RX8 engine or EJ20

[MinamiKotaro]

RX8 is $850, EJ20 is $950. Both are availabe through my work for a 20% discount. I understand the DOHC heads on the EJ20 will require some extra clearancing (or get some EJ22 heads). RX8 engine comes with all those wonderful Wankel quirks.

I'm ready to make the conversion plunge, talk me into (or out of) either one.

[jhoefer]

Rotary is going to run hotter so could need a larger radiator, larger oil cooler, and you'll have to deal with more exhaust heat. EJ is more common so you have more resources for help and knowledge. I don't believe you'd have much difference in the actual work involved with either one, any water-cooled conversion is going to be a lot of work. One consideration is what ECU you plan to use with each as one may be easier to implement from that angle.

[panel]

What HP do both come with? Also what are your HP goals?

[Piledriver]

All I can say is every single person I have ever spoken with that did a rotary conversion wishes they had put something else in.
They loved it when it worked...

I'm sure the RX8 motors are better, but if everything in the cooling and oiling system isn't absolutely perfect FIRST, plan on a second motor, and perhaps third.
They are absolutely intolerant of being overheated.

The RPM range and limited TQ of a rotary would make it great for a "normal" (not $5K) close ratio T1 box, which could save a ton of $$$.

I'd love to have one with boost in a 914, but I'd have to put the same cooling system in as a LS6...

If you can get together with someone who has successfully done the conversion in a reliable daily driver and learn from their mistakes, it might be viable.

[MinamiKotaro]

I hadn't considered the cooling issues of a rotary. Thanks to your posts, I did more research and decided to go with the EJ20. Besides, I found out the $850 RX8 engine was shortblock only. No accessories, intake, etc. EJ20 is full long block, so it's on the way! I like the idea of a rotary but I'm sure I'll be happier with the EJ20. Now I just need a twin-screw blower to stick on it.

Wish me luck!

I had found some "stock" fuel and spark maps for a Renesis to plug into MS, so that would have been nice, but I'm sure I can find something for a Subie. The RX8 supposedly has 212HP stock, not sure what an aspirated EJ20 will have, though I'm sure it will be about what the 2276 has (~130).

[WooleyNelson]

not sure what an aspirated EJ20 will have.

don't know about the EJ20, but a normally aspirated EJ25D was rated @ 155/165hp from the factory

[jhoefer]

Depends on the actual engine, but a normally aspirated EJ20 would likely be 120 - 150HP.