Erra

Why came Vortech´s kit 2001-2003 LS1 cars with 34 tooth pulley.
And 1998-2000 with 30 tooth.?
I can understand that LS6 need 34 tooth, but why LS1?
I now reed 6 psi @ 6000 rpm, to low I think.

/Thanks Erik

MelloYellow

I thought the standard was a 32 Tooth on the SC for the LS1?
Not sure if S-Trim and SC-Trim come differently.

I am 2 sizes smaller at a 28 Tooth for the standard LS1 Kit.

octaneman

They lowered the boost, as the 2001 up kits both for ls1/ls6 use the 34 cog tooth, we saw only six pounds of boost compared to 8 on the older kits, you can upgrade either the jackshaft pulley to a 32 or the blowr cog to a 32 to get 1 to 1.5 lbs of boost, but you will need something like ls1 edit to tune it.

Steve

Erra

Thanks Steve!
You seem to know Vortech`s kit very well.
I had in mind to change the blowr cog to 30 tooth.
Together with long tub headers that will lower the back pressure.
I hope to reach about 7,5 psi.
Or what do you think?

7LitreC5

I am running the 30 tooth pulley on mine. My head unit is an SC trim. With this pulley my car made 8.5 psi at sea level and maked 6.5 psi here at home (7000 feet). These boost levels were seen with my FLP headers on the car.

Bigben

Vortechc5 what king of dyno numbers are you running @ that boost level?

7LitreC5

My car with the Vortech @8.5psi, FLP headers, and a Blackwing made 501.5 RWHP on the dyno at Xtreme Motorsports in Tempe. I did the installation and Xtreme did the tuning.

Erra

What a difference in boost/altitude. I think 8,5 psi is pretty high
on stock bottom.
I thought long tube headers would lower the boost, or have 98-00 kit's
different jackshaft pulley also, that make your boost that high with 30 tooth blowr pulley.

octaneman

Depends on your altitude, I think you will be closer to 8lbs plus at sea level, also depending on the rpm you are taking it. We do a lot of spring/retainer/pushrod/ upgrades. and take the motor another 200-400 rpm, and we are seeing approx 500-510 at the wheels for power.

Steve

7LitreC5

That is quite correct. I would not trust 8.5psi on a stock bottom end. I set it up that way knowing that I would loose boost at my home altitude.

Erra

What about the bypass valve?
Do someone know when a standard Vortech bypass valve blow off?