compound turbos?

[luigi90210]

alright so pretty much i was at the local toyota dealer and i got to see a supra with compound turbo setup

pretty much it was like a twin turbo kit but it works like a single turbo but it offers 0 lag because you have one super small turbo that spools up for great low end but when it reaches a certain boost level, a wastegate will divert as much exhaust gases to the bigger turbo which would have spooled up by then

this video explains it better then i can but i was wondering how possible would it be to do something like that on the 370z?

http://www.youtube.com/watch?v=y-Me6yWApzY

[Chuck33079]

I would think you'd run into some plumbing and packaging issues. Maybe a mid mount and a rear mount turbo?

[Mitco39]

Guys do it on the Diesel trucks all the time. From what I read the lag on a twin turbo setup is next to none anyways. You would have so much more piping and have parasitic losses from all the bends and length.

[Chuck33079]

From a packaging standpoint, it may be easier to run a supercharger and a turbo instead. It's been done on other cars. I don't see why it wouldn't work on the Z with a large enough wad of cash. I'm not sure it would end up being worth the effort and cost at the end of it. Someone with too much money or insane fab skills needs to give it a shot.

[luigi90210]

Originally Posted by Mitco39

Guys do it on the Diesel trucks all the time. From what I read the lag on a twin turbo setup is next to none anyways. You would have so much more piping and have parasitic losses from all the bends and length.

while the twin turbo kits offer good spool time, isnt twin turbo kits only good for low and mid power?
from what i understand a big single is good for mid and top end and a small single is good for low end so wouldnt a compound turbo setup offer the benefits of both?

i understand there is going to be some power loss because of restricted flow but wouldnt the power from boost make up for the lack of exhaust flow?

Originally Posted by Chuck33079

From a packaging standpoint, it may be easier to run a supercharger and a turbo instead. It's been done on other cars. I don't see why it wouldn't work on the Z with a large enough wad of cash. I'm not sure it would end up being worth the effort and cost at the end of it. Someone with too much money or insane fab skills needs to give it a shot.

i saw something like this on a 350z, it had the stillen roots blower and the STS rear mounted turbo kit

[Mitco39]

Originally Posted by luigi90210

while the twin turbo kits offer good spool time, isnt twin turbo kits only good for low and mid power?
from what i understand a big single is good for mid and top end and a small single is good for low end so wouldnt a compound turbo setup offer the benefits of both?

i understand there is going to be some power loss because of restricted flow but wouldnt the power from boost make up for the lack of exhaust flow?

You also have to remember that its not so much boost as it is flow. A awesome flowing truck at say 30PSI can produce just as much HP as 60PSI, boost numbers does not necessarily mean power. Also with compound turbos (where one is not a VVT turbo) I could see issues with lag being caused from the small turbo having to get the larger turbo going. On Diesel trucks the vains in the smaller turbo can be controlled and thus you have much more control over the system.

I am just speaking from a truck standpoint since that is what I know, but I cant see it being much different for cars. If you want a sweet system put a supercharger on the car with twin turbos. You would have to figure out valving such that the supercharger is used in the lower rpms and then it gives way to the turbos. Again it comes down to room for piping.

[Mitco39]

Here is a picture of the turbo/supercharger setup in one of Gale Banks boats. Someone figure out how to make this work on our cars. haha.

[Chuck33079]

Originally Posted by Mitco39

You also have to remember that its not so much boost as it is flow. A awesome flowing truck at say 30PSI can produce just as much HP as 60PSI, boost numbers does not necessarily mean power.

I was just typing this. Even the wording was eerily similar.

Originally Posted by luigi90210

while the twin turbo kits offer good spool time, isnt twin turbo kits only good for low and mid power?

No. Even with a smallish .64 gt28, there's a dramatic power increase all the way up to redline. It's all in the turbo sizing. You could get a smaller single turbo and see the same kinds of spool times you see with twin kits. You could get two larger twins that have the same amount of lag as a single.

Originally Posted by Mitco39

If you want a sweet system put a supercharger on the car with twin turbos. You would have to figure out valving such that the supercharger is used in the lower rpms and then it gives way to the turbos.

This would be awesome. Have the turbos feed a roots blower.

[Chuck33079]

Originally Posted by Mitco39

Here is a picture of the turbo/supercharger setup in one of Gale Banks boats. Someone figure out how to make this work on our cars. haha.

Is that a diesel?

[Mitco39]

Yes its a Chevy Duramax Engine.

Well technically its a Isuzu Engine, haha

[Chuck33079]

Sweet Jesus. I want one. I have no use for it, but that's just a pretty engine to look at. I'll make it into my coffee table. Might have to reinforce the floor a bit.

[blackonorange]

Lol but why?

[SS_Firehawk]

You would need to have a serious built motor to even think about something like that. It would cost less to build and stroke the motor to reduce spool time than try and fab up something like that.

[TopgunZ]

Originally Posted by Chuck33079

This would be awesome. Have the turbos feed a roots blower.

Yeah, I did this with my 350z. Powerlab kit feeding the stillen.

[ZSIZZLE]

a compound setup is a turbo & supercharged engine, 2 turbos is still just called a twin turbo