4-link/chassis setup slippery tracks

Shocks, Springs, Brakes, Frame, Body Work, etc

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coolchevy
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4-link/chassis setup slippery tracks

Post by coolchevy »

Guys,

I have read so much in here and gained a lot of information for which I am grateful indeed.

Since I am running in a unconventional Pro Outlaw class which is exclusively run on normal airfields which are totally unprepped my suspension setup differs greatly from a "normal" 4 link setup on glued tracks.

Still, there is so much information in here and I would like to hear others opinion on how they would setup a 4 link for a car for such an application. I am sure there are lots of other ways to do it and I am interested in different, maybe even controversial, setups.

car facts:
2400lbs tube frame doorslammer (68 Camaro)
front/rear weight distribution 50/50% to 48/52% depending on ballast
side to side distribution 53/47 %(higher is driver side)
competition TH400 with brake, solenoid shifted
rear slicks 33-17-15 Hoosier D06 super soft
rear gear 3.50

old engine 472 blown BBC + nitrous about 1400hp
new engine 632 blown BBC - nitrous

what we do is:
-run special double adjustable shocks upfront with at least 6" extension travel to have maximum weight transfer without lifting front tires
-run low rear gears as we can't put power down with steep gears
-run extreme anti-suwat values around 200%
-pedal car out of hole and put all power we got in by second gear onwards
-leave line with 3000 rpm on brake, sometimes more.

Usually gets 1.35 to 1.40 60' times, but there is potential for better.

I tried a non reactive SuperGas 4 link setting and it did not work, I could leave with 6000rpm without spinning tires but ET was slow

what would YOU do?
coolchevy
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Posts: 673
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Post by coolchevy »

nobody got any opinion, all run on perfect tracks only and have car setup perfectly? :?:
Ed-vancedEngines

Post by Ed-vancedEngines »

Not to be rude, but yes I have a lot of opinions. My first opinion is that 6 inch shock travel in the front is outrageous. They do not make to my knowledge any front Drag Struts or shocks with that much travel in them. Even if they do, for the liefe of me I can't understand why.

If the rear suspension is set up right and is doing it's job you will be planting tires, front will rise. I have run on streets years ago and on airport runways and I can't understand needing 6 inches of upward shock travel to get enough weight transfer to get any traction. Basically what you are talking about is racing on a track not well prepped.

Without being a smart butt, but tat is the way I am sounding, All that anti-squat and percentage of rise theory crap is just that crap. My friend whom I admire and respect Mr Billy and I will forver not agree on that.

My opinion is no matter what anti-squat percentage you have if the car is happy and is working well that is all that matters, and each car is unique and will tell you what it needs if you can rewad the evidence.

So with all my wasted time in trying to type you still have not been given any advice. I can't. I have no eartly idea how your suspension is set up now or how the car does or what the car does.

If you can downlaod the 4 link wizard or chasis wizard demo programs and then take the info in them and measure your car as far as where all the bolt holes are and the bar lengths and angles and give me all info I need and how much power you are launching with I can probably help you. I don't care about theoretical ideal 100 % anit-squats either. What is ideal is not found in a computer program or in a slide rule. What works is found with facts and measurements and an experienced person interpreting all the known facts using his experiences of what should be a good starting baseline. Then the car will tell you what fine tuning it needs and that will change track to track. I try to base line a car so only shock adjustment changes will usually work.

It does sound though that you will need suspension settings similar to what a 10.5 car is happy with.

Whaen planting the tires you only want enough tire shock to the ground to get the car moving forward. Any more can make things worse.

Ed
Ed-vancedEngines

Post by Ed-vancedEngines »

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