udlose99ta

iTrader: (18)

i have a lt1 with a vortech v-2 s trim. I am looking into a forged 383 for it. My question is what pulley set up will i need to run 12 psi and can the s trim even do it on a 383, or do i need to upgrade. I also have an aftercooler, plan on runnin 60# injectors or bigger if needed and a mild blower cam. thanks

DeltaT

iTrader: (5)

I could only get a max of about 8.2# on my SBC 383 with the V-2 S-trim, after a big A2A FMIC and the throttle. That was with good E-tec 200 heads, a solid roller 230/236@.050" (.575/.584 net lash, 112LSA, approx equal to a 222/227 in a hydraulic roller but better), and 1 3/4" longtubes. 60# injectors would be OK, but I recommend going straight to 72's (RC Engineering calls them 75's) so you have some headroom.

On the S-trim, to get that boost I was running an 8-rib setup: 7" lower and the 2.95" upper. I could spin the motor to 6900rpm, but the cam really ran out of steam around 6350.

Jim

My Site: http://home.mindspring.com/~jim_fisk/id1.html

udlose99ta

iTrader: (18)

great info, thanks for the reply. So if i ran a 7" lower and a 2.75 blower i should see almost 10lbs?

DeltaT

iTrader: (5)

Well, you would be overrevving the S-trim probably. How much rpm do you usually run?

Jim

engineermike

First of all, the S and T trim blowers share the same compressor curves, which means they make the same boost when spun the same speed. The T does it a little more efficiently, though.

I ran the T-trim through a water/air on a 383 with AFR 210 heads and a 224/236 cam and it made 13 psi consistently. The pulley combo was the steepest offered by Vortech at the time: 6.66/2.75. At full weight, I ran 10.40's at 133 mph.

Also, a few years ago, LJ ran 9.9 at 139 mph using an S trim on a 383 and 7.00/2.75 pullies. I believe he claimed around 12 psi boost.

udlose99ta

iTrader: (18)

thats is all i was looking for, thanks guys for the input

Capown

iTrader: (5)

I Have a 2.75 pulley for a V-2 Strim its polished aluminum. I ran a 2.95 and a 7" crank pulley on a 306 and seen 12psi. consistently. Ill sell you the 2.75 if you want it pm me a offer

udlose99ta

iTrader: (18)

ok, so i decided to go with the 2.75 upper and 6.66 lower pulleys on the 383, stock lightly ported heads and long tubes. Now i need some advice on a cam. I have 2 in mind.

choice #1- Comp Cams TS233XR Camshaft 233/242 duration @ .050", .569"/.576" lift with 1.6 rockers, 114lsa. Amazing top end pull, extremely lopey idle in stock displacement engine. Nitrous use 200 shot, supercharger 8-16psi.

choice #2 - Comp Cams TS224XL Camshaft 224/236 duration @ .050", .536"/.555" lift with 1.6 rockers, 114lsa. Nitrous/supercharger camshaft, designed for engines running up to 150 shot N2O, 5-12psi supercharger.

any advice?

Jake@EPP

Either or really, the centri blowers tend to not have a favorite. Basicly choose where you want your lower end at, then pick the cam that puts it there. As you know the centris are a peak hp generating blower, not much middle at all.

Something like a 226/230 114 .600 would work well in a street car for a daily driver if chosen to. While you can still run those larger cams, most of the time, its not needed.

engineermike

Jake speaks the truth. The centri pulls like crazy up top, so keep that in mind when choosing a cam.

I have the 224/236, but I'm using high lift lobes (.605/.6xx) and it works reasonably well. I urge you to consider a 224/230 or maybe 230/236 for top end. The 233/242 would probably require more rpm than your valvetrain can handle.

Jake@EPP

Also keep in mind, those cams are spec'd for a stock inch motor. Adding displacement will greatly effect the results.

udlose99ta

iTrader: (18)

thanks guys for the input, I'm thinkin just need a custom grind.... Oh, and Jake how is EPP on tuning Lt1's?

Jake@EPP

We used to tune them back in the day, but with all the new advances we have stepped aside in tuning them. The pricing and the difficulty in getting the tuning licensing is just too much of a hassle any more.

Ls1 swap it lol.

udlose99ta

iTrader: (18)

lol, i've got a pretty quick ls1... i want to see what the good ol lt1 can do