Got my bumpsteer kit, now I have questions.....

JPhil

Huh?
Joined
Mar 26, 2008
Messages
1,361
Location
Loveland, Colorado, USA
OK, I recieved my bumpsteer kit from VBP. I realize it's only a compromise, but I am not going to get all 'Norval' about this. I won't be installing them any time too soon, but I do have a couple "nooby" questions :D about it....

First, it appears that I have to drill out the taper of the holes in the steering arm for the bolts, so this will be a permanent modification. Will this modification, which is needed on lowered cars (ie, shorter 550# springs), preclude me from ever being able to put taller springs in again (should I or any future owner choose to) without adversely affecting the steering? If so, well so be it--I like the 550s but cannot accept the exaggerated bumpsteer problems which have resulted from their installation.

Second, and more importantly, should I have the holes drilled out by a machinist on a mill or is it something I can do on my drillpress? I do not have the wherewithall to precisely index the drilling although I have done some pretty darn good junior millwork with my drillpress before.

Any thoughts on the matter before I proceed will be appreciated....

Thanks, JNoob
 
Yep, if you drill out the taper you will not be able to go back. The good news is those steering arms are pretty common and can be found cheap.

Are these the triangular shaped blocks, 2 allen bolts in the arm and a hole for the rod end? If the kit has 1/2 inch bolts you won't need to drill the arms, just a thought.
 
Yep, if you drill out the taper you will not be able to go back. The good news is those steering arms are pretty common and can be found cheap.

Are these the triangular shaped blocks, 2 allen bolts in the arm and a hole for the rod end? If the kit has 1/2 inch bolts you won't need to drill the arms, just a thought.

I agree with Bagman there, I never heard of modding the spindles/arms one bit...bolt in....

:thumbs:
 
Are these the triangular shaped blocks, 2 allen bolts in the arm and a hole for the rod end? If the kit has 1/2 inch bolts you won't need to drill the arms, just a thought.


Yeah, those are the ones. These have 5/8" bolts, which definately do not fit into the tapered tie rod end hole on the bumpsteer block.
 
Are these the triangular shaped blocks, 2 allen bolts in the arm and a hole for the rod end? If the kit has 1/2 inch bolts you won't need to drill the arms, just a thought.


Yeah, those are the ones. These have 5/8" bolts, which definately do not fit into the tapered tie rod end hole on the bumpsteer block.

The bolts themselves have a 5/8 cap...should be 7/16 diameter no??

the shand should not be 5/8 diameter, that's total overkill....

as I recall the 7/16 should fit easy....maybe just the top 1/8 inch of the tapered part need drilling out?? I never heard of that aspect of it....

do they fit the blocks nice and snug?? but just not all the way through the taper....??

:clobbered:
 
Nope, it's the shank that's 5/8". They're some big mofos.

Do those fit through the supplied adaptor block holes??? very surprised they that large....don't seem right at all, there are TWO of them Christsakes, makes no sense to me....

:stirpot:
 
Nope, it's the shank that's 5/8". They're some big mofos.

I have the same ones JPhil. I drilled out the spindle "arms" on my drill press and it worked fine. First I filed and sanded one side of the arms flat (GM left them pretty rough). Then I was just REALLY careful on the drill press.

I did have to do a small amount of hand fitting on the 2nd bolt holes, but it was very minimal and had no ill effects. I used a 5/8" drill bit for the 5/8" bolts, that's why I had to do a small amount of hand messaging to get the fit correctly. The first hole drilled has no slop and the other just about normal for a bolt hole (but 90 degrees to the direction of the load).
 
White,

Cool, thanks, that's what I needed reassurance about.

What do you think about the handling now? Did it help? How far is your car lowered in front? I have 27" to fender arch, over an inch lower than it used to be. (& about 28" on the rears, but I'm afraid to lower them any more because of exhaust pipe scraping clearance) (The car used to look like a dingdang jeep, now it looks more proper.)

John
 
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White,

Cool, thanks, that's what I needed reassurance about.

What do you think about the handling now? Did it help? How far is your car lowered in front? I have 27" to fender arch, over an inch lower than it used to be. (& about 28" on the rears, but I'm afraid to lower them any more because of exhaust pipe scraping clearance) (The car used to look like a dingdang jeep, now it looks more proper.)

John

It is an excellent improvement IMHO. The car is very stable at speed and I have no noticable bumpsteer any more. I highly recommend this mod to anyone with a lowered C3.

I set my ride height per Greenwood's recommendation in his VIP article, but I just did a quick measurement to the top of the front fender arc and its at 26 1/8" so I'm a little bit lower than you. If you go that low, watch out for your shocks bottoming out. I had to drop the lower mounts in the a-arms to compensate for my ride height.
 
I drilled mine out on a mill, but I think no difference if I were to use a drill press. I had to hand work them a little bit to get them to fit.
I don't know what my fender height now is, but I lowered the car approximately to the 1" Z height. They seem pretty good right now, but it does seem to be a touch "twitchy" on the country roads. I set the front toe to about 0" with a set of toe plates, so I might go a little to in to help cure this.
One other problem I had was with the front wheels hitting the bump steer block. I had to grind a chamfer in them to get some clearance. May not be a problem for you, but thought I would give you a heads up.
 
I don't know what my fender height now is, but I lowered the car approximately to the 1" Z height. They seem pretty good right now, but it does seem to be a touch "twitchy" on the country roads. I set the front toe to about 0" with a set of toe plates, so I might go a little to in to help cure this.

I can see where 0 toe in racing can be advantagis, but on street, it's a PITA. Too Darty. 1/8" toe makes a world of difference in drivability. I've tried it both ways. Never again.
 
I don't know what my fender height now is, but I lowered the car approximately to the 1" Z height. They seem pretty good right now, but it does seem to be a touch "twitchy" on the country roads. I set the front toe to about 0" with a set of toe plates, so I might go a little to in to help cure this.

I can see where 0 toe in racing can be advantagis, but on street, it's a PITA. Too Darty. 1/8" toe makes a world of difference in drivability. I've tried it both ways. Never again.

My toe hurts, just reading this.....:eek::thumbs:
 
Sorry guys, it's still sitting on the shelf. I got involved in some other stuff and now I'm getting ready to go see my girlfriend in Portugal over the holidays, so it will be yet another couple months at the soonest--assuming I don't get all involved in working on the bike instead.....sheesh! :rolleyes:

John
 
Sorry guys, it's still sitting on the shelf. I got involved in some other stuff and now I'm getting ready to go see my girlfriend in Portugal over the holidays, so it will be yet another couple months at the soonest--assuming I don't get all involved in working on the bike instead.....sheesh! :rolleyes:

John

Portuguese gal eh?? moving up in the world are we???
:cool:
 
Well she's French & I married her 20 years ago, but hearing you guys talk about Brazilian babes, I figured I could add a little spice to the mix.....In fact we will celebrate our 20th wedding anniversary in about 3 weeks somewhere in Spain or southern France...:D
 
Well she's French & I married her 20 years ago, but hearing you guys talk about Brazilian babes, I figured I could add a little spice to the mix.....In fact we will celebrate our 20th wedding anniversary in about 3 weeks somewhere in Spain or southern France...:D

Yeh, several guys I have known/worked with over the years were married to Latin American women, never saw one appearing unhappy either....one guy had been married some 10+ years and was still flipping ecstatic over her....:lol::harhar:

Funny, in that my son dated a gal from Peru? for a few weeks, and found out rapidly there were no 'benefits' to be had, and so moved on,......he figgered something was remiss in the relationship....but well culture clash.....
I really had no comment as I dunno shit about that stuff on that personal a level.....

:eek::surrender:
 
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