rolleyes:
[QUOTE]But you're right, they don't need to LFB to spool the turbo, but they all use it extensively to adjust their lines and weight transfer.[/QUOTE]
Since you've already proved my inferior knowelge, I'll pose this as a question... Is it not true that when the left foot adjusts the brake the right foot also lessens the gas? I too have seen the foot box cam and it seemed to me that a tap on the brakes usually coincided with a slight release of the gas. LFB does not equal hitting the brakes with the pedal to the metal, it only implies using your left foot to brake so your right can continue to control the gas.
I wish I could find the article, but in the Brit mag EVO I was reading about an ice racing school where they taught people to ice race. One of the Finnish instructors comments was something like this - "there's no point in hitting the brake and the gas together, it's like stretching a cat." That stuck in my mind because the cat comment was werid... :lol:
Alex "I don't care if you agree with me" Kuhner
Why, because someone on nausia might call me on it? :rolleyes:
[QUOTE]But you're right, they don't need to LFB to spool the turbo, but they all use it extensively to adjust their lines and weight transfer.[/QUOTE]
Since you've already proved my inferior knowelge, I'll pose this as a question... Is it not true that when the left foot adjusts the brake the right foot also lessens the gas? I too have seen the foot box cam and it seemed to me that a tap on the brakes usually coincided with a slight release of the gas. LFB does not equal hitting the brakes with the pedal to the metal, it only implies using your left foot to brake so your right can continue to control the gas.
I wish I could find the article, but in the Brit mag EVO I was reading about an ice racing school where they taught people to ice race. One of the Finnish instructors comments was something like this - "there's no point in hitting the brake and the gas together, it's like stretching a cat." That stuck in my mind because the cat comment was werid... :lol:
Alex "I don't care if you agree with me" Kuhner
| bohica | 04-08-2003 02:26 AM |
[QUOTE]Alex "I don't care if you agree with me" Kuhner[/QUOTE]
dude chill....
dude chill....
| akuhner | 04-08-2003 09:02 AM |
[QUOTE][i]Originally posted by bohica [/i]
[B]
dude chill.... [/B][/QUOTE]
It's so hard get the right idea across on the internet... my point was that it really doesn't matter to me if I'm right or not - how can you be more "chill" than that??!! :p
[B]
dude chill.... [/B][/QUOTE]
It's so hard get the right idea across on the internet... my point was that it really doesn't matter to me if I'm right or not - how can you be more "chill" than that??!! :p
| slalom274 | 04-08-2003 07:11 PM |
[QUOTE][i]Originally posted by AndyRoo [/i]
[B]I have a question about double clutching.
I understand the concept and all and have done it before, but why do you have to put it into neutral to blip throttle? Can't you just blip the throttle with the clutch in between shifts? [/B][/QUOTE]
i dont understand this either, someone please elaborate..
[B]I have a question about double clutching.
I understand the concept and all and have done it before, but why do you have to put it into neutral to blip throttle? Can't you just blip the throttle with the clutch in between shifts? [/B][/QUOTE]
i dont understand this either, someone please elaborate..
| AndyRoo | 04-08-2003 08:27 PM |
yeah seriously quit arguing about stupid stuff and help us!
...please?
...please?
| sethtasy | 04-08-2003 08:47 PM |
[QUOTE][i]Originally posted by AndyRoo [/i]
[B]I have a question about double clutching.
I understand the concept and all and have done it before, but why do you have to put it into neutral to blip throttle? Can't you just blip the throttle with the clutch in between shifts? [/B][/QUOTE]
Wow, after months of lurking, my first post! I am going to try to explain this to prove to myself I understand it after learning about heel and toe and LFB and double clutching.
OK here is my explanation (this assumes a downshift):
The idea behind double clutching is to get the input and output sides of the transmission spinning at the same speeds before you put it (the tranny) into gear.
Think of the drivetrain in three parts:
ENG. engine (and half the clutch)
IN. Input side of tranny (and other half of clutch)
OUT. Output side of tranny
Clutch in disconnects ENG and IN
Tranny in neutral disconnects IN and OUT
With the tranny in neutral, you rev the engine with the clutch out to get the IN part spinning to the right speed to match the OUT part. Then the clutch goes in, disconnecting ENG from IN, so IN is spinning free. Then the tranny goes in gear, and if IN is spinning at the same speed as OUT, the gear change will be very smooth.
Then the clutch is released and ENG is now connected to OUT and you're good to go.
Or remember this, if you could do this perfectly you would not need a clutch. Put the tranny in neutral, rev the engine to match the IN side to the OUT side, and slide into gear.
As someone else said, heel and toe saves the clutch and double clutch saves the tranny. Nowadays synchronizers (basically little clutches in the tranny) save the need for this.
I hope I got it right! :)
SDC
[B]I have a question about double clutching.
I understand the concept and all and have done it before, but why do you have to put it into neutral to blip throttle? Can't you just blip the throttle with the clutch in between shifts? [/B][/QUOTE]
Wow, after months of lurking, my first post! I am going to try to explain this to prove to myself I understand it after learning about heel and toe and LFB and double clutching.
OK here is my explanation (this assumes a downshift):
The idea behind double clutching is to get the input and output sides of the transmission spinning at the same speeds before you put it (the tranny) into gear.
Think of the drivetrain in three parts:
ENG. engine (and half the clutch)
IN. Input side of tranny (and other half of clutch)
OUT. Output side of tranny
Clutch in disconnects ENG and IN
Tranny in neutral disconnects IN and OUT
With the tranny in neutral, you rev the engine with the clutch out to get the IN part spinning to the right speed to match the OUT part. Then the clutch goes in, disconnecting ENG from IN, so IN is spinning free. Then the tranny goes in gear, and if IN is spinning at the same speed as OUT, the gear change will be very smooth.
Then the clutch is released and ENG is now connected to OUT and you're good to go.
Or remember this, if you could do this perfectly you would not need a clutch. Put the tranny in neutral, rev the engine to match the IN side to the OUT side, and slide into gear.
As someone else said, heel and toe saves the clutch and double clutch saves the tranny. Nowadays synchronizers (basically little clutches in the tranny) save the need for this.
I hope I got it right! :)
SDC
| MattDell | 04-08-2003 09:21 PM |
[QUOTE][i]Originally posted by ITWRX4ME [/i]
[B]
I found the same thing, but, for me, it depends on my speed when I try it. At 10 mph, it's practically sucked into first. Above that, it gets harder and harder to push it into gear. [/B][/QUOTE]
Dude, I did it at like 20mph. I can pop mine into first at like 10, so you're definately not doing it right.
-Matt
[B]
I found the same thing, but, for me, it depends on my speed when I try it. At 10 mph, it's practically sucked into first. Above that, it gets harder and harder to push it into gear. [/B][/QUOTE]
Dude, I did it at like 20mph. I can pop mine into first at like 10, so you're definately not doing it right.
-Matt
| ITWRX4ME | 04-09-2003 11:09 AM |
[QUOTE][i]Originally posted by Cobreth [/i]
[B]
Dude, I did it at like 20mph. I can pop mine into first at like 10, so you're definately not doing it right.
-Matt [/B][/QUOTE]
Didn't say I couldn't do it, just said it gets harder as the speed increases. By harder, I mean the effort to push the gear selector into gear. With any other gear, it is effortless. To ammend my prior post, I did find that first gear is easy(effortless) up to around 15mph or so.
[B]
Dude, I did it at like 20mph. I can pop mine into first at like 10, so you're definately not doing it right.
-Matt [/B][/QUOTE]
Didn't say I couldn't do it, just said it gets harder as the speed increases. By harder, I mean the effort to push the gear selector into gear. With any other gear, it is effortless. To ammend my prior post, I did find that first gear is easy(effortless) up to around 15mph or so.
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