Super charger and turbo question

[Louis-Alain_Richard at computerhorizons.com]

Louis-Alain Richard
Expert technique, projet Renault F2K
Horizons Informatiques
514.840.6274 




"John Larson" <j.d.larson at verizon.net> 
Sent by: quattro-bounces at audifans.com
2004-07-30 01:13

To
<laraa at sympatico.ca>, <quattro at audifans.com>
cc

Subject
RE : Super charger and turbo question






ScottyCBoy at aol.com said:
"Do I have the turbo's blow into the supercharger or do I have the
supercharger blow into the turbos?

Then Louis-Alain said:
You may want to contact Lancia, motorsport dept... They've built many 
rally
cars with such a set-up during the eighties (Delta S4, Rally 037). And 
they
were quite fast, IIRW..."

Then John said:
You might also look to Detroit Diesel.  They've been running engines with
compound turbo/superchargers for decades.......  John

Then Louis-Alain says:
You are absolutely right.
There is a former Detroit-Diesel guy here, and he says that these engines 
are blown and turbocharged indeed. These are 2-stroke diesel engines with 
4 exhaust valves per cylinder, intake ports in the bottom of the 
cylinders, pistons with rings at the top and at the bottom; strange but 
very nice design...
And the flow path is:
twin turbos blows into the supercharger, compressing the intake charge 
before the blower push it into the intake.
More, the blower is a vital part of these engines, because they wouldn't 
run it there was not more air than what the engine needs. Since the 
cylinders share a common bottom end, there wouldn't be any vaccuum to fill 
the cylinders. Hence the need for a blower to push the air trough the 
intake ports.

I'd love to see (and hear...) an Audi V8 with such a setup...

Louis-Alain