| jsalassi | 12-28-2004 08:29 PM |
Do screeching tires make slower cornering ?
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I was pondering on the way home last night the �art of cornering. On the track, when entering the corner...if the tires start screeching does that mean your going to fast...I don�t believe so but I�m not to up on race driving. There are obvious disadvantages to screeching the tires mostly due to increased tire wear vs. taking the corner slower and not screeching but then you�re losing on entrance speed in the turn. Is there a certain balance that must be maintained in order to not wear your tires to nothing vs taking the corners too slow? :confused:
| jmolaver | 12-28-2004 09:40 PM |
I think you'll find that some tires are more "communicative" then others when pushed to their limit (and that this may or may not directly correlate to tire wear / chunking). If when entering the corner you're getting understeer then you probably came in too hot.
Remember the fastest line is on the knife edge of the limits of your car and tires... But don't forget the old saying... "In slow, out fast. In fast, out dead."
If you're serious about learning about vehicle dynamics and cornering I strongly suggest a racing school and several follow-up HPDE's..
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[url]www.fuh2.com[/url]
Remember the fastest line is on the knife edge of the limits of your car and tires... But don't forget the old saying... "In slow, out fast. In fast, out dead."
If you're serious about learning about vehicle dynamics and cornering I strongly suggest a racing school and several follow-up HPDE's..
------------
[url]www.fuh2.com[/url]
| kwak | 12-28-2004 10:04 PM |
How easy street tires make noise depends a lot on which brand/model the tire is.
You can use a tire which easily makes noise as a learning tool. Can you get them to make the same amount of noise throughout the whole turn!? Not the loud wailing noise, less than that.
I do not like my tires to make noise on the street, ever. That kind of stuff is for the track.
You can use a tire which easily makes noise as a learning tool. Can you get them to make the same amount of noise throughout the whole turn!? Not the loud wailing noise, less than that.
I do not like my tires to make noise on the street, ever. That kind of stuff is for the track.
| leecea | 12-28-2004 10:21 PM |
I used to autox on Yoko AVS 100s and was given advice that no noise = too slow, slight noise = good, wailing/screeching = over driving. I used those signals as learning aids for autox.
| afpdl | 12-29-2004 12:41 AM |
It depends mostly on the tire. On full tread re92s they should be making pleanty of noise all the time, they have alot of tread squirm which is where most of the noise comes from. On bald azenis you shouldnt be making too much noise. There isnt a universal you can apply to all tires.
| SgWRX | 12-29-2004 01:38 AM |
this was a great question! this was my first year doing a few solo 2's in d-stock class. my tires squealed a lot! RE92's. i was actually a little embarrassed. but once i went around the track and tried not to get so much howel out of them, my time was considerably slower by 3-4 seconds! so i figured that maybe with the re92's you "had" to get them yelling to get the most out of them.
on the otherhand, maybe i was just trying too much to slow down and not hear them?
but it sounds like some tires will report more than others and it's not necessairly a sign of slowness.
on the otherhand, maybe i was just trying too much to slow down and not hear them?
but it sounds like some tires will report more than others and it's not necessairly a sign of slowness.
| ITWRX4ME | 12-29-2004 08:43 AM |
Many times sliding into/through a corner is the fastest way through. The tires will probably make some noise when they're sliding. But I'd think it's more important to focus on how the car feels through the steering wheel and your seat rather than how the tires sound.
| Jack | 12-29-2004 09:01 AM |
If they're sqeeling, it's usually ok. If they progress to a grating aaaargh kind of sound, then you're overdriving. If you can drive on a long oval (like NHIS) you can practice. If you're overdriving the fronts, unwind a bit and you'll notice that you're not turning any less.
jack
jack
| jsalassi | 12-29-2004 09:59 AM |
Thanks for the feedback...so from what i have read it appears there�s not really a direct relation between tire screeching and your speed in the corner. From the comments I have gathers that a little squeal should be expected on cheaper tire specifically experienced with the RE92. Whenever using a high performance tire the speed in which you are going into the corner could be the same or faster but with none or considerably less squeal. I�ve also gathered that the squealing is not the bad part but essentially when the car begins to slide and the tires begin to scream that is when the car starts to lose speed in the corner and you�ve now gotten into an �inefficient� corner per say. This affirms the logic of �slow in fast out� where you don�t get to hot in the corner and then have to risk slowing down so much that it would have been faster to come in at a slower speed. So the rule of thumb should be practice on your tires to find that perfect harmony between holding the corner and not sliding all the way through it.
With the �slow in fast out� theory is it logical for the car to begin sliding outward as you exit the corner? So at the apex of the turn you basically mash the pedal down, hold the wheel at the same angle and the sliding of the car will do most of the exiting for you?
With the �slow in fast out� theory is it logical for the car to begin sliding outward as you exit the corner? So at the apex of the turn you basically mash the pedal down, hold the wheel at the same angle and the sliding of the car will do most of the exiting for you?
| PaulC | 12-29-2004 12:00 PM |
[QUOTE=jsalassi]With the �slow in fast out� theory is it logical for the car to begin sliding outward as you exit the corner? So at the apex of the turn you basically mash the pedal down, hold the wheel at the same angle and the sliding of the car will do most of the exiting for you?[/QUOTE]
In a WRX, due to the differential setup, the car will tend to push on power when exiting a turn. This means you'll be sliding your front end more than the rear. So try to get your turning (mostly) done before you get back on the throttle and the effect will be minimized. This means you want your wheels pretty much straight when you hit the boost.
Keep in mind that entering a turn as fast as possible may be slower overall since you'll have to wait longer to get back on the gas. Try cornering with the specific intent to get on the gas as early as possible. With a turbo car this is twice as important as you need a moment to bring the boost up.
I highly recommend practicing all this on an autocross course. The street is no place to learn this stuff.
In a WRX, due to the differential setup, the car will tend to push on power when exiting a turn. This means you'll be sliding your front end more than the rear. So try to get your turning (mostly) done before you get back on the throttle and the effect will be minimized. This means you want your wheels pretty much straight when you hit the boost.
Keep in mind that entering a turn as fast as possible may be slower overall since you'll have to wait longer to get back on the gas. Try cornering with the specific intent to get on the gas as early as possible. With a turbo car this is twice as important as you need a moment to bring the boost up.
I highly recommend practicing all this on an autocross course. The street is no place to learn this stuff.
| LyveWRX | 12-29-2004 12:05 PM |
"Many times sliding into/through a corner is the fastest way through"
uhhhh,, cough, cough,,,, I thought that sliding was the fastest way to scrub speed on corner entry. and that the fastest way through the corner was to maintain traction the whole time.
uhhhh,, cough, cough,,,, I thought that sliding was the fastest way to scrub speed on corner entry. and that the fastest way through the corner was to maintain traction the whole time.
| jsalassi | 12-29-2004 12:21 PM |
[QUOTE=LyveWRX]"I thought that sliding was the fastest way to scrub speed on corner entry. and that the fastest way through the corner was to maintain traction the whole time.[/QUOTE]
:devil: what he said
:devil: what he said
| afpdl | 12-29-2004 01:08 PM |
[QUOTE=LyveWRX]"Many times sliding into/through a corner is the fastest way through"
uhhhh,, cough, cough,,,, I thought that sliding was the fastest way to scrub speed on corner entry. and that the fastest way through the corner was to maintain traction the whole time.[/QUOTE]
Braking is the fastest way to scrub speed on corner entry, maximum traction is produced with the tires at a slight slip angle, so they are slightly sliding at maximum grip.
uhhhh,, cough, cough,,,, I thought that sliding was the fastest way to scrub speed on corner entry. and that the fastest way through the corner was to maintain traction the whole time.[/QUOTE]
Braking is the fastest way to scrub speed on corner entry, maximum traction is produced with the tires at a slight slip angle, so they are slightly sliding at maximum grip.
| ChrisDP | 12-29-2004 02:04 PM |
As I was taught at Skip Barber... "a happy tire squeals in delight, an unhappy tire screams in pain." There is a difference in the way each feels, and you usually feel the vibration increase through the steering wheel when you're pushing too hard out of a corner and you begin to exceed the maximum grip slip angle of the front tires.
Cornering attitude will also be somewhat dependent on what type of corner you're in... Big fast on-cambered sweepers might be taken with a little howl the whole way through most of the corner (Hogpen at VIR comes to mind) without much car rotation and you're still clawing your way forward by keeping your foot in the gas and building exit speed since this turn pours onto a big straightaway, while T5 at Summit is a slow-speed tight corner where you'll want to scoot the back end around fairly quickly and get the car pointed in the right direction. You might keep a longer dull howl going through one type of turn and get a quick screech with a big rotation in a tight corner.
Cornering attitude will also be somewhat dependent on what type of corner you're in... Big fast on-cambered sweepers might be taken with a little howl the whole way through most of the corner (Hogpen at VIR comes to mind) without much car rotation and you're still clawing your way forward by keeping your foot in the gas and building exit speed since this turn pours onto a big straightaway, while T5 at Summit is a slow-speed tight corner where you'll want to scoot the back end around fairly quickly and get the car pointed in the right direction. You might keep a longer dull howl going through one type of turn and get a quick screech with a big rotation in a tight corner.
| kwak | 12-29-2004 02:38 PM |
The relationship between slip angle and traction is a curve like a hill. A little bit of slip is good and reaches the peak of the hill, but more than that and the traction falls off.
Going back to the original post, on corner entry if you turn the wheel and the car goes straight you are entering too fast. Let's make it obvious. :D With experience you will learn to feel the difference between a little slip and too much slip when the wheel is turned too far.
[QUOTE]With the �slow in fast out� theory is it logical for the car to begin sliding outward as you exit the corner?[/QUOTE]Yes.
[QUOTE]So at the apex of the turn you basically mash the pedal down, hold the wheel at the same angle and the sliding of the car will do most of the exiting for you?[/QUOTE]No. Holding the wheel at the same angle on exit is a sure sign that you are understeering and scrubbing off speed. From the apex out (when you can visually see the exit of the turn) you should be slowly unwinding the wheel. Remember that two totally different things can cause exit understeer -- a car that is set up with understeer or a driver who applies power too early.
Going back to the original post, on corner entry if you turn the wheel and the car goes straight you are entering too fast. Let's make it obvious. :D With experience you will learn to feel the difference between a little slip and too much slip when the wheel is turned too far.
[QUOTE]With the �slow in fast out� theory is it logical for the car to begin sliding outward as you exit the corner?[/QUOTE]Yes.
[QUOTE]So at the apex of the turn you basically mash the pedal down, hold the wheel at the same angle and the sliding of the car will do most of the exiting for you?[/QUOTE]No. Holding the wheel at the same angle on exit is a sure sign that you are understeering and scrubbing off speed. From the apex out (when you can visually see the exit of the turn) you should be slowly unwinding the wheel. Remember that two totally different things can cause exit understeer -- a car that is set up with understeer or a driver who applies power too early.
| LyveWRX | 12-29-2004 04:02 PM |
[quote]""I thought that sliding was the fastest way to scrub speed on corner entry"-me
"Braking is the fastest way to scrub speed on corner entry"-afpdl"[/quote]
ooopsss.... I meant on very low traction surfaces, on pavement the brakes are definately the fastest (safe) way to scrub speed.
"Braking is the fastest way to scrub speed on corner entry"-afpdl"[/quote]
ooopsss.... I meant on very low traction surfaces, on pavement the brakes are definately the fastest (safe) way to scrub speed.
| drex28 | 12-30-2004 12:17 AM |
Let 'em squeal!
| CirrusWRX | 12-30-2004 02:18 PM |
I'll just add two more "catch phrases" that I like:
Slow in, fast out.
Fast in, spin out.
If the birds are chirping, it's okay.
But if the dogs are howling you're doing something wrong.
But also bear in mind that different surfaces will greatly affect the way a tire will sound/squeal. At Limerock, the differences between the asphalt and concrete is like night and day. You can have one tire barely audible, and the other squealing like death at the same instant because of two different surfaces. :)
Slow in, fast out.
Fast in, spin out.
If the birds are chirping, it's okay.
But if the dogs are howling you're doing something wrong.
But also bear in mind that different surfaces will greatly affect the way a tire will sound/squeal. At Limerock, the differences between the asphalt and concrete is like night and day. You can have one tire barely audible, and the other squealing like death at the same instant because of two different surfaces. :)
| ITWRX4ME | 12-30-2004 02:27 PM |
[QUOTE=PaulC]In a [b]stock[/b] WRX, due to the differential setup, the car will tend to push on power when exiting a turn. This means you'll be sliding your front end more than the rear.[/QUOTE]
Fixed that ^^^.
With stiffer rear anti-sway bar, the car will exit more neutral.
Fixed that ^^^.
With stiffer rear anti-sway bar, the car will exit more neutral.
| ITWRX4ME | 12-30-2004 02:30 PM |
[QUOTE=LyveWRX]...and that the fastest way through the corner was to maintain traction the whole time.[/QUOTE]
Good luck with that. I'll be waiting for you at the finish line. ;)
Good luck with that. I'll be waiting for you at the finish line. ;)
| jmott | 12-30-2004 06:18 PM |
[QUOTE=LyveWRX]"Many times sliding into/through a corner is the fastest way through"
uhhhh,, cough, cough,,,, I thought that sliding was the fastest way to scrub speed on corner entry. and that the fastest way through the corner was to maintain traction the whole time.[/QUOTE]
its not quite that simple.
you actually get the most lateral acceleration from a tire when it is sliding a "little"
just how much sliding is ideal depends on the tire.
victoracers for instance have a good bit of slip angle.
a3s03 hoosiers not so much.
however, if you are looking like the drift king, that is not the fast way around the turn =)
uhhhh,, cough, cough,,,, I thought that sliding was the fastest way to scrub speed on corner entry. and that the fastest way through the corner was to maintain traction the whole time.[/QUOTE]
its not quite that simple.
you actually get the most lateral acceleration from a tire when it is sliding a "little"
just how much sliding is ideal depends on the tire.
victoracers for instance have a good bit of slip angle.
a3s03 hoosiers not so much.
however, if you are looking like the drift king, that is not the fast way around the turn =)
| jmott | 12-30-2004 06:19 PM |
[QUOTE=LyveWRX]ooopsss.... I meant on very low traction surfaces, on pavement the brakes are definately the fastest (safe) way to scrub speed.[/QUOTE]
like what, sand?
like what, sand?
| XtianLA | 12-30-2004 07:13 PM |
I noticed my yoko avs es100's like to squeal a lot as well. Usually this worries most of my friends when I take them for ride alongs because they don't know that these tires get squeal happy, so they think i'm about to lose control, when in fact i can feel they have a helluva a lot more in em when they squeal a little bit. I think I'm going to fork over for some good race tires though...maybe a048's or something crazy like that.
| Rich10 | 12-30-2004 07:42 PM |
After a couple of autocrosses, I realized that by continuing to add full throttle when the car is already understeering, only makes the car slower. At this point, the tires were loudly screaching.
By backing off and letting the tires stay at the limit of their adhesion, I seem to go fastest. At this point, the tires are barely squealing.
By backing off and letting the tires stay at the limit of their adhesion, I seem to go fastest. At this point, the tires are barely squealing.
| RRR-K2 | 12-30-2004 08:06 PM |
[QUOTE=jmott]
<SNIP>just how much sliding is ideal depends on the tire.</SNIP>
[/QUOTE]
Exactly!
Example: We run our rally car at the local (tarmac) hill-climbs, mostly for sponsorship exposure. The car was a stock 1996 2.2L (135 HP) Impreza, and since we run just for the heck of it we never bothered spending ANY money on tires. Because we�ve literally grown up on �the hill,� we know the course like the back of our hand. Add to that the fact that it's such a "slow" car and it�s a blast to scare people when we were able to honk out tunes on the horn as we flew by. :lol:
So, running in a very low HP car with used, el-cheapo street tires on steel 15� rims meant that the quickest way around the corners (especially the seven 1st-2nd gear switch-backs) was to essentially slide the car through the turns, which allowed us to keep up our speed. Being an AWD car on squealing low/no traction street tires also meant that they could hear us coming several corners up the hill. In fact, at the finish/turn-around area several of the �pavement pounders� said they could hear us coming half-way down the hill and asked us about it�
We now have a WRX engine and drive-train stuffed into the car, and have bought some (albeit pretty used) AutoCross tires to use for pavement. So when we ran the events this year a lot of squealing became our enemy, at least coming out of the corners. Going into them was another story :rolleyes:
Matt Kennedy
[URL=http://www.RockyRoadRacing.com][COLOR=DarkRed][U]www.RockyRoadRacing.com[/U][/COLOR][/URL]
<SNIP>just how much sliding is ideal depends on the tire.</SNIP>
[/QUOTE]
Exactly!
Example: We run our rally car at the local (tarmac) hill-climbs, mostly for sponsorship exposure. The car was a stock 1996 2.2L (135 HP) Impreza, and since we run just for the heck of it we never bothered spending ANY money on tires. Because we�ve literally grown up on �the hill,� we know the course like the back of our hand. Add to that the fact that it's such a "slow" car and it�s a blast to scare people when we were able to honk out tunes on the horn as we flew by. :lol:
So, running in a very low HP car with used, el-cheapo street tires on steel 15� rims meant that the quickest way around the corners (especially the seven 1st-2nd gear switch-backs) was to essentially slide the car through the turns, which allowed us to keep up our speed. Being an AWD car on squealing low/no traction street tires also meant that they could hear us coming several corners up the hill. In fact, at the finish/turn-around area several of the �pavement pounders� said they could hear us coming half-way down the hill and asked us about it�
We now have a WRX engine and drive-train stuffed into the car, and have bought some (albeit pretty used) AutoCross tires to use for pavement. So when we ran the events this year a lot of squealing became our enemy, at least coming out of the corners. Going into them was another story :rolleyes:
Matt Kennedy
[URL=http://www.RockyRoadRacing.com][COLOR=DarkRed][U]www.RockyRoadRacing.com[/U][/COLOR][/URL]
| 0260B4U | 01-02-2005 03:11 PM |
With my 451's a good chirp and a bit of short screechin is ok, but if they are howling at you to hit the brakes. You probably should.
| Digitalfiend | 01-02-2005 03:48 PM |
[QUOTE=0260B4U]With my 451's a good chirp and a bit of short screechin is ok, but if they are howling at you to hit the brakes. You probably should.[/QUOTE]
Wow I would never hit the brakes in a turn while at the extreme limits of traction. Not a good idea.
One of the most seemingly counter-intuitive things I learned at a racing/driving school course was if you come into a turn a little hot and start to understeer, just unwind a bit and then turn in again. I thought that was the craziest thing I'd ever heard and thought it would put you into the grass (or worse a wall). It works though and it was much easier to negate the understeer in my RSX by doing this. Not sure if this works the same with the STi though.
Wow I would never hit the brakes in a turn while at the extreme limits of traction. Not a good idea.
One of the most seemingly counter-intuitive things I learned at a racing/driving school course was if you come into a turn a little hot and start to understeer, just unwind a bit and then turn in again. I thought that was the craziest thing I'd ever heard and thought it would put you into the grass (or worse a wall). It works though and it was much easier to negate the understeer in my RSX by doing this. Not sure if this works the same with the STi though.
| 0260B4U | 01-02-2005 03:54 PM |
Ooopppps, perhaps I stated that wrong. I str8 line brake then cut into a turn.
i used to drive and brake when I thought the car was at its limits in the beginning, but then eventually learned that it just caused the car to become more unsettled. And had to really wrench the wheel to get it back to where it should be.
i used to drive and brake when I thought the car was at its limits in the beginning, but then eventually learned that it just caused the car to become more unsettled. And had to really wrench the wheel to get it back to where it should be.
| Digitalfiend | 01-02-2005 04:02 PM |
[QUOTE=0260B4U]Ooopppps, perhaps I stated that wrong. I str8 line brake then cut into a turn.
i used to drive and brake when I thought the car was at its limits in the beginning, but then eventually learned that it just caused the car to become more unsettled. And had to really wrench the wheel to get it back to where it should be.[/QUOTE]
During my first driving school I entered a corner too hot and the backend of my RSX started to step out. Instead of applying more gas, I ever so slightly pressed the brakes which provided me the opportunity to experience a 200+deg spin. I'll never make that mistake again. :)
i used to drive and brake when I thought the car was at its limits in the beginning, but then eventually learned that it just caused the car to become more unsettled. And had to really wrench the wheel to get it back to where it should be.[/QUOTE]
During my first driving school I entered a corner too hot and the backend of my RSX started to step out. Instead of applying more gas, I ever so slightly pressed the brakes which provided me the opportunity to experience a 200+deg spin. I'll never make that mistake again. :)
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