Need help with understeer and holding curves

[RaceComp Engineering]

OP: just a suggestion but if you're looking to make the car more neutral you should think about stiffer springs/dampers instead of relying on only the sways. It's a false sense of security that will become scarily apparent when the car is pushed to the limit, as you may have discovered while autox'ing.

It's probably been said thousands of times before on every car forum, but a good spring/strut combo will take care of 90% of your understeer. The sways should be used to fine tune where exactly you want the remaining roll to go.

 

I generally agree with this. Swaybars should mostly be used to fine tune understeer/oversteer. But they are cheap and you don't need to get an alignment after installing. It's a noticeable upgrade. I would recommend front and rear together to keep things sort of balanced.

 

BUT the stock dampers on the Legacy are just not very good at all and will be a glaring weakpoint if you do upgrade bars first. IMO they are one of the first things that should go (as well as tires + alignment).

 

There is always debate between stiff springs soft swaybars vs. soft springs vs. stiff swaybars. There are many ways to go...it's just important to keep the total picture in mind, especially tire compound.

 

- Andrew

[grimsleeper]

So lets say I put a stiffer rear swaybar on the car, it would reduce rear body roll and increase front body roll by your explanation.

 

Then if i get a bigger front swaybar, it would reduce front roll and increase rear body roll.

 

If I did both, would I then be back to square 1 and have the same amount of body roll I started with?

 

The answer is no.

 

I think you're getting body roll and weight transfer mixed up.....they are not the same.

 

Adding more rear roll resistance, whether through stiffer springs or stiffer swaybars, increases rear weight transfer. This means the front sees less weight transfer since total weight transfer stays the same in a given corner for a given car (except if you change track width, weight, COG, etc.)

 

Reducing weight transfer at the front (with a stiffer rear swaybar) means more even loading of the front tires, which means more grip up front. But it doesn't mean more front body roll.

 

Increasing weight transfer at the rear (with a stiffer rear swaybar) means more uneven loading of the rear tires, which means less grip at the rear. You do get less body roll in the rear, which can add some grip back by reducing suspension geometry changes.

 

- Andrew

 

you're right, I confused weight transfer with body roll:redface: Although wouldn't the transfer of weight naturally cause more roll on the receiving end, even if it's a minimal amount due to a proper suspension setup? I didn't mean to say that one would negate the other, but rather allows you to dial in the slight amounts of roll that remain in order to maximize grip by using different sway bar sizes/mounting points.

[blklgt05]

I had a lot of questions myself about the settings and I asked buddy who is a very experienced certified master mechanic for toyota, MB, and currently a certified beverly hills ferrari mechanic. He personally owned/modded/tracked 2jzgte supras, wrx bugeyes, sti, evo, ae86, mr2s, 350z..... and many others, 200 some hp hayabusa...

 

This is his preference(for daily):

CAMBER Front: -1.5*

CAMBER Rear: 0*

Front Toe: +0.5*

Rear Toe: -0.5*

This toe setting is to help the tires hug the road better, with 0* toe settings (which i currently still have) can cause the car to wander at high speed.

 

Swaybars: Depends on the way you drive, some like it stiff, some like it soft, depends on your spring rate+personal preference.

 

I didn't fully understand when he tried to explain about suspension adjustments and how they all play together. He fine tunes to a degree where just for his supra, he had 8 sets of springs all with different spring rates for different track. Theres just way too much information to tune and fine tune your car and they can be very costly when you start adding them up. My buddy's best "bang for the buck" recommendation for all who wants better handling(including myself) is to simply enroll yourself in driving schools.

 

I didn't ask about castor, but i have the AVO positive castor bushings and they do help with cornering entrance. Whiteline PU steering rack bushings helps a lot with steering feedbacks.

[loopless]

I am still struggling to get my 05 GT wagon to have a nice 'initial' turn-in. I have STI wagon pinks with Bilstien HD's, Cusco F/R and LCA bushing with offset. The LCA's really improved the feel at the 'straight ahead' but I do feel they created more initial understeer as 'the return to center' effect is quite strong.

 

I have a favorite off ramp (not concrete) - if I attack it aggressively the car feels pretty good with some stabilizing understeer, but at 5/10ths the car feels too understeery and hard to place on the road- I swear it almost feels like I have big old 185/75 profile tires ( I have summer 245/45/17 PZero Nero's at the moment).

 

I have driven a friends '08 330i coupe around the same corner more than a few times, so have a good idea what the 'gold standard' is for that corner.

 

Next thing to try are the steering rack bushings...

[ifbiker]

Do you know if you are rolling the front tire over? If you are you might want to add a pound or 2 of air. I would also check the alignment, if your toe is off in either the front or the rear it will make the car dance. You might also want to check the condition of the LCA bushing to be sure it hasn't degraded any.

[grimsleeper]

I am still struggling to get my 05 GT wagon to have a nice 'initial' turn-in. I have STI wagon pinks with Bilstien HD's, Cusco F/R and LCA bushing with offset. The LCA's really improved the feel at the 'straight ahead' but I do feel they created more initial understeer as 'the return to center' effect is quite strong.

 

I have a favorite off ramp (not concrete) - if I attack it aggressively the car feels pretty good with some stabilizing understeer, but at 5/10ths the car feels too understeery and hard to place on the road- I swear it almost feels like I have big old 185/75 profile tires ( I have summer 245/45/17 PZero Nero's at the moment).

 

I have driven a friends '08 330i coupe around the same corner more than a few times, so have a good idea what the 'gold standard' is for that corner.

 

Next thing to try are the steering rack bushings...

 

I had the same issue until I installed a roll center kit, steering rack bushings will not improve your terminal understeer.

[Sebastian]

Going autocrossing this weekend, looks like it might rain. I was planning on putting my Cobb RSB on the stiff setting to see how the car handles, but is that a good idea to do in the rain, or is it gonna cause my rear end to be all over the place?