Lifted Suspension, Change in Steering

[defdes]

I raised my car to the max of the coil over, I have 12" springs in the rear, I cant remember the front length. It still sits lower than stock a the steering has gotten REALLY twitchy especially when hitting a bumps which will grab the steering. Do I need to remove the bump steer spacers, reduce caster or what? I ma going to have it aligned but I'd like to get it close,

[Pista_510]

The raised ride height has probably put you in the region of severe bump steer and it may also now be toeing out causing a similar effect....I'd start with removing the bump steer spacers as a first step for sure. If you're able to run a string line to check toe once the spacers are out, you might want to adjust the tie rods to correct that (zero or toe in).
Let us know how it goes...

[defdes]

The raised ride height has probably put you in the region of severe bump steer and it may also now be toeing out causing a similar effect....I'd start with removing the bump steer spacers as a first step for sure. If you're able to run a string line to check toe once the spacers are out, you might want to adjust the tie rods to correct that (zero or toe in).
Let us know how it goes...

Thanks, Is there a fixed height of cross member of other hard dimension to pull off where the bump spacers become needed? My cars suspension was all set with them when I bought it.

[icehouse]

It's not the bump steer spacers. Those change the roll center mainly, which I doubt anyone ever racers would notice. The toe change is insane when changing ride height, your toe is out. My buddy Sam moved to Vermont, you guys should go on a 510 drive together.

[defdes]

It's not the bump steer spacers. Those change the roll center mainly, which I doubt anyone ever racers would notice. The toe change is insane when changing ride height, your toe is out. My buddy Sam moved to Vermont, you guys should go on a 510 drive together.

I’ll string it first then to see where I’m at, I need to get some new rubber before I do anything else though. Suggestions for a dirt tire?
Hook me up with Sam’s contact info, I’ve yet to see another 510 in my 13 years here. Glad you chimed in, it’s been a long time!

[icehouse]

Isn't there a Subaru backed ralley shop out in vermont? Maybe you can get some of their take off tires, better yet some suspension!

[iceman510]

Isn't there a Subaru backed rally shop out in vermont? Maybe you can get some of their take off tires, better yet some suspension!

Yes, Vermont SportsCar, one of the best rally shops around.

https://vtcar.com/

[defdes]

They were super cool guys and as helpful as they could be but run 15” tires and are sponsored so just call the manufacturers when they need them (nice). I have a call into another NewEngland rally place, barring that I found some nice block treaded winter tires in 175/65-14 which I will try just to get me rolling again.

[defdes]

Good call on the toe. I strung the car to adjust it and was at about 1” total.”, what’s the crossmember height on a stock car, I was wondering at what point do the bump steer spacers start working against you ?

[TheDman]

You get less toe change with suspension bump/rebound travel when the LCAs are operating about a nominally stock position (angled slightly downwards relative to horizontal). When you install shorter springs/struts, the LCAs will tend to angle upwards above horizontal, and toe changes become more extreme with bump/rebound. The bumpsteer (aka roll center) spacers, restore the LCA angle closer to stock, where the toe curve is less sensitive to suspension travel. If you raise the ride height from stock, say, for more ground clearance, the LCAs will angle even farther downwards, and the same thing happens, but since there's no such thing as negative thickness spacers to bring the LCAs back closer to the stock angle, you're kind of stuck. Fortunately, dirt/gravel/mud is pretty forgiving of changes in toe versus pavement. Basically, if you want to raise the ride height from stock, don't use bumpsteer spacers.