98Zheadsncam

iTrader: (26)

Ok, any thoughts on this would be much appreciated. I'm running PRC 5.3 heads, 236/242 duration on the cam, .598 lift. I just swapped out the stock rockers with Comp Cams Ultra Gold 1.72 rockers. I also installed the updated knock sensors and harness(I had the old 98 sensors in there), and an ls6 valley cover. I started the car up, and immediately noticed the exhaust sounded different, the cam lope sounds faster at idle, even though the idle hasn't changed. At any rate, I drove around with a buddy, with EFI live hooked up, and the ECM began to intermittently pull timing, starting with about 4 degrees, all the way up to 15 degrees, all while babying the car, taking the rpm up to about 2800. So, my question is, I shouldn't need a tune for just the minimal rocker swap, should I? Could it be the car was tuned with a bad knock sensor, or would that not have an effect either way? I'm taking it back to the tuner on Monday, just thought I'd see if anyone had any suggestions. I'd take a log with EFI live, but my buddy had the tuning software, and he's not in the area now.

Thanks!

turbodarryl

iTrader: (4)

any update on how u like the new rockers??

bww3588

iTrader: (49)

Leave the tune, put the stock rockers back on.

99Bluz28

iTrader: (35)

Those rockers will only up the lift to about .605", and any other changes from them would be minimal. Have your tuner check for any knock sensor issues.

98Zheadsncam

iTrader: (26)

I just found this thread again, so I'll post an update. I'm actually about to swap the stock rockers back on. After having the car tuned again, the idle surges when the car is cold; the tuner couldn't tune it out. Also, and the biggest problem is, the motor is getting valve float after 6000rpm. So, yea, these rockers are no bueno, at least for my setup.