Hi all

After chasing a gazillion posts - no real answers.

Will a SBE 6l with square port heads, and a stage 3 BTR twin turbo cam, spool up twin 78/75 journal bearing turbos.

.96 T4 open, or 1.25 T4 divided are my housing choices. ( I am thinking the .96 to keep flow speed up? )

Car is strictly a drag car, TH400 with a dump valve, and have yet to choose a converter until I know something about the ability to spool.

Would like the converter to be in the 3000 rpm range as the spool valve will bring me up a few hundred rpm

So I guess besides the ability to spool these big turbos, is at what rpm will that begin to happen?

Anyone out there running, or has run, twins of this size, who can tell me what to expect?

thanks

 

Can't speak for the squre ports but mine is 6.0 10-1 compression, AFR 230's softened chambers, LJMS st2 twin turbo cam, super victor intake
twin s369's .88 turbines, PTC 9.5" 14-0 converter, powerglide. Makes 4lbs on the brake in 1-2 seconds from going wot, 2 step at 3900 rpm.
Still on 93, havent tried e85 yet.

 

Guy I know runs twin PTE 7675's on a 5.7 and uses a small hit of nitrous to get them going quickly, 6.0L probably wouldn't need it.
Strictly a drag car then look at running higher compression to get things moving faster, 10-11:1 on race gas outta be no sweat.

 

I am running E85, and I know small turbos work - I am specifically asking about larger 78mm turbos and spooling
I do thank you both for responding

 

If its strictly a drag car, you might want to reconsider that 3000 rpm stall converter.

My 4.8 was able to spool up a pair of them. Lazy AF on the street, but no issues at the track.

 

so what would you suggest for stall.
With the dump valve, that 3k converter will act like it is a 3500, or so stall

 

It certainly will! I ran VSR 7875's with .96 housing on a 5.3 and a 6.0 with a manual and an auto. Manual car I launched about 4000RPM, for a drag only car I would get a stall higher than 3000 I ran a 4500 but don't have a dump valve. A 4000 with the ability to vary rpm a few hundred should get you where you want to be.

 

Make sure the tune is good to go while trying to spool. If it’s too fat when you try and get on the chip or build boost, it’ll be lazy. PM SLOWSEDAN, he runs those turbos on a 5.3 I believe and has no issues. The converter is going to be based on the amount of power your gonna make. 3000, 35000, doesn’t mean anything. Turbo setups make a bunch of torque and it’ll change the attitude of the converter when the power is turned up or down. It’ll be the last thing adjusted once you’re all in.

 

He said, "Get on the chip"

Man it's been a long time since I've heard that.

 

Lol, the days of a small plastic container with MSD chips, ah I remember.

 

Tree'd! True story! Too fat and not enough timing before the turbos are lit are the ones you see the most. The converter manufacturer should ask details about the setup but I'd prefer to err on the side of too lose than too tight with a combo like this.