2QUIK4U

iTrader: (7)

I would say the numbers are slightly low. My Z28 had the VRX3 cam and made almost the same power with stock heads and stock LS6 intake. I would think you should be around 420rwhp. It could be in the tune. Do you have a copy of the dyno graph? However, dyno numbers arent everything. Get it to the track in the spring and see what it runs.

Red99TA

iTrader: (11)

I understand - gotta learn sometime. Compression basically depends on the volume between the top of the piston and the bottom of the combustion chamber. So if you increase the volume by running a thicker head gasket, cutting valve reliefs into the top of your piston, running an aftermarket piston with valve reliefs already in it, or removing some material from the combustion chamber during porting, etc. then you'll have lower compression. I would ask the Vengeance guys again what they meant as it doesn't sound like they changed anything to result in lower compression.

As for your power 400RWHP from a stalled auto isn't horrible - it might be 5-15HP less than expected but as mentioned take it to the track to see what it traps. Trap speed plus the weather conditions and your race weight will help determine what it's really making.

ParkerSS

iTrader: (2)

I do. I'll post it up as soon as I can. We just had a snow storm hit so power has been out and I'm doing this via my iPhone. Atlanta and we still have like 6in of snow..rediculous lol

But thanks for all the input guys! I'll check on this compression thing and post up my graph as soon as I can. I'll also look in to the tune a little bit.

desertLS1

iTrader: (8)

I made 415rwhp same set up, bigger stall, with a badly slipping tranny.

ParkerSS

iTrader: (2)

I've been having tranny issues as well but not on the dyno.

Who did your tune if you don't mind me asking?

01ssreda4

iTrader: (96)

It seems down a little on power, not much. The autos just dont dyno well. A trip down the track and a look at mph would be a good indication of the dyno indicating slightly low or not. I am running a very similar setup and would hope to crest 400 although not by a ton. My car feels strong though and thats whats important. Coming from a TR224/241 heads to a Cam Motion 228/232 with 799 heads I feel like I picked up 40 hp. And thats what really matters

And +100 on compression going up. You went from a 67cc chamber to about a 63 (I think). Not gonna make a ton of difference on the dyno though.

firefighter813x

iTrader: (6)

yup.... your power is kind of low. I have a factory LS6 and I would be really bummed to have a cam of that size combined with a Fast making 400. My older stalled LS1 auto with the MTI X1 made 377,387,395 on three different dyno's with a Vig 3600 and 806 heads. The highest dyno was with the LS6 intake too...

ParkerSS

iTrader: (2)

Thanks for all the input guys!

So what could be causing my low numbers? Tune possibly?

HoLLo

iTrader: (17)

My guess is tune, or other problems with the motor

ParkerSS

iTrader: (2)

Such as? I have no abnormal noises and it isn't driving odd at all and has never threw a light other than when I did a mod that would set one.

01ssreda4

iTrader: (96)

It could simply be a lower reading dyno. All dynos do not read the same, even with the correction factor.

kdavis

iTrader: (14)

How is the valvetrain noise? I put a cam similar to that one in my trans am and it is pretty loud.

PREDATOR-Z

more bench racing please.
That is good power for the size cam and overlap at hand.

ParkerSS

iTrader: (2)

It's not that bad IMO anyways

Omega Doom

iTrader: (2)

my car made 414rwhp/390rwtq at RPM in lewisville tx this was with just a RPM 5 cam long tube headers,true duals, TSP lid,Yank 4200 stall and Sam88gta1 tuned it's a stock block,intake, tb,241 heads,and no pulley or ewp and thru a stock 3.23 rear! so i would think your heads would have made the numbers a bit more?