Guess my HP?

[Nvincent4708]

Okay as many of you know. I have an LSX376 in my car which is rated at 450HP out of the crate.

I'm curious to see what my car will lay down to the ground..

I have XS-Powers full kit.
I'm putting on granatelli's cold air intake here shortly.

And I have HPtuners, so tuning is no issue.

Any guesses on what I should be able to put down? BTW, I have the revised LSX376 which is 10.7:1 compression, not the original that was 9:1.

I'm hoping for atleast 400 wheel.

[SlingShot]

Hmmm ... I say with headers, intake and tune = 425 RWHP / 430 RWTQ

Based on what I've seen LS3 do with the same setup ...

[Nvincent4708]

Originally Posted by SlingShot

Hmmm ... I say with headers, intake and tune = 425 RWHP / 430 RWTQ

Based on what I've seen LS3 do with the same setup ...

I'd be happy with that.

[nancygrl]

[Nvincent4708]

I will be posting dyno sheets once i'm done..but that could be a month or two

[CamaroKid300]

You were the guy who threw a pushrod or something through the engine right? So you had to buy a new motor on your own?

[Nvincent4708]

Originally Posted by CamaroKid300

You were the guy who threw a pushrod or something through the engine right? So you had to buy a new motor on your own?

Yeah through a connecting rod through the block.. yeah bought a new motor on my own.

[SGOS252382]

I read this over in the Vette forum. You might want to read it. The lower compression (made for forced induction) seems to be holding it back NA.

This guy made 403 rwhp with full bolt ons and tuning on his LSX 376.

Here's the quote:
So I purchased this engine, under the impression it made 450 hp (with a stock style setup (LS3)) Well I have mine set up that way, and after doing some thinking, tuining, and dynoing my car is where it should be with this engine. However, I think they should use their claimed HP numbers and lower them from the crate LS3. Because this motor was built for boost, and is essentially a LS3. Yet the compression ratio is 9:1. Making it have less power. Both have the same size cubic inches, heads, cam, the pistons are forged on the LSX 376 however, and the block is made of iron instead of aluminum. My setup consisted of:

99 FRC with a LSX 376

LSX 376 Long block
LS3 intake manifold
Kooks 1 7/8 long tubes
Kooks off road X pipe
Borla Straight pipe
Vararam Intake
LS3 Water Pump
LS3 Throttle Body

I did some "bench dynos" and with the claimed 450 HP the engine should have, I guestimated roughly 430 RWHP with the mods.These numbers would be correct if the compression ration was higher. But I believe my best numbers for today after tuning were

403 rwhp 396 rwtq

Which would be spot on for a lower compression LS3. Now I just wish GM would market that crate engine like that. Im a little disappointed because of the 450 HP claim. Not saying it is not true, it's just not true with the LS3 configuration or "Production Style" as they claim. Overall I'm happy though, because when I do throw a blower on it will be ready to handle it!

[Texas2SS]

With full exhaust and a Cold Air intake I'm guessing 415.

[Nvincent4708]

Originally Posted by SGOS252382

I read this over in the Vette forum. You might want to read it. The lower compression (made for forced induction) seems to be holding it back NA.

This guy made 403 rwhp with full bolt ons and tuning on his LSX 376.

Here's the quote:
So I purchased this engine, under the impression it made 450 hp (with a stock style setup (LS3)) Well I have mine set up that way, and after doing some thinking, tuining, and dynoing my car is where it should be with this engine. However, I think they should use their claimed HP numbers and lower them from the crate LS3. Because this motor was built for boost, and is essentially a LS3. Yet the compression ratio is 9:1. Making it have less power. Both have the same size cubic inches, heads, cam, the pistons are forged on the LSX 376 however, and the block is made of iron instead of aluminum. My setup consisted of:

99 FRC with a LSX 376

LSX 376 Long block
LS3 intake manifold
Kooks 1 7/8 long tubes
Kooks off road X pipe
Borla Straight pipe
Vararam Intake
LS3 Water Pump
LS3 Throttle Body

I did some "bench dynos" and with the claimed 450 HP the engine should have, I guestimated roughly 430 RWHP with the mods.These numbers would be correct if the compression ration was higher. But I believe my best numbers for today after tuning were

403 rwhp 396 rwtq

Which would be spot on for a lower compression LS3. Now I just wish GM would market that crate engine like that. Im a little disappointed because of the 450 HP claim. Not saying it is not true, it's just not true with the LS3 configuration or "Production Style" as they claim. Overall I'm happy though, because when I do throw a blower on it will be ready to handle it!

Most educated guess yet... guess it's going to be the dyno that tells the truth. I mean I am doing a supercharger next year..so if i don't like the number, i'm sure i can make it something I like.

[SGOS252382]

Originally Posted by Nvincent4708

Most educated guess yet... guess it's going to be the dyno that tells the truth. I mean I am doing a supercharger next year..so if i don't like the number, i'm sure i can make it something I like.

Yeah, with that lower compression you should be able to safely turn up the boost. So in the long run, you should be able to make more HP (safely) than if you were running a regular LS3.

[Nvincent4708]

Originally Posted by SGOS252382

Yeah, with that low compression you can safely turn up the boost. So in the long run, you should be able to make more HP (safely) than if you were running a regular LS3.

Especially with the forged pistons.. I'm only going to put 6-8psi through it. I figure that'll be enough to make me smile all day.

[The Stig]

I'm assuming we are doing this Price is Right style correct? Well if we are, I say 1 rwhp 1 rwtq

[Nvincent4708]

Originally Posted by stieger

I'm assuming we are doing this Price is Right style correct? Well if we are, I say 1 rwhp 1 rwtq

I think i'll do this on the "whoever is closest" scale.