No forward drive

[eclipsegse]

Ok have ump modified car is wicked fast when is tacky but when it slicks off has no drive from center off chevelle clip lf spring 700 rf 600 Lr 200 16 inch rr 225 13 inch lift arm car spring behind 4 bar 48.6 cross 56.7 rear 57.3 lf side weight also have question about 4bar radius rods when looking from rear of car bars are inline with brackets when at full drop radius rods are to the left probably to left 3 inches on both sides just moved them does this effect load on rear tires used to be almost straight before moving also this car has very aggressive tie downs in front any help would be great

[mudeater18]

Ok have ump modified car is wicked fast when is tacky but when it slicks off has no drive from center off chevelle clip lf spring 700 rf 600 Lr 200 16 inch rr 225 13 inch lift arm car spring behind 4 bar 48.6 cross 56.7 rear 57.3 lf side weight also have question about 4bar radius rods when looking from rear of car bars are inline with brackets when at full drop radius rods are to the left probably to left 3 inches on both sides just moved them does this effect load on rear tires used to be almost straight before moving also this car has very aggressive tie downs in front any help would be greatThe first thing I notice is left side weight percentage is too high. Wouldn't want to be much over 54% with driver.

[dirtracr33]

you didn't list your wheel weights but your cross seems a bit low for slick and your left side seems high.
looking from the back of the car we usually toe in the rs rods a little and opposite on the left. and you could bump up rf spring 50#...didn't mention your pull bar but we run the 700-2000 progressive..just some thoughts, good luck

[eclipsegse]

Has a lift arm with 300 in spring this is a rhulman car

[eclipsegse]

Don't know wheel weights off hand car turns anywhere u want just has no drive from center off doesn't matter where u put bars doesn't help run about 120 pounds Lr 1/4 inch of preload in lift arm

[eclipsegse]

This car runs a bump stop in rf car seems a little better if we put more shims in rf bump stop would taking rf rebound out and less tie down

[mudeater18]

What does Brian recommend for left side weight percentage ?

[eclipsegse]

It's exactly where Brian wants it

[Anonymous24]

Something is fudged up here. 56 rear percentage....that car should have a ton of forward drive.

[eclipsegse]

Have tried everything on car and doesn't mKe a difference in the slick do u think taking tie down out of rf will help

[Anonymous24]

What's the rebound and compression of RF shock, and brand.

[eclipsegse]

It's a Penske it's like a 3.5/16

[Anonymous24]

16 being the rebound and 3.5 being the compression? That high of rebound wouldn't let the weight transfer back very quickly and would inhibit forward drive.

[speedbuggy]

you didn't list your wheel weights but your cross seems a bit low for slick and your left side seems high.
looking from the back of the car we usually toe in the rs rods a little and opposite on the left. and you could bump up rf spring 50#...didn't mention your pull bar but we run the 700-2000 progressive..just some thoughts, good luck

Here's his wheel weights:
LF RF
624 415

LR RR
751 610

[eclipsegse]

Those are pretty close

[speedbuggy]

Here's his wheel weights:
LF RF
624 415

LR RR
751 610

Whoops...

For some reason, I was thinking you already said the car weighed 2400. Now I don't see that above anywhere. These weights are calculated for 2400 total weight with those percentages.

If you know your actual total weight, I can adjust the wheel weights for that.

[eclipsegse]

2589 is total weight with driver

[speedbuggy]

2589 is total weight with driver

That makes the wheel weights:
LF RF
673 448

LR RR
810 658

[JustAddDirt]

ditch the huge RF tie-down and go with about half of that amount, and see if it improves. It should greatly

[oldtrackchamp4x]

I think your bars being 3 inches out of alignment may possibly be an issue. Are you sure the car is not to tight on entry, which will hurt exit on a slick track. Maybe go up another 30 lbs on bite, which will give more drive off and loosen entry also. Are you dropping tire pressures when the track is slick? Are you leading or trailing the left rear? And have you talked to your chassis builder about this specific problem? Just some thoughts. JMO

[mudeater18]

What is making the car so heavy? Is there alot of added ballast ?

[powerslide]

Have you seen ruhlman? Haha all in fun, I'm about 240 myself. I think JAD has the best suggestion yet take off the high rebound rf and cut it down to about 6-8 on rebound

[eclipsegse]

How will more Lr loosen entry

[drtrkr244]

Off the gas more lr will loosen entry. You have taken weight off of RR.

[Ruhlman Race Cars]

It's exactly where Brian wants it

Not sure who this is (eclipsegse) or what car you have but the numbers you have posted are NOT what we recommend for our cars.

We offer unlimited tech support to all of our customers so if this is one of our cars, please call us directly at 517-529-4661 9am-9pm and we will make sure you get the correct information.

Brian Ruhlman