LQ9CHEVELLE

iTrader: (2)

Ok...i am obviously new @ reading compressor maps...but from my calculations, from 3400-6500rpm, my 6.0 needs between 34-74lbs per minute of air @ a pressure ratio of 1.8 (12lbs boost @ sea level). Cut in half for twins, this equates to 17 - 37 lbs per minute. Looking at the S200 Map, that would me at OR above 70% efficiency the whole time....spending most of the time in the 74% island. This of course, is assuming you could achieve 12lbs of boost @ 3400 and hold it till 6500. Am i correct in the way i have read this? Also, has anybody ran these S200's in a twin configuration? They have a 1.15 A/R hot side, which sounds a little big. But i know thats just a ratio, and not a reflection of the actual physical size of the exhaust housing....so maybe it might work? they are available in a 1.0 and a .83 also, but with a T3 exhaust flange. Will twin T3 flanges be to small for a 6.0? Looking to make 550rwhp on this bottom end....but end up around 75rwhp when my forged bottom end gets finishd. Opinions? I attached the link to the compressor map below. THANKS AGAIN GUYS!
https://ls1tech.com/forums/attachmen...s200map-1-.jpg

LQ9CHEVELLE

iTrader: (2)

The Map dosen't go below a PR of 1.7....so its kind of difficult to figure how they would react @ lower boost levels. If you extend the lines on the comp map down at their same path of travel....it still looks good @ 8psi. I dont know how the turbo speed would react below 60k though. But 10-12 pounds is a realistic boost # for my build (6.0, l92 unported)

hellbents10

iTrader: (10)

I have seen 256's and such work pretty good at those power levels. Call up Jose and he will get you a great deal on some units that will work great for your car.

LQ9CHEVELLE

iTrader: (2)

thanks for the reply. Anyone else? comments on the A/R? Worth it to go with a T3 to get a smaller A/R? Can you run a T3 in a twin config, or to restrictive? The 1.15 A/R T4 flange model is a twin-scroll housing

LQ9CHEVELLE

iTrader: (2)

:bump:

TOOSLO5

Running a pair of T4 flange 256's on my car. At 8 PSI I made 520/517 rwhp/tq. At 10 psi I made 577/563 rwhp/tq. I am running a stock LQ4 other than a good set of springs, pushrods and a 215/230 117.5 LSA cam.