Evo 9 retune for cosworth M3 cams
Evo 9 back in for a retune after swapping his Cosworth M2 (272/272) for Cosworth M3 (280/272) cams.
Put it back on the dyno and it didn’t make any power gains, it was actually down on torque since last time, which was very odd since he want to a larger intake cam. The last three times this car has been on the dyno it never really made any gains. I knew at this point something was wrong with this Evo.
Took it off the dyno and did a boost leak test. Found a fairly large leak at the FMIC to upper IC pipe connection. Fixed that. Then found another one at the Upper IC pipe to BOV connection. Fixed that and no more boost leaks.
Put it back on the dyno and finally found the car running correctly. Amazing what a couple boost leaks can do to the power eh?
Dotted lines are with all the same mods but with the boost leaks, Solid lines are after fixing the boost leaks and retuning the car for it.
Mods:
TBE 3” no cat
GST open air filter
RC 750cc injectors
Walboro Fuel Pump
Ported OEM exhaust manifold
Cosworth M3 Mivec Cams
ARP head studs
Springs and retainers
GM 3 port boost solenoid using ECU controlled boost
Nisei FMIC
LICP
91 octane
GST Custom dyno tune (oem ecu flash)
For some reference, here is what the car did with the M2 cams and all the same mods above:
