I think I’m going to buy the used 20b I posted about a couple weeks ago.  But over the weekend I read that a stock Renesis engine makes 250 hp and can easily be tweaked to hit 300.

 

So my question, before I commit myself to the 20b, is whether people recommend bumping up the horsepower slightly on a Renesis (lighter engine so less hp somewhat offset by weight reduction) rather than using a 20b.  I haven’t seen any recent discussion on this and couldn’t find anything in the archives, but I’m sure it was covered at length at some point.

 

Is the Renesis a candidate for an ES?

 

Thanks,

 

Michael McMahon

Lancair ES

The HP numbers for the RX-8 were reduced from 250 HP after early owners dynoed their cars and got a lot less than advertised power. Mazda bought back some of the cars, and started advertising HP in the 230 range. The automatic version is less HP than the manual shift models. Those HP numbers are produced at well above 8,000 RPM.

 

In an aircraft about 6700 RPM is the limit to keep the prop tips subsonic, so a 2.78:1 reduction gives you 2410 prop RPM. Like a piston powered aircraft. So 24 inches and 2,400 RPM sounds normal. In stock form the engine can stand much more RPM so a smaller three bladed prop and more revs can go faster. I wouldn't count on more than 200 HP continuous at 6,500 RPM from two rotors. The three rotor would be 300 HP so installed.

 

That 300 sounds a bunch better to me. Copy the intake system from Mistral or buy theirs.

Reduction and controllers from Tracy.

 

Lynn E. Hanover