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I'm also running 87
octane, but now that you mention it, I'm wondering if I should run 91.
I have the stock low compression (turbo) rotors in mine, so I "assume"
that 87 octane is OK. I'll be interested to see what kind of feedback
you get on this.
I'm not sure what Mazda
required for the 2nd gen turbo, but I would never even think about
running 87 octane in a turbo rotary. I know that the FD required
premium, and they weren't kidding. I'd bet that using regular 87
octane fuel probably killed more FD engines than anything else. My
advice would be to immediately switch the the highest octane you can
get, particularly John, since he's running higher boost levels. Also,
make sure you keep the mixture quite rich during boost time.
John, since everyone's
picking on your prop, I guess I'll pile on. Remind me again why you
want this oversize prop? Are you trying to set max speed cruise at
some low rpm like 5000? On the list of safe ways to increase power in
a rotary, running higher rpms is probably number 1, and turbo charging
is waaaaaaay down there. I think you'll be much safer with 7000 rpm,
and minimal boost, vs 5000 rpm and lots of boost.
I believe Ed has mentioned
before that you can't just look at the top power number when setting up
a prop for your engine. The rotary doesn't produce a ton of power at
low rpms. (Lots of made up figured follow) If you told Clark that you
would be making 250 HP at 6000 rpm, then I'm sure he would be able to
make the prop correctly for that amount of power. The problem is that
the same prop might require 150 HP to turn at 4000. Even with a turbo,
the rotary probably will have trouble making that due to the low RPM.
In other words, your prop might be just right for max power, but "you
just can't get there from here".
Cheers,
Rusty (probably raining out
my engine run)