I have b+g springs with oem dampers. How can I get rid of the massive understeer problem? It's an 02 wrx wgn.

 

i'd start with a rear sway bar and end links. check out the sticky swaybar thread in the suspension forum. the wagon comes with a smaller rear sway bar than the sedan, and lots of wagon owners go to the sedan rear bar.

 

The problem isn't with rear grip, all front. If anything I would want to get the rear to pivot more. As things are now the only way to get her to turn is to induce a drift and that definatly isn't the fast way around the corner. How will a rear sway give more front grip?

 

I know, its wierd. Goes against all conventional suspension tuning wisdom, but its true with these cars for some reason. I only put on endlinks and my car understeers less. Couldn't tell ya why.

 

the rear sway bar limits the ammount of independent wheel travel in the rear suspension, and changes the suspension geometery of the rear suspension under cornering load. during a turn, the car wants to lean to the outside, compressing the outward springs, and allowing the springs on the inside to unload. the swaybar will force more of the car's weight onto the inside wheel/spring assembly until the the suspension on the outside is bottomed out and the inside wheel lifts. as such, the rear sway bar doesn't always increase grip in all situations, but it does change the handling balance of the car.

and no, it doesn't actually go against conventional suspension tuning wisdom.

another thing you could try would be dialing in more negative camber in the front, somewhere between -1 to -1.5 degrees. this will help the front tires maintain a larger contact patch (hence more traction) during a turn.

 

I first did this on my sedan, but dialing in 1.5 degrees negative front camber didn't do enough, so I installed a Whiteline 20/22/24mm adjustable RSB, with Kartboy endlinks, and at the middle or 22mm setting, my car now handles very neutral.

Tire pressure is also a factor, and you should adjust accordingly, i.e. raise front tire pressure slightly, and lower the rear slightly, and see how this helps.

Believe it or not, it is about front and rear tire grip, and you want your front to be the pivot, not the rear.

To avoid understeer, you want your front to have more front grip, and the rear to have less, so that your front stays planted, and you rear end pivots on the front, at your discretion.

 

a cusco rear sway bar, and perrin end links were the first changes that i made to my suspension, and they made a very large differance in the car's balance.

i also found that the whiteline ALK made a big differance when it came to reducing understeer when apexing and exiting a corner on the throttle.

 

I guess I'm coming from a front engine, rear drive perspective. Stiffen up the front a bit for more bite and better side to side weight distribution, soften up the rear a bit to aid front bite and get a better transition to oversteer.
Naturally you can go too far in both directions Heh.
-M

 

actually, the front sway bar helps a lot if you're running stock springs. the car has way too much body roll with the stock springs, and the front bar will help keep some of that under control during transitions. with an adjustable rear bar, you can tune out the added bit of understeer pretty easily.

 

i've run a couple of differant combinations on my car so far. i started with just an adjustable rear sway bar and endlinks, then added a whiteline alk, and then the front sway bar and end links.

with just the rear bar, the front of the car rolled too much due to the spring rates. there was a whole lot less understeer even with the rear bar on the softest setting.

the alk only reduced understeer while exiting corners on the throttle, it did absoluetly nothing for turn in.

with the front sway bar, the car felt more balanced all arround but still had a tendency to understeer at the limit. that said, i feel i was able to carry greater corner speeds with it, due to the reduced ammount of roll in the front. things were just a lot more predictable.

right now, i'm running JDM STi ver. 8 spec-c struts and springs, which are hugely stiffer than stock. the ammount of body roll in corners is almost non-existant. i'm running -1 front camber, about -.5 in the rear, and 0 toe.

with setup, the front bar is probably not needed, due to the spring rates of the STi springs. if i had the stock front bar, i'd consider putting it back on to test things out and find out for sure. i am going to increase the stiffness of the rear bar to dial out the litle remaining understeer, and right now i have two settings to play with (medium and full stiff).

on a side note, i'll second the recomendation for the Perrin end links, i have them and really like them. they're a high quality product. as for the front bar being hard to install, it takes longer than the rear, but isn't that difficult. it took me maybe an hour and a half to get it done.

 

it's not that the front bar reduced understeer, it's that it didn't create more that i couldn't dial out with the rear bar.

NASA lumped me into ESP, though in the SCCA they might do things a little differantly.

 

I believe the SCCA changed some wording in the rules which allows the ALK, now.