Leon Promet wrote:

Howdy Paul,

What's with the 20 PSI BOOST?  Don't you mean 20 PSI MAP (Manifold Absolute
Pressure)??

Maaaaaaaaaaaate,  20 PSI BOOST;  that's 460~480 Clydesdales at sea level.

Yep your right 5 psi boost. 20 psi map.  Brain fade. PL

Just for your benefit Barny,  have a read of a post I made a few days ago.
 Topic was "Exhaust Temps & Power Outputs and Water Injection was RE: small
vs large  turbo"

I've attached a copy if you don't have it or can't find it.

To summarise,  the secret of making grunt,  and getting good BSFC is to run
the highest compression ratio possible (consistent with the octane rating
of the fuel),  and therefore you will need less boost to get the SAME BHP.
 If you want more BHP,  you just turn up the boost,  or rev it a bit
harder!!

A stock '89 turbo engine makes 255 BHP with 8.5:1 rotors.  .  The later
model FD '92~on REW engines come standard with 9.0:1 rotors and make 275
stock,  blowing thru a pair of cats and some mufflers!!  I will personally
be running 9.7:1 rotors in my 13B REW '92~on FD engine

Based on experience in road cars,  I expect to get well in excess of 300
BHP @ 5,700 RPM with about 5 PSI boost (20 PSI MAP) at sea level,  and will
get much better BSFC at part throttle cruise because of the higher
compression ratio.  Only extensive dyno time and practical experimentation
will tell.

I will also use a decent size intercooler,  and water/alcohol injection, as
I intend to be able to increase the boost well above 5 PSI for short
periods for aerobatics and emergency climb. Works fine in a car,  but I'm
currently working out the control details for aircraft use. Setting up
separate throttle and manifold pressure controls. The engine management
system takes care of the fuel and ignition requirements.   I  will be
extensively testing it in an airboat before risking my butt in the air.

Rotary engines are different to reciprocating engines.  All the details are
in the attached post.  One impotent thing with turbocharging rotary
engines:  you have to STOP thinking like it was a rod wholloper (quaint
Aussie expression for a reciprocating piston engine) with pistons that
melt,  valves that burn,  and cylinder heads that crack, bearings that
pound out,  rods that break etc.  Totally different animal is the Wankel..
 The only thing that is a bit fragile are apex seals, but only if the
engine detonates.

Detonation is an apex seal killer (and yes, you can buy stronger apex
seals, ... for a price, ... from  Hurley Motors in England or the Iannetti
ones from Mazda Comp in the USA).   However,  if the engine is detonating,
 it ain't tuned right,  or the charge air is getting too hot,  or it is
being run too lean for the boost!  Keep the engine cool,  use an accurate
fuel injection/engine management system  that responds to changes in inlet
air temp,  water temp,  boost  etc,  run conservative advance/retard curves
 and some water/alcohol injection at high power settings,  and the engine
should never detonate.

Best wishes and kindest regards,

Leon Promet
leon@promotorsport.com.au

 
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