Caltrac Tuning Info LOOK HERE
After fighting with inconsistent launches I decided to move the CalTracs on my '70 Duster drag car to the upper holes in front. I had to take the cutoff wheel to the front spring brackets to allow enough clearance for the bolt heads of the CalTrac through-bolts. Upon inspection I discovered that the leaf spring shackles were for a B or E body and appeared to be binding, so I replaced those with the correct A-Body ones. The drivers side shock tang on the spring plate was also bent upwards about 30 degrees, so I straightened that out on a shop press. Also had to replace several U-bolts that were stripped. I probably should have replaced the other 2 at the time but didn't.
Calvert said to start off with about 1/4 turn of preload and put the Calvert 9 way shocks (Rancho) on 8 since I footbrake. They said if it spins about 30 or 40 feet out to go UP on the shock number! Well, starting on 8 didn't leave me much room for adjustability so I started at 7 and hoped for the best.
We took it to TNT Friday to a moderately prepped track full of street cars. I figured if it would hook after the street cars pulled up whatever prep was there it should be okay for a well prepped track on race days. It seems to be hooking well after going up to about a full turn of preload and no change on the shocks. I see a little bounce down the track, but that may be the 1st to 2nd shift causing that. Back end seems real stiff but if it works I'm fine with it.
60' and overall numbers were a little low but it was very hot/humid and it ran very rich the whole night. The DA's were in the 3300-3500 range, compared to less that 1000 last weekend! Going to take it out again this Friday in prep for Saturday's race and see if we have it set right.