I have a 1985 GSL which I had upgraded to a 13B Mazdratrix streetported etc etc $$$$$ motor. The dyno tests show 168hp at the rear wheels but the acceleration sucks - My old beat up 12A was much more fun. The work was done by Legendary Motorcars of Halton Hills Ontario Canada. A reputable musclecar shop. Any ideas?

 

Really, Legendary? There must be a stupid amount of money in that car.

Did you run it on the dyno? If not, then perhaps there is currently a fault with the engine that was not present when it was originally dyno'd.

Any more information on what 13B was used and in what configuration? There are a lot of choices from 100HP 4 port 13Bs to 250+ twin turbo 13Bs. 168HP seems to indicate to me that it is a 6 port 13B from the S4. If that is the case, and the aux ports are wired open, then low end will suck but high end should be much improved over the 12A.