I've put some minor aftermarket performance mods on my '97 Firebird
Formula, and my biggest problem to solve at the track has seemed to be
getting some better tires so I can "hook-up". Right now I'm turning
in 13.9 @98mph, but badly spinning my rear tires off the line (I
know...I shoulda gotten Drag Radials or Z rated tires, at least).
Anyway, I recently bought a Hypertech programmer and have subsequently
developed a new problem I can't explain. If I jump on the throttle
too quickly I hear a BAM! or sometimes BAM! BAM! coming from beneath
or behind the drivers seat. I can feel the shockwave go throught the
car. I can get it also when the car is moving and I open the throttle
to downshift, but it's most pronounced off the line. I have an SLP
Shift Improvement module that I've put on a toggle switch. With that
off and the Hypertech shift improvement off, I still get the BAM!
Thinking it might be the weight shift I bounced the rear of the car in
my garage, but didnt' hear anything.
Next I'm thinking of marking the tire position on the rim to see if
the tires is slipping on the rim.
I'm concerned it could be some slippage in the tranny or differential.