parish8, could use your experience on this one. going from a 4 3/8" pulley to a 4" pulley on a single belt setup. i'm guessing 9-10lbs. of boost spiking to about 11-11.5 before the shift. think i'm going to blow it up? i am going to run it on 100 octane gas too. will it be safe to drive around with that pulley on? only going to use it at the track though and only in cold weather.

 

on a stock lq4 i ran 6-7psi on 92 octane without KR.
then i tried 8psi and saw instant 8deg of continuas KR

then i put in some zylene, what should have beed right around a 100octane mix and with the same 8psi pully saw 0 KR, later uped it to 9psi and still saw 0kr, these tests were on 70deg days or so, not any hotter though. my smallest pully was an 11psi one and with that i saw some KR at launch at shifts but not a full 8deg of continuas KR. i think it is when you peg the KR at it's max and dont let off is when the damage can happen.

going from that i would say i could have ran 10psi and seen very little if any KR. i never worried about the boost spike or counted it when i stated the boost numbers. there wasn't much and it was real quick.

it would be nice to use a scan tool to make sure you are ok though. if you do keep an eye on your timing and KR and 02's. also you might be geting close to the limits of the fuel system seems like i started running out of fuel about then but on a 6.0.