[Procitation]

Adjusting the 4 link is our weakest area of knowledge. Need some help understanding terms.

We purchased a Tim McAmis Chassis Master program and measured things accordingly, but have a poor idea of what the results mean.

The car is a 114 whl base 1995 RJ ProMod Monte Carlo. According to the program, we were running an I.C length of 53.48, I.C Height of 7.13 with a 5% squat percentage. We have little idea of what the percentage of rise or in this case squat should be and need a better definition of the term.

You can check out sections in our video to see what the car is doing. We think maybe the car needs to bite harder.

What is a good all around Squat percentage in your opinion??

Video: http://www.youtube.com/watch?v=u6Jw5HpuLLs

 

[DRAGRACR]

Looks like the car is bouncing on the hit. Where are your rear shocks set?

 

[Syclone383]

You might want to try over here also.

http://www.promodzone.com/forumindex.php

Lots of PM guys there.

 

[CurleysRacecars]

The IC length is real short compared to say an NHRA Pro Stocker, but maybe thats what the PM guys do. Im not sure. If I had to guess from the videos, Id say you need to raise the wheelie bar a bit. It looks like the car is trying to transfer weight, but the wheelie bar is preventing it from happening. Remember, even though they may be X inches off the ground when the car is sitting there, the first motion of a car launching is the rear shocks extending, slamming the rearend closer to the ground, which in turn, makes the wheelie bars even closer to the ground.
Just for shits and giggles, raise them and see what happens.
Kyle

 

[7817]

It looks like the right rear is getting pushed up in the tub pretty far. What are the corner weights?

 

[race9899]

How fast is this car now?

Auto or Clutch, Lenco or Liberty? Nitrous?

The 4 link setting is pretty close to where the ProMods I have been around are. But they are 800 inch nitrous clutch cars


What is the angle of the lower bar with the car ready to race and the driver in position. with the 7 inch high intersect point it looks to be pretty level depending on what height tire you are running.

Some better video would be a big help and also a shot of the wheeli bar marks and the tire tracks after the car had launched

 

[BillyShope]

In the automotive industry, it's always presented as "percent anti-squat," so your "5% squat" would be "95% anti-squat."

I haven't looked at the video, but someone mentioned a rear tire being pushed up into the tub. This would indicate the rear of the car is coming down on launch (squat). Ideally, you want the weight transfer to occur smoothly. In other words, you don't want the rear of the car bobbing up and down. This is accomplished as you get the IC as close as possible to 100% anti-squat (or 0%, according to your software supplier). Don't worry about the IC length and height; just find a setup which will get you to 100% anti-squat or slightly above (100%+).

Unfortunately, you'll still have the driveshaft torque unloading the right rear. To cancel this, you can adjust to more than 100% on the right side and less than 100% on the left. How much more and less? This information can be found at my web site, along with a means of directly measuring the rear wheel loading during launch without even starting the engine. This asymmetrical adjustment also provides the most safety, as the wheel loadings will remain symmetrical all the way down the strip.

Also...and I probably shouldn't mention this after you've spent the bucks..., there's a free spreadsheet at my site for determining IC location with a 4link.