We have a new project on the go to test out some new products and to show the ability and reliability of older projects.

Scope:



List of Parts:

Rebel 3" stainless intake
3.5" Throttle Body with spacer
Rebel 4-1 Stainless Header (equal length)
2.5" Stainless Header back exhaust
60lb's Siemens Injectors with harness
Innovate LC-1 DB kit
CNC port intake, exhaust and chambers
Diamond honed guides, valve job and deck skim
SI Valves Intake Valve - GM Ecotec - 36.1mm (+1mm)
SI Valves Exhaust Valve - GM Ecotec - 31.1mm (+1mm)
Ferrea GM Ecotec Titanium Retainer - use with S10057 valve spring
Ferrea GM Ecotec Dual Valvespring - 75lb on seat, 14mm max lift
GM Valve Seal - GM Ecotec
Head studs
Cosmetic Head Gasket
Rebel Twin Screw Kit









Performance Numbers:

But first a little backgound...

The dyno we use is a dynojet and has always read low or accurate, which ever way you look at it.

Here is a GM Stage 2 dyno:

With...

GM Stage 2 with 3" pulley
GM Honed manifold
GM Cat back exhaust
Rebel 3" Stainless Intake



Now to our results:

Stock:



Ported head, intake and exhaust:



That's a gain of 58WHP and 30WTQ!....stock pulley, stock boost

Ported head, intake, exhaust, 3.5TB, Twin Screw kit:

~~COMING SOON~~

 

subscribed

 

nice!!! any chances u dynoed w/ just a ported head?

 

well we didn't want any bottle necks so we can let the ported head breath properly

 

All that work, why not put stronger pistons/rods in, or neutrals?

 

we actually did this without removing the motor (yes pain in the butt) but we figured out a method.

That will be done next summer.

 

Um, I did all the things I mentioned without removing the motor...

 

should be fun

 

wow that's great

 

um yeah?

 

we're taking the motor out for a few other things next summer, didn't need them for this project anyways

 

what header, downpipe and cat-back were used so i can get a better idea of the gains on hte head

 

ours...

the header is our first which uses 1.75" primaries, equal length and 4-1
downpipe is 2.5" with high flow CAT
cat-back is 2.5" with 18" resonator and straight through muffler

 

This will be nice to see

 

thats a nice gain on stock boost

 

nice numbers on my car guys now lets see what we do for a stroker kit for next year

 

 

Very good numbers! Hooray for stock boost levels!!! Hey Rebel, with the ported head was your increase in flow, and loss of restrictions enough to lower the boost pressure? Thanks


MIke

 

Sick.

 

nice numbers

 

Who makes upgraded crankshafts for the lsj? Isn't it already forged (as well as rods)? As far as I know the pistons are basically the only thing that needs to be replaced (along with pins)...maybe the sleeves as well.

I don't expect Crower to step in for a stroker kit.

Oh and RAW, you didn't swap or grind cams with the new valves?

 

This interests me greatly. I have been looking into the twinscrew, but I've also been checking out the twincharge kit. Trying to figure which system will make about 300-350 whp efficiently and safely. Good luck with the build, keep us updated with many pics and videos of dyno runs when completed!

In the mean time, your stage 2 kit for my m62 is an option.

 

Very nice. And people think there are no gains with aftermarket exhausts for the lsj

 

The boost pressure stayed the same, maybe down .5psi but that's it.
No change in boost level might be due to the restriction in the lower manifold but regardless we have let the engine breath a lot easier.

Some of the gain can be attributed to the fact that if the exhaust gas can exit the combustion chamber more efficiently and at a more complete level. Then less fumes are left in the chamber after the exhaust valve closes allowing more air/fuel mixture to get in during the next cycle>>>more power

no, we just wanted to see how the head would perform itself

 

WOW, that is SUPER impressive. I would love to dip into some headwork like that, but I'm gonna wait till the car is paid off. I promised the wife that I wouldn't get too crazy with the car too soon. LOL.

BUT, just to point out a few things, you guys gained 58whp and 30wtq with the stock rev limit. I took notice to that small piece of info. If you guys would have actually reved to about 7000rpms, which I think you would easily make power too now even on stock cams, I'm willing to bet another 10-15whp especially with tuning. Was there any tuning done to that? or was that on stock tune?

That's really impressive, JUST WOW! How much is a head like that? I may tell the wife I just can't wait.