HORRIBLE bumpsteer...ideas?

[harlockssx]

I recently picked up a new project car to put all my 180sx goodies into, a 1991 240SX Hicas model. It's got ~173,000 miles on it, and needs some work! It had some dangerous Ebay coilover kit that uses stock type shocks/struts, the springs weren't properly installed & everytime the car hit a bump they would completely unseat themselves...there was at least 3" of freeplay between the top of the spring & the upper spring seat area on all of the springs when the car was raised in the air! I got a set of stock suspension & tossed it on today (also replaced all the brakes & put on two new front calipers). It's rolling on steelie 15's with 195/60's all around (junk!)...one of the directional tires was reversed, so I switched it to the correct side.

Here's my problem:

Any bump or rut in the road will cause the car to suddenly lurch in that direction, even with both hands on the wheel. I am trying to get some new coilovers (see my classified want to buy ad) but want to fix this problem before it causes me to have an accident. It seems to be the front wheels that are doing it, REALLY bad bumpsteer...the worst I've ever experienced. I got another set of stock hubs/bearings for the front & will try swapping them on. I was thinking that maybe the ball joints may also be contributing to the horrible handling. I don't know how long that crap Ebay suspension was on the car, but I'm thinking it probably contributed to destroying the majority of these components, although I wasn't able to find anything overt. Any other ideas/suggestions? I'm putting some new tires on tomorrow, as these ones that came with it are complete trash, & two are bald. I don't want to do an alignment until I'm done swapping in new parts...

[gotta240]

before just replacing any and all suspension parts, i would recomend dropping the 50 bucks to get an allignment. See what they can get in spec....whatever they cant get into spec is what you need to start diagnosing. They are usually more than glad to tell you what is damaged/worn as well, simply because they think you will pay them to fix it...or just ask them to inspect all parts while doing the allignment.

[harlockssx]

Well, I took the advise & took the car in to get all new tires & alignment (also ordered some new coilovers for the car). It turns out the frame was slightly tweaked & a front lower control arm was bent. The repair & straightening actually wasn't that expensive to get done...the car should be done the end of the week...next week all my goodies are getting delivered from Japan...complete SR swap from my old 180SX!

[GSXRJJordan]

wow ~ sounds good! Glad to see a Tech thread that actually got solved, and in only 2 posts!

[SiI40sx]

good to hear, because im in the same exact boat as you

[Creizai]

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[theicecreamdan]

roll center adapters won't fix bumpsteer caused by broken stuff.

Alignment shop was probably the best idea, and it diagnosed a problem that would not be solved by throwing parts at it.

and if that doesn't fix it, check your steering rack bushings too. I had a car that was following bumps BAD. New bushings solved that.

[Creizai]

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[harlockssx]

I just got it back from the shop...it's all good now. I lucked out with this place, they were very reasonable & did excellent work. My new coilovers will be here next week & I'll be installing them ASAP. All my JDM stuff's getting delivered to my place Monday, so I'll be pretty busy installing all my goodies. Those RCA's...where exactly do they go? Do they replace the steering rack bushings or something? I'm not going to be slamming my car, but it will be about 2" lower than stock.

[Creizai]

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[harlockssx]

Your bumpsteer is fixed now so you should be good now and not need them. Between Lower Coilover mount and huh .. I forget the name but yeah its an easy install.

Yeah, but I'm going to be installing my new coilovers & other suspension mods & it will be lower than it is now, thereby increasing the bumpsteer again, so I'll probably go with these. The roads around here have a LOT of ruts, which pull you this way & that...

[SoSideways]

Your bumpsteer is fixed now so you should be good now and not need them. Between Lower Coilover mount and huh .. I forget the name but yeah its an easy install.

Are you sure about that? Usually bump steer is associated with the front of car, and there's nothing that really looks like those roll center adjusters will bolt to on the front of the S-Chassis...