[Diy_efi] tiny injection

[Marc Reviel]

>Full size car centrifugals like Vortech, ATI, Paxton/NOVI and the like 
>expose the compressor to full atmospheric pressure at all times and have to 
>have a "bypass" system open most of the time, This wastes energy during 

Actually, it cavitates.  The "bypass" is not there to continually bypass 
s/c flow; it is there to 'blow-off' the large surge when the throttle 
plate slams shut.  The blow-off valve is always manifold vaccuum 
activated.  At least this is the way it is *supposed* to be designed. 
Some systems utilize a continual bypass for getting to max boost earlier, 
then blowing off the excess.

When the s/c cavitates, it is almost as good as being in a vaccuum.  The 
air near the impellor is swirling like a blender using very little power 
to do so.  Keep in mind, it's not moving the air, thus very little work 
is being done.  It works very well.

One thing we are working on is a dual throttle body set-up where a 
computer controlled t/b is placed before the s/c.  This approach allows 
the s/c to be sized much more aggressively for much earlier boost, as 
well as slightly more efficient operation.  (Recall that all these crank 
driven centrifugal s/c have a boost output linear with RPM - a 
disadvantage compared to exhaust-driven, or pos. displacement.) Like a 
wastegate function, except there is no "waste."




Marc Reviel
PowerLogix, http://powerlogix.com, co-owner/CTO
Forced-Air Systems of Texas, http://www.f-a-s-tonline.com, co-owner



_______________________________________________
Diy_efi mailing list
Diy_efi at diy-efi.org
http://www.diy-efi.org/mailman/listinfo/diy_efi