Originally Posted by Les2

I got a dumb question or maybe I misunderstood it, but what keeps the smaller turbo from over spooling and over heating? Now I assume the big turbo keeps it from getting to hot by pulling the exhaust thru it faster?

Do you have a pic of how this is set up? I'm pretty sure I understand it, but curious.

Ok on reading it again I got it.

After thinking some more.... It would suck if you blew a turbo cause no matter what one you blow its gonna take out the other.

The big turbo pushes the intake air through the little turbo, but the exhaust is always under pressure trying to exit from the cylinder until it gets past the big turbo. The reason I want the wastegated exhaust housing on the small turbo is to lower the exhaust pressure from the cylinder to the small turbo. Once the wastegate opens exhaust is bypassing the small turbo turbine wheel and going directly into the big turbo turbine wheel to spool it. The small turbo has a small turbine wheel for the Hp the engine is producing, so it becomes a restriction to building HP by raising Exhaust Gas Back Pressure in the exhaust manifold. Relieve this pressure with a wastegate and you gain Hp.

You ask why the small turbo isn't over sped by the air moving through it. It is helping the big turbo move air on the intake side, but has a low load or resistance on the compressor wheel and shaft because it is having air pushed through it at the same time it's trying to push the air. It also helps slow down the speed of the big turbo, becuase it is turning to help the air along. So both turbos actually slow down when you would compare the speed of the big turbo running as a single system supplying air to the engine. The 362 Pete used a stock CAT 435 turbo on the manifold and a BW OEM C-16 replacement turbo for the big turbo with the wastegate disabled. I actually had the BW Rep I know go over my sizing to assure I wouldn't over speed the turbos for an 800 Hp engine. How can a 600 Hp replacement turbo move enough air to support 800 Hp? The volume of air increased without increasing the speed of the turbos by using a twin set up........they weren't over sped doing his. One turbo helps the other to move the air........ think of the small turbo as a secondary air pump to keep the air moving to the engine when build max power with the big turbo.

This type of twin system has evolved alot recently and has become more attractive to use in my mind, but it is expensive to build. It does give you your cake and eat it too answer to big Hp and turbos to feed this Hp and solves the low RPM throttle response issues. It makes the truck/engine much easier to drive at high Hp levels when compared to a big single. But I also feel that it robs some power to do it in the grand scheme of max Hp numbers.

Hey Kurt stuff the Turbo's!!! I have been emailing you a progressive Blow by Blow on your injectors SO check your emails!!!!

Whilst I'm here I think setup right its a good combination which brings me to wanting a small small Turbo and a BIG waste gate to take it out once we have boost.

Originally Posted by 07-379Pete

Whats up with the remote oil filter?

probably because it has a cat retarder on it and there isnt any space left!!

Originally Posted by Rig Wrench

Would a staged system be able to have a broader operating range compared to a single system. Say if you had a 750HP engine set up for a single turbo and you wanted to add another 200HP through a (for example) Power Box or a higher performance ecm, you would then be overworking that single turbo. could a twin/staged setup be built so that it still responded well to lower HP settings, yet could deliver enough air/ durabilty for a higher setting? kinda like having best of both worlds.
Just shootin from the hip here

yes, this is basically what happened with the truck I described with having a 860 Hp twin set up. The big turbo he used could easily support 1150 Hp to the tires. He had good throttle response and fuel mileage with this system and had the capabilities to add more fuel to raise his Hp levels, which he did when he installed the bigger injectors at a later date

Originally Posted by Far_Call

Hey Kurt stuff the Turbo's!!! I have been emailing you a progressive Blow by Blow on your injectors SO check your emails!!!!

Whilst I'm here I think setup right its a good combination which brings me to wanting a small small Turbo and a BIG waste gate to take it out once we have boost.

OH ####!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

See Ya guys I have other things to check out...........

yes sir, you have the correct idea on the turbos

Originally Posted by 07-379Pete

Whats up with the remote oil filter?

Looks like a water filter to me.

The engine has a Brakesaver on it and this is why it has a remote oil filter