Where can I find flow rates of wastegates? I'd like to see what a good one would flow to help bypass the small turbine once its spooled. And by bypass i mean regulate the small turbo and keep drive pressure down while feeding it to the big turbo/turbine.

 

The precisions largest is 66mm.
You will need 2 gates. And a good amount of room. Hot side would be straight forward.

Would you run both compressors outlets to a common plenum?

 

The big turbo feeds into the little turbo. In doing so the little turbo won't have to over speed to keep up. Think of its if you live well below sea level. You wouldn't need a huge turbo because instead of seeing 14.7psi on its Intake the little turbo will be seeing around 24pounds of absolute pressure. Then the big turbo will just think its feeding a really big motor with low pressure. Then of course the down pipe of the little guy will go striaght into the inlet of the big turbine. With enough wastegate to by pass all of the in needed pressure into the big turbine too.

I think I found a good pair to do this with. A gtx3582r and a gt5533. Should net me 10psi by 2-2500rpm and carry to 4000 where the big guy should be lit off and rolling in. If so this would net me some BIG down low torque numbers with a really flat curve to 6200ish.

 

I know these LS engines are tuff but they are nothing like the ag based engines used in tractor pulling.. We are talking Extremely high cylinder pressures lasting only 10 to 15 seconds long at a time. All the compounded diesel or alky tractor pulling engines all use billet cranks swinging in girdled blocks with filled water jackets in the blocks just to get them to survive.. Just get on youtube and search for tractor pulling exploding and see what and does happen fairly often...

 

i'm not looking for extreme boost. that is not the point of this setup. its to get a good flat torque curve. 20psi manifold pressure total at the top end. no more than 10psi down in the low rpm.

not all compounded diesels run billet cranks and all that. there are many compounded dmax and dodges running around. they use the stock vvt turbo with a big one for top end power. some with wastegates others manage to open the turbine vanes up almost as far as they go to get good flow and lower drive pressures. others just use a big single with nitrous to launch.

 

There's a guy here local that has a compound cummins with like a 200 shot of nitrous! Said he usually launches at 40-50psi and is 60psi by the end of the 1/8 mile.

 

yeah, there are sooo many diesel guys with compounds. the new thing is trips though. three turbos about the same size, then two feed into one and they spool faster than two compound setups. but i'm not looking to go that crazy! just want down low torque with the tcc locked and a good flat torque curve to 6200rpm. no i'm not gonna consider a supercharger. i have 4 kids that wine enough, i don't want my truck to wine too.

 

Man, you got me thinking compounds again...

 

 

Well the wife and I decide the Dmax swap wasn't I the budget right now and we just got the title in for the Tahoe. (Woot woot). So I decide I wanted diesel torque but big power. She said ok so after deployment it's ******* on. I'm gonna try it out on my trusty ole stock 5.3 but have pistons and rods on stand by. I talked to forced inductions today and they said they deal with this all the time and said my turbo selection was on point. I'm really looking forward to it and KB if your interested I'd love to chit chat about it.


Atomic: I can't stand the superheater wine. Lmao. I rather whistle while I work. but that is a funny *** pic. But, I have a feeling I should be spelling it "whine". Lol