My little 10 second bracket car slowed down about 5 months ago, and I've tried everything I can think of to identify the problem.
'70 Duster with 750hp GenIII Hemi, all motor, Pro Systems 1050 Dominator, MSD 6Hemi ignition control. Built in 2013.
Ran consistent numbers since 2014, then they started falling off drastically. Losing .1 to .2 on 60ft 1 second on ET 1/4 mile.
New valve springs. Will run smooth at 7500rpm. I usually don't run it past 7000.
Replaced/cleaned everything in the fuel system, no change.
Replaced coils/plugs/ignition controller/batteries in the electrical, no change.
Advanced/retarded timing, jetted up, jetted down, very little change.
Plugs read just about normal.
Any suggestions?? Compression check??
