I have been autoxing a lot lately and have been battling horrible understeer on my car. My car seems to get a lot of mid corner push and it is holding me back. I recently installed RS3 tires and modified my rear diff in hopes to eliminate this issue but it still understeers and lacks input while turning the wheel. No matter what psi I set my tires too it does this. Smike recommends upping my rates on my Fortune Auto coil overs but I am undecided on my rates. Currently I have 7k/9k rates with no name springs that came with them. I am upgrading to swifts but trying to choose between 7k/11k or 9k/11k.

Handling mods:
235/45/17 RS3's
Fortune Auto 500 series coilovers 7k/9k
Re-arranged diff plates
Drilled stock sway bars
Whiteline RCA
Camber -3f/-1.5r

 

So turn in is ok?

Does this mid-corner push happen while accelerating, deccelerating, while on steady throttle or no throttle at all?

Does corner exit have oversteer issues or do you continue to push the entire way through the turn?

Dan

 

Wider wheels and tires would probably help... I would also recommend a rear bar if your gonna keep those springs. If your gonna change them out, go with the 9k/11k for sure.

 

Did you add any plates to the diff or just rearranged the ones in there?

A larger rear sway bar might help as the rear one is a bit soft and maybe reducing chassis flex may help you.

 

9k/11k swift springs on FA will handle nice and rotate the car very well. like grillpt said, think about getting a adj RSB to go with your mods and the springs.

spot on about the wheels/tires. gl

 

Skip rear bar for now, up the spring rates, and play with the dampening/rebound adjustments.

 

While wider wheels and tires will help with overall grip, it does not change the overall balance of the car, just puts a higher limit at which understeer occurs.

Rear bar could definetly help, but may not be needed.

High rate springs do not create more grip and may or may not help the balance of the car. If you are hitting bumpstops due to inadequate spring rate, then change the springs for sure, but until that point, figuring out what the car is doing to cause understeer and at what point would be more helpful.

I run 14k front springs and 10k rear with a larger front bar and rear bar on its softest setting and have lift throttle mild oversteer, mid corner the car is neutral and end of corner mild understeer with throttle (primarily because of having a bunch of power)... most people would say this would be a recipe for massive understeer everywhere, but it's not...

Dan

 

your setup isn't too bad. Wider tires might help, with the coil overs you can easily fit 275s with minimal rubbing (it's all subjective right? ). Ideally, you would want to run a 285/30/18 as it's the widest tire that can fit without fender flares and expensive body kits.

the biggest question I would have for you is to ask: Where does the boost hit in the corner? Ideally you want to time the boost to the apex of the corner, not your throttle inputs.

Without seeing how your driving, I would guess that you are getting on the throttle too early, or your not braking enough on corner entry. Brake harder and later. The brakes on this car in stock trim can suck your eyeballs out of their sockets if you try hard enough.

 

RevMoto, maybe I'm being ignorant but did you have your car properly corner balanced? I asked because you didn't mention it in your OP.

 

I was just going to say it sounds more like a driver issues than car issue.

7k is a bit lite for a front rate and could be part of the problem but more than anything sounds like your driving, braking to late and cranking to hard trying to get turn it to late, also are you down shifting or anything like that which can upset the balance of the car?

 

I tried two driving styles at the event to check if it was just me entering turns too hot but even when braking hard and early I maintained throttle until mid throttle and then on corner exit I hit full throttle. The minute I start turning the wheel things get sloppy. Wider wheels aren't an option right now as I just got these. The car isn't corner balanced at the moment. I am going to order 9k/11k rates then and see how the car reacts to those and go from there. Thanks for the help guys. I will take videos of the next event.

 

Well I think 11k rears is too stiff unless you do a lot of HPDE stuff. You will actually lose rear grip without the speed needed to take advantage of higher rates. Your EVO should rotate very well on throttle with that kind of power and some steering input again unless you are just coming in to hot and have way to much forward weight transfer from being on the brakes to hard or to late and hard. Another question what types of corners are these? The EVO does not like 180* hair pins unless you take it slower (which feels slow but is actually faster) It's a strange concept trust me.

 

Yeah I struggle on 135 degree turns but take them VERY slow. The course designer owns a miata and you can tell too. 11k isn't too high as national guys run 16k in the rear. My most favorite event to date was one in the rain and the car rotated perfectly around turns. If these springs don't do it then a TRE 12 plate will.

 

Ok just got a video sent to me on one of the annoying turns. Tell me your thoughts.

http://www.youtube.com/watch?v=e1Tcbsq44EA

 

You tried more camber up front?