In traffic a few minutes ago, had a third gen RX7 in front of me. Choppy idle, bunch of guages on B pillar and dash, 4" fart can, goofy looking wing, bright "Arrest Me" red paint. Whay intrigued me was his Florida license plate- 3rotor. I'm not a rotor head, but I thought they were 2 rotors. Is this possibly real or another ricer poser?
20B (Three rotor) came in the non US Cosmo (a sport coupe). Quite possible it was real, choppy idle is odd unless it had a MASSIVE port job.
yes they are rare in the US.. but there are a handful or so here.
So it is possible that he went to a JDM importer for his? Again, this is Florida, Land Of The Free.
FD was never factory optioned with a 3 rotor. What you saw was a cu$tom conver$ion.
There are a few of them running around the country.
Pettit Racing in Florida performs 3 rotor conversions.
http://www.pettitracing.com/
Several people can supply the hardware you need to build a three rotor - the main piece you need is the longer eccentric shaft to carry three rotors instead of the usual two. The rest just builds up in the usual rotary layered cake fashion. And yes, they tend to sound choppy at idle, like a V8 with a really hot cam that doesn't want to idle. They all do that, even though they're idling smoothly.
Over here one of the rotary specialists (Carl Hayward) has a three-rotor in a 1st gen RX7 running on downdraughts. Matt black, or at least it was the last time I saw it. Sounds pure evil at idle.
Hmm.
I think I need another rotary in my life but not with the fuel prices we've got over here. Offloaded both my restored FC Turbo II convertible and mildly tuned FD last year...
Tim, Three rotor engines were built by Mazda as stated they were labeled as 20B, in fact one powered the 787B to win LeMans. The only thing you have to do is find one at an importer or buy it off a forum and install it, just be sure to get all the wiring, sensors and computer.
They used to build PP 3 rotor sports sedans in Oz to race against the big block cars.
http://www.youtube.com/watch?v=D8K9RGUF3Bo
http://www.youtube.com/watch?v=xbKtHL06xmQ
http://www.youtube.com/watch?v=wkPRTOL82uA&feature=related
Yeah from what I understand there is something of a limited supply of them these days, but I've seen a few. Some guy in Morgantown showed up at the street races back when I was in college with a 3 rotor claiming over 450 hp and over 300 ft lbs of torque. It sure was a monster... very fast, very evil sounding car.
Wasn't there also a 4 rotor at some time for the prototype racing series?
if someone wanted to be clever and just start manufacturing the center shaft in 12a and 13b rotor sizes, I should think there'd be money in that.
aussiesmg wrote: Tim, Three rotor engines were built by Mazda as stated they were labeled as 20B, in fact one powered the 787B to win LeMans. The only thing you have to do is find one at an importer or buy it off a forum and install it, just be sure to get all the wiring, sensors and computer. They used to build PP 3 rotor sports sedans in Oz to race against the big block cars. http://www.youtube.com/watch?v=D8K9RGUF3Bo http://www.youtube.com/watch?v=xbKtHL06xmQ http://www.youtube.com/watch?v=wkPRTOL82uA&feature=related
The 787b used the 26b four rotor engine from heaven. Infinitely variable intake, three plugs per rotor, 800+hp peripheral port.
Check out the SpeedSource GrandAM three rotor PP RX-8 videos on YouTube for pure sekz.
belteshazzar wrote: if someone wanted to be clever and just start manufacturing the center shaft in 12a and 13b rotor sizes, I should think there'd be money in that.
Kiwi and a few others make aftermarket 3 and 4 rotor e-shafts. The limited production runs mean they retail >$2k.
Wonder what those things weigh? Lot's of HP/#
RX7 guys call the 3 rotor 20b "heavy." I don't know what heavy is in rotary terms, but supposedly heavier than a well dressed lsjuan.
aussiesmg wrote: Tim, Three rotor engines were built by Mazda as stated they were labeled as 20B, in fact one powered the 787B to win LeMans. The only thing you have to do is find one at an importer or buy it off a forum and install it, just be sure to get all the wiring, sensors and computer.
Yes, I'm aware of the 20B in the Eunos Cosmo, I've actually seen a few of those in the flesh and nearly bought one 
a while back.
My point is that you don't need to cannibalise one of them (they're a rather rare car) as you can get the bits to build a 20B (or an 18B) from various other sources than Mazda.
cwh wrote: Wonder what those things weigh? Lot's of HP/#
... and scary fuel consumption if you drive it WOT.
Define scary.
Even deeper into single figures compared to an FD. Not fun at around $7/gallon that we pay over here for fuel. IIRC the Cosmo is around mid-teens.
Might not sound too bad if you're in the US but it's a heck of a lot given our fuel prices.
We are now at 2.50/ gallon today. Lot's better than 4.00 in the not too distant past. We must remember those days. Are you saying that an FD got less than 10mpg?
The exhaust noise of an uncorked 20b is a beautiful thing.
Strangely enough fuel's been going up quite considerably here over the past few months and we've just had another fuel tax rise that puts unleaded (the equivalent to regular) over £1/litre. Of course the good stuff (97RON or higher) is over £1.10/litre.
Easiest way to get an FD into single figures is to take it on the track - if that doesn't get you into single figures then you're not trying hard enough . Normal consumption (adjusted for the smaller US gallon) would be around 15 I'd say so it's similar to the Cosmo at that point. Open the throttle on the Cosmo in the same fashion you do on the FD and it'll start gulping fuel like it's going out of fashion.
andrave wrote: RX7 guys call the 3 rotor 20b "heavy." I don't know what heavy is in rotary terms, but supposedly heavier than a well dressed lsjuan.
Yes, yes it is. Rotary engines aren't light, they're compact, which artificially gives the vehicle they power the advantages of a light motor in terms of weight distribution and rotational inertia. Every somewhat reliable source I've come across says Turbo 13Bs weigh about the same as a 5.0, and LS1s are lighter than that.
Not to mention just buying a JDM 20B is expensive in the first place. I haven't seen an engine importer list a 20B for less than $4000.
Feedyurhed wrote: Wasn't there also a 4 rotor at some time for the prototype racing series?
Dunno about that. I have seen this 4-rotor FD from SCOOT of Japan making the rounds on the t00ner boardz. The engine is made from two 13B-REWs put together and the bodywork is so wild, it's hard to tell it was an FD in the first place. It is nasty... in a very good way. Enjoy.
It sounds like an avalanche of Husqvarna 2 stroke chain saws rolling down a mountainside while tearing through pristine wildlife filled forests.
Truly the sound is magnificent.
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