smapzy

First off, I wouldn't call people stupid while he

RomEG6

smapzy i didnt mean to offend him...sorry if i gave off that idea.
so would the AP2 subframe with add ons be better then a aftermarket suspenion to get rid of the bumpsteer? because from my understanding the AP2 full subframe assembly with all the control/a-arms and knuckles were better positioned that made a huge difference...im asking this because i want my (future) AP1 to have the same suspenion and be able to be better when modded. wonder how much would it cost if the swap was done? i mean to those who have not done the AP2 subframe swap did your AP1 modified suspenion as good as the AP2 modifed suspenion?

thanks hecash

street_ruler

bumpsteer comes from suspension geopmetry. how the suspension compresses and where the wheels travel (toein vs out vs no change). it has nothing to do with dampeners, springs ect. you have to alter the vertical path of the wheel and thus suspension.

you could make it elss....impacting by using a stiffer compression shock and spring thus giving the car a way stiffer ride so it doesnt compress but thats sort of exterme.

soe ap1 guys run like....2-3 degrees toe in in the rear to solve this but the ap2 is much less....pronounced

1320performancefreak

i am doing the same conversion in about 2 months. i am changing to full ap2 tranny diff whole rear subframe. i will try to take pic of the project and do a write up. my current set up have some bad ass bump steer almost loss it a few times. i hope this will fit the problem.

negcamber

RomEG6...welcome.

To answer your question, yes, there are easier and less expensive ways to correct the bumpsteer in the ap1 rather than swapping the entire subframe, a-arms and knuckle. The OP said he wanted to use all OEM parts...more power to him.

But if you want to do something less radical to correct the issue, you can get an anti-bumpsteer kit. TC Design sells a really nice one that most of the track-day junkies use (I have one and it was amazing the improvement...I just took an AP2 owner for a ride on some very bumpy curves and he said it has less bumpsteer than his car). But Megan sells one for much less money that appears to work well too.

Other things you can do to tame the ap1 rear is to go with an ap2 smaller rear sway bar. And if you don't do coilovers, you can get the MY04-05 shocks + springs at all 4 corners. If you get coilovers, make sure you set your rear shocks much softer than the fronts.

maluch

Why would you want to set your rears softer than the fronts? Most performance springs i have looked through have the opposite trend. Thanks.

ej0513

wow, lots going on in the last day. well the reason im doing all this is because i have obtained the majority of the parts for very cheap. the labor is cheap also, as long as i help on working on my car, i get a big break on the labor at my buddy's shop. the cost is really not much of a factor for me.

as far as the aftermarket goes, i am a firm believer in OE stuff, i know that TC design and other companies have their solutions, but after reading about the TC design failure a while back that sort of scared me away from using their products. why should i possibly put myself into a potentially dangerous situation when i can make the change to something else OE and have the reliability. i drive my car the majority of the time on public streets... where paying attention to the road can be put second to the phone and whatever else people prefer to do while driving.

so the bottom line is really that i want a bump steer fix that is of the most reliable type, OE fits the bill. ill keep everyone updated as this project goes on. i still need to order the knuckles and buy an installation kit for the diff.

street_ruler

to increace over steer run a stiffer rear setup, wany more understeer, run a stiffer front setup. and thats relative to the other end of the car

ej0513

^agreed, also softening up your dampers in the rear will allow quicker weight transfer to the rear which allows for better rear traction.

BTW, thanks for the support on this guys. i just ordered the knuckles, all i need now is some time to swap the whole thing over. it should be pretty soon.

negcamber

The rule of thumb is: soften the end you want to stick better. So if you want the rear of the car to stick better, use softer shock valving OR softer springs, or a softer swaybar (which effectively uses the springs on both sides of the car to double the spring rate).

Would you want both soft springs and soft shocks? No, probably not...you need to tune appropriately so that vibration is damped but the suspension travel is not impeded. It is the suspension travel that allows the tire to stay in contact with the road.

So why is stiffer usually considered better? Weight transition. A softer suspension will allow weight to be transferred to the opposite direction of desired travel...so if you are tuning, the body will roll to the outside of the turn; if you are braking, the nose will dive and tail rise. The more weight on a tire, the more work it has to do.

So overall, it is a balancing act between suspension stiffness and sprung weight transition that determines the sweet spot for handling. And that is where suspension tuning comes into play.

Here is a link to a nice cheat sheet:

http://www.240edge.com/performance/reference.pdf