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-   -   traction issues (https://www.racingjunk.com/forums/showthread.php?t=22518)

proclassmonte 12-15-2008 09:23 PM

traction issues
 
when leaving on the nitrous my car wants to chatter the rear tires. its a 3500# car with 28 /9 tires 4.33 gears and a 4500 stall. are there any easy fixes for this.

us7race 12-16-2008 02:23 AM

Air pressure is my first idea, how much do you run? How fast?

proclassmonte 12-16-2008 06:35 AM

air pressure
 
13# runs 10.80s at 122

fla1976 12-16-2008 02:03 PM

chatter
 
You may want to video the car from the side. You may be bottoming out the shocks and unloading the tires. It's easier to see in slow motion.

us7race 12-16-2008 04:54 PM

What suspension are you running? Seems like you are hitting the tires real hard causing the chatter or shake. Have you tried launching at a differant RPM?

proclassmonte 12-16-2008 05:30 PM

rear suspension
 
the lower control arms are stock, with poly bushings. the upper control arms are art morrison adjustables, the springs are stock, and the shocks are three way adjustables set on the firmest setting. and call me crazy, but, it also has a suspension technoligies antisway bar. when it leaves it lifts the front tires about 6 inches off the ground and then it starts to chatter. it never totaly spins them.

mopar1968 12-16-2008 06:53 PM

''fla1976'' i think you are right i had the same problem and that was my problem shocks bottoming out, getting rear 4 link redone.

proclassmonte 12-16-2008 08:31 PM

bottoming shocks
 
the car barely even squats if at all i'm pretty sure it isnt bottoming out. i have pictures of the car launching and it looks almost as if the car actualy raises up a little in the rear.

curtisreed 12-17-2008 04:08 AM

Re: bottoming shocks
 

Originally Posted by proclassmonte
the car barely even squats if at all i'm pretty sure it isnt bottoming out. i have pictures of the car launching and it looks almost as if the car actualy raises up a little in the rear.

If the car is seperating you may still be running out of shock travel on extension.

Curtis

dparker 12-19-2008 05:35 PM

I think your pinion angle is wrong causing it to raise the ass end instead of transfering. Have you ever scaled the car?

proclassmonte 12-19-2008 06:54 PM

no i have not. this is what i was thinkig my self, but i'm not sure what to do from here. can you give me a breif run down on how to set it properly

itsabird 12-20-2008 04:25 AM

what kind of 60' do you get? and are these m t et street slicks you are running?

proclassmonte 12-20-2008 08:48 AM

it pulls1.45 60s the tires 28/9 mt slicks not street.

dparker 12-20-2008 10:54 AM

If you can get ahold of a set of scales to see where your at on preload, ect. On your car your probably going to want to start at 60lb heavier on the right rear than the left and 100lb heavier on the left front than the right front. This is just to get you in the ball park. I bought a car that was acting close to what your talking about. We found it had about 250lb more on the pass. side rear just way to much preload, and the rear springs were too stiff. We changed the springs and turned the shock settings up. It fixed our problem, but every car is unique. It might help if you went to a 5500 converter from the 4500 you have now. I know your trying not to blow your narrow tires off, but you still have to set the chassis up.

proclassmonte 12-20-2008 12:26 PM

this is good information, thanks for taking the time to help out.

mopar1968 01-02-2009 08:32 PM

Like i said above, just got my car back from a NC chassis shop, my problem was i only had 1 inch of shock travel, It was trying to unload the rear tires, this was causing my car to chatter slicks on take off, the chassis shop had to redo the 4 link and make longer shock mounts, in doing this the car sits 4 inches lower in the rear. PM me and i will give you the shops number.


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