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 Post subject: How much caster?
 Post Posted: Thu Feb 26, 2009 11:59 am 
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Joined: Wed Jan 28, 2009 10:58 am
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Location: South Carolina
I'm getting my alignment checked today. I installed del-a-lum bushings and offset shafts over the winter. All the front suspension is "stock" 69 Camaro.

Before we had 5 deg of caster in it and it drove well. I had to give up 1/2 degree of camber on one side to get that much. That shouldn't be a problem now.

How much caster would you shoot for?

Before we set everything with the front end raised about 1-2 inches. It sits pretty low.

Any advice appreciated!

Thanks!

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 Post subject: Re: How much caster?
 Post Posted: Thu Feb 26, 2009 12:15 pm 
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Joined: Wed Apr 19, 2006 4:11 pm
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Location: Shepherdsville, KY
5* on an a-arm is plenty. Keep in mind as you move the upper ball joint back to increase caster you will likely create some bumpsteer. This is because you tilt the spindle back and that will raise the tie rod attaching point. I usually shoot for a mininum of 2* on an a-arm and a max of 5* and set the camber to 0 + 1/2.

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 Post subject: Re: How much caster?
 Post Posted: Fri Feb 27, 2009 11:18 am 
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Joined: Tue Apr 18, 2006 10:44 pm
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Location: Tennessee
Chuck, I have my 69 set about 6 or 6 1/2. The 67-69 camaro is rear steer, so the steering arm will go down with more caster. Mine drives easily with this much caster and corrects well if the back end gets loose.
Greg

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 Post subject: Re: How much caster?
 Post Posted: Fri Feb 27, 2009 12:14 pm 
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Location: South Carolina
We used a computer 4 wheel alignment. First thing we found is the rear end was not square. This was verified with a tape measure from the CL mark I made on the front frame. Glad I did that. We got that corrected.

We were able to get 4.5 positive caster. Camber close to zero. I think it was about -.5 on both sides.

The problem is the bump steer is excessive. I'm not sure why. It is toed out in compression and toed in in rebound. It was moving about 1/4" which is too much for my liking. So, what parts do I need to work on this, and where do I get them. I'd like to get it fixed!

I was perplexed about what to do. I decided to leave it 1/8" in at +2 1/2" ride height and it is about 1/8" out at ride height. I can certainly make adjustments at the track if needed.

I really want to get this situation resolved!

Thanks!

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 Post subject: Re: How much caster?
 Post Posted: Fri Feb 27, 2009 2:02 pm 
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Matt, look for worn parts, I have raced three different 69 camaros and few 67, 68 as well and I have never had one of them that had a bumpsteer problem using the stock box and linkage.
Greg

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 Post subject: Re: How much caster?
 Post Posted: Fri Feb 27, 2009 2:35 pm 
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I agree.

I checked the bump steer before with the 2x4 and tape measure method and it looked OK. When it was aligned before it had the rubber bushings and stock upper shafts. The shop told me they were able to dial in 5 deg caster. They lined it up with the bubble type equipment. That was a couple years ago.

I changed all the bushings to del-a-lum and installed the offset upper shafts. When I reassembled it I added 1/8" shims to all locations so it would be close. When we put it on the computer it was showing 3.5 deg caster. ???

Again, It is back to no shims (if I remember correctly) in the front passenger side. Computer said it is 4.5 deg caster now. I find it hard to believe the offset shafts only got me 1 deg of caster? The more I think about it, the more I doubt the computer!

I'll take a look for anything loose. It is doubtful as I installed all new parts when I rebuilt the car and it's only seen about 100 passes. It will be worth a check and double check anyway.

Also, I want to do the 2x4 method again for a reference.

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 Post subject: Re: How much caster?
 Post Posted: Fri Feb 27, 2009 4:53 pm 
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StrokerCamaro wrote:
Chuck, I have my 69 set about 6 or 6 1/2. The 67-69 camaro is rear steer, so the steering arm will go down with more caster. Mine drives easily with this much caster and corrects well if the back end gets loose.
Greg


I had forgotten those cars were rear steer but it doesn't matter if you raise or lower the steering arm it can cause bump steer either way. When I do a race car alignment I check the bumpsteer after the camber & caster are set.

There are a lot of things that will affect the caster reading you get. If you change the rear ride height or if the car isn't level when you check it it will change the reading. The caster is referenced from the ball joint center line to a level line not the chassis.

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Chuck Woloch

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 Post subject: Re: How much caster?
 Post Posted: Fri Feb 27, 2009 6:06 pm 
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Chuck...thanks. I did lower the rear end since the first alignment. I hadn't thought about that.

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 Post subject: Re: How much caster?
 Post Posted: Tue Mar 03, 2009 3:29 pm 
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Joined: Wed Jan 28, 2009 10:58 am
Posts: 105
Location: South Carolina
I spoke with Global West about my problem. They are very helpful!

I was told the outter tie rod will need to go down to fix the problem. In rebound this will "pull" the toe out since the Camaro is rear steer.

They recommended using a rod end on the outter tie rod which requires straight boring the steering arm. They make a kit for this. Unfortunately I'm on the cheap side right now!

Also another option they recommended is to heat up the steering arm and bend it down a little. The problem is knowing how far to bend it!

I'm most likely going to try option 2 first because I'm cheap! I'm trying to source some more steering arms just in case I damage mine. I've got a couple leads going.

I'll let y'all know how it works out. I don't have a torch so it might take a little while to get this done.

Thanks!

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