818 Mazda Rotary?

[Hayai]

(Flame prevention suit) Yes, I know the chassis is specifically designed for the Subaru Boxer 4, and no, I dont know what would be required to pull this swap off. This is just a bit of fun speculation. (/flame prevention suit)

I've been thinking for awhile now that a Rotary engine would be a great engine for the 818, specifically the 13B. I think the sound of the engine and the high revving nature would be just right.

The I found this on Speedhunters. (http://www.speedhunters.com/2013/01/rotary-buzz-re-amemiya-20b-europa/)

They have a Rotary in a mid engine position, using an adapter plate to bolt to a Subaru transaxle. I think the 13B would be short enough to still fit in the engine bay of the 818, and would be REALLY light. What do you guys think?

[riptide motorsport]

I think Its a fantastic idea.

[Mechie3]

Rotary turbo would be cool. Three rotor turbo would be amazing.

[Hayai]

Yeah, an NA 3 rotor with individual throttle bodies would be amazeballs, but I'm afraid it would be too long to fit, 2 rotor with a single turbo would still be great.

[Erik W. Treves]

yep...go for it!!!

[PhyrraM]

I would wager that a fully dressed rotary (esp turbo) is no lighter than the Subaru EJ series motors.

I think the N/A RX8 motor would be the sweet spot for the 818. The reduced torque (offset by the high redline) would actually work to make the Subaru transmission last longer.

In any case, I think a clutch and bell housing adapter kit is already commercially available, so only motor mounts to the chassis would need to be fabricated.

[Hayai]

Good to know clutch and bellhousing adapter are available. I dont think engine mounts and exhaust would prove to difficult; I think the biggest headache would be figuring out a wiring harness solution. I think I'd end up having to go with a Mazda harness instead of a subaru. Or just use the subie harness for lights/chassis stuff, and go standalone for the engine.

[Hayai]

That's a good sound.

http://www.youtube.com/watch?v=Q-0BjrIq0ws

I should mention that I'm an Audio Engineer. I place a much higher priority on sound than most people do, and I think about and interact with it in a different way. The Subaru Boxer 4 has a very distinctive sound, and it's a good sound, I like it. But since I've seen the 818 I havent escaped the feeling that I want it to make a much more higher pitched, almost raspy tone. I quickly figured out that a rotary spinning away a 9k-10k rpm is pretty much the sound I want coming from the 818.

[Flamshackle]

A brilliant engine configuration and option for the chassis I agree. Just a bunch more stuffing about to make work BUT DO IT!!!

[oki-ra]

I have a buddy out here in Okinawa that wanted to do that since I showed him the 818. Overall I think it would be awesome so go for it

[longislandwrx]

http://www.kennedyenginc.com/Pages/default.aspx makes an adapter.

[rjh2pd]

One thing to keep in mind is the height of the engine. I know the subie engines aren't tall since they are boxers, but I have no idea about the rotary engine. Just something to think about.

[Mechie3]

Make it wound like a Furai. :drool:

[Turboguy]

.......and it's a good sound, I like it. But since I've seen the 818 I havent escaped the feeling that I want it to make a much more higher pitched, almost raspy tone. I quickly figured out that a rotary spinning away a 9k-10k rpm is pretty much the sound I want coming from the 818.

How about this?

Here is a clip of a newer EZ30 (Subaru flat-6) that was transplanted into a Porsche 914:


http://www.youtube.com/watch?v=MAfQMPtz2-k

[Nuul]

I can't really tell from this pic but it does look a bit taller than an EJ to me.

http://i.imgur.com/hIq7mAr.jpg

[Niburu]

you could probably find a Renesis motor from an RX8 about as cheap as you're going to find a running TII motor
with the same power and without a turbo needed

this is a serious conderation for me as well
I've gone through 2 FC's and an FD
I'm still a rotard at heart

[longislandwrx]

I have a NA 13B in my garage with a cracked apex seal/scored housing. It was supercharged and putting out serious power when the seal let go. Needs to be put back together. I'd sell it to you for $30 if you were local.

I think a camden supercharger on a ported 13b would be awesome in this car and would require hardly any wiring. Just as low as an ej20 with a side mount blower.

[Hayai]

Turboguy: I've seen that video before, yeah the EZ30 sounds really nice :D It's another option I've considered.

Nuul: Do you think moving the intercooler would help with the height problem on that engine? if nothing else a Renesis would do well, ditch the intake and go individual throttle bodies.

Niburu: Glad to see you're also a rotary fan, you're experience in owning them will be very helpful. I've wanted an FC or FD for awhile.

Longislandwrx: Thanks for the offer, but I have a lot of student loans to take care of before I start this project. Plus i'm getting ready to move and cant take on more stuff.

[rschoeni]

Link to Diasio 962R 2 Rotor Renesis Turbo:
http://www.youtube.com/watch?v=hxw6cIkVbBg

From the Diasio.com website: "The D962R Turbo has all the features of the standard D962R, but adds a Garrett G35 Turbo, Turbosmart 50mm external wastegate, intercooler, and larger primary injectors. The engine produces 435 bhp, and 235 lb-ft of torque at only 9 psi of boost. This means that the engine retains its reliability while producing 181 more horsepower than the standard Renesis D962R motor. The weight of the car is 1440 lbs.; that is a 3.4 lb/hp ratio- a truly awesome number!"

Zoom Zoom:cool:

[Samiam1017]

I had a formula car with a 3rd gen rx7 engine in it. Made about 450 hp in a 1600 car. That was a little fun to drive. Man I miss that car!

[Niburu]

the big downside for using the 13B-REW is it's relative rarity also stock to stock the Renesis puts out the same power without the turbo
the 13B-REW does have way more potential with it's turbos, I would be sorely tempted to go single over the pre 99 twin set up though

[Xusia]

I could listen to the EZ30 all day long. MAN, I love the sound of that!

[riptide motorsport]

This is what it should sound like!!!

http://www.youtube.com/watch?v=_jqEyAIRR1c

http://www.youtube.com/watch?v=_jqEyAIRR1c

[Turboguy]

This is what it should sound like!!!


http://www.youtube.com/watch?v=_jqEyAIRR1c


yeah! That sounds SCHWEET!

[Turboguy]

Kind of reminds me of the Jim Downing Kudzu Mazda's that used to run in the American LeMans series:


http://www.youtube.com/watch?v=YhHRloPwVM0

[Vman7]

Ich frage mich, ob Felix Wankel je gesehen habe so etwas wie dies geschieht.

I can just here Felix Wankel if he was still alive and looking around his shop saying, "Wo zum Teufel ist der Wankelmotor"

[Exidous]

Absolutely no flame suit needed. I currently own a FD RX-7 and while I did swap in an LS motor for MPG and ease of service I would 100% consider using the 13B at a motor for the 818. The main reason for my swap was I daily drive mine and needed something worry free but a blast to drive. The 818 with a N/A PP 13b or seq 99 spec twin rew would just be nuckin futs. Just the idea of a 10k rpm rotary in the 818 has revived my interest in the 818. :-)

[Joe Scott]

Funny how this is posted and talked about, we have been toying this idea here in the tech room for about a month now.

Joe@FFRtech

[metalmaker12]

I personally like the sound of the rotary at like say 10-12k. I also like a ej207 revving to 8k. It has that rumble and raspy high end whistle. Wicked cool idea and go for it

[Hayai]

I'm glad you guys are so supportive of the idea. Sadly, it's going to be a few years before I can think about this project (student loans :( ). Which is okay, because it will give me time to sift through the tons of possible ways to go with this idea. Reading this thread, it seemed like the RX8's Renesis would be the way to go for the NA simplicity, but after reading this thread (http://www.rx8club.com/rx-8-discussion-3/newbies-guide-modding-rx-8-a-233937/) it looks like there's really not much power to be made past stock while maintaining NA due to the exhaust ports. The RX7's engine seems more mod-able, but with the added weight and complexity of the turbo system. Decisions, decisions.

[leetfade]

Hmm... I have an FD and an extra 13b laying around.... Now I just need more friggin money to make this happen!

The height of the 13b block is actually less than the EJ. It's the ridiculous rats nest of solenoids (first thing to go on my FD) and then the intake on top of that which create the additional height. As far as weight, though. I am amazed how much that little 2 rotor bare block weighs.. Geesh. I pulled the extra out of my buddy's trunk and that was a friggin chore!

A PP NA 13B-REW with older gen rotors (NA for more compression) with ITBs would make a heck of an auto-x car... Go 13B-REW with big single GT35r (or greater) and you'd have a crazy track car!

[Turboguy]

Guys with more rotary experience can probably shed more light on this, but I recall reading that modified rotary engines can be a bit spendy (as the Brits would say) to keep on the track -- frequent expensive rebuilds you have to contract out, etc.


Could make for a nice, compact, low weight alternative for someone looking for more revs and a unique exhaust note, along the lines of what a late-model Subie H-6 offers.

[thestigwins]

If you guys want high revs... Huyabusa engine? The 818 is light enough.

[Samiam1017]

I remember needing to replace apex seals after over heating mine. Didn't take much to cost a lot to repair

[Darkpiggy's dad]

I found a Chart under the heading 'Motor Weight Comparison' at a website for Funco Motor Sports. Their vehicles are rear engined sand cars. They claim to have weighed several engines over the years at the point where they were ready to install. The engines As weighed included: "headers, big air cleaner and plenum, power steering pump, turbo and inter cooler (where noted), transaxle adapter, flywheel, clutch and pressure plate". Here are their Mazda and Subaru engine weights.

Subaru 2.5L N/A 285lbs. Motor mounts weigh 4lbs.
Subaru 2.5L Intercooled turbo 320lbs. Motor mounts weigh 4lbs.
Mazda rotary 2 rotor 285lbs
Mazda rotary 3 rotor 480lbs

There are a few more engines included in their list.

[Flamshackle]

If you guys want high revs... Huyabusa engine? The 818 is light enough.

No it really isn't light enough. Check out Z-Cars in the UK for some awesome Busa mini's that weigh around 600KG. Adding 200 KG will make the 818 a slug with the Busa motor when compared with the WRX engine.

Anyway check out this little ripper made right here in Aotearoa!

http://www.7tune.com/video-ppres-6-rotor-beast-is-alive/

[Niburu]

Guys with more rotary experience can probably shed more light on this, but I recall reading that modified rotary engines can be a bit spendy (as the Brits would say) to keep on the track -- frequent expensive rebuilds you have to contract out, etc.
.
turbo versions if you manage to damage the turbos can be spendy
just about everything else is replacing seals

as with anything automotive if you are going to contract out for motor repair it'll be expensive

rebuild kits range from $350 base to $1700 master rebuild ($2200 if you manage to find a 3 rotor 20B)
http://www.atkinsrotary.com/index.php?pag=5

with the NA motors as long as you don't overheat it I wouldn't worry about rebuilds

[Xusia]

If you guys want high revs... Huyabusa engine? The 818 is light enough.


No it really isn't light enough. Check out Z-Cars in the UK for some awesome Busa mini's that weigh around 600KG. Adding 200 KG will make the 818 a slug with the Busa motor when compared with the WRX engine.

Anyway check out this little ripper made right here in Aotearoa!

http://www.7tune.com/video-ppres-6-rotor-beast-is-alive/

I was also thinking it really isn't light enough. The Hayabusa engine certainly puts out enough HP, but is comparatively low on torque which is important because of the additional weight (when compared to a motorcycle). I'm sure you could get it to work and drive the 818, i just think the performance and longevity of the engine/transmission would be poor.

[Xusia]

Could make for a nice, compact, low weight alternative for someone looking for more revs and a unique exhaust note, along the lines of what a late-model Subie H-6 offers.

From my perspective, the H6 engine thread seemed to get a fair amount of negative comments ("turbos are better," "you'll get more HP out of a turbo H4," "There are more tuning options available for a turbo engine," etc.), but I've not seen any such comments here. It just seems funny to me that a non-turbo SUBARU engine is panned, while a MAZDA rotary engine swapped is welcomed!

For the record, I don't have a preference. N/A H4, turbo H4, H6, 13B, Hayabusa, whatever. Use what you want...

[Hayai]

but I've not seen any such comments here. It just seems funny to me that a non-turbo SUBARU engine is panned, while a MAZDA rotary engine swapped is welcomed!

Which surprised me a little, I totally expected the same attitude a lot of people took with the H6, which is why I started with the "flame prevention suit" paragraph. haha.

I'm also totally behind people doing the H6 swap, I've been watching that thread and think it will be a cool idea if it fits okay.

[Turboguy]

turbo versions if you manage to damage the turbos can be spendy
just about everything else is replacing seals

as with anything automotive if you are going to contract out for motor repair it'll be expensive

Actually, if you deal with a good re-builder like ADP, turbo maintenance costs are pretty minimal.

I've heard that DIY seal replacement on a rotary typically lasts for 1 drive around the block and that of all engines, they are ones that absolutely require a professional rebuild. Is this not the case?

[STLMARSHALL]

I found a Chart under the heading 'Motor Weight Comparison' at a website for Funco Motor Sports. Their vehicles are rear engined sand cars. They claim to have weighed several engines over the years at the point where they were ready to install. The engines As weighed included: "headers, big air cleaner and plenum, power steering pump, turbo and inter cooler (where noted), transaxle adapter, flywheel, clutch and pressure plate". Here are their Mazda and Subaru engine weights.

Subaru 2.5L N/A 285lbs. Motor mounts weigh 4lbs.
Subaru 2.5L Intercooled turbo 320lbs. Motor mounts weigh 4lbs.
Mazda rotary 2 rotor 285lbs
Mazda rotary 3 rotor 480lbs

There are a few more engines included in their list.

Add the aluminum LS1 to the list. Mine weighed 391 lbs with Fidanza fw, coils, intake and wire harness. For the extra 70 lbs I would take the LS1 that made 400 HP bone stock. Not sure it would fit though.

[jkrueger]

Actually, if you deal with a good re-builder like ADP, turbo maintenance costs are pretty minimal.

I've heard that DIY seal replacement on a rotary typically lasts for 1 drive around the block and that of all engines, they are ones that absolutely require a professional rebuild. Is this not the case?

If you can rebuild a piston engine, you can rebuild a rotary. It just takes some different techniques. I've rebuilt a couple of rotaries (and owned 5 RX-7's over the years). The first rebuild took some time just because it was new to us, but it wasn't hard. The hard part with these engines is the tuning. They are very intolerant of detonation and over heating.

JC

[Niburu]

Bringing this back to life, the hardtop/coupe/targa version FFR is working on has thoroughly renewed my interest in doing this.
It'll be like the RX-9 mazda should have made.

Bit of related trivia:
I know a couple of folks that work at the Renesis reman plant just down Rt 95 south of Richmond a bit.
The whole rebuild procces on the line takes 40 minutes.
Crazy.

[projectrally]

Somebody make this happen!

[C.Plavan]

Too bad rotary motors sound like poop. :)

[Canadian818]

Too bad rotary motors sound like poop. :)

More like bleeding eardrums at 9k+rpm...it's all a matter of opinion, some think the "boxer rumble" sounds like poop. Some think the best sound is a Ferrari V12, others an American V8 or Porsche turbo. I'm quite sure we can all agree though that the new F1 V6's sound just wrong, lol

[Niburu]

Locally I have access to a JDM engine reseller, they regullary stock the 20B (the 3 rotor motor).
I'm hoping it'll fit since they crammed the Suby H6 in.
The next question is wether to Peripheral Port it and run some IRTB's, or 3 little turbos, or one big turbo.

[flynntuna]

:cool: very cool, if there's a will there's a way.

[Turboguy]

Locally I have access to a JDM engine reseller, they regullary stock the 20B (the 3 rotor motor).
I'm hoping it'll fit since they crammed the Suby H6 in.
The next question is wether to Peripheral Port it and run some IRTB's, or 3 little turbos, or one big turbo.


Unfortunately, the "new" Subie H6 engines are less than 3/4" longer than the WRX's 2.5L turbo flat-4.


Anyone know how long a 20B is?

[Samiam1017]

I don't think a three rotor will fit. 13b with a street port and a td06 turbo will easily make 450hp

[Canadian818]

20b will definitely not fit, it's over 6" longer than 13b. The 13b will fit, may require a electric water pump though. However, an adapter is no where to be found from what I can tell. Every forum disscussion turns up Kennedy Engineering, but I just heard back from them and they don't make a 13b to any subaru tranny adapter.

[Hindsight]

An adapter should be relatively easy to prototype and fab, then have milled. Probably spendy though.

[Turboguy]

OK - a 20B is 6" longer than a 13B. But without knowing just how long a 13B is.....we still don't really know if either of them will fit or not. SO - how long are they ?


Just to throw fuel on the fire - I'd bet a 20B would fit in a GTM. I wonder if you could make it fit using the STi 6 spd tranny too?

[Ironhydroxide]

I'll have to measure the 12a and 13b in the basement... This is intriguing.

[Canadian818]

An adapter plate would be easy enough, but I have no idea what's involved for flywheel/clutch combo. The clutch would have to fit the tranny, so I'm guessing subaru clutch and drill the Mazda flywheel to bolt it onto?

[Ironhydroxide]

I'd think just use the Subaru friction disk in an aftermarket Mazda flywheel/pressure plate setup.

[Niburu]

I don't think a three rotor will fit. 13b with a street port and a td06 turbo will easily make 450hp

those are WAY cheaper, sadly I really like the 20B sound, though I suppose I could live with turbo 13B

some usefull links....sorta

http://cp_www.tripod.com/rotary/pg04.htm

http://www.rx7club.com/old-school-other-rotary-63/my-project-impreza-awd-rotary-881128

https://www.youtube.com/watch?v=1u8-xDavO-M

[Cbus]

I'm a 18 year rotary veteran. I am also thinking about this conversion. I would like to
Have the higher redline of the engine too. Though I haven't ruled out using the subi engine
As the kit was intended.

[Niburu]

I'm thinking for streetability, with the relatively lower torque it might keep the wheels from braking loose, we've all seen what happens with a 400 HP 818.
I'm on the fence about using the Renesis 13B's, because of the exhaust port relocation, if an apex seal does let loose the pieces don't have an easy way out and do more dmage than the older design. On top of that the local JDM engine importer can get TII motors for $1500 all day long, so same HP as the Renesis with turbo complications.

[Cbus]

I'm thinking for streetability, with the relatively lower torque it might keep the wheels from braking loose, we've all seen what happens with a 400 HP 818.
I'm on the fence about using the Renesis 13B's, because of the exhaust port relocation, if an apex seal does let loose the pieces don't have an easy way out and do more dmage than the older design. On top of that the local JDM engine importer can get TII motors for $1500 all day long, so same HP as the Renesis with turbo complications.

I am going to use a TII engine set up. Or a 13B REW tuned to around 300hp. Could do it with either set up easily. But will probably go with 13B TII as it will be cheaper.
I won't use a Renesis. I just don't like the side port exhaust design. It's ok at stock power levels. But other than that it's not desirable to me.
I have a 2010 Rx8 R3 right now. I thought about swapping in the 13B REW. But for what it would cost me to get that done and working I could have most
of (or a good chunck of) my 818 done. So I'm going to leave the Rx8 stock and build me a 818 and have both.

[Flamshackle]

I can't stop thinking about this engine in the 818. I Have exclusively owned and driven subarus and built a Subaru race car BUT... the rotary would deliver the power in a much more 818 friendly fashion. Hmmmmmm can't wait to see someone build a rotary 818

[Wayne Presley]

I've had a 13B on the dyno at 29psi making over 600 RWHP at 9700 RPM.

[Turboguy]

Way to throw fuel on the fire, Wayne - lol

[Cbus]

I will for sure do this. I will do a build thread for those contemplating on doing one too. I would if Joe Scott from factory five are stilling looking at this
option? I would be more than happy to work them on this on making a conversion kit for those that would like the rotary engine instead of the the Subaru
engine. Either way this will still be a unique car driving around town.

[Wayne Presley]

Here is the dyno sheet

http://i213.photobucket.com/albums/cc175/vcpinjectionpb/gonzalez-dyno.jpg (http://s213.photobucket.com/user/vcpinjectionpb/media/gonzalez-dyno.jpg.html)

[Wayne Presley]

http://i213.photobucket.com/albums/cc175/vcpinjectionpb/th_VID00002.mp4 (http://i213.photobucket.com/albums/cc175/vcpinjectionpb/VID00002.mp4)

[xatudor]

Is the rear hatch open for down force or cooling?

[Canadian818]

Any specs on the engine Wayne? Did you build it? Did you tune it? What type/brand ecu? The power delivery is sooo smooth!

[Wayne Presley]

Ported 13B with a older Haltech on it with staged injectors and I did part of the tuning.

[Niburu]

damn I spelled breaking wrong in the last post

[Canadian818]

We'll soon find out!

[Tamra]

We'll soon find out!

Awesome! I love this idea.

[Wayne Presley]

Where do you get the adapter for the rotary to subaru trans?

[Flamshackle]

I like the idea of an NA rotor better but will be good to see how this performs

[Canadian818]

Where do you get the adapter for the rotary to subaru trans?

I don't have one, and from what I can tell online, there isn't one. I'm going to attempt to make one, if that doesn't work out then I'll have to send Kennedy a subie trans.

The 13b-rew is slightly longer than the EJ20. I'll get some exact numbers with a strait edge once I split the Mazda trans. But it appears to be just over an inch longer. I'll be ordering some new pulleys right away to take an inch off the front by going to only one belt and removing the power steering, A/C, and air pump. I'll have more info and better pictures this weekend in my build thread.

[Cbus]

Great! Can't Wait To See Some Of The Builds! Keep The Updates Posted! :)

[Canadian818]

http://i1113.photobucket.com/albums/k519/pope83/CIMG1963.jpg (http://s1113.photobucket.com/user/pope83/media/CIMG1963.jpg.html)

It fits!