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Author Topic:   Camaro build up question #3
Eljojo
Dirt Forum Champ
Total posts: 968
posted September 22, 2004 08:17 PM  
Upper a arm monts
My Steve Smith book shows the upper mounts mounted parallel to the line of the lower a frame muonting locations. Then I see myself mounting the pivot rod onto that bracket with a buch of shims to get the desired caster and camber for either wheel. The book also never touches on anti-dive angles. How about some advice on locating the mounting points and getting the geometry right? Thanks.

Jon

rico 08
Dirt Forum Champ
Total posts: 1139
posted September 22, 2004 08:35 PM  
I don't think it's as important side to side as it is up and down,moving the pivot point in with shims is a fairly small adjustment,however moving the pivot points up or down makes a big difference in the roll center/camber gain.Anti-dive according to steve smith is a very bad thing on a dirt car,but all the fast cars that i see have the stock anti-dive angle still in the uppers,i think that if you take all of it out heavy springs would have to be used to counter the car wanting to pitch more coming in.I've never tried the no anti-dive like he says to do this is just my theory on what would happen.

[This message has been edited by rico 08 (edited September 23, 2004).]

redneck racing
Dirt Forum Champ
Total posts: 860
posted September 23, 2004 08:02 AM  
Try running the adjustable a-arms thats what were putting on my new car. Eddie

340duster
Dirt Maniac

Total posts: 195
posted September 23, 2004 12:10 PM  
Currently in the process of building a camaro clip car with tubular uppers. We bought Bob Bolles new book "Stock Car Set-up Secrets" It is mostly pavement but there is a good section on dirt. He covers in great detail what moving the arms does. Bolles looks at the front geometry as a whole system (dive and roll). Wereas Steve smith just looks at each wheel bump only.

Bolles has some software (which we bought) that allows you to dive and roll the front suspension and see what happens to the geometry and roll center. The only problem we are having is figuring out how much dive and how much roll we will actually have on a car we haven't built yet! But we assumed some numbers and began playing with the geometry. It ends up being a comprimise of roll centre and camber change.

The angle of the arms locates your roll center and also sets you camber change curve.

Try this link
http://www.racingsoftware.com/

JohnG
Dirt Maniac

Total posts: 137
posted September 23, 2004 04:45 PM  
You cant mount your uppers like steve smith says with stock uppers......

I removed all oem anti dive and was getting too much body roll to the rf on dirt. I put oem upper a arm mounts back on and it was much better.

I also used steve smiths program to locate my upper mounts height wise, and lowered them to 2.5 of the clip, which at a 5.75 ride ht put my roll center at 4-5 inches.. Maybe that was too low, and it wasnt the anti dive..

Steve smiths latemodel plans that you are looking at are very old school, I actually raced one of those cars in 2001 for a guy, and we ended up re clipping it, back to oem front end parts, except we used lefthanders tubular uppers which go directly over the lower and are all heim joints and tubes..


marshalr
Dirt Maniac

Total posts: 148
posted September 24, 2004 12:42 PM  
I drilled another hole at the front of my camaro UCA mounts. I set the car at ride height and then levelled the cross bar on the shaft. That should be Zero Anti dive.
As I understand Anti dive causes the front suspension to get mechanically stiffer under compression.
I left the stock mount hole as well so i can go back though i never have.
I was told if the front end would start skating badly, beyond a push, to put the UCA back where it was.
I run a 950 LF and 1050 RF, the RF shows about 3 inches of shock travel.

Eljojo
Dirt Forum Champ
Total posts: 968
posted September 24, 2004 06:58 PM  
Thanks for y'alls help! I got some welding to do before I get to the next question!

Eljojo
Dirt Forum Champ
Total posts: 968
posted October 19, 2004 08:11 AM  
Sept 22

    

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