Thread: SC confused !
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      11-06-2012, 05:25 AM   #309
BimmerPost Supporting Vendor

Drives: Slow
Join Date: Feb 2008
Location: Luton, Bedfordshire

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Originally Posted by pbonsalb View Post
As you noted above, peak potential CFM on a compressor map does not mean the same power is made on all engines. It may well be that to the 550 rwhp range, the Rotrex and Vortech are pretty similar on the S65, but that does not mean they will necessarily be pretty similar after that. The compressor maps probably are not identical.

AA, for example, gave up on the Rotrex because it could not flow enough on a low compression S65. On the other hand, ESS has run the Vortech to 645 rwhp on a low compression S65.

It may well be that for more efficient stock compression motors making 550 to 600 rwhp, the Rotrex works just as well as the Vortech. We will have to see some dynojet comparisons at some point.

One thing I did not notice from the Rotrex C38-91 dyno comparison to the Vortech is any indication the big Rotrex has any torque advantage over the Vortech. I had been wondering whether the big Rotrex would sacrifice that. But daily drivability cannot be seen on the dyno, which is constant full throttle in one gear. Hopefully, on the road, the Rotrex offers some advantage over the Vortech.
We need more people like yourself on this thread.

Just to point out - the comparison can only be really done on setups where the overall efficiency of the system is similar.
Just a quick example - put the air filter at the back of an ESS kit and leave it open. Watch how the efficiency of the setup (not the Vortech) just takes a nose dive.
Put a HS Marstons 3000 intercooler on our Rotrex kit - see the efficiency go up.
Put a truck core in the place of our curent intercooler core - see it nose dive. More boost but less power because of the core quality rejecting too much heat.
Take the ESS kit and change the charge cooler core a really poor one with a high pressure and high heat rejection - you see the efficiency drop. Less boost and even less HP.

I hope people are beginning to understand what I am talking about now.

The C38-91 on the S65 comparison shows more HP being generated upto the red line. If it producing more HP at the same RPM's it is producing more torque.
I can post or send you the power vs torque graph of the same examples.

The very reason that one compressor behaves better in different situations is the reason we don't care about which blower we use. If we find an ASA (523) or Vortech to be better on really low compression engines then so be it, we will use it. It's pretty common knowledge now that the Vortech bracket/belt drive is already developed by us.