i know im not the first one to think of the concept of having both a turbo and a sc. but, has any one successfully done it?

zoom'* car ran 9'* on a twin charged setup.....I don't know why you would want to twin charge with todays turbo technology but to each his own.

well its been talked about, and If i recall it is better to just gut the SC and have turbo only
Willwren is planning on doing this to his car unless plans have changed, he would be able to fill you in alittle better once he sees this thread (he'* donr lots of research on the matter)

Yes, it'* been done. In fact, GM has produced it in one unit on a commercial vehicle in the last 50 years. See if you can find it.

ADTR and I were seriously discussing doing this to my SSEi nearly 4 years ago.

And what conclusions did you come to? You see the twin charger engine for the new VWs and wonder why people haven't tried this already? I think it would probably be a LOT more difficult than one would think.

Someone made this comment that I saw on another web site:


This may be a miles off topic, but the best solution to all these turbo problems with todays technology, seems to be to combine a turbo with a positive displacement supercharger, (with the compressors simply run in series). This has now been succesfully done on three mass produced production engines.

Nissan did it with the March, a small hatchback not sold outside Japan, it combined a Garret turbo with a roots blower.
Lancia did it with the Delta S4, again a KKK turbo with a roots blower, and two intercoolers.
VW are doing it right now with the Golf GTI hatchback just released in Europe this year.

I built an experimental system like this myself over fifteen years ago, the results were exceptionally good in all respects. The corporate bean counters are probably the only real obstacle to overcome, otherwise I am sure many more forced induction production engines would now be using this system.

It combines lag free low end torque, with high top end airflow. The advantages of being able to keep boost pressure just above exaust back pressure should not be overlooked. The torque curve can be made any shape you wish to make it, and it is relatively simple. Initial cost is the only real disadvantage.

wouldnt the blower become a resrtiction at higher rpms :?:

Here is ZZP'* version:

I don't understand how that works.
If the SC is a positive displacement device, it will only move a fixed quantity of air.
I thought the Turbo cars remove the SC rotors. :?

Well at low RPMs, you have boost from the SC and at higher RPMs, more effective boost with less robbing of engine power because the SC hardly sets any resistance to the engine belt drive when receiving boost from the exhaust gases.