Bump steer
Thread Starter
Melting Slicks
Joined: Dec 2009
Posts: 3,224
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From: Thunder Bay
Bump steer
My '79 has a Steeroids rack and pinion setup. The steering still is a little vague. I'm trying to tighten it up a bit. Tonight I put on a Speed Direct spreader bar. Nice part. Haven't had a chance to test drive it yet though.
One of the advantages to the Steeroids setup is that it is adjustable for bump steer. I understand the concept, but how does one adjust for bump steer?
One of the advantages to the Steeroids setup is that it is adjustable for bump steer. I understand the concept, but how does one adjust for bump steer?
Melting Slicks
Joined: Mar 2008
Posts: 2,989
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From: Meriden CT
My '79 has a Steeroids rack and pinion setup. The steering still is a little vague. I'm trying to tighten it up a bit. Tonight I put on a Speed Direct spreader bar. Nice part. Haven't had a chance to test drive it yet though.
One of the advantages to the Steeroids setup is that it is adjustable for bump steer. I understand the concept, but how does one adjust for bump steer?
One of the advantages to the Steeroids setup is that it is adjustable for bump steer. I understand the concept, but how does one adjust for bump steer?
I don't see any significant bumpsteer in my car, but I just got an alignment for the steeroids and tubular upper control arms and that vague steering feel is gone.
FWIW my daily driver Oldsmobile has noticeable bump steer. Not on a racetrack, but on the Merritt Parkway Connecticut, which is the same thing
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Melting Slicks
Joined: Mar 2008
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From: Meriden CT
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Thread Starter
Melting Slicks
Joined: Dec 2009
Posts: 3,224
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From: Thunder Bay
I just had a chance to test drive the car today. (Snow finally went away - why do I live in this country?) I cannot believe what an improvement that spreader bar is!!! 80% of the vagueness in my steering is gone. Still some room for improvement, but that spreader bar has got to be the best bang for the buck in Corvette handling on the planet!
Melting Slicks
Joined: Mar 2008
Posts: 2,989
Likes: 198
From: Meriden CT
I just had a chance to test drive the car today. (Snow finally went away - why do I live in this country?) I cannot believe what an improvement that spreader bar is!!! 80% of the vagueness in my steering is gone. Still some room for improvement, but that spreader bar has got to be the best bang for the buck in Corvette handling on the planet!
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How I normally adjust for bumpsteer is with a laser level and with the spring out. With the spring out and a jack under the control arm you can move the suspension up and down freely. Put the laser level on the spindle and have it shine on the wall or piece of poster board. You can see how much it steers in droop and compression. Adjust as necessary and then put the spring back in.
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From: Graceland in a Not Correctly Restored Stingray
For those who have access to a Chevy Power book, the section on Vehicle Dynamics includes various bumpsteer curve illustrations that may prove helpful to better understanding the cause and effect side of the problem.
IMCO it's worthy of note that while bumpsteer blocks commonly on offer will tend to improve outer tie-rod end height on lowered C3s, they don't offer a fine tuning adjustment, and will necessarily result in shorter than optimal tie-rod lengths while increasing Ackerman (the latter of which is worthy of its own debate). That said, before anyone drops a bundle on new kit, there are other cost effective solutions available which don't require reengineering the entire front end. My $.02, HTH.
TSW
IMCO it's worthy of note that while bumpsteer blocks commonly on offer will tend to improve outer tie-rod end height on lowered C3s, they don't offer a fine tuning adjustment, and will necessarily result in shorter than optimal tie-rod lengths while increasing Ackerman (the latter of which is worthy of its own debate). That said, before anyone drops a bundle on new kit, there are other cost effective solutions available which don't require reengineering the entire front end. My $.02, HTH.
TSW