Tech Contributor Gold
Join Date: Dec 2004
Location: Amish Wonderland Of Central PA
Re: a few tire psi is difference between spin and hop
I just had some time to look at the videos. The first one might have been better with a lower RPM launch or maybe 50lbs added to the trunk. The burnout is fair as you can see a little smoke.
The 2nd one looked rough and you can see the leaf spring jumping. The front looks like it has good travel with the 8088's but the rear acted up before the weight was transferred. Its not really crushing the tire like you'd think it would with less air and there is not much separation in the rear either. The rear acts stiff, but I don't know if a stiffer spring is warranted. It is possible that the shocks bottomed out. The burnout sucked as there was no smoke-that didn't cause the hop.
The rear shocks could be bottoming out as you deducted. I setup my shocks with 1 to 1 1/2" of travel before the shock is fully compressed when the car is at rest. That allows for more shock extension movement. Simply crawl under the car, unbolt the bottom of the shock, set shocks to "1" and then compress the shock as much as possible to see how far it rises off the perch. You can also check how far the shock extends by removing it out of the perch and extending it as far as possible.
The rear suspension could also be binding. It is imperative that it move freely. You should loosen the front and rear leaf spring mounting bolts, remove them, and then put a little grease on the length of the bolts. Reinstall the bolts and replace the nuts with nylocks. Don't fully tighten the nuts on the bolts (allowing the bolts to be able to spin in the springs' mounts. The cams of the Caltracs should also move freely and hot be grabbing the spring.
The least amount of hit on the Caltracs has been proven to be with a slight air gap of the cam bolt from hitting the spring.
Another issue you may have is clutch related. If the clutch hits hard when you dump it the abrupt hit will cause wheel hop with slicks at the track. The slicks should be fine as I started with 26x10 Hossier QPT's and they worked well when my car had similar power as yours. (Typically 1.6x 60'ers using stock springs, Calvert shocks, Caltracs and a 4500-4800 rpm launch.) I didn't know anything about messing with the front suspension at that time so it was also stock.
What type of 60'ers do you have at what MPH to you cross the stripe?
65' Stang Street/Strip. Dart 434W NA, Victor heads, G101A 4 Spd, 4:56 rear gear, on 93 octane pushing 3550lbs. [email protected]