Hey Guys,
I've started to look at my current maps and decided to start tweaking them...
My current tune was originally for 91 octane, but since I have access to 94 octane, I want to take advantage of that (I've been filling up with 94 octane anyway).
As per other posts, I've got essentially a USDM stage 2 STI setup (engine-wise, it's really a FXT, but has all the sti components, except for headers).
Specifics for those that don't know: 2.5L USDM STI block, VF39, mostly catless (except for stock 3rd cat, which isn't too much of a bottleneck as per logs)
Boost wise, I'm boosting up to 17-17.5psi in 3rd, and hitting 18 in 4th...
I think the 91 vs 94 octane really is in the timing... I think the timing I am currently using is very conservative, I've seen other stage 2 with prob about 3-4 more degrees... however, I also understand that timing that provides maximum cylinder pressures isn't necessarily just before knock... ie. if 30 BTDC causes knock, 29 BTDC doesn't necessarily provide the most power, it could be in fact 20 BTDC... some say that there really isn't any formula, it depends on the engine and timing is best tuned on a dyno...
Anyone care to comment on this ? How should I go about changing the ignition timing to accomodate 94 octane vs 91 octane ?
thanks,
Wayne