promod 4 link setting

Looking for a baseline instant center setting on a 3020lb blown alky powerglide car. 52% weight is on the front tires and the crank centerline is high. At least ten inches. The engine makes around 2000hp. I took a guess at the IC and the car is violent launching at idle. I'm planning on mapping the 4 link this weekend to see where i'm at. Thanks, Mike

 

Define "violent". Too much wheel speed? Too much wheel stand? Do you have a computer on the car? What type of chassis do you have, double frame rail or back half?

 

4 Link

Good Starting Point From 6.5 To 7.5 High And 45-48 Out
Lower The Ic More Violent The Transfer
10 In Crank Cl Is Ok

 

By violent I mean hard on the wheelie bars and the rearend is seperating from the chassis. I launched at 3000 rpm once and it instantly hit the rev limiter. The chassis is a double rail tube frame. Thanks Mike

 

Maybe with a Ladder Bar setup Shawn - but not with a 4 link I don't believe.
The more you lower the IC - the softer you will hit the tire. The car will separate less, or start to squat as you lower the IC.
The initial movement will always be separation regardless of IC, as the housing moves down into the tires.

 

If its hitting the wheelie bars too hard chances are the IC is too long. Try a short (45 in or less) IC around 6 1/2 up, there are probably many ways to get there with your setup but try and keep the 4 link bars as close together as you can. Patrick Budd wrote a good article on 4 link tuning. ck out www.procarperformance.com

 

My current IC is 48.5 7 inches up. I'm going to try lowering it a little,maybe a little longer. I'm sending my shocks out for inspection. They're old double adj Koni's. Everybody is pushing Santhuffs but we don't have the budget for it right now. thanks for all the info guys. Mike

 

I've been told that the Santhuff shocks have a problem with the oil foaming during tire shake and losing control. I dont know, I cant afford them either, I just have a set of Strange double adjustables with their "Pro Mod" valving, I send them back every year to be freshend up, so far we've gone 4.20 in a powerglide NOS car and their are fixing to get hit with a blown Hemi and a clutch!

 

We ran 46 and 6 with Santuff Shocks and very rarely hit the tires hard, if anything it was a little soft on the tire.