Twincharging SC>Turbo or Turbo>SC? 2

[Max965]

For those who are 'pro' twincharging I am interested in discussing the technicals of the combined Supercharger and turbo used in series.
The 3 states are 1) Supercharger by itself (low revs), 2) turbo by itself (high revs) and 3) the change over point.

Will there be any difference between an SC blowing into a Turbo vs the other way?

My view is that its more effcient to have SC>Turbo. Why? If a SC is 50% efficent and a Turbo is 70% (or just more than the SC) as the turbo begins to spoil to catch up with the SC, it needs less CFM than the SC needs for the SAME boost pressure, so the SC can provide the turbo with the air (as its trying to blow more) no problem, infact it will supply the turbo with more air than needed and so you will achieve a compound effect or boost pressure inbetween the SC and Turbo.

With Turbo>SC I would of thought the turbo cannot start boosting until it spins and sucks in more CFM than the SC needs so there will be no compound effect.

Clearly after these CFM points the turbo starts to need more air and the change over begins. But I am interesting in the point where the turbo starts to catch up.

What are the thoughts on this or I am way off?

Max

 

[patprimmer]

And these

http://www.eng-tips.com/viewthread.cfm?qid=163535&page=6

http://www.eng-tips.com/viewthread.cfm?qid=108188&page=2

http://www.eng-tips.com/viewthread.cfm?qid=137731&page=7

Regards

eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[thruthefence]

Check out this guy's toyota

http://www.geocities.com/MotorCity/lane/1231/page2.html

 

[5secondracing]

Here's one that will make you all scratch your heads, a centrifugal blower compounded into twin turbos. It works fantastic and there is no lag. Try 2000+ horsepower on 4.0 liters. Just thought this might shed a little light on an old post.

http://www.prologger.com/projectcar.asp