C6ROLLER

I'll get straight to it, a buddy of mine bought a 2011 Camaro SS...he said he couldn't spin the tires because at some point someone put 87 octane in the tank and when this occurs the computer detects it and lowers the hp of the engine to accommodate...he said you have to pull fuses 5 and 20 and wait at least 3 hours for the computer to reset itself. He said this affects the C6 vette as well with the LS3 engine. I found threads about this on camaro forums but nothing in regards to the corvette. Does anyone here know anything about this?

Dano523

Its spark that is retarded when you are using lower octane fuel, since the knock sensor picks up the knocking and retards the timing to prevent it (car using either the low or high octane spark tables).


As for the ECM, it self learns what the motor is doing pretty quickly, so putting 93 back in the car, and the car will go back to normal (high octane tables) pretty quickly to stop retarding spark timing.

If you want to get the system back to stock spark timing quicker, then just unplug the negative battery for a few mins, which will reset the ECM back to it starting tune point to start re-leaning what the car is doing (knock) to compensate for it again.


As for between the two tables, would dare to guess a difference of maybe 35HP, so even with the car using the low octane tables, your still at over 400hp on the LS3, with still enough HP to burn the tires to the ground spinning them (just need to be in comp or all-off mode for the car to allow the tires to spin freely)

C6ROLLER

Thanks Dano523,

Gearhead Jim

Someone posted once that if the computer detected a certain amount of knock, it would pull timing to "solve" the problem and stay in that mode until a certain amount of gas had been pumped into the tank. Then it would reset.

Not sure which C6 engine(s) that was supposed to apply to.

skar

bump