123quattro

I would tend to disagree. There is no cheaper engine to build for the hp vs $. And they don't blow up when tracked.

SeanR

Looks great, but I would put some screws on the rear license plate before it falls off.

dprantl

Sure they do. I have seen some first-hand. And the cost to increase the HP on a stock S4 by adding a S/C does not include tearing down the engine, so in the end it really is much cheaper.

Dan
'91 928GT S/C 475hp/460lb.ft

hacker-pschorr

You don't know many Corvette owners with track cars, I've seen everything from timing chains denigrating (bent valves), to spun rod bearings and any other track related issue.

My friends T1 class (meaning stock engine) ZO6 has a massive oil cooler and accusump to keep the engine alive. His traveling mechanic (one of my best and longest friends) did the mods since he knows how to keep these engines alive & the car was setup by Phoenix Racing before they bought it.

Now you want to talk about modified engines? How about the $20k each, two of my friends have into their strokers (one of them is on his 2nd motor...)
Both running lap times on par with Jean-Louis Murf928 supercharged EuroS (Kibort ran similar times when he was in Elkhart with the stock Holbert car).
Another friend is on his third "race" LS based engine.

Sure the C6 - ZO6 is a great track car since the engine comes dry sumped. I have yet to see one LS conversion that came with the dry sump system.

Cosmo Kramer

Paging Mark Kibort, please report to this thread ASAP for discussion.

AO

123quattro

Don't get me wrong. I am very impressed by supercharged 928 engines. But....I don't think anyone here can argue that 928/944 engines are durable when tracked. Mark will, but he is a serious outlier in track time vs spun bearings.

dprantl

Outlier? Maybe we should ask Mark Anderson and Joe Fan how reliable their motors are on the track...

Dan
'91 928GT S/C 475hp/460lb.ft

smith 928

So he is seeing around 60 to 75 hp at the wheel with a 125 shout .. Give or take .

soupcan

No, LS engines love the bottle. He was 301/305 off the bottle and 420/430 on.
Corvette only weighs 3200 with him in it. Over 500 less than mine.

Jon B.

+928.

My Corvette would do mid-high 12s stock, and weighed about 100lbs less than this one. It was basically "stock" though.

anonymousagain

... isn't your stage3 500whp? seems a bit unfair with 80+ more power, even if 300lbs or so heavier.

you ever see his dyno sheet with NOS to verify 430? seems he's sandbaggin' a bit

soupcan

Mine is 3572lbs with 2/3 tank of fuel. Add me and you get 3768lbs, his was just over 3200. That's 500+lbs.
Dyno's are big and heavy and don't go to quick at the dragstrip, I have watched the car run 11.4's at low 120's and that's all that really matters.

IcemanG17

I also disagree with this....... while there are plenty of options to increase the HP of the 928 engine to impressive levels....it still costs roughly double what it would cost in an LS engine.....sure supercharger kits cost the same...but the bottom line is "street" racing or even dyno pulls don't stress the engine all that much......

when you take a 928 engine and race it on track...where its stressed at full throttle lap after lap for 20+ minutes at a time is a different story...under these conditions the oiling system faults become painfully obvious..... but with a few easy fixes they can be reliable......drysump, accusump, OB pan + spacer, scraper all improve things......

also don't forget that an LS engine is 150lbs lighter than the 928 engine....

Jon B.

Seriously though, you can swap out the cam and heads and have a 10 second car. Those engines just make power stupidly easy.