I wanted to alert everyone with centrifugal superchargers (Vortech, Procharger) that there is apparently a problem common to both brands when pushed to above about 7 lbs of boost. My 'vette never made it home from the shop last Friday: it threw and shreaded the belt half way home. The belt, or course, took the opportunity to tear up a whole lot of stuff under the hood before coming completely off -- just my luck.

My car was only set up to run 6.5 lbs boost and I did not think the SCr was working very hard at this boost level, but my shop says it is spinning fast enough to put 12 or more pounds into a stock block - here, pushed air into a bigger displacement and through really wide, ported heads that breath about 30% better than stock, the boost pressure at that flow is far less. Anyway, the point being my SCr was really working and under a lot of stress.

What happened to my car and apparently happens to lots of others is that the bracket holding the SCr to the engine flexes when under full power, only a bit, but enough. It is hard to believe it would (its a centimeter thick solid billet piece, but I say it with my own eyes and the shop showed me other brackets taken off other cars that have permanently warped slightly.

What happens is that at full throttle and RPM the bracket bends and vibrates just a tiny bit, but enough that the pulleys vibrate or shift until the belt slips and pops sidewyas a rib or two.

This is common enough on both Vortech and Procharger that there are various manufacturers of solutions, including, in Prochargers case, upgrades that cost quite a bit to strengthen the brackets, etc. But on advice from my shop (Carolina Auto Masters, Durham) my shoip has ordered an A&A bracket for my car


https://www.aandacorvette.com/cart/s...p?MainCatID=18

I have been told the same thing happens as often or more often with Vortech Scrs but have no details of who or where you get reinforced brackets for those. I am told if boost is held below 7 lbs on stock block C5s and C6s this does not happen. The fact that someone took the time to manufacture and sell a part like this upgraded bracket convinces me that this must be a pretty common problem.

 

Thanks for the warning Lee. What a shame[:@]

 

Good thing Im boosting 5lbs Thanks for the warning though.

 

Not only that, but with 5 lbs, a stock block will last a good long while. It is so tempting to go to a smaller pulley and 7, or 8, but it reduces engine life to like, 2000 miles.

 

Holy crap! Oh my God.... how bad was the damage, Lee? I hope it's not too bad.

 

thanks for the in lee. i am in the market to buy a novi 2000, i will ask about the bracket to them,

 

I was at Rocky Mountain Corvette getting my oil changed and they were trying to tempt me into getting a smaller pully. Im still tempted, im also tempted to boost up to 7 lbs aswell.

 

The only LS1 I have ever seen that split the block was running a Magnusen at 7.5 lbs on a stock bottom end.

Only other stock engine with 7 lbs (Vortech) just blew the pistons apart.

My stock LS1 (Camaro) engine came apart (spectacularly) at 510 RWHP