Turbo Idea
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On The Tree
Joined: May 2004
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From: FWB, FL
Turbo Idea I was just curious what the pros and cons were of running 3 turbos would be. Running two small twins "incon style" to a much larger turbo to feed a 403. It seems to me that if you could keep the charge temperature up on the small turbos that it would be more efficient than running one single large turbo without. I read some theory on tandem turbos and diesels which use a smaller turbo to feed a larger turbo and it seems to work for them. I have very little in the way of turbo experience but the idea fascinates me. I used to own a Mercury XR2 with a "very" small turbo and a 1.6 but that is a far cry from any V8...
Thanks in advance.
Thanks in advance.
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The 2 small turbos would choke the exhaust way too much. Multiple turbos work on diesels because they can compress air and then compress it again without worry of detonation. Lag isn't going to be an issue with a 402" motor and basically any size turbo.
Thread Starter
On The Tree
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From: FWB, FL
I think you misunderstood what I meant, or maybe I misunderstood you. To clarify my question. I am asking if using the small turbos to spool the large turbo has been done. Run the exhaust through them and out the back of the car. Then use the boost charge from them to spool the larger turbo. Hopefully that makes a bit more sense.
People have used a supercharger to spool a turbo, I think it was on an engine for a tractor puller. Also you might want to check out some supra forums because I have seen a couple pics of a supra with 3 turbos.
Originally Posted by lilone
I think you misunderstood what I meant, or maybe I misunderstood you. To clarify my question. I am asking if using the small turbos to spool the large turbo has been done. Run the exhaust through them and out the back of the car. Then use the boost charge from them to spool the larger turbo. Hopefully that makes a bit more sense.
the reason it hasnt been done is that the laws of physics would prohibit this setup from being more efficient than just the single large turbo, even if the two smaller turbos operated at 100% efficiency (impossible), you would still have the exhaust restricted by the small turbos and the extra piping you would need plus friction...and on and on.
on twin turbo applications with one turbo bigger than another, the smaller turbo spools easier and feeds boost to the engine at lower rpms, until it is overtaken at the higher rpms by the large turbo. this is to lessen the effects of turbo lag. they would never use the charge to power the second turbo...that would be wasted air you could be forcing into the engine.
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From: FWB, FL
Originally Posted by jerrad
People have used a supercharger to spool a turbo, I think it was on an engine for a tractor puller. Also you might want to check out some supra forums because I have seen a couple pics of a supra with 3 turbos.
I have also seen the opposite. There is a miata that uses a turbo fed into a roots blower. Recompressing the compressed charge from the turbo.
Ok I think I am beginning to understand why it wouldn't work. If the small turbos were only say 74% efficient then you would only get that amount of potential transferred to the larger turbo. Thus it would not spool any faster with their charge. So if the larger turbo was 74% efficient then you would only get about 55% efficiency max.
Originally Posted by lilone
I have also seen the opposite. There is a miata that uses a turbo fed into a roots blower. Recompressing the compressed charge from the turbo.
Ok I think I am beginning to understand why it wouldn't work. If the small turbos were only say 74% efficient then you would only get that amount of potential transferred to the larger turbo. Thus it would not spool any faster with their charge. So if the larger turbo was 74% efficient then you would only get about 55% efficiency max.
Ok I think I am beginning to understand why it wouldn't work. If the small turbos were only say 74% efficient then you would only get that amount of potential transferred to the larger turbo. Thus it would not spool any faster with their charge. So if the larger turbo was 74% efficient then you would only get about 55% efficiency max.
