Blue04RedLine

I was finally able to get into the shop to have the pully installed and dyno'd, before and after the pully just like I hoped. I went to Kelly Chevrolet/Kelly Performance (for those in South Fla) and had a guy named Angel help dyno and install the pully. For most of the runs I was actually the one running the computer, which was pretty cool. So I printed out sheets for all runs in both uncorrected numbers and SAE corrected ones. The computer was using a correction factor of 1.19 all day, so I figured it would be best to have both. Well the three runs before the pully were 208/194, 214/193, 215/191 (uncorrected). Those 3 runs were with just K&N CAI. We then installed the pully (right there w/o bothering to unstrap or remove the car). It's the 3.15 inch from Billetflow. I think the ECU was pulling timing at first, because the first three runs after the install was the first time that the car was on with the pully, and it didn't quite understand the extra air. After the first two runs, I did the little boost bypass mod, and it was extremely noticable (not only in overall power, but a longer powerband as well). Those 3 runs were 211/202, 212/199, 229/199 (<-- after the bypass mod); also uncorrected numbers. I uploaded the SAE corrected sheets as well. Could that third run increase in power be caused by only the bypass mod, or was the ECU getting used to the pully? O yeah, SAE corrected numbers after the pully were 252/241, 252/237, and 273/237 (<-- after bypass mod). By those numbers, you can see why I wanted the uncorrected ones as well. Sorry for the long post also guys (and gals). BTW, runfiles 7,8, and 9 were done before the pully (with just K&N CAI) and runfiles 10,11, and 12 were done after the pully. Runfile 12 was done WITH the boost bypass mod.

Blue04RedLine

Also, here are some pictures of the pully. It's purty .

freakaccident

How does it feel? Much difference in the butt dyno?

R33P3R007

Did you change the belt or the tensioner? or just swap the pully. how long was tyhe install. mine is still siting on the table. I have to get the exhaust fixed on the car before I mess with a smaller pully

TxLonghorn#1

One question...what the hell is "I did the little boost bypass mod"? What exactly is that mod?

freakaccident

https://www.cobaltss.net/forums/show...ght=bypass+mod

zinner

Your graphs say 24.97 inches of hg thats pretty low for florida. Like right now it's 30.96 inches of hg in orlando.

Might wanna ask your shop why their reading is so off.

Blue04RedLine

Yeah, we were talking about this on the RL forums as well. That's why the correction factor was so high, and I believe inaccurate. Thus the reason i'm only going by uncorrected numbers. The butt dyno feels very good. I have to go back at the end of the month to redyno, because the way we did it was not optimal (same day=good, car not used to pully=bad). The install didn't take very long at all. The hardest part was getting the belt back onto the tensioner pully (soooooo much pressure on that thing). O, the stock tensioner is good for this size pully, no need to swap.