Jones618

Ok so I'm new to this site but I'm looking to build a 408 stroker out of a 6.0l with a mild cam and a little head work going to go with the carb instead of fuel injection and I am wanting to run a twin turbo blow through system. I am new to the turbo game and curious what size turbos would get me to 800 rwhp at low boost?? Turbo sizes and suggestions on turbos plz?!?

Captain_Stabbin

precision 76's

Jones618

I hear a lot of ls guys running gt45 for a single what is the power range and is there a lot of lag

Chris@CBR

A pair of T4 turbos with a 61mm compressor and 65mm turbine wheel with a .68 A/R turbine
housing will make 1000+ HP and spool lighting fast. With a mild cam you will make good power up to about 6000 rpm.

If you put enough cam in it to make power to 6800-7000 the same turbos with a .96A/R
will let it make better power a higher rpm.

Jones618

Has anyone heard of anyone making over 800 hp on twin gt35's just curious new to the turbo world

Chris@CBR

GT35's will do the job as well. I think Speed Inc built a Typhoon with a pair of those on a 400+ CID LS motor. It runs real good!

Jones618

Do u know the specs on there gt35's?

toytech93

iTrader: (2)

Seems a little on the small side for a 408, I have that same setup on my 6.0L

NemeSS

iTrader: (127)

Twin tc78s w .96 a/r

Chevy406

iTrader: (12)

I have twin 66mm with 65mm turbines and .68 A/R on my 408. It put down 910 rwhp around 18 psi. I'll try again with my bigger injectors and more boost. I do think the .68 A/R housings are limiting me a little up top though.

Jones618

Where is ur power range and are them 66's laggy

Chevy406

iTrader: (12)

I set my 2-step at 4,200 rpm and leave with 6 psi on the boost controller. Lag is dependent on your stall converter, vehicle weight, and gear ratio along with turbo selection. With my 9½" PTC converter, 3,700 lbs, and 3.08 gears it flashes the rpm up quickly and lag is not an issue.

Chris@CBR

It depends on your goals. A mild 408 will work good with this small setup.
Now I say small in contrast to a pair of 78/68's or 78/75's. Ether one of those can make 1500+ HP. Look at the Nova in the video, 5.70's @ 122! on almost the exact turbo.

He has 66mm and I suggested 61's.

The 61's are good for over a 1000 HP easily. That's a lot of power to drive on the street.

stevieturbo

Of course the other thing is not all 66mm's are equal, or indeed any other diameter.

A Cheapo chinese 66mm, a basic branded cast 66mm, and fancy billet 66mm, and on top of that volutes will all give the same inducer size turbo very different characteristics and power delivery/ability

Is it street use, drag use, manual/auto etc etc ?

Jones618

Be street use auto Trans power glide and two e85 carbs

Jones618

May see a little strip action but not what it is intended for

zittman

iTrader: (4)

Try the BW s366 with a .96 a/r( or smaller) with 74 exducer. They can be picked up for around $620 each.

Jones618

What kind of power are them be s366 putting down as twins

wrp

I was running twin 6266's making 1145/1269. CAr was absolutely uncomfortable on the street. Could have went back to pump gas and lowered the boost, would have helped. I'd suggest looking for 500-850 and get the whole combinations etup before you start forgin on past 1000. JMHO

2000RATA

Look at that...another guy proving you don't need a pair of 76's to make big power. The guys that have done it preach it yet the majority ignore it. You can lead a horse to water...