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by MattBearman 4238 days ago
As an RX8 owner (and enthusiast), I can tell you Wankel Rotaries aren't categorically better, or worse. They have strengths and weaknesses:

- The vast majority of rotaries will need a full rebuild before 100k - worse

- They rev to 10,000 RPM with an unbelievably smooth power delivery - better

- I'm lucky to see 22 mpg - worse

- The engine is so small and light that the RX8 has perfect 50/50 weight distribution - better

- If you turn the engine off before it's warm it can flood - worse

- 231 bhp from a 1.3 litre engine? - better

Oh, and the noise - BETTER!

I do believe with more time and money invested the Wankel Rotary could be better than a standard Otto Cycle IC engine in every way. But electric is the future now, so that won't realistically happen.
2 comments
phkahler 4238 days ago
You missed one - perfect balance. The CG of a properly designed rotary does not move. It's the reason it can rev so high. And flat torque across most of the RPM range is the reason for the power density since torque*speed=power you increase power by spinning faster. Oh wait, you did say smooth power delivery. It does go together with the others.
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IanDrake 4238 days ago
Learned stick on my second gen RX-7...

-Almost no torque at low rpm - worse

-Easy to flood, then once flooded major work - worse

-Feed it a quart of oil every 1,000 miles - worse

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MattBearman 4238 days ago
No torque at low RPM is true, but I've not found it to be an issue. I use the engine in the same way as I do on my motorcycle - pretty much always above 4000.

The flooding issue I mentioned. It may have been different with the RX7, but the RX8 has a de-flood procedure that works 9 times out of 10. And failing that a bump start usually does it. Although I've never flooded mine, I'm always careful not to shut her down cold.

Oil usage in the real world is not much worse than many other performance cars, in fact it's better than most Honda S2000s. But for people who are not used to having to regularly top up oil I could see it being a ball ache.

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IanDrake 4238 days ago
> I've never flooded mine

Neither had I...just never let a valet, mechanic, or relative try to start your old RX-7 ;)

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Sophistifunk 4238 days ago
We have a bunch of old rotary race cars in the showroom at the 9-5, you wouldn't believe how much noise and oil they put out the back whenever they need to be moved around :)

wank-wank-wank-wank-BANG!-wank-wank-wank-wank

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virtue3 4238 days ago
no torque at low rpm is pretty common among the smaller inline 4 cylinder japanese cars as well ( I really learned stick on my integra GS-R - 189hp 4 cylinder). basically if you don't keep the rpms up when you shift you're just pissing away acceleration power. It was probably more noticeable with the honda engine tho (that vtec).
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