I'm running a S-trim with stock pulleys in SCCA open track events. The engine has been dyno tuned for a 'safe' tune with a Superchip Custom as described below. The car exhibits a surge of power almost always near the end of a short section of straight away. What is happening is as I exit a turn, I'll be in third gear at 4000 rpm or so, I will apply the throttle as I exit the turn and the boost shoots up to 5 lbs. Then as the engine's rpm increases, usually at some point at or just over 5000rpm, the boost shoots to 10 lbs. and the car surges with power, just as I am approaching the next turn. When I say "surge", I mean the power surge is dramatic, like a hit of nitrous or spike in the horsepower curve. The engine does not exhibit this surge of high rpm power on the street, only on the track and usually at the top of 3rd or 4th gear after exiting a turn. What do you make of this and can any thing be done to smooth out the on track power surge or is this just the nature of a centrifical blower?
Background info:
306 SBF
Edelbrock Performer Heads
GT-40 intake
10 lb. S-Trim
42 lb. injectors
40 lb. fuel pressure
100 octane race gas
JMS/Superchip custom dyno tune
WOT 8% richer than stock
10 degrees base timing
26 degrees total timing
18 degrees total retarded timing (retarded while under boost)
2 degree retard at 220 degree ACT temp
11.65:1 air fuel
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