Strange single turbo setup....

[MWP]

Hi all,

Look carefully at this photo:

Notice the turbo is only supplied by exst from one bank of the V8.

Anyone seen a setup like this before?
Seems it would simplify a single turbo setup a lot.

 

[Lextech]

That is a strange looking deal. With all of the technology and high end fabrication that is in that picture there has to be a good reason for that type of build----very interesting.

 

[bango]

Maybe its unfinished>>?

 

[MWP]

Ok, my guess is that since its a Cart engine which is always revving very high, there is enough flow from one bank of exst to give the required boost.
It would probably spool up much later than if it used both banks, but this isnt a problem for a high RPM race engine.

 

[Calorus]

Kind of makes sense, I guess - although this would be difficult to replicat in a road application, because thetwo banks would need to betreated to all intents and purposes as to seperate 4 -pots on the same crank. Right down to the choice of internals. Not a rare issue, though it's quite like the various dimensioned cylinders on a Honda V5 GP bike.

 

[Toysrme]

A single bank turbo? Yes they're not entirely uncommon.
SAAB's newest v6 is a single bank turbo with a GT17 (before that a GT15) @ .1 then .15 bar of boost.
After years of me talking about doing our fwd v6's as a single bank turbo (Front bank only) becase of horrible space issues, somebody in Germany picked up the idea & did it on a v6 mr2 swap LoL!

Most modern Toyota rotating assemblies are fine with the added backpressure on one bank. If you're running big power on one, it is reccommended to choke off the non-turbo bank to approximate the same overall backpressure as the turbo bank.
You can also get away with using a cheaper/more common small turbine with a big compressor that would normally not be suited for single turbo'ing a large, relatively big power engine.

 

[Calorus]

Would you actually needto to treat them as an engine, though? As long as there were no major heat differentials within any given bank, surely, only the cylinder would need to be balanced individually?

 

[souprat]

Hi all. this is my first post here. usually i just read but i found this very interesting. i'm alittle confused on the advantages. if you have to choke the other bank to keep the load on the engine the same, why not just run a normal setup, or go twin? you could run a bigger turbo, but have similar spool because it would have twice the exhaust gases to work with right? very very cool though, thanks for sharing.

 

[Calorus]

As I see it, the only reason to choke the un-turbined bank would be to match the thermal loadings across the the engine, however, one of the main reasons for only connecting one bank to the turbine would likely be space and weight.

Spool rate is only of importance in transient applications; since the turbine would need to be brought up from idle. In race applications like this, the turbine's own momentum and the consistently high exhaust velocity should prevent any problems. Once on boost the turbine should run very well "free", all the way to the wastegate opening.