Want feedback on C3 "Bumpsteer Kits"

[Craig1979]

Looking for user feedback on the C3 Bumpsteer Kits offered by either Guldstrand Motorsports or Vette Brakes & Products.
Anyone have first hand knowledge/experience installing one of these kits?? and the improvement to vehicle steering??

 

[norvalwilhelm]

I have no experience with this kit but alot of experience removing pump steer from C3's. I make my own kit.
That kit to me is very expensive, does only a little and increases your turning radius.
Parking will be harder.
A quick improvement but by no means eliminating bump is just dropping the outer tie rod with a 1 inch spacer.
I use 5/8th heim/rod ends and 16 mm bolts. A 5/8th heim joint fit with a 5/8th bolt has about .012 slop. A 16 mm bolt is about .001 too big so a little polishing with emery paper and it fits with no clearance.
I will grab a picture or two and add to the post.
To totally remove bump you need 3 inch longer tie rod sleeves, drop the outer tie rod about 2 inches and shorten the cross link the matching 3 inches per side.
I will just post some pictures.

 

[norvalwilhelm]

This is the bump block I welded and screwed to the outer tie rod location. It is welded and bolted to the steering arm and a 5/8th heim joint was used.

 

[norvalwilhelm]

This is a modified drag link with 4 different mounting points. The stock one plus 3 extra's that are also higher. I ended up after testing using the link hole 2 inches longer then stock.
Sorry for the large size but I don't want to downsize it.

 

[norvalwilhelm]

This is a proper sway bar link. It will not bind regardless of suspension travel. Stock ones using bushing or donuts run into bind, bend the through bolt and are not too easily adjusted.
Sorry agian for the large picture

 

[Craig1979]

NORVALWILHELM:
Wow those are some big pictures.

In the first photo I'm sure you modified both spindle steering arm to be mirror images of each other.
How much lower is your outer tie rod end after fabricating/welding the blocks in place??
Have any problems with tire clearance? I'm running 50 series tires on 8" rims and I can't lower the outer tie rod end from the original location without causing interference with the inside tire sidewall.
The aftermarket "bumpsteer kits" not only lower the outer tie rod end a little over an inch, but they also move the tie rod end 1" towards the middle of the car (eliminating the tire interference problem).

 

[norvalwilhelm]

NORVALWILHELM:
Wow those are some big pictures.

In the first photo I'm sure you modified both spindle steering arm to be mirror images of each other.
How much lower is your outer tie rod end after fabricating/welding the blocks in place??
Have any problems with tire clearance? I'm running 50 series tires on 8" rims and I can't lower the outer tie rod end from the original location without causing interference with the inside tire sidewall.
The aftermarket "bumpsteer kits" not only lower the outer tie rod end a little over an inch, but they also move the tie rod end 1" towards the middle of the car (eliminating the tire interference problem).

They are big pictures but they are old and I will not resize them. I don't use them often. I wanted to totally eliminate bump and got all the right equipment to measure it. Won't post that picture. It is another large one. Anyway taking all the time it needed I did many tests and let the car tell me what it wanted and after 4 complete changes I settled on .007 pump over 7 inches of travel and if I would have cut a washer in half I could have gotten zero.
The outer blocks are about 2 1/2 inches long but that is alot longer then you would need since I have a raise roll center with longer spindles then any C3 has. Once again won't post that picture either.
I have 3 1/2 inch back spacing with this settup without a problem but I have new 18 inch rims comming with 4 3/4 inch backspacing and they fit over the blocks even at this length.
The kit takes you in the right direction but costs alot, reduces the turning radius and slows the steering ratio. All this for $100 plus where a simple heim joint, 9mm bolts, drill bit and spacers could do the same thing better.
Get the kit, install it and take your chances but if you are really serious about your suspension then you have to get some tools for measuring, learn all you can about how the suspension works, work through the problems, testing all the way and correct the shortcommings.
I spent an entire winter studying how things work, what and how to make it work and proved to myself that everything was right.
We all want to improve/hot rod but most just want to bolt parts on and believe what they read in the advertisements. That is the blind way to do things. Buy suspension books, read/learn how/why things work. Buy the proper tools and conscentrate on that one thing until you know it/fix it and prove to yourself that the claims are right.
I bored alot of people over on Corvette forum with my bump steer posts over and over again but in the end I completley beat the problem and now I basically forget about it.
Good luck