Rotary Development

[NoDOHC]

Originally Posted by classicauto

If you really wanted to do something experimental, try my next project.

300-350whp max, small turbo (T04-E 57 trim likely.....) with straight water AI.......................................on 87 octane. I don't care what type of block you use, but has to be low grade fuel. That's what I'm planning to do with my recently acquired FB, one day.......one day.

Turbo engines can be reliable. Certainly not as "bullet proof" (ie. as low powered) as an N/A, but don't think you can't just because people have problems....its no reason to stay under the 300whp mark

This sounds like a worthy project (not just pump gas but 87 octane - pretty strict).

Unfortunately, my experience lies primarily in the naturally aspirated engine building field. According to my friends, I should stick with NA. For that reason, I think I will avoid turbo projects until I see how high I can go with the NA build.

I wish you the best, for now I will leave the turbo-related development work to those of you who understand the reliability issues caused by turbos and I will work with the naturally aspirated engine, as I understand the potential failure modes on a NA engine.

Please don't misunderstand me as saying that NA engines are bullet-proof (meaning that they are low powered). I mostly am trying to say that I understand the few and logical ways that an NA engine can fail, while many turbocharged engine have given up the ghost for reasons that their owners can't even guess at.

There is no sense of foreboding or danger when I back my NA RX7 onto the dyno rollers. I tuned the engine based on my seat-of-the-pants guesses and ran again to see how that effected the power. I have run AFRs from 12.0:1 to 17.0:1 and ignition timing from 62 BTDC to 26 BTDC and have done my engine no harm.

If I had a turbo, I would be worried about my fuel curve, my fuel pump, my MAP sensor accuracy and my ignition map. I would be watching boost, fuel pressure, water temperature, IAT, AFR, etc. like a hawk during the entire run. With the NA engine, I watched the tach and datalogged.