it may, it may not..there is NO golden rule with Pulley sizes and given mods, the best thing to do is Scan, scan, scan, scan and run the smallest pulley you can with out KR

Yup. every car reacts a little differently to boost levels, and occasionally you can even get some drastic differences, like the "factory freak". Plus, most of our cars are pretty high mileage, and every car wears in differently.

Boy, I'll tell you one thing I learned. I had no KR at all with a 3.4", was running a 725 belt, after a while I added a over sized tension pulley and still had 0 KR. Dropped to the 3.3" MPS and the belt rubbed at the tensioner. So I went back to the stock tension pulley, and it was very loose. Ran down to autozone and got a 715 belt. Much tighter now, and I get about 2* of KR. Sometimes 3*. It'* not horable, but made me decide to order a 3.4" pulley to get rid of it completely. Makes me wonder how much the belt was slipping before. One thing I noticed now with the new belt is how fast the boost gauge jumps. didn't do it like that before.

Ok, just made a run and watched my KR and timing advance. I had 0.0 KR with one small exception, it made one small jump to about 1.5 then dropped back to 0.0 even up to lets say high speeds. Timming advance for the most part never dropped below 15 with one exception where it dropped to 14.5 for just a moment. Hung at about 15.5 for the most part. The outside temp is a bit warmer then yesterday. Perhaps I misread the gauge. The sun was bright and was glaring rather badly. I will keep a close eye on the KR. But for now I'll leave the 3.3 on. I should have my enhanced codes for autoenginuity any time now. Then I will be able to graph KR and advance and I'll post the results. Is there anything else I should be watching?

Dan also Keep in mind that the PCM is adaptave and has to learn the new air flow

Wow, I never thought of that. That'* a good point. That would explain why I had about 3* yesterday, and getting 0.0 today.

I'm also willing to bet that your KR showed up at the 1-2 shift. If that'* the case, then it'* probably torque management kicking in a little. I get about 2* right after the 1-2 that immediately goes away.

Yesterday I had a lot of KR threw the whole exceleration. Today I had nothing at all, other then a small spike but that was at a much higher speed and was also at the same time I had a drop in timing. Before I installed the PEMs and 1.9:1 rockers I had KR of 2* or 3* at the shift points.