snap steering? [Archive] - DirtyImpreza Forums

I Like It Sideways

10-22-2007, 11:07 PM

It happens fast. Really fast. Faster than you can crank the wheel back around to correct it.
Weight transfer is what will get you in hairy situations like that. You can power out of situations like that, but you have to be quick with the steering wheel to straighten out the car... a lot of foot/steering coordination, timing the steering with the gas pedal.
A lot of people will panic in an oversteer situation, and lift off the throttle. This will induce more oversteer most of the time.
Another common problem is when someone corrects the car, but lets off the throttle when the car is "straight" again, but the momentum of the rotation keeps the car spinning beyond equilibrium, and letting off the throttle at that point will further increase the weight transfer, and you will end up facing backwards

A smooth right foot will help keep your car pointed where you want to go. Although sometimes you need to mash the throttle to correct the oversteer.
What I do to practice in the loose stuff, is to throw my car back and forth and induce a pendulum-like motion with the back end (throw the steering wheel left and right). I practice using the throttle to control what the car does, along with steering input. I practice letting off the throttle at different points, as well as tapping the brakes. A long stretch of gravel road is good for this, so long as there are no ditches heh. Snow is good too. Gives you more time to react.

rollo

10-23-2007, 07:05 AM

Two videos from the same corner (Castle Combe, UK) illustrating snap oversteer rather vividly:
http://www.youtube.com/watch?v=F_Yn3mNnvW4
http://www.youtube.com/watch?v=88QT5JD46NE

And one of a guy in a Caterham at Brands Hatch who obviously knows what he's doing, you can see the micro-corrections to stop it before it starts, so he doesn't end up in the barriers. If it didn't say 'snap oversteer' in the description, you'd hardly be able to tell.
http://www.youtube.com/watch?v=F_Yn3mNnvW4

As Sideways says, the problem is that your natural reaction when you start to lose the back end is to either get off the power (bad) or hit the brakes (worse) - throwing the weight forward is the last thing you want to do. If you do it earlier in the slide you'll go around in the direction you're turning, later and it's more likely to snap the other way. It tends to be worse on asphalt than dirt just because the grip is so much better so the transitions are more sudden. Plus you're expecting to slide on a loose surface, so you're more ready for it.

If I am thinking correctly, a stiffer rear sway bar will make the rear end less compliant, giving you sharper turn-in, but also making it more difficult to catch an oversteer situation before it gets out of hand (i.e. it will snap more readily and more suddenly). Maybe try it in GT4 or whatever, it's a lot cheaper if you mess up there :)

MetalNeverDies

10-23-2007, 04:54 PM

i thought you were supposed to let off the gas as you went into the corner and just glide into the turn and as you come out of it start on the gas again? isnt that how you avoid this snap steering or over steer?

and now that i know what that is that happened to me in my 87 blazer and i though it was just cause of the massive body roll taht every time i let off the gas and went straight i went sideways again. but that was not fun cause it was a one lane road with cars all lined up on the left side and a brick wall on the other. i managed to come out of it ,and it was raining too so that was way fun...

what is the biggest size rear sway i should get ? i want to try to avoid snap steer but want to beable to do good on road and off road. should i try to get ahold of a stock wrx wagon set? because mine are only a little bigger than what the size of a screwdriver bar is. its so pathetic.

BlueREX04

10-23-2007, 06:31 PM

yea that happened to me the other day.. .but I did not crash in the wall.

noisycricket

10-23-2007, 07:32 PM

snap oversteer is f'ing scary. early rx-7s were known for it and i experienced it a few times. once on a road course in a high speed sweeper!

the kicker is that the distribution shifts like a light switch with a strong spring. you're understeering hard, then *poof* you're hard oversteer. try to catch it and the rear end bites hard again.

I *think* it's caused simply by having a suspension tuned for oversteer because of roll centers, not springing. You can drive around it to some extent by doing things that cause understeer, but the car's base characteristics always win in the end and it snaps at you.

Fortunately, most Subarus have nice low roll centers which make for stable handling at the expense of roll control. They don't *ride* as nice as something with softer springs and swaybars (and the higher roll centers used to control lean with that) but the handling benefits win out.

MConte05

10-23-2007, 08:23 PM

Would the 1:25 mark in this video be considered snap steering? http://youtube.com/watch?v=e7dzIwSQ9Yk

That was during one of my runs, turned to avoid the cone, weight flung it around like crazy, but still somehow managed to make it sideways through a gate without hitting the cones.

UP2MTNS

10-23-2007, 08:38 PM

Interesting thread/discussion so far......rollo's vids/examples above are the extreme/negative view of snap steer. If its induced on purpose, and controlled, its a very effective way to to turn your car in slaloms and hair pin turns...especially on the dirt, and especially if you're in a subaru that understeers like a pig in the hairpins.

For those of you at Ant 2, you'll understand this example...for those of you who weren't, try to imagine a few cones where the NSX went off and crashed:

Right turn sweeper (tightens) into hairpin 180 degree left. Rollo, sound familiar? :) It was the far corner sweeper/180 turn after the big figure 8 sweepers. so look at what the Nissan did.....right turn sweeper <snap> and did a full 180. Now, unfortunately he was on grass and went flying off.....but at controlled speeds, look about how quickly he pulled a 180....ever wish you could do that for the hairpin at your last rally cross?

Its difficult to learn and harder to get good at, linking two or three tight turns with 'snap steer'. its all part of the 'Scandinavian Flick'.

So lets say you're in a right turn, little bit sideways, coming up on a left turn (could be a slalom, or a tight figure eight).....you're sideways and counter steering, BEFORE the left turn (you gotta look ahead), you will let up on the gas, putting your weight forward, and now your counter-steering wheels will really start to grip, and turn you left, and the snap steer begins, your butt starts right and will QUICKLY and SMOOTHLY (its basically floating) snap over to the exact other side. (at the same time, you're turning the wheel to center, and then as you enter the turn and your butt is now on the right side, you'll turn it right which is counter steering in the left hand turn.

The key is letting up on the gas to induce the snap steer (and doing it on purpose, if its on accident, you end up like the above sti and nsx). The harder 'counter steered' you are on one side, that's how far you'll snap steer to the other side, so be ready for it if you're really sideways in one direction, when you let up while counter steering, it'll snap back around to almost the same postion, but on the other side. This is essentially what you see drifters do when they driver through slaloms/multiple corners.

So going back to the ANT2 example...I snap steered around that 180 once, I was coming out of that right hand sweeper pretty hot (I thought too hot) and was way over turned to the right, as I approached the 180, I let up on the gas, turned left, and the back end just whipped around and I just pivoted right around that cone. it was awesome, and I couldn't get the car to do it again. LOL

wow....long post, did that all make sense? I've had a few drinks tonight, :mrgreen:

noisycricket

10-24-2007, 09:44 AM

Would the 1:25 mark in this video be considered snap steering? http://youtube.com/watch?v=e7dzIwSQ9Yk

That looks like an attempted Scandinavian flick turned into a tank-slapper.

lorenkb

10-24-2007, 10:52 AM

Sounds about right to me Jon.

From a wagon driver's perspective it seems like I have to help it along further by LFB to get enough weight transfer to snap it around. I still get throttle off oversteer, but not enough to really get it to snap oversteer at the speeds we see in rallyx. With the little driving I did in Albert's car the past weekend (STi suspension) it seems like it is much, much easier to get the car to rotate. The only time I've really encountered snap oversteer is by forcing it at high speeds: second gear flinging the wheel back and forth... after about the second or third back and forth you get enough weight transfer going to where if you aren't paying attention that rear end is coming around no matter what. 360's anyone? :mrgreen:

UP2MTNS

10-24-2007, 11:30 AM

Would the 1:25 mark in this video be considered snap steering? http://youtube.com/watch?v=e7dzIwSQ9Yk

That looks like an attempted Scandinavian flick turned into a tank-slapper.

well, its hard to tell, but it looks like it started out as a flick, but I assume you let up on the throttle cause you thought you were gonna tag that cone? The little back and fourth motion on the right turn got your back end hard left.

so from 1:34 to 1:38 you snap steered around that one cone that I guess you didn't hit. Notice your butt was way to the left, you snapped around the cone (), then you're butt was way right.

so you 'over snapped' there a little, but you can see how effective it would be if you could control the amount of snap....fly through that corner, miss that cone...keep flying w/o hitting the brke.

WRXCMM

10-24-2007, 02:23 PM

...keep flying w/o hitting the brke.

or trees :shock: :roll: :mrgreen:

sorry jon i just couldn't help it.

MConte05

10-24-2007, 03:38 PM

Honestly I didn't really have any "technique" going. I did do a quick flick to the left cause I thought I was going to hit the cone, then turned it a bit too hard to the right to get back on course then the weight just started getting tossed everywhere. All I was doing was frantically trying to get the car pointed straight, it wasn't till I looked at the video and heard from the officials that I didn't tag a cone that I felt pretty good about what I did. :P

rollo

10-24-2007, 04:40 PM

Jon - no, you're absolutely right, it's all the same thing, basically it comes down to weight transfer (actually pretty much all driving theory seems to come down to managing weight transfer and the friction circle). I brought up the 'negative' aspects as in my experience, when it's called 'snap oversteer' it's always a bad thing and always happens on asphalt.

But yeah - a Scandinavian flick is a deliberately induced case of snap oversteer. You throw the car the wrong way coming into the corner and use the 'snap' to bring you around. Given the characteristics on a loose surface though, as I said, it's a lot easier to manage than on asphalt, and it's also easier to provoke and manage in any car.

You wouldn't generally deliberately provoke it on asphalt, unless (a) you're a drifter (i.e. "feint drift") (b) you're a rally driver on a mixed surface special stage and you've had to compromise on tyres (c) you're in a European rallycross.

They occasionally have rally stages on road courses, and it is pretty cool to see rally drivers take familiar road course corners with a Scandinavian flick.. but there's a reason you don't see 'proper' road course drivers doing it.

NC brings up the point of understeer turning into horrible snap oversteer, which I can definitely back up from hard experience. I remember seeing a Neon in a race at Road America understeer into a fast downhill right. He let off the gas to try and get it back and the thing snapped back so hard that he ended up in the barriers. It's caught a lot of people out - sometimes it turns into a tank slapper but mostly it's understeer into oversteer into "hang on until it stops". Of course the only cure for oversteer in a FWD is to steer in the direction you wanna go and get on the gas - a completely unnatural reaction to being "out of control".

UP2MTNS

10-24-2007, 07:09 PM

...keep flying w/o hitting the brke.

or trees :shock: :roll: :mrgreen:

sorry jon i just couldn't help it.

haha....yeah.....and to Phil's point above....yes, snap steer on pavement usually = bad. unless you drift.

my tree tapping incident wasn't snap steer though, I shoulda just LFB around that corner, but with some folks on the inside of the turn, so if I overturned and cut too much inside, that would have been bad.

MetalNeverDies

10-24-2007, 07:49 PM

when i slide around corners going like 20ish then floor it and slide alittle more or snap the rear out a little thats not snap steer is it?

WRXCMM

10-25-2007, 07:19 AM

rollo

10-25-2007, 10:31 AM

when i slide around corners going like 20ish then floor it and slide alittle more or snap the rear out a little thats not snap steer is it?

No. At least in my understanding, when people refer to the "snap", they mean that it happens quickly and often unexpectedly, and it's usually a function of braking or letting off the gas (i.e. weight transfer to the front) too abruptly and/or at the wrong time. I've never really thought about why the behaviour you're describing happens, but my guess is that by punching the throttle, you're continuing/exaggerating the sideways movement by asking the tyres to accelerate and corner more than they can (back to the friction circle, or possibly the 'lack of friction circle'). And what happens is that they can do some of both, so you slide sideways and get forward movement. Someone leap in and say if I'm talking out of my backside.

Going back to something earlier in the thread:
i thought you were supposed to let off the gas as you went into the corner and just glide into the turn and as you come out of it start on the gas again? isnt that how you avoid this snap steering or over steer?

It depends on what you're trying to accomplish. It probably reduces the chance of it happening, but it isn't the fastest way round a corner. A single-seater racer once told me that in a competitive situation, time spent not giving the car throttle and/or brake input is time you're losing. Makes sense to me... you just have to manage the inputs real carefully if you drive on the limit.

MetalNeverDies

10-26-2007, 04:05 PM

is it easier to gain control back in a snap steer situation with an awd fwd or rwd?

noisycricket

10-26-2007, 06:55 PM

UP2MTNS

10-26-2007, 07:09 PM

is it easier to gain control back in a snap steer situation with an awd fwd or rwd?

actually, its easier to gain control back with experience ;)

haha......seriously though, I have no idea.

rollo

10-27-2007, 01:34 PM

There are much more important factors at play than which end is driving the vehicle. Things like suspension tuning, polar moment of inertia (barbell vs. bowling ball...), how quick the steering is... basically most of the factors that determine if the car is prone to snapping in the first place!

Heh.. yeah I was thinking the same thing. Probably the location of the engine is more important than the driven wheels, since it tends to determine the weight distribution of the car. I guess that with FWD you really only have one tactic to recover from oversteer, which is to jam on the gas. You see it (and hear it) quite often in road racing (e.g. Speed Touring Car) where an Integra or whatever is tagged in a corner and starts to slide, and you hear the engine scream as the driver stands on it to try and pull out of the slide. With AWD and RWD you have to choose the best combination of inputs for the moment.

Probably the safest thing to do (in any car) when you start to lose it is clutch in, brake hard and hang on.. sometimes using the gas turns it into a much worse situation than just spinning would have been (i.e. it suddenly hooks up and spears for the nearest solid thing).

But if you look back at those YT vids I linked to, it's difficult to say what either of those guys could have done to regain control once the car had snapped back. As NC alluded to, their best bet would have been to not let it happen in the first place :D

UP2MTNS

10-27-2007, 01:46 PM

[quote=noisycricket]

But if you look back at those YT vids I linked to, it's difficult to say what either of those guys could have done to regain control once the car had snapped back. As NC alluded to, their best bet would have been to not let it happen in the first place :D

I think both situations would have been cured with LFB. Both guys were going into the corner too hot (back end came around), and instead of holding on or LFB, they let up on the throttle, which caused the fronts to grip, the back end to whip around (snap steer) and voila....hit the wall.

Had they just held their course (stayed on throttle), tapped LFB, that would have slowed them down considerably but kept them going in the right direction, instead of whipping their car into the wall.

of course, its hard to tell what really happened, but it makes some sense. Just like in rallyX.....sideways, counter steering and going wide? stand on LFB.

noisycricket

10-27-2007, 03:08 PM

Heh.. yeah I was thinking the same thing. Probably the location of the engine is more important than the driven wheels, since it tends to determine the weight distribution of the car.

Not so much as you might believe. BMW gets their trendy 50/50 weight distribution by shoving the front wheels and the rear wheels as far forward as their wheelbase target will allow, and then dealing with the interior volume issues that come from that.

I guess that with FWD you really only have one tactic to recover from oversteer, which is to jam on the gas. You see it (and hear it) quite often in road racing (e.g. Speed Touring Car) where an Integra or whatever is tagged in a corner and starts to slide, and you hear the engine scream as the driver stands on it to try and pull out of the slide. With AWD and RWD you have to choose the best combination of inputs for the moment.

You could also just countersteer, but the problem with that, and let's get really general here, is that for a front drive vehicle, oversteer is not the natural order of things. Given all the things that the front tires are asked to do, and the assumed weight distribution inherent to a front driver (nose heavy), the front tires get overloaded first.

If the rear is sliding, it is normally just due to a transitory thing, like brake lockup or camber change or crap in the road or help from another car :) and as soon as it can, it will start gripping again, because that's the natural order of things. If you're countersteering to deal with the oversteer, when it grabs, you snap around the other way unless you catch it *before* it starts to come around. So the trick is to not countersteer so much as try to get some weight back on the rear with throttle, which has the additional benefit of unsettling the front tires, if there's enough power.

That's why my own FWD is (was) scary to take corners at 80mph. If it transitioned to oversteer, it felt like there wouldn't be anything I could really do to save it :( Taking those interchanges that fast required full throttle just to keep from slowing down, no additional power available. There was a revelation I had one day when I did finally overcook it: When a very light car slides on grippy tires, it loses a lot of speed in very short order. So, if the back end starts coming around, the friction will slow the car down in good time. Makes for a very aggressive thow-it-at-the-corner driving style. (Reminds me of my GL :) ) It's almost unspinnable.

[quote]Probably the safest thing to do (in any car) when you start to lose it is clutch in, brake hard and hang on.. sometimes using the gas turns it into a much worse situation than just spinning would have been (i.e. it suddenly hooks up and spears for the nearest solid thing).

If you're too far gone, yeah, lock 'em up. Takes a bit of humility :)

UP2MTNS

10-29-2007, 07:02 PM

snap steer at JV5!!
http://www.youtube.com/watch?v=BBBZzkYmpM0

odi

10-30-2007, 07:51 AM

I think the challenge of JV5 was not to allow snap steer in many sections especially the slaloms. The car would try to snap because as you steer right left you are flicking the weight around. But with left foot braking and getting on the gas harder at the right times the car stayed somewhat straight and went faster throught the slaloms 8) . Just drifting the ass end aroung them cones back and forth through the slalom really slowed people down.

Disclaimer: That is just my thought and experience, I'm not a pro nor do I have more than 2 rallyx events as experience :tongue: .

rollo

10-30-2007, 09:07 AM

Heh.. yeah I was thinking the same thing. Probably the location of the engine is more important than the driven wheels, since it tends to determine the weight distribution of the car.

Not so much as you might believe. BMW gets their trendy 50/50 weight distribution by shoving the front wheels and the rear wheels as far forward as their wheelbase target will allow, and then dealing with the interior volume issues that come from that.

I was thinking more extreme, e.g. the NSX which is MR and thus has a low PMOI, making for quicker transitions - good if you're in control of them, bad if they're in control of you. Or the 911 (the older, more vicious ones without the electronic nannies anyway) which have the weight all behind the rear axle.

If the rear is sliding, it is normally just due to a transitory thing, like brake lockup or camber change or crap in the road or help from another car :) and as soon as it can, it will start gripping again, because that's the natural order of things. If you're countersteering to deal with the oversteer, when it grabs, you snap around the other way unless you catch it *before* it starts to come around. So the trick is to not countersteer so much as try to get some weight back on the rear with throttle, which has the additional benefit of unsettling the front tires, if there's enough power.

Interesting.. so turn it into a four-wheel-drift, kinda thing. That'd work and be easier to hold onto, as long as you have the room.

That's why my own FWD is (was) scary to take corners at 80mph. If it transitioned to oversteer, it felt like there wouldn't be anything I could really do to save it :( Taking those interchanges that fast required full throttle just to keep from slowing down, no additional power available. There was a revelation I had one day when I did finally overcook it: When a very light car slides on grippy tires, it loses a lot of speed in very short order. So, if the back end starts coming around, the friction will slow the car down in good time. Makes for a very aggressive thow-it-at-the-corner driving style. (Reminds me of my GL :) ) It's almost unspinnable.

We're into individual car handling here though.. my Corrado is based on the same basic platform as your GTI (A2 right?) but the dynamics are significantly different.. the Corrado is a lot heavier of course, but has a tendency towards lift-off oversteer.. which counteracted too strongly (or with panic reactions) can turn into a snap, of course. The point being that in the same situation - the fast interchange - if the back end starts coming around and you don't do anything, then it's gonna carry on coming around and it'll overtake you in short order :D Of course the Corrado has power to spare at 80 in 3rd or even 4th.

Probably the safest thing to do (in any car) when you start to lose it is clutch in, brake hard and hang on.. sometimes using the gas turns it into a much worse situation than just spinning would have been (i.e. it suddenly hooks up and spears for the nearest solid thing).

If you're too far gone, yeah, lock 'em up. Takes a bit of humility :)

And we all know that racing drivers (and wannabe racing drivers) are usually blessed with an abundance of humility :D

rollo

10-30-2007, 09:12 AM

UP2MTNS

10-30-2007, 10:40 AM

snap steer at JV5!!
http://www.youtube.com/watch?v=BBBZzkYmpM0

Hehe.. with all due respect Jon, I'd class that as a tank-slapper more than snap-steer :D But we're into semantics now... the transitions are so much more gentle on dirt that 'snap' seems strictly asphalt to me. I mean on dirt you know it's gonna happen long before it does. And Odi you're right.. keeping it neat in the slalom was where a lot of the time in that course was. Don't carry too much speed and a lefty stab at the brake for each turn in was a good combo.

Incidentally, I was watching that onboard video action from the start line.. I remember cos I thought, oh that's nice of Jon, he's giving me back those two seconds I gave up on run 1.... :P

hahah....well, the I guess I was looking at the 'snap' to the left after the tank slapper. ....came off the big sweeper into the right turn, back end came around to the left, and I oversteered too much and let up on the throttle and that whipped me around to the wayyyyy right, then I straightened out for the straight away. Wouldn't that be considered snap steer? If I was on tarmac, I'd have flipped a 180 and gone off course probably, haha.

rollo

11-20-2007, 09:44 AM

x-a-AdLBiG8

409industries

11-20-2007, 10:33 AM

when i slide around corners going like 20ish then floor it and slide alittle more or snap the rear out a little thats not snap steer is it?

Naw, this sounds like just inducing oversteer with the throttle. Its a piece of cake to do in the STi with some all season tires on. Just dump the clutch 1/2 way through a turn in 2nd gear and instant drift action!

strat

12-02-2007, 07:37 AM

in my experience, a lot of snap oversteer is caused by driver over-correction combined with braking and or letting off the gas...

i've experienced it in both fwd and my awd. fwd was scary as i was on pavement, coming around a corner at high speed. lifting (like an inexperienced driver) coupled with a larger rear sway bar put the rear out, i over compensated, the rear caught traction and then i did a 180 and slid backwards for a bit. luckily i didn't tag anything.

rollo

12-12-2007, 09:04 AM

9k1a4yj8VjA

LUCKY

UP2MTNS

12-12-2007, 09:21 AM

LUCKY

i guess so.

I don't get that lucky. If I did that, there'd have been a big rig in the other lane that couldn't have stopped.

I Like It Sideways

12-12-2007, 09:47 AM

LUCKY

No kidding. That was nuts, I expected it to smash the guard rail. I didn't think about the oncoming traffic

disturbed1

01-14-2008, 10:12 PM

damni exprienced this when i upgraded the sway bars in my STI to the cobb tubulars front and rear. i was speeding down some canyons corners and i was experiencing slight understeer when all of a sudden the rear end tries to swing out on me. i quiickly try to counter steer it and mash on the gas a lil and saved it. what i have donw to keep this from happening again i run the rear tires 5-7 psi lower than the fronts.

RS-ti_Andy

01-14-2008, 10:25 PM

so thi is actually called something eh? wow..ive overcome this a LONG time ago lol.. to much messing around in my cars and trucks lol.. oh well..more practice the better

brd360sk8

01-14-2008, 10:36 PM

So is a bad or good idea to upgrade to cobb stage 1 suspension kit. Im lookin for beefy off road stuff with high speed on road capabillities still... Anyone recommend any other kits...

disturbed1

01-14-2008, 10:52 PM

i recomend the kit. the difference is night and day. upgrading to any rear sway bar will induce more oversteer. its just that i was driving it for the first time and was not use to the oversteer. the car corners much better and faster than before its just that i was pushing the car to its limits so that i can get use to it.

BlackParis

01-15-2008, 08:45 PM

9k1a4yj8VjA

LUCKY

almost looks like a bigger wing could have saved him ;)

MetalNeverDies

01-16-2008, 01:06 PM

disturbed1

01-16-2008, 03:07 PM

lol i would have crapped my pants.i thought wit the awd system the fronts had to have less than the backs to deal with weight and all that fun stuff. what should i run for street presures on an 05 2.5i wagon? 29 front? 32 rear?

i only deflate my tires when i do canyon runs. to reduce oversteer you need lower air preasure in the rears. if you inflate the rears more than the fronts you will create oversteer. for normal street driving just run the recomended tire preasure to prevent premature tire wear. play with the air preasure and see how you like it. on the street i run 42 PSi all the way around.

BlackParis

01-16-2008, 04:47 PM

i only deflate my tires when i do canyon runs. to reduce oversteer you need lower air preasure in the rears. if you inflate the rears more than the fronts you will create oversteer. for normal street driving just run the recomended tire preasure to prevent premature tire wear. play with the air preasure and see how you like it. on the street i run 42 PSi all the way around.

not necessarily the truth...

i always lower the rears to induce overstee

BTW I always run 38 front 35 rear... and auto-x i go up to 42f and 38 rear

disturbed1

01-17-2008, 07:35 PM

MetalNeverDies

01-17-2008, 07:58 PM

yupp it is the higher the more slide/squierly that end gets so higher in rear = more over steer

MetalNeverDies

01-17-2008, 08:08 PM

do i have to run the stock pressures that the car door has on it for the street though? or will they blow out on the freeway at high speeds if i have them up from what the door says. all i know is my tires cant go over 44 psi. the fronts always look like they are flat when i run 29 up front though

disturbed1

01-17-2008, 08:12 PM

ok here is one i found. scroll all the way down to where it says dealing with tire preasure http://www.porschenet.com/bfgtires.html

disturbed1

01-17-2008, 08:17 PM

for you i suggest that you run them at what the tire specifies on the side wall. it should say max inflation ??psi. do not go by what the door says unless your on stock tires. the stock tires on my STi ran at higher preasures than my new BFG KDW II. also i think that 29 psi is too low. your sidewall might be flexing too much and actually hurt the tires performance. 35 psi is a good general rule for the street.

do i have to run the stock pressures that the car door has on it for the street though? or will they blow out on the freeway at high speeds if i have them up from what the door says. all i know is my tires cant go over 44 psi. the fronts always look like they are flat when i run 29 up front though

MilesFox

01-17-2008, 10:39 PM

run the tires within 10%.
if hte tire says max 44 psi, the n 10% is 4.4, take that off of 44 and you have 39.6, essentially 40 lbs.

if the tire says 35then minus 3.5 and thus 31.5 roughly 32 psi

98obster

01-17-2008, 10:44 PM

on the highway, tires do heat up and increase in pressure-I guess how much would depend on a few things like outside temperature and tread?

BlackParis

01-20-2008, 09:20 AM

umm...you lower air apreasure in your tires to get traction right. well if your front tires have less traction than your rears how is it going to break loose before your front tires. trust me i have lots of people who can ring in about this topic. look it up. drag racers lower their rear tires so they have more traction and bite more. raise your rear tires preasure higher than your fronts next time you go auto-X and you'll prove me right. people at the canyons have thanked me for this advice. some one on nasioc also posted on the topic of how you can tune your car's handling.ill find it and post the link.

Lower air pressure does give a better straightaway grip.. but it also allows the tyre to wash out/roll in corners... Put 25psi in you back tires and tell me your car isn't loose as hell...

I said it can work either way... I just found that 42 front (2 below maximum) and 38 rear is the best combo for me @ auto-x... Also, there is no room to fill up the rears MORE cause max pressure is 44psi... Cause I would prolly need 48-50 in the rears to get the same amount of "looseness" when turning....

ALSO.. Less than 40 in the fronts is tooo washy, tyres roll and you drive onthe sidewalls...

disturbed1

01-21-2008, 09:12 AM

Lower air pressure does give a better straightaway grip.. but it also allows the tyre to wash out/roll in corners... Put 25psi in you back tires and tell me your car isn't loose as hell...

I said it can work either way... I just found that 42 front (2 below maximum) and 38 rear is the best combo for me @ auto-x... Also, there is no room to fill up the rears MORE cause max pressure is 44psi... Cause I would prolly need 48-50 in the rears to get the same amount of "looseness" when turning....

ALSO.. Less than 40 in the fronts is tooo washy, tyres roll and you drive onthe sidewalls...

i completely agree with your statement. too low will cause the tires to ride on the outer part and create a smaller contact patch. their is a great way to find out how to get the perfect amount of traction. it involves shoe polish and alot of time.ill find the link for you guys.

MetalNeverDies

01-21-2008, 01:18 PM

i found out that after your tires heat up they go up in psi by about 4lbs

disturbed1

01-21-2008, 03:26 PM

it does but it depends on the amount of temp. every 10 deg F its 1 PSi.

brd360sk8

01-23-2008, 09:49 AM

Bad case of snap steering this morning. Taking a Right turn that merged into a 3 lane road. Down into second and gave it a little gas. Back end just flipped out. Good thing I've practiced that situation about a million times in a big parking lot. So I just kept constant gas feathering it a little bit and drifted it out. It tried to kick back again the other way but I got it back in line. I went across all 3 lanes lol. I knew the coast was clear before I turned just incase it happend. Soooo yeah fun morning saw a 08 sti too... lawl:lol2:

disturbed1

01-23-2008, 03:09 PM

good to hear you recovered and and not hey i wrecked my car after i saw initial D

brd360sk8

01-23-2008, 03:39 PM

hahaha stupid asians.... and there miatas lmao

RS-ti_Andy

01-23-2008, 06:54 PM

u making fun of asians?.. i love asians! we can brawl over this soon..

dman my yellow fever! hahaha

rte7x9

02-28-2008, 05:30 PM

Initial D??

Come on, there's only one Subie in that show anyway, why waste your time!? =P

rollo

03-18-2008, 08:55 AM

Another one for the collection. No room to snap here..

7Wdrm-DatWE

No co-driver, must have been a sprint or a hillclimb I guess.

russellshireman

11-29-2011, 01:47 AM

I know this is a REALLY old thread, but something I've learned a lot about recently. I started autocrossing in VWs, some mk2 cars, a mk4 GTI, and most recently a Corrodo SLC, and actually induced snap oversteer on hairpins and some sharp corners, but was able to control it better. Between the VWs and my wagon, I hopped in a classic BMW with tons of body roll and the RWD was a welcome predictable friend. Getting into the old wagon, though, for the first couple of times, the snap oversteer was completely unexpected for me, and would happen when I was being easy on the car, especially in slaloms. My first event with the car was at Subaru Challenge 2011 @ SIA in Lafayette, IN. My girlfriend told me to go easy with her in the car, so I casually went through the course which I never do. I have a heavy right foot. The final slalom, the car did a completely unexpected 180 around the last cone so I threw it in reverse through the timing lights... It turns out that my weight was transferring so much to the front with the old worn out suspension when i would back off the throttle for turn-in, that my inside tire would lift significantly off the ground and the rear would just do what it wanted. (see pics)

http://i123.photobucket.com/albums/o318/russellshireman/6081037563_05bff59b87_b-1.jpg

http://i123.photobucket.com/albums/o318/russellshireman/3wheelinlikeabaus2-1.jpg

The next day, my local region had an event and one of the corner workers I knew started recording my runs(shhh... I know he needed a spotter:nono) as I came through his station because I kept having snap oversteer issues, so I have this lovely video to share.

http://www.youtube.com/watch?v=TEv2p1c8W7k

I've since lowered my center of gravity significantly and added some rigidity to keep all 4 tires in contact and the weight centered better so it drives very predictably to my style.