08C6

Hey Guys ... Just got done yesterday pulley swap on 08 Coupe with Magnuson S/C... Arun @ Dasilva Motorsports of course worked his magic again...Car pulls down low in the rpm's and doesn't let go...Definetly say for a street car it's way more than enough !!! Numbers from dyno 565 rwhp - 535 rwtq ... on 10 PSI ... Thanks to the guys again and yourself Manny for making this happen...

old motorhead

So....fill in a few blanks. What other mods do you have? What pulley were you running and which one are you running now? A6 or M6? Heartbeat or earlier version Maggie?

08C6

2008 Corvette Coupe Automatic...Magnuson Heartbeat unit ... LG Motorsport header package - Borla Type S ... Installed a 81mm pulley...96mm I believe was on... Car pulls hard...

old motorhead

I can guarantee you that you're having a HUGE amount of belt slip. You should be way over 10psi with the way you're set up. My rig is an LS3 with Heartbeat, blower cam, 81mm pulley, and all the bolt ons. My boost peaked in the high nines at 3500 rpm and went south shortly there after. It should have held in the mid nines from 4000 on up. I changed to a shorter "Gatorback" belt and all is good now. IIRC, it's a 96.7" Gatorback belt. Change to that belt and you'll get your boost back. I'd bet you'll be in the 12psi range. You might check with your tuner before going WOT with the new belt.

08C6

Haven't talked to my guy yet...I'm pretty sure there is no belt slippage... I still wanted a somewhat " safe " tune installed also...I was expecting a little more rwhp... But haven driven with this tune car is a frigging beast...All is good with me with these numbers ...

old motorhead

See if he logged the boost on the dyno runs. I had a 97" belt on mine that was about the smallest I could fit on there. Lots of slip. My boost went down to 6psi on the top end. I didn't think I had belt slip either. No obvious signs of it and the thing still pulled hard on the top end.

You might check the coolant hoses that are above the tensioner. My original belt would stretch enough, under load, that the tensioner came up high enough to touch one of those hoses. It cut two nice grooves in one of them.

08C6

What were your numbers with the smaller belt ...

old motorhead

I haven't been on the dyno since the belt slip issue was fixed. 640's with the slip.

08C6

640's with the slip ... Will only imagine... with what I have now I am happy with... Met a guy last Thursday at the speed shop with a 08 Z06 and 1000 rwhp... frigging insane...When is really enough for the street ... Your car should be the insane category ...