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Discussion Starter #1
Hi Guys,

Please help me decide if it's worth the PITA and added alignment time and expense to install a bump steer kit. Below is my combo and this is just a daily driver with frequent canyon runs for fun (1991 GT).

Stock K-member, arms, spindles....
JBA 600# Blue springs (sits low, but was missing the spring isolators which have been added now)
MM center drilled rack bushings
MM steering shaft
ProCi CC Plates (one long supplied spacer (15mm) underneath the plate, two short (10mm x2) spacers on top for the strut shaft - clears hood!)
Bilisteins (std) all around (These struts came with their own bolts, should I use them or stick with the OEM setup?)
Suspension Techniques front and rear swaybars (this might be overkill -any comments?)
The above also includes poly sway bar and end link bushings


Anyways....I have a BAER bumpsteer kit sitting around, but after reading about properly setting it up...I think I want to call it quits now. Will I regret this decision later? I am hoping the favored 90-93 outer tie rod will pick up the "slack" or is that wishful thinking?

Thanks in advance.

-Eric
 

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Stock K, arms, and spindles? Stock balljoints, no X2s? Skip the bumpsteer kit IMHO.
 

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Discussion Starter #3
Yup stock ball joints. Do you like those X2's? I keep reading conflicting reports about them. As a note, I do have SN-95 arms with uerathane bushings and X2's sitting in a box, but maybe I'll save that for a later date (or just not sign myself up for that kind of NVH harshness).

Thanks,

Eric
 

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I liked the X2's, they were worth some time for me on course, but if you install them you will need a bumpsteer kit, properly adjusted.
 

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Its not so much of a question should it be INSTALLED, but more of should it be ADJUSTED.

You can install C/C plates, now do you wish to "adjust" them?
Similar for bumpsteer, you can bolt on any part, its how you tweak it, will make a difference.


Was it worth the several hours to get within .020" on +/- 2" of travel...? YES (for me).
 

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I can't answer for your current situation but I did switch to a bumpsteer kit when I went to the '96+ spindles and modified K-member. I was much happier with driving the car on the street afterwards. It was noticeably less darty.
 

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Discussion Starter #7
I took a look at my used Baer kit, which didn't come with any extra shims other than what was already installed on the tapered stud. According from what I read on the boards is that with my fairly stock setup, I need to get the stud to sit as high as possible through the spindle. Fortunately, my used kit was set up that way...it has the .25 shim on the bottom and the .30 on top, which just covers the non threaded sections of the stud.

It's been an even 50/50 split from people advising on me to go for it or not to waste my time. I could just save these for my SVO which I know has a BS issue due to it's off-set rack bushings.

-Eric
 

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Shim material could be made out of washers, a chunk of tubing or what have you to get the right stack height. Afterwards, you could get the exact length cut from, for instance, 0.120" or 0.188" wall tubing of the appropriate size so the bolt shank fits inside and you're good to go.

I can tell you how you might approach the problem but don't know if it is a problem in your situation.
 

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The way my car drove and rode after steed did my bumpsteer kit and adjusted it was night and day. I would do it.
 

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A couple of observations...

Bumpsteer is really, REALLY sensitive to the front end's geometry and more importantly, tolerance stack-up.

The stiffer your suspension bushings, and the less compliance you have (from stiffer sidewalls, shorter sidewalls, stiff springs, sticky tires, etc...) the more affect bumpsteer will have. Severe bumpsteer in a factory setup with rick-hard street tires may not be noticeable at all. Slight bumpsteer in an AIX car with rod ends for bushings and race slicks may be very noticeable.

The factory design puts the null in the bumpsteer curve (the area of suspension travel where bumpsteer is the least,) at static ride height, That way, as the suspension cycles, it's moving through an area of minimal bumpsteer. If you do anything to change the static ride height (like lowering the car,) you will no longer be in that area of minimal bumpsteer.

So, if you're tightening up the suspension, or of you're moving away from factory ride height, you're going to increase the affects of bumpsteer. Will it be enough to be significant? No way really to tell without driving the car, unless you're moving a long, long way from the factory setup.

You've got the kit -- you're not going to hurt anything by installing it and adjusting it properly other than an afternoon of your time.
 

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A couple of observations...

Bumpsteer is really, REALLY sensitive to the front end's geometry and more importantly, tolerance stack-up.

The stiffer your suspension bushings, and the less compliance you have (from stiffer sidewalls, shorter sidewalls, stiff springs, sticky tires, etc...) the more affect bumpsteer will have. Severe bumpsteer in a factory setup with rick-hard street tires may not be noticeable at all. Slight bumpsteer in an AIX car with rod ends for bushings and race slicks may be very noticeable.

The factory design puts the null in the bumpsteer curve (the area of suspension travel where bumpsteer is the least,) at static ride height, That way, as the suspension cycles, it's moving through an area of minimal bumpsteer. If you do anything to change the static ride height (like lowering the car,) you will no longer be in that area of minimal bumpsteer.

So, if you're tightening up the suspension, or of you're moving away from factory ride height, you're going to increase the affects of bumpsteer. Will it be enough to be significant? No way really to tell without driving the car, unless you're moving a long, long way from the factory setup.

You've got the kit -- you're not going to hurt anything by installing it and adjusting it properly other than an afternoon of your time.

Steeda bump steered my car and did an excellent job. One observation i have is my car has always ran 245/40/17 street tires, now i just put on a set of hoosier r6 slicks and decieded to try the 225/40/17s up front over the 245's and i notice a huge increase in bumpsteer. I assume it is both the reduced height of the tire and the fact they are slicks. Correct?
 

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Steeda bump steered my car and did an excellent job. One observation i have is my car has always ran 245/40/17 street tires, now i just put on a set of hoosier r6 slicks and decieded to try the 225/40/17s up front over the 245's and i notice a huge increase in bumpsteer. I assume it is both the reduced height of the tire and the fact they are slicks. Correct?
I think you're confusing bumpsteer with tramlining. Two completely different things, but yes, the shorter, stiffer sidewall will contribute to it.
 

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Tire and wheel size has no effect on bumpsteer.

You are probably feeling increased camber thrust from the Hoosiers and maybe some steering torque from a higher scrub radius from the different offset wheels.
 

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I think you're confusing bumpsteer with tramlining. Two completely different things, but yes, the shorter, stiffer sidewall will contribute to it.
Excuse my ignorance, but I thought they were the same thing. If following the imperfections of the road isn't bumpsteer, what is?
 

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Tire and wheel size has no effect on bumpsteer.

You are probably feeling increased camber thrust from the Hoosiers and maybe some steering torque from a higher scrub radius from the different offset wheels.
Yeah im no expert in that field but the car rides/drives way worse with the slicks on.
 

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My car was downright SCARY after I went 5-lug, the tie rod angle was terrible and the car would jump violently and tramline terribly, the car just wasn't fun to drive.

I bought the bumpsteer kit from MM and installed it with all of the spacers on top of the new tie rod end. I didn't even measure it, because even if I did I don't have enough range of adjustment to get it where it needs to be due to the tapered and not bolt-on kit I used. Just doing this made a HUGE difference, car is so tame on the roads now and predictable.

FWIW, I am planning a MM K-member and reaming out my spindles for the bolt-on bumpsteer kit, so I didn't worry too much about just bolting it on and not adjusting it properly.
 
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