Re-tune for 10psi pulley?

[wbartholomeusz89]

Hey all,

I have a supercharged vt with a twin 3" catback exhaust and a cold air intake. Lately the car feels a bit restricted to its full potential. What would be the next best modification? Either extractors, high flow cats, or a 10psi pulley. If i get a smaller pulley will i have have to re-tune and re-map the computer or can i just replace it?

Thanks.

[Sheany]

Go the 10Psi pulley and you'll never look back. The standard computer has the mapping to handle 10psi without a retune, but it means you MUST run nothing lower than 98Ron fuel.

[wbartholomeusz89]

Cheers man, i'll look in to it. Outta curiousity, what would the worst case scenario be if i ran 91 or 95?

[MICKY.D]

Not running high octane fuel can result in detonation

Eg:
Knocking (also called knock, detonation, spark knock or pinging) in spark-ignition internal combustion engines occurs when combustion of the air/fuel mixture in the cylinder starts off correctly in response to ignition by the spark plug, but one or more pockets of air/fuel mixture explode outside the envelope of the normal combustion front. The fuel-air charge is meant to be ignited by the spark plug only, and at a precise time in the piston's stroke cycle. The peak of the combustion process no longer occurs at the optimum moment for the four-stroke cycle. The shock wave creates the characteristic metallic "pinging" sound, and cylinder pressure increases dramatically. Effects of engine knocking range from inconsequential to completely destructive.

Cheers
Micky.D
YT

[wbartholomeusz89]

So basically octane or else.. Lol, cheers for that man.

[alien]

Sorry to hijack thread, but would it still be wise to re-tune even with the 10psi pulley?

[Sheany]

You'd achieve better results, definitely. However, I've been running my L67 at 10psi for getting onto 2 years or more, with exhaust and whatnot, and I haven't suffered any catastrophic failure *crosses fingers*