Renesis Conversion, Would I? Should I? Could I? Options

[The Kelzer]

OK here goes....I got this idea. V8 conversions are great, I drove one and liked the power, didn't like the added weight or the required tranny work and the un-exoticness of it all.....did LOVE the sound though.

Now having owned several RX-7's I LOVE that rotary engine and have had over 200K miles on each with NO problems whatsoever. The new RX8 "Renesis" 13B puts out wonderfully SMOOTH horsepower and torque that are well within the apparent tollerances of the stock 901 tranny. Not to mention it's a VERY light motor that loves to rev and is more powerfull than a well built 2.0 4cyl.

Has anyone done a rotary (12A or 13B) conversion?

Does anyone know where to get a tranny adaptor plate?

I tried contacting Racing Beat who are the rotary guru's but they have nothing yet. So basically I'm starting from scratch and any info would be GREATLY appreciated.


Aloha,
Kelly

[Brad Smith]

Thanks for the info soloracer. I went to Reddawg's site (which is embarassingly poor by the way) and also Kennedy Engineering (MUCH better). I sent them both e-mails asking about the conversion.

About your 20B motor where did you get it? How much was it etc.....

I'm open to all options as long as they are rotary related. I was drawn towards the Renesis motor for it's reliability stock over a built 13B (4 or 6 port). However, you're right regarding the cost difference. Maybe I should be looking at old 13B 6 port motors. Do they adapt well to carbs?
I'd like around 200hp or so and if I recall the N/A 13B is in the 145hp range.

Let me know your thoughts/links if you have any.

Aloha,
Kelly

Stock 86-88 13B 6 port (non-turbo in other words) is 146 hp. I picked up about 20 hp at the wheels (dyno confirmed) with just an exhaust and air filter change. (the stock stuff is VERY restrictive. ) That's with a 3" single exhaust WITH a cat, and a "cone" (i.e. K&N copy) filter. Losing the catalytic converter is probably good for another 5 and maybe even 10. (Stock 86-88 cars run about 110 at the wheels... I was putting down 130) NO other mods, although I was spinning it to 7800 RPM (right before the fuel cut.)

89-91 6 port motors have lighter rotors and more compression, and the manifolds are different. They're 160 hp stock. The "redline" is 8000 RPM instead of the 7000 rpm limit that I ignored on my earlier car. (IMG:style_emoticons/default/laugh.gif) They're actually good to about 9000 RPM in stock form, although it's not worth it as the power starts to fall off up high unless it's modded a bit.

Rotaries are finicky- yes, you can make good peak power numbers with a properly tuned carb, but the throttle response, driveability, and gas mileage will all suffer. (and as you know, rotaries are not "economy" cars to begin with!) Put an aftermarket fuel injection unit on there. A stock 89+ motor with a good tuneable fuel injection unit, header and free-flowing exhaust, and otherwise pretty stock should get you 180-190 hp with stock reliability, and lighter and more compact than a V8.

If you want to go turbo, I suggest staying with the earlier motors just because of expense. 275 hp at the wheels with a stock motor (not ported) is about the limit, and that will require a hybrid turbo. (stock hot side, perhaps clip the wheel a bit, and a T04 compressor section.) A little porting and a hybrid turbo will get you up to about 325 hp. (at the wheels) Beyond that you have to increase the cubic dollars quite a bit.

Brad