Tech Contributor Gold
Join Date: Dec 2004
Location: Amish Wonderland Of Central PA
Re: 393W not running up to expectations
I don't doubt that the MPH would be a little lower in a auto vs stick car. Maybe in the order of 2-3mph?
Fuel is a good place to look--hook up a pressure gauge and see what its doing when the motor is pulling. Might make sure the throttle blades open all the way when the pedal is pushed (verify.) Mess with the timing a couple of degrees each way at the track to see how the motor responds. Perhaps the converter is not up to snuff and is robbing more power than it should?
But then again, it could just be that the motor is not capable of making more steam. Although the heads may have been fine for the 351w, for the the big block bore of the 393w they are not adequate to increase performance to the levels that you are looking for. Big block cubes need to be properly fed in order to perform.
65' Stang Street/Strip. Dart 434W NA, Victor heads, G101A 4 Spd, 4:56 rear gear, on 93 octane pushing 3550lbs. [email protected]