L92's on a turbo car?
 

I just want see if it would be a good idea or not. I know L92s flow well but will it hold up to 20 psi of boost.

Why wouldn't they ? Parish has 18 psi on a set of stock 5.3 heads. In fact because the L92's flow better you may not see as much boost yet still make the same power. someone out there correct me if I'm wrong.

I think the problem is deck hight, Just wanted to see who if anyone is running them with a boosted car

I think Veee8 is running them on his car, just dynoed at 830 thru a TH400 (blowing thru the converter)

https://ls1tech.com/forums/forced-in...o-results.html

I was wondering the same thing. I wanted to make a 408 iron block PT88 and use these heads. I work at GM so I can get them cheap. The flow numbers looked good. Anyone run these and know for sure how they work? G :chug:

We did a 402 LS2 w/94mm build with stock L92 heads. The car put down 1042 rwhp 837 rwtq through a powerglide and hydraulic roller camshaft. It has ran 8.56@162 at 10psi. This is in a Fox body chassis.

When you say "stock L92 heads", you mean no port work and no mods of any type, right? Also, hom much cam are you running to elicit that type of power from that 402? I'm very interested, as I am attempting those same horsepower numbers! Thanks for your help.

wrapping up a 408 with livernois stg 3 L92's and a F1A. Hopefully somewhere between 14-16psi. any guesses on rwhp through a m6?

Yeah 830 rwhp so far at 14 psi and 12* timing. It pushed a little water on the dyno with the pump gas cocktail. I retorqued the studs, (both banks had the front two and rear two studs down to 55-60 ft lbs.) and we are hitting the dyno again this week.
I am now running E85, and I can't tell you enough how this fuel has been working out great. Very impressed so far. I am at 18* timing, and we will likely take boost to the 18-20 psi level, if all goes well.
I will have new tires this week too, going with a 28" tall M&H drag radial. It was spinning bad last time on the rollers. It left a pile of rubber behind each roller. There is zero traction on the street over 8-10 psi. But the Pirelli P-Zero's I have on there now suck. They were over priced pieces of junk.
So hopefully we will tickle the 1000 hp mark to the tires this time.

Sound like you have a killer combo, What cc is the combustion chamber on the head and do you have a -cc pistion?

Flat top with -4cc relief pistons. The chambers are 75cc.

I run L92s on my 402 (9.1:1). they are off the shelf stock with just upgraded springs and yella Terra l92 rockers. custom grind cam...stock l76 intake. made 728rwhp @9psi on pump gas 93 octane.

My 408 made 780 before it ran out of blower- d1sc with out of the box l92's. I'm going to see how they hold up to an F-2 this spring.

wow, those numbers are awsome, cant wait for track times!

1999 Formula Hardtop M6 cars RULE!!! :headbang:

Mine is far from stock though. Back on track: What kind of split does that cam of yours have?? I will have a 375" motor so the actual duration numbers will be less, but what about the split??

No port work, just upgraded springs. I believe it was somewhere around 242/236 116LSA. Here's the car http://www.ls1gto.com/forums/showthread.php?t=274571

Hmmmmm. A reverse split turbo L92 cam that makes 1042rwhp from a 402. vee8 has a traditional split turbo L92 that makes 830rwhp from a 370. I wonder if a straight cam on a 376 motor would split the difference??

No dyno numbers but on a stock LQ4 bottom with a 236/240 and gt47-88 ~18psi it went 5.72 @ just under 3300lbs. Thats with outta the box L92s with stock valves, PRC springs/retainers. Got a forged motor for '09 and a PT101, same heads.

Haha....yeah they do...tryin my hardest to keep her stock but its hard.

cam wise...its a traditional split 238/246 on a 117lsa. here's an idle vid:

http://www.youtube.com/watch?v=g8gRCx8_fs0

man that's alot tamer than our old 236/240 LQ4 setup was. But it was on a 112 too.