BRZ stock suspension understeer... what to do?

[mtimney]

Thank you all for the advice. I appreciate your input and will put it to use at my next autox August 4th.

[GTB/ZR-1]

Originally Posted by Sccabrz192

Whether you are a hair over or a mile over if you are over on your entry speed, you will under steer or push. Slow in fast out is the mantra you need to start with to learn. 5 mph too slow on the entry is better than 0.5 mph over.

And nails it again...

I'm surprised when I get in the car w/ people that have years of experience that still do this. the 2 main things I preach: in slow--out fast & LOOK AHEAD!

[Captain Snooze]

Originally Posted by Sccabrz192

You are overcooking corner entries.

Yeah, it still gets me and I have a hard time dealing with the fact, that sometimes you go faster by going slower.

[Element Tuning]

Well I say continue to go fast in but fix your car to accept it

With that said make sure you have all your driving aids off. Like others I always felt stock with race tires that I always had way more grip and steering inout than I had rear grip. I was always chasing the ass around until I added aero.

[3essess]

Check to make sure your traction control FULLY off. If not, it will push a LOT more than when it's fully disabled.

[track junkie]

Originally Posted by Sccabrz192

Whether you are a hair over or a mile over if you are over on your entry speed, you will under steer or push. Slow in fast out is the mantra you need to start with to learn. 5 mph too slow on the entry is better than 0.5 mph over.

Reason is if you enter slow, you can get on the throttle earlier and make some of the lost time back. Earlier throttle can also induce throttle on oversteer and rotate the car. If you enter with too much speed, all you can do is sit there and wait. If you enter with too much speed, you will find the more steering angle you use will not provide any additional turning of the car until it has slowed appropriately... You use the scrubbing of the front tires to finish breaking.

Are you serious?

[track junkie]

This is helpful.
http://books.google.com/books?id=ETi...20slow&f=false

Third paragraph from the bottom page 258.
"You should aim to enter the turn just slightly faster than the traction limit dictates...." According to this pro coach.

[Captain Snooze]

Originally Posted by track junkie

Are you serious?

Are you serious?

[whataboutbob]

Pay attention to what the car is doing. Slow down and round off your turns. You can't make the car turn more than it is capable of turning.

If it starts to push, let off the throttle and unwind the wheel.

[Sccabrz192]

Originally Posted by track junkie

Are you serious?

Yes, you will be much more successful giving up just a little bit at every turn than hard charging and overdriving a corner or two, the goal is to minimize time lost by mistakes. The proper way to start learning is build to the limit, not blowing through turns and trying to slow down more and more and more to get back to the limit, plus your tires wont be destroyed after 2 events.

Sure, there are techniques to minimize errors when you come in hot to a turn but when you are learning thats not the right way to learn. Agree with whataboutbob. If you do come in too hot what I meant by "waiting" is exactly what he describes, let off the throttle and unwind the wheel until you are within the traction limit of the tires.

[Element Tuning]

What some of the more experienced drivers are trying to explain is that going fast for a given setup is maximizing grip which means maintaining the contact patch with the tire and finding the best line that provides the most grip.

Part of maintaining the contact patch is to manage your weight transfer properly and to do this you often need to slow down your inputs. So it's possible the OP is hard on the brakes, then hard off, then a quick agressive steering input along with throttle application (so weight transfer from one tire to the other is too abrupt). So he could be very quickly unloading the weight from the front tires, tranfering to the rear, so too much mechanical grip (weight) is lost off the front resulting in understeer as more weight moves to the rear increasing grip there.

I tend to brake into my turn (trail brake) which keeps the weight on the front tires as you turn in but also makes the rear lighter which helps rotate the car. As I need more rear grip i'll ease of the brakes and ease into the throttle. Transferring weight to the contanct patch I need the most grip at.

[DarkSunrise]

Originally Posted by feldy

If you dive bomb the corners and are still in the brakes while turning you are going to push wide.

Isn't staying on the brakes while turning just trail-braking? In autocross, when I'm over my ideal corner entry speed, I find it better to stay on the brakes while turning to induce turn-in and rotation. I would think lifting off the brakes would just make the understeer worse, unless this has something to do with how ABS or EBD operate -- perhaps try to keep you in a straight line. I might be mis-reading your comment though.

[solidONE]

I found that my factory FR-S pushed at turn in as well even with uprated tires, understeer is even more pronounced under trail breaking. It would then oversteer mid turn when throttle was applied, but that's another issue. I'm sure one can compensate for this with technique, but it's not ideal. cough* @CSG Mike cough* After adding some negative camber at the front wheels, turn in was very noticably better. You may want to look into some camber bolts. I used SPC bolts and they were worth every penny and then some. IMHO

Edit: Okay so you have already added camber. My current set up with just the front camber, I don't feel much understeer with stock or RS3 Hankook tires, although the oversteering with even the slightest throttle mid corner has stayed the same. I was able to remedy this by unhooking the rear sway bar. I decided that I should learn to deal with (compensate by adjusting throttle and steering input) the oversteer with the rear sway bar still hooked up since I didnt like the sloshy feel of the rear when it was unhooked. While this is not the same problem you are having, I think it would be a good idea to adjust your inputs to compensate until you find a solution. I think this approach will make you a better driver in the long run.

[Racecomp Engineering]

Slow in, fast out becomes fast in, faster out with experience.

Agreed with Phil below on smoothness being key. Especially with cars on stock or soft springs that are in reality very progressive since they are bumpstop active. That can be a very sharp ramp up in spring rate that suddenly overloads the tires and it's just exaggerated if you're not being smooth.

That's my guess as to why we hear a lot of people talking about corner entry understeer, then sudden mid-corner oversteer.

- Andy

Originally Posted by Element Tuning

What some of the more experienced drivers are trying to explain is that going fast for a given setup is maximizing grip which means maintaining the contact patch with the tire and finding the best line that provides the most grip.

Part of maintaining the contact patch is to manage your wait transfer properly and to do this you often need to slow down your inputs. So it's possible the OP is hard on the brakes, then hard off, then a quick agressive steering input along with throttle application (so weight transfer from one tire to the other is too abrupt). So he could be very quickly unloading the weight from the front tires, tranfering to the rear, so too much mechanical grip (weight) is lost off the front resulting in understeer as more weight moves to the rear increasing grip there.

I tend to brake into my turn (trail brake) which keeps the weight on the front tires as you turn in but also makes the rear lighter which helps rotate the car. As I need more rear grip i'll ease of the brakes and ease into the throttle. Tranfering weight to the contanct patch I need the most grip at.