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2000 2.5 RS Impreza 4 door
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Discussion Starter · #1 ·
This is actually a thread to keep from junking up tnice17's thread. http://www.rs25.com/forums/showthread.php?t=86421

Here are the related posts:
How come I have a big RSB and I can never get my back end loose?
whiteline adjustable on the stiffest setting

stock everything else for suspension
Hmm I have a adj. whiteline RSB on the stiffest setting as well. :(
Two words: trail braking

From reading tnice's story it sounds like he tightened up on the brakes mid corner, this a perfect way to induce oversteer every time, and the very definition of trail braking, he just wasn't ready for it + the varying traction of the dirt on the side of the road vs the pavement is what did him in.

You could also use the old scandanavian flick.
Yah I can get the backend loose with a high speed (~35-45 mph) scandinavian flick. So maybe a stab of the brakes mid corner would help? I think Ive tried it before but maybe Ill go out to an empty parking lot one day and try again. I just wish I could do some power induced oversteer or even snap-oversteer insted of power induced understeer. :(

As far as suspension Ive got 22-24mm WL RSB, Front and rear endlinks, KYB AGX + SPT springs, -1.75 F -0.75 R camber, 0 toe, 235/40/17 Azenis, and I think thats all thats really relevant.
it's almost impossible to get the RS drivetrain into power induced oversteer on dry pavement. I can't even do it with my swap. Wet surfaces and gravel is another story.

Trail-braking is a very useful technique, but difficult to practice safely.
You are probably just going into corners too hot. It honestly doesn't matter what kind of car you drive, you will still plow like no tomorrow if you go too fast into a corner, and mashing the throttle won't help much.

Mid corner is usually too late for low-medium speeds (<45mph). Assuming you are taking the corner aggressively, your front tires will already be loaded close to the max... if you jab the brakes you are usually more likely to overwhelm the front than the back = moAr understeer :( If you are "plowing" mid-corner the only thing you can do is let off the throttle if you're on it. What you want to do is basically have the brakes still applied a bit as you begin to turn so you still have the back of the car unloaded.

Also, if you want you car to be more tail happy, set the rear camber closer to 0, and front closer to -2.5 or so.
I don't think kainam00 was talking about for sliding around the back roads. I'm pretty sure that he and poleboy were talking about for inducing rotation for autox/rallyx.
I know the basics of understeer and oversteer. What I try to do it brake at the beginning of the turn to get better turn-in and then hold the traction limit the best I can through the corner. But what I was trying to say was when I break the traction limit anywhere in the corner it is understeer. I just always hear about people saying they get the back end loose w/ their RSB all the time. And I dont want to have more chamber cause it have to DD my car more than race it.
You want oversteer? Lift
0 out the rear camber, it will help the car rotate.

Also, camber alone doesn't eat up tires that much. Camber + toe does. As long as your toe is close to 0, your tires will be fine.

People may also be lying... and/or driving on crappy tires. I can induce power oversteer on 195 width snow tires no problemo... even on dry pavement.
You will still get some camber wear on the inner edges over time.

:hijack:

We are taking this way off topic though. I'm sure we could discuss this in the Susp. area.
Im not going to get more chamber because I dont need anymore wear on the inner portions of my tires. But it may be true people are on crappy tires and thats why the back end is coming out. As far as camaroz, you mean lift, like throttle-lift/snap oversteer? That definately doesnt work on my car. Maybe I should look at ass-happy center diffs in the future?
 

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1998 2.5 RS
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Not necessarily oversteer will be induced by lifting off, but it will aide in rotation. I have a Whitline adjustable bar also (older 20-22-24 model) and I am able to experience this on the lowest setting on R-comps. The 2.5 doesn't have enough power to effectively transfer the weight to the rear to be able to induce throttle oversteer.

I don't have alignment specs with me, but mine are not as aggressive as kainam was recommending (I believe somewhere in the order of -1.5 in the front, and a little in the rear also). Kainam is correct in stating that camber alone will not cause the tires to wear excessively. I have a friend that ran -2.5 to -3.0 in his all the time. Of course this also depends on the tires you run (soft, hard, etc.)
 

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2000 2.5 RS Impreza 4 door
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Discussion Starter · #4 ·
Not necessarily oversteer will be induced by lifting off, but it will aide in rotation. I have a Whitline adjustable bar also (older 20-22-24 model) and I am able to experience this on the lowest setting on R-comps. The 2.5 doesn't have enough power to effectively transfer the weight to the rear to be able to induce throttle oversteer.

I don't have alignment specs with me, but mine are not as aggressive as kainam was recommending (I believe somewhere in the order of -1.5 in the front, and a little in the rear also). Kainam is correct in stating that camber alone will not cause the tires to wear excessively. I have a friend that ran -2.5 to -3.0 in his all the time. Of course this also depends on the tires you run (soft, hard, etc.)
I have the same RSB you then. My alignment settings (if you didnt see them already) are 1.75 F and 0.75 R camber and 0 toe. I dont know, maybe the next auto x I go to Ill see if I can pick up pointers from expierenced drivers and maybe they can drive my car to help w/ analyzing and driving techniques.


thanks man.
Sorry for getting off-topic, didnt expect it to go on that long.
 

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overdeveloped beater
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Disconnect your front bar with the big rear bar still attached and I guarantee you will be spinning. You won't be faster through the course, but you will get oversteer.

Conversely, if you have a big front bar and the correct camber for the car and tire combo, you won't need nearly as much bar in the back to keep the car balanced.

If you enter the corner too fast, there's no hope. You simply HAVE TO weight the front end down to make it bite. Lifting just after you initiate turn-in will unweight the rear end and let it come around.

I can do this with no bars at either end and 600F/450R spring rates that, while stiff for a daily driver, are still 150lbs softer at the rear.

Camber and tire wear are only barely related. Toe and tire wear go hand and hand.

Finally, sometimes you can't have the cake and eat it too. Driving hard wears tires unevenly when the alignment is setup for mediocre daily driving, milage, and predictability.
 

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GF8
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I have no problem sliding the car to correct a hot entry to a corner or just to throttle steer. My suspension is totally stock except for a Cusco RSB on the middle setting. Like Storm said, just lift on turn in and you should experience some sort of oversteer. If you don't, go faster.
Just my 2 cents...

-Kurt
 

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2000 2.5 RS Impreza 4 door
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Discussion Starter · #9 ·
What tires do you run, and what are your pressures? Pressures may have a lot to do with it.
235/40/17 Azenis RT615, last auto x I had the pressures set as 46/44 cold then bumped all of them down about 4 psi.

Disconnect your front bar with the big rear bar still attached and I guarantee you will be spinning. You won't be faster through the course, but you will get oversteer.

Conversely, if you have a big front bar and the correct camber for the car and tire combo, you won't need nearly as much bar in the back to keep the car balanced.

If you enter the corner too fast, there's no hope. You simply HAVE TO weight the front end down to make it bite. Lifting just after you initiate turn-in will unweight the rear end and let it come around.

I can do this with no bars at either end and 600F/450R spring rates that, while stiff for a daily driver, are still 150lbs softer at the rear.

Camber and tire wear are only barely related. Toe and tire wear go hand and hand.

Finally, sometimes you can't have the cake and eat it too. Driving hard wears tires unevenly when the alignment is setup for mediocre daily driving, milage, and predictability.
Well as I said before I try to brake into the corner so I can get turn in bite but what I dont understand is after I turn-in I usually get off the brake and modulate the gas. But what you said is to lift off the throttle? Im usually not on the throttle during turn in. So are you talking about left foot braking when turning in? Im confused there.

And also with a FSB I should get more front end grip right?

I just got alignment about a month or two ago and people were saying that much difference in front and rear chamber should make the car rotate enough. So I dont want to get another alignment for a while because it costs a lot. :(
 

· Ex-Mooderator
2001 RSTi, 2011 WRX Hatch
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I run -2.3 front, -1.4 rear, have for the last 2 years.

I have no inner tire wear.

The secret is to run ZERO toe so that your tires aren't scrubbing when you are driving in a straight line.

Also, adding a big RSB does NOT cure the understeer, it causes the rear to lose grip at an earlier point, but does nothing to stop the front from scrubbing. It can even cause more front understeer, as the front swaybar will become the weakest link, and will absorb any/all bodyroll possible while turning. This will cause you to overdrive your front outer tire and understeer MORE than you would have otherwise.

What you end up doing is a 4-wheel drift all the time (which is not fast), instead of actually getting less understeer.

A lot of the competitive autoX guys are now running as high as 27-19mm front, and anywhere from 13-20mm rear to get the car to hook up. I'm personally running 24/17 on-course and the car is perfectly neutral. I need to move up to 27/17 though.

I'm also running 24/20 on my other RS (with gymkhana springs), which mostly feels the same, but I'm getting rear inner-wheel lift on tight turns when decelerating, so I'll probably drop down to a 17 or 13mm in the rear there.

-- Dave
 

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2001 RSTi, 2011 WRX Hatch
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Yea, Im planning on getting a Tribeca FSB at some point in the future, Ill see what that does to affect understeer/oversteer.
I'll have to dig up some info on the tribecca bar, but from what I remember on the way it mounts/how long it is...it rougly equates to a 22mm FSB on the GC?

22 isn't much of a change from the stock 19/20mm FSB, but for $50 from Subaru, it's great to try =)

You may wanna find a big parking lot and do a skidpad test and see how tight of a circle you can turn before/after to measure the amount of understeer cured...

-- Dave
 

· aka RFoy2.5RS-T
98 RS
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I'm having problems with my car It under steers really bad on turn in. I am able to drive through it with the power(swapped over 350whp) but It's not the fastest way to get around the course and I often end up going way to fast to make the next transition. Here is what I have

Megan Racing Coil covers. I have the front top hats rotated 45deg. with the camber plate all the way in giving me caster and dynamic camber. I swapped the springs front to rear (in an attempt to cure my understeer) I have a cusco 24mm RSB a WRX wagon FSB. Mechanical LSD rear diff. oh and I'm 225/45R17 RT-615s

Any Ideas? Could I make setup changes with the coilovers that would help me out?

Judging by this picture I'd say I need a larger FSB


And here I am powering out of a turn.
 

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Miatamiatamiata
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i'm running a whiteline 20mm RSB, at the tightest setting, and bilstein coilovers.
the car is lowered, and the coilovers are adjusted to 4 in the front, and 3 in the back (damper settings)
that's stiffer in the back.

with everything else stock, handling is perfectly neutral.

if i set the front damper settings looser and the rear settings tighter, i get oversteer.

but loosing traction's no fun now is it.
 

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2.5RS Rally Car
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I'm having problems with my car It under steers really bad on turn in. I am able to drive through it with the power(swapped over 350whp) but It's not the fastest way to get around the course and I often end up going way to fast to make the next transition. Here is what I have

Megan Racing Coil covers. I have the front top hats rotated 45deg. with the camber plate all the way in giving me caster and dynamic camber. I swapped the springs front to rear (in an attempt to cure my understeer) I have a cusco 24mm RSB a WRX wagon FSB. Mechanical LSD rear diff. oh and I'm 225/45R17 RT-615s

Any Ideas? Could I make setup changes with the coilovers that would help me out?

Judging by this picture I'd say I need a larger FSB
Judging by the pictures you are also cooking your tires. Azenis work best at lower temps and overheat VERY easily.
 

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2001 RSTi, 2011 WRX Hatch
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so i already have a 17mm rear bar, are you saying if i put on a bigger front bar it will help reduce understeer?
Yes.

I'm having problems with my car It under steers really bad on turn in. I am able to drive through it with the power(swapped over 350whp) but It's not the fastest way to get around the course and I often end up going way to fast to make the next transition. Here is what I have
If you're running more than -2.5deg of front camber, turn-in will have issues hooking up, as your contact patch isn't very large. I'd slow down more before the turn and then get on the throttle sooner on the way out to make up for it. It looks like you're probably overdriving your tires a tad too...

Judging by this picture I'd say I need a larger FSB
Yeah...and a smaller RSB to keep that inside tire on the ground.

-- Dave
 

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overdeveloped beater
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I'm thinking that overdriving has alot to do with it. Shorter tires (40 series and such) are more prone to breaking free sooner. The sidewall is so short that the line between grip and slip is pretty thin. Braking and turning is not the best way to initiate a turn....especially if you're braking at a level to slow you from the last straight.

Brake in a straight line. Modulate throttle to carry speed into and through a corner. Lifting midcorner will result in the rear end getting lighter....if the front end is biting. If it's already slipping, you have to unwind the wheel slightly (while lifting off the gas instead of braking) to regain grip. So many times I read about this setup, that setup, this tire, pressures, power levels, etc....but most times I see people simply overdriving.

If your car does not grip despite all attempts to make it do so, you just have to slow down SOONER. The sooner you slow down, the sooner you can turn in. The sooner you turn in, the sooner you can get on the damn gas. If the car understeers when you're on the gas....then turn in SOONER! You know you can always gas it to slide around a cone....
 

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Discussion Starter · #20 · (Edited)
I'm thinking that overdriving has alot to do with it. Shorter tires (40 series and such) are more prone to breaking free sooner. The sidewall is so short that the line between grip and slip is pretty thin. Braking and turning is not the best way to initiate a turn....especially if you're braking at a level to slow you from the last straight.

Brake in a straight line. Modulate throttle to carry speed into and through a corner. Lifting midcorner will result in the rear end getting lighter....if the front end is biting. If it's already slipping, you have to unwind the wheel slightly (while lifting off the gas instead of braking) to regain grip. So many times I read about this setup, that setup, this tire, pressures, power levels, etc....but most times I see people simply overdriving.

If your car does not grip despite all attempts to make it do so, you just have to slow down SOONER. The sooner you slow down, the sooner you can turn in. The sooner you turn in, the sooner you can get on the damn gas. If the car understeers when you're on the gas....then turn in SOONER! You know you can always gas it to slide around a cone....
My first auto x I would brake before the turn then modulate the gas during the turn like you said. I dont remember the back end coming around like you said when I lifted off. Then again it was my first auto x and now I have wide stickier tires so I guess it hard to compare.

The last auto x I figured if I braked under turn in that would transfer weight to the front tires giving me more traction preventing turn in understeer. It seemed like it worked but that couldve been just the tires (though I tried to factor that in).

And when you say, "You know you can always gas it to slide around a cone...", if I do that its instantly just understeer. Unless you mean slide in a different way or something.

EDIT: Heres an example:

http://www.rs25.com/forums/showthread.php?t=86548

"I highly recommend this upgrade to anyone that wants to correct the snap over steer that your ubgraded RSB gives you"

How come I dont get this oversteer?
 
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