20lbbooster

iTrader: (3)

I'm going to be starting a twin turbo project on my LS3 equipped G8 GXP. The motor is stock and will remain that way...(until it gives up anyway). The car is 6 speed and will be equipped with meth injection. I will be running between 7-10psi. I'd like to see at least 600whp.

Originally I was going to run a single 76 or 78 but decided that it was going to be a pain to route a fat downpipe down between the steering components and exhaust manifolds and decided to run two smaller turbos.

My question is which turbos? I'm trying to decide between the tried and true 60-1 with stg III turbine (not sure AR) or twin precision billet 5857s journal bearing with v-band in/out turbine side or twin precision billet 6262s journal bearing with v-band in/out.

Anyone have any input for me? I know the 5857 and 6262 are very popular on the import side but I just can't find much info on a twin turbo v8 set up.

Any help is appreciated.

ttbestas

i would like to know that as well. twin turbos 4 ls3...

20lbbooster

iTrader: (3)

Well, I ended up gettig two precision 6262 journal bearing turbos for my TT project but sold them 2 weeks ago with the intention of getting 2 6265 ball bearing turbos instead. Right now I'm not positive what I'm gonna get. It's either going to be 6265 ball bearing or two of the new Borg Warner EFR turbos. I'll be making a decision and purchase late next week.

'Trust'

iTrader: (24)

Those are the exact turbos I have, what are your a/r's? Billet wheel 6262's, v-band housing. They should be efficient for me to about 1200rwhp, then they'll be out of steam. I'll have numbers this week, or next weekend.

ttbestas

which ones of EFR turbos you wanna get? why?
so far i collected such info for ls3 twin turbo (front mount only):
1. IPS twin garett GT3586R 1.03 a/r - 650+whp
2. Granatelli precision twin PTE6265 65lb/hr turbos - 600+whp
3. Hellion twin turbonetics 61mm -600+whp
4. UPP twin T04B-SH 600+whp
EFR turbos are expensive, same goes with GT3586R or PTE6265 and all of them could make good power.
What do you think how twin Master power T61 T3 .96 would suit stock LS3?

skyhighsami

iTrader: (8)

Parish built a turbo G8. It seemed to work very well. Search what he did

20lbbooster

iTrader: (3)

Parish used precision 60mm ball bearing turbos. His car is not an ls3 but it doesn't matter, he made good power and ran good numbers. He was one of, if not the first person to fab his own kit for a g8.

I decided to use precision 6265bb with a v band inlet/outlet turbine and .82 ar. I'm looking for the 700whp ballpark at 10psi. We'll see how it goes. I'll be ready to roll in a month or so.

westtexasbuff

iTrader: (40)

I am using billet precision 6265s .81AR on my forged LS3 build.

20lbbooster

iTrader: (3)

Nice! I'm curious to see how that turns build turns out. My motor is not
forged so I'll be looking for less power than you. What is your goal?

Granatelli

the Precision PTE6265 65 lbs/hr are 650hp at 2 bar as an example we have a customer with our Camro kit that make 800 rwhp at 12psi - factoring 15% loss (which is conservative) that is 920 crank hp. Each lbs of boost is typically worth 60 hp so if we added 2.7psi times 2 turbos that works out to be 2.7 x 2 x 60 = 324 more hp

920 + 324 = 1244 hp (in a perfect world it should have been 1300hp) just goes to show how the math works out. This post will probably confuse a few but I hope you get what I am trying to say.

in short a PTE6265 is better than 600+ it is more like 625+