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Author Topic:   Four Bar rear suspension
hoosier transplant
Dirt Maniac

Total posts: 104
posted January 08, 2005 09:52 AM  
I am a little confused about my stock 84 Monte rear suspension. It is a four bar(link) system. Right now all links are angled down(looking from rear to front). My setup book seems to be more for modifieds, so in the section for the four link system mainly is for a bird cage system, which I can not run. In the book they say to angle both upper links up and run the bottom links either level or slightly down. Does this still apply if you don't run bird cage. The way I understand their reasoning is that with the uppers angled up will tighten up car(which is the main handling problem I have). Any and all suggestions on this would be appreciated. Also, if anybody runs a car like mine, and has it hooked up, and would like to share their setup please PM me. Thanks.

kevinwardracing
Dirt Full Roller

Total posts: 35
posted January 11, 2005 06:06 AM  
We run our rear lower control arms angled up for the reason mentioned in the section under rear steer. Understand we are able to run a Ford 9” and when the lower control brackets were put on they had two holes pre-drilled in them. Stock position for us would be the top hole and it makes our lowers flat (parallel to the track), but dropping 1” to the lower hole and adding about 5 degrees of angle had a dramatic effect in loosening the rear up. As an example, my notes and in using AutoWare’s Rear Suspension Geometry program, suggest our stock position would be right for ¾ mile track. If we only lowered the Left we could run a slightly smaller track…however, if we lowered the right only…we could get in the 5/8 area…both lowered would get us even closer to the ancually ½ mile arena we do run in. Again, the big gain comes off the right side. Now..Shhh...What we did to get us right for our track and to even allow us to be really fast at smaller tracks is to add a single hole 1" above the stock one in lower chassis mounts. When we run 3/8 tracks we run both lower chassis mounts in the upper hole and both lowers on the rear at the bottom, giving us maximum angle. Our half mile setup is somewhere in-between…but I know very few cars who pass as well as we do in the turns. The next trick will be keeping the *** under you off…we do it with shocks.

Good luck…

hoosier transplant
Dirt Maniac

Total posts: 104
posted January 11, 2005 05:10 PM  
Great information, Kevin. I was beginning to think I wasn't going to get any replies. Where are your upper links angled? Right at the moment mine are angled down but everything I read suggest they should be angled up 15-20 degrees. Of course this is with bird cages. I just not sure if the same setup relates over if you don't run bird cages. Also, rather than make adjustment available on the rearend, can you mount a half moon bracket on the chassis and get the same results? Thanks again for the help and good luck this coming year.

racer17j
Dirt Forum Champ
Total posts: 5390
posted January 11, 2005 06:38 PM  
I agree about angling the upper links on a stock chassis...it sounds to me like he's runnning a floater four bar and not using the stock mounts. For us we'd call it a grand national...or super stock. So...if all are down -- are you still tight? Which you shouldn't be if the all are down.

And, where on the track are you having the ??? trouble?

kevinwardracing
Dirt Full Roller

Total posts: 35
posted January 11, 2005 10:53 PM  
Never mind...you PM stated loose off. Yeah...work the rear shocks like I PM'ed you back about.

racin78p
Dirt Freak

Total posts: 333
posted January 12, 2005 05:30 AM  
Hoosier transplant: If you are looking for reference material, Steve Smith has a Street Stock and Stock Car books out there that really tell all. You can get it on line from Speedway Motors.

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racin78p
if it ain't fun, then don't run

hoosier transplant
Dirt Maniac

Total posts: 104
posted January 12, 2005 04:34 PM  
Thanks to everybody. Race78 I have his Stock Car Dirt Track book but it really is more late model and modified. I'll send and get his Street Stock book, maybe it will have more information that pertains to a Super Stock.

kevinwardracing
Dirt Full Roller

Total posts: 35
posted January 15, 2005 06:53 AM  
Another book I'd recommend is Bob Bolles, "Stock Car Setup Secrets." The book caters to any form of racing, recommend the fundamentals and touches on just about everything however it does avoid most of the math. He has two solid computer programs that get more into that...his Roll Center program and Chassis R & D program (which I see he now has a dirt version of). He states on the cover of the book however, “Everything you need to know to start winning.” So, it be worth your effort to get a copy.

    

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