In reply to Appleseed :
Custom setups. Custom machined e-shafts, flywheels and center plates. Racing Beat had a 4-rotor for sale for $40,000 a while ago, I don't see it on their site anymore.
As far as parts go, there are a few places that are starting to re-coat rotor housings, so there is hope. It's not cheap by any means. There are some billet rotaries out there too, but the prices on that stuff make the RB 4-rotor seem reasonable.
Appleseed said:I know 3 rotors came from the Cosmo. Where do 4 rotors come from?
SOME 3 rotors came from the 4th-gen Cosmo. It was an optional engine, not standard, standard was a twin turbo 13B that was different from the FD RX-7.
Probably most 3 rotors were 13G engines straight from Mazda for circuit racing. They broke from the Mazda naming convention of centiliters of displacement per revolution combined with a letter suffix that had nothing to do with engine family. The 13G was a peripheral port 3 rotor that shared rotor dimensions with the 13B, and is quite a bit older than the 20B. (Note that means the 20B is the second 2l-per-revolution rotary, so it's B)
(yes, there was a 13A. It was completely unrelated to the 10A/12A already in production, so when they stretched the 10A/12A another 20mm longer, they called it the 13B. The 13A is so rare that apparently the first-generation Luce that Mazda has in their company museum does not have an engine in it)
The 13J was the four rotor version of the 13G. It too was a racing only engine. The 26B was an evolution of the 13J... notice that it's a "B" engine, it's the second type of that displacement... probably more a coincidence than anything.
Not too long ago you could still buy 13Js and 13Gs from Mazda, it appears that they are all gone. Now you have to build your own around 13B parts and some one-off bits.
I still think engines over 2 rotors sound bad, but that doesn't mean I don't appreciate the fangle factor in making something like this:
20B, 26B, and 39B(???) eccentric shafts, from .au, where else?
https://www.billetrotary.com.au/eccentric-shafts
From what I've seen, Mazda still produces brand new 13B-REW engines from time to time in small batches. Occasionally you can find a vendor who scoops up a bunch when this happens:
http://www.irperformance.com/product/13brew-mazda-new-engine-93-rx-7/
It’s probably because pushrods V8’s are so prevalent but boy do Rotary engines intrigue me!
In reply to Armitage :
Gosh darn it. Not challenge friendly.
Outside of rotor housings and rotors themselves, although I’ve seen some billet ones getting closer to production, are the only pieces left not being made in the aftermarket.
39b is a six rotor. What was the dyno number on that, 700rw?
The aftermarket is getting pretty close to the economic breakpoint where it's going to make sense to roll their own rotors and housings. Billet Rotary and Billet Inc already have a good install base of the front and end plates, Mazdatrix was experimenting with billet rotors back in 2010.
PAC Performance has basically everything else required for early RX cars. Shipping isn't cheap though.
Also remember this exists: https://www.youtube.com/watch?v=Ay9pTLa3mSE
And never forget this hero (Smith Power)
2400 HP Turbocharged 12 rotor for offshore racing.
https://www.youtube.com/watch?v=KBOGCljbLsA&feature=youtube_gdata_player
Appleseed said:I know 3 rotors came from the Cosmo. Where do 4 rotors come from?
swiss bank accounts
They'll have to be running out of old Mazda sedan bodies soon at the rate they're using them up. Insane horsepower.
Used to race with RX powered sports racers in practice - needed earplugs to be beside them. They were the only cars that you could track by ear all the way around the 3 mile track, sitting in the stands.
These guys have obviously solved the issue of lack of low rpm torque - always drive up at red line!
In reply to TheRX7Project :
I'm still trying to figure out if Racing Beat actually manufactures their own aluminum rotor housings or what. They're not cheap by any means but they exist, which is the important part for when the OE supply eventually dries up.
There's a couple of companies out there that'll rechrome the rotor housings. They're about 1/4 of the price of new housings which is a freaking bargain if true. I was actually looking into them recently.
The real danger is corrosion in the cooling wall seal. There really isn't a fix for that as far as I know, though I wonder if they could be machined and sleeved. I doubt it since I can't be the first person to think of that.
Did I see some people in there NOT wearing ear protection!!!!
"you can never have to much HP or too loud of an exhaust"
"... uhm, we need to take a quick trip to Australia"
Maybe it's just me, but if all types of drag racing where like that it would be a LOT more interesting to watch.
The0retical said:
2400 HP Turbocharged 12 rotor for offshore racing.
https://www.youtube.com/watch?v=KBOGCljbLsA&feature=youtube_gdata_player
Yeah, but you need 1000 of that HP to tow the fuel barge behind you!!!
In reply to aircooled :
When drag racing becomes as much as “will it make it down the track on 4 wheels?” As much as how fast, it’ll be much more entertaining!
In reply to ebonyandivory :
When there is 4000hp on board, I’ve seen some passes where the only time it’s on 4 wheels is when it’s staged waiting to launch.
Ive seen multiple tripped the timing beams on the rear wheels before too... oh at 190-200mph in the 1/8th...
In reply to Ranger50 :
I actually meant that the cars wouldn’t be sliding down the track on thier sides after hitting the wall but carrying the front wheels through the 1/4 is nothing short of amazing
Ranger50 said:In reply to Armitage :
Gosh darn it. Not challenge friendly.
Outside of rotor housings and rotors themselves, although I’ve seen some billet ones getting closer to production, are the only pieces left not being made in the aftermarket.
39b is a six rotor. What was the dyno number on that, 700rw?
Pretty sure that Logan's 4 rotor made close to that.
The0retical said:In reply to TheRX7Project :
I'm still trying to figure out if Racing Beat actually manufactures their own aluminum rotor housings or what. They're not cheap by any means but they exist, which is the important part for when the OE supply eventually dries up.
There's a couple of companies out there that'll rechrome the rotor housings. They're about 1/4 of the price of new housings which is a freaking bargain if true. I was actually looking into them recently.
The real danger is corrosion in the cooling wall seal. There really isn't a fix for that as far as I know, though I wonder if they could be machined and sleeved. I doubt it since I can't be the first person to think of that.
Racing Beat does not make rotor housings, they make side housings. They are aluminum, run something like $1500-2000 each, and intake ports are optional.
IIRC nobody is rechroming rotor housings. There are people who smooth out the chrome, but this does not help if you have a 12A with half the chrome gone. If there ARE people rechroming, then I have a waist high stack ready to be redone.
The real problem with the billet junk on the market is that it is oriented for drag racers who want to make power for six or seven seconds. Not road course or street friendly. The water jackets in the billet rotor housings and side housings that I have seen were laughable.
AClockworkGarage said:There is nothing you can do to make a rotary sound good,
add RPM, over 9k they start singing
Appleseed said:I know 3 rotors came from the Cosmo. Where do 4 rotors come from?
I'm pretty sure you can stack as many rotor housings and center plates as you want as long as you can make an e-shaft made for it.
There is a running and driving RX4 with a 6 rotor in it
Appleseed said:They drove fuel altereds in the 60s. This is a full bodied equivalent.
Amazing I WAS thinking the Exact same thing. Damn things prob. make the same power. AA/FD is credited with the first 200 pass but I've heard Willie Borsch was first at Bakersfield with his AA/FA AND DID QUALIFY IN THE MIDDLE OF THE FIELD 8TH OF AN ALL DRAGSTER SHOW IN 64.
edizzle89 said:Appleseed said:I know 3 rotors came from the Cosmo. Where do 4 rotors come from?
I'm pretty sure you can stack as many rotor housings and center plates as you can as long as you can make an e-shaft made for it.
There is a running and driving RX4 with a 6 rotor in it
O. M. G. 
The0retical said:In reply to TheRX7Project :
I'm still trying to figure out if Racing Beat actually manufactures their own aluminum rotor housings or what. They're not cheap by any means but they exist, which is the important part for when the OE supply eventually dries up.
There's a couple of companies out there that'll rechrome the rotor housings. They're about 1/4 of the price of new housings which is a freaking bargain if true. I was actually looking into them recently.
The real danger is corrosion in the cooling wall seal. There really isn't a fix for that as far as I know, though I wonder if they could be machined and sleeved. I doubt it since I can't be the first person to think of that.
from what I've noticed with the "re-chroming" is a bit of a lie. they don't add to the surface they cut the surface to make it smooth again but if you have heavy gouges and chrome flaking at the ends its not going to fix that. but it is literally is half as much as new housings so if you have some borderline ones should be fine.
Appleseed said:I know 3 rotors came from the Cosmo. Where do 4 rotors come from?
People who make their own eccentric shafts who find ways to mate the other rotors together. I know of at least one 4-rotor where the creator detailed CNC'ing the shaft and the engineering involved- it was pretty extreme.
yupididit said:Okay a few points:
That burnout at 10:10 was a top 5 burnout I've ever seen.
I love crazy rotarys in little cars. Those cars were like baby rabbits on cocaine with a hive of bees up their ass.
I absolutely loved how these untamed beast still had beautiful body work knowing they could hop into a wall any second.
What's the lightest rwd car you can buy here in the states?
How much power can one extract out of a NA 13B?
Don't know about *lightest* car, though it's probably just under a ton for oddball 1980s toyotas and such. The 1980s Starlets were around ~1900 pounds wet, but they were front-wheel only.
As for power? I know you *can* hit 400 or more from a 13B, but at that level you had to hog out your intake ports and you effectively have no idle. You'll also have to remove the oil metering pump in exchange for premix in the tank, but that's more for reliability at that speed.
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