general23cmp

iTrader: (1)

I can do the math on the compressor side and read maps, but how does one go about deciding on the turbine housing? How do you know what will choke what, what AR is apprpriate for your application, etc.?

Thanks.

HydroStream6

iTrader: (16)

I'd post up your engine/drivetrain/car combo here and get peoples' input.

general23cmp

iTrader: (1)

I'll try that again, but it usually boils down to several posts telling ne to contact so-and-so. Apparently this info isn't usually freely given.

408 iron block. 8.5:1 compression, beefed up 700r4 with 3000-3500 stall, 9" ford rear with 3.93 gears, in 1971 chevelle. Looking for pump gas performance, maybe 750-850 flywheel hp with single or twins (maybe 15psi). Twin 60-1 turbos look to have promising compressor maps, but how to know if turbine side is sized right?

Thanks.

XtremeDime

iTrader: (16)

Twin 60s would work good, also a single 88mm or maybe a little bigger. Whats your budget look like? lol

lordrazo

iTrader: (18)

for myself i read alot of other successful set ups and then contacted forced inductions and gave a complete spec of what i built and what my goals are which is very important 100 hp can change a turbo and ar smaller turbo will require more ar and bigger will be less of course but im not a turbo expert as much as i would like to be so contact them they are good and many ppl on here will agree he can even enplane more on how to calculate an ar

general23cmp

iTrader: (1)

Thanks for the help. I feel confident I can get the compressor side on my own. The turbine side is my main question...

kbracing96

iTrader: (25)

With a 408 and twin 60-1, I go with a T4 based hot side and around 65mm Ptrim turbine wheels with .96 a/r's. If you want a faster spooling setup, then look for something in a .68 a/r. What brand turbo are you looking to go with? Those turbos are good for about 450rwhp each.

general23cmp

iTrader: (1)

Thanks. That was precisely what I was leaning toward on the exhaust side. I was actually considering turbonetics units, but can probably find something more economical for the same quality?? What rpm differences would you expect between the two AR's at wide open throttle to hit max boost? I know that's probably a guess, but would be useful.

HydroStream6

iTrader: (16)

I made 530rwhp on a single Garrett T60 with a .81 hotside, P trim. Granted it was completely out of breath.

What heads are you going to run? And cam? Seeing as your auto I wouldn't be afraid of a .96 AR. .68s will spool faster but will hold you back on the big end, plus they won't really be necessary with the auto. I'd lean towards .96s or .81s.

reamo04

iTrader: (9)

if you want a faster spool but keep the top end up, look at the turbonetics TC66 with a .96 A/R. I believe those would be pretty close to what your looking for