marc mularz wrote:

Paul,
Two questions that are at least slightly related to this post.
1.  Why does the Mazda run at such a high temp and egt compared to piston
engines?

My understanding is there is unburned fuel in the exhaust that was hiding
in the nooks and crannies of the combustion chamber. This fuel then burns 
in the exhaust manifold.  Perhaps the new side exhaust port engine will reduce 
this as it will tend to recycle the unburned fuel rather than sweeping it out
into the exhaust port. Another factor may be there is no exhaust valve to
absorb some exhaust heat.

2.  Under normal driving conditions (at 70 mph) what rpm does an RX-7
operate at?

As I recall my first gen RX7 manual TX ran around 4000 RPM but the power and
throttle opening was way down. I would guess the HP at around 30
at 70 MPH. It would probably get better gas mileage with an over 
drive and more throttle opening. Common in late car models. My 94 Cougar is
down around 2000 RPM at 70 MPH.  I have no idea what it is for second 
gen and third gen RX7's.

Paul Lamar
 
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