fast13b

What's up fellas, it's been a while. Sold the TII (which some guy just recently grenaded at 30+psi apparently..) and got a 94 R Miata a couple years ago, then put a Flyin Miata turbo on it. Well, I work for FM now doing tuning and tech support. I have been running reliably at ~300rwhp at 15 psi on a disco potato, but the engine is just getting tired. Oh, and I want more power. Specifically, rotary power!

I've always had the dream of putting a turbo rotary in the car. Well the other day, my friend picked up an automatic 93 RX-7 that was pretty beat up for a song. The plan was for him to put an LS-1 in it and completely rebuild it, so he said I could have the engine if I would put it in my Miata. Free. Come to find out that it was a factory remanufactured 95 engine in the car with only 8,000 miles on it! What a freakin' score.

I have since been doing research on this swap, and considering the tools and help I have it shouldn't be too hard. I need to acquire a 5 speed, a rear end, engine management, a turbo manifold, and decide on a turbo. I will be getting rid of the auto tranny and all the factory twin turbo stuff. My plan is to write an article on the procedure and so I will be documenting everything. I plan on posting this here and also at miataforum.com to track progress, get ideas, and also feedback from others. I hope that this turns into someting productive for everyone! Oh and a beast for me to drive. My car weighs in right now at 2210, btw..

So now for my first questions. I have been out of the rotary loop for a couple years, and my knowledge is a little rusty. Not to mention I am not up on new developments.

-What engine management is being used these days? I had a Haltech E6A (I hated it) before. I remember the E6K being better. I see there are new systems now. I'm not a fan of the Electromotive because I think it is a PITA to tune. Don't know anything about the Microtech. I have been developing the Hydra for the Miata at work, but they say that it is a no go for the rotary right now. That sure would have been nice.. I would like something that has been used a lot so there are good base maps to start from.

-What turbos are hot these days? I live at 4600', so that has to be taken into account. In addition, I know the limits of the 13BT which I had, but not so familiar with the 13B-REW's limits. Do I go for the 350hp range? The 500 range?? I plan on leaving the engine alone for now, and maybe rebuilding it in a year or two after I have paid for all this.

-I have removed the twins, the rat's nest, etc. I have the factory service mauals. What of that mess do I need to retain? We do not have emissions where I live, so I plan on removing all of the air pump, EGR, and other stuff that is not necessary. I want to keep it simple. (My 94R Miata is the equivalent of the GTU / GTUs; power nothing and spartan)

-Will a TII tranny bolt to a REW, or do I need a 93+ 5 speed? Is the 93+ box lower profile? Clearance is an issue. (I have noticed however that the REW oil pan is even shorter than the custom oil pans that guys have made when putting 13BT's into Miatas)

So yeah. It begins. If anyone has any other thoughts or ideas, please do. I'll be posting everything here. I plan on it taking months since I'll be doing it after work and on weekends, and also to source the parts. My first steps now are to clean the REW and prepare it to sit for a few months (put some ATF or MMO in the chambers and seal it up?), and to get a 4x4 for the winter so I can yank the engine from the Miata and start selling off the parts. Any other engine maintenance I should do in the interim? I want to replace the oil pellet in the eccentric shaft with the solid unit and remove the OMP system since I will be premixing.

OK enough for now.

~Jeremy

rotorbrain

ecu. . . look into microtech. . . they even give you a base map to go on!!!! and people are making some very good numbers using these ecus. . . dont really know what the deal is with that, but it seems to be better. . . IMO. it is cheaper for an lt8s than an e6x

turbos that are hot. . . the gt series turbos seem to be the hot ticket lately. something like the gt35r or larger would definately suit your needs. . . im sure.

yes, a tII tranny will bolt up to an REW. . . i believe youd need to use the TII clutch setup because of the difference. . . push type (TII) vs. pull type (FD)

sounds like fun. . .

how on earth did that yahoo decide to run 30 psi on the TII? he must have been shifting mad quick yo!!!1one

good luck,
paul

fast13b

I know Dave Gibson was selling the Microtech for a while, not sure how that is going. I had one customer grenade his Miata with one, but who knows if the guy could tune. What I do want is an ECU that has closed loop WBO2 autotuning and timing retard based on knock sensor input.

Not sure what that guy was thinking, running 30+ psi from the T-66 on a S5 engine with an E6A no less.

I did some reading last night, and the GT35R does look good. I see that it comes in a T3 or a T4/DT footprint. I would love to go divided tangenital. Depends on the manifold selection and clearance I suppose. My TII had a TO4, DT, P trim 1.15 hotside and it spooled a little slow (when I lived at sea level).

rotorbrain

that might have had something to do with the 1.15 hotside. maybe something a little smaller would have produced more desireable results. i currently run a 1.0 hotside on my 60-1 and it spools up very well. . . i think. . . not tremendous lag. . . some lag, but not like a t78 or anything.

i havent heard of anyone blowing motors while using microtech on a rotary. . . especially due to the ecu being a POS at all. i dont know if it has autotuning or timing retard at all. i know most of us (now-a-days ) have kinda black listed that option in fear of the autotune correcting TOO much. im sure there are ways around that. . . and its probably just an ignorance issue.

and yes, the gt35r DOES seem to be the hot ticket lately. . . i wish it was something i could easily go for. . . but finances and lack of time to afford to the car say, "NO!!!!" hahaha.

i, also, wonder if theres a way to use the powerfc in that car. that way, you could still use the OMP (and switch to 2stroke injection via the rotary aviation omp plate), have access to the thousands of users/tuners, and get to have a looksy at the new tuning software that is coming out for it. . . FCTUNE. . . check the powerfc forum. look for "fasthatch" and youll find all about it. hes done some NICE things with it. i dont see why you COULDNT use a powerfc since youre going with an REW. . . but the powerfc might use the rest of the car for some of its stuff. . . i dont know the depth of its intricacy. might be a worthwhile possibility though.

edit: also, fasthatch is trying to integrate an autotune feature into his new software.

fast13b

I do have the factory ECU in the car available to me where I could use the Power FC, however since I will be removing so many things like EGR, etc., I was concerned that it would just throw CEL's all day long. Even if I did keep the OMP, I would still premix. Seeing engines torn down that did and did not premix, well, I will. Not to mention that the harness under the manifold is fried. It wasn't hurting my feelings about creating a new harness. Good idea, just not sure how productive it is in the long run.

I do WBO2 closed loop autotuning in both the Link and Hydra ECU's I tune at work, and other than at idle with the Hydra it works quite well. I think it comes down to the programmer's code for the job. I did play with the fuel on my TII a lot, and I do it every day at work, so I have that down. I will need to brush up on the nuances of timing tuning for the rotary however. Having a knock sensor voltage feedback screen in an ECU is key, and having it retard based on exceeding a certain voltage is ideal.

fast13b

Ok I suppose I need to figure out exactly what the Power FC is. I thought it was a piggyback. Is it? Is it a standalone? It seems to have a lot of features..

rotorbrain

hehe. . . the power fc IS a standalone. it plugs directly into the engines harness. total plug and play. . . and it comes with a commander that you can do small changes with. . . as well as view readings. . . such as knock, though it is not voltage.

the datalogit and fctune are software interfaces that have proven to be one of the best setups for a novice. . . and for higher end tuners. people make plenty of hp on the ecu. the fc tune writer is coming out with his own box now (and i must say. . . its niiiiiiiice), and is getting some of the final adjustments done on his fctune software. . . the software is very nice also. . . a much needed improvement over the exhausted datalogit (which still does a great job. . . just a little old).

as far as the premix thing. . . to each his own of course. i personally dont care for it, as i dont like the idea of having to worry about whether the mixture is enough or too much for the application at hand. the car is driven too much to be handled as though its a weed-eater or snowmobile that only has one real function. . . WOT!!! the omp does a great job. . . and i have to say. . . using a 2stroke bypass is ingenious if you ask me. by doing so, you get clean, unused, synthetic, BURNABLE oil into the combustion chamber. . . AND whats better is that the powerfc can be used to up the voltage to the OMP at certain points. that way, you can add more oil to the seals via ECU. . . that option is used via datalogit software though. . .

so, just keep that in mind.

paul

also. . . check here for the OMP adapter. . . http://www.rotaryaviation.com/oil_in...p_adaptors.htm

zion77

Excellent

gotzoom?

I am also starting this same project. I was stripping the car of its engine today and starting thinking about the power plant frame. How will this all go back together. If we use a FD tranny, will the PPF just bolt back up? Jeremy, what is the benifit of using a Tll tranny rather than the FD?

fast13b

Nope. We get to weld up a new PPF from scratch. Read = lots of measuring and welding. As far as the trannys, I do not know which is best for the job yet. I still have to look into all that.

gotzoom?

Does the Tll tranny have a point to attach the PPF?

gotzoom?

Actually, i found the answer to my own question. It doesn't.

I also see that the PPF in the miata is on the right side and the RX7 is on the left. deffinitly some fabricating.

fast13b

Been working on the project lately. I have the engine and tranny (TII) bolted together and lowered in the car to start measuring stuff, working out driveline angles and all. There are a a couple different ways I could go.

Of course, it would be ideal to get it as low and as far back as possible. Doing this would mean massive modification to the front subframe and trying to figure out where to put the DP since the bellhousing takes up all of the tunnel. It might help (as I heard in another thread..?) to put a GSL-SE oil pan on (backwards) for more clearance around the subframe. Actually called Mazdatrix on that one today and they said that this would leave a nice gap beyond the end of the front cover. Huh. I would have to mod the tunnel some. The engine mounts would be a PITA like this. Oh, I would have to relocate the steering rack as well.

I could sit the engine higher and farther forward, and not have to hack up the subframe much. It would actually be sitting more where the stock engine did in terms of balance. The engine mounts would be much easier to make. The DP would have space. The clutch slave would clear. The turbo and manifold would be easier. The fabrication involved includes fabricating the tranny tunnel a couple inches higher from the turret to the firewall. Also, I would have to make a custom radiator fill neck. The intake manifold would fit with the stock hood, but likely not with my CF extraction hood.

Read an idea in another thread today that was a *duh* idea. Make spacers to go between the subframe and the body. I know there is thread sticking out there. This might help make a happy medium between the above ideas! There are a couple spots that I don't need much. Also, I have coilovers so I can lower the ride back down.

I need to decide if I can get away with hard mounting things, or if it would cause problems. I don't care about NVH in this car if it will benefit chassis rigidity, seeing as how it is a convertible..

Got a smokin' deal on a TO4S 60-1, too good to pass up. Guess I'll be starting with that turbo. It limits me to around 400rwhp- oh no haha Oh yeah and a HKS cast manifold for now, another good deal. My thought is that when I get around to porting the engine in the future I'll upgrade to a tubular and a GT40R- go for ~500hp. Just trying to keep the budget in check for right now.

Had an idea on engine management. I really like the Hydra that we are using at work on the Miata. No other ECU out there for the RX7 has all of the autotuning/ WB cosed loop/ knock sensing and retard/ boost control/ random controls and safety features that it has. Plus I'm writing the manual haha. My thought was to combine it with some MSD boxes: run the leading spark as normal. For the trailing, just wire it up off the leading but use the static retard function in the MSD box to set the gap on the trailing plugs. Not perfect, but it would make it driveable until Hydra comes up with a 3D trailing gap map (which is on the to do list).

I still need a TII rear end and an aluminum flywheel/ clutch setup. IIRC I can use my Miata short throw shifter in the TII tranny Really the big thing at this point is to decide on a direction for the fabrication so things can be worked out.

Just got some 15x8 ATS Comp wheels, 13.8lbs each. Going to run RA-1 225/45/15's. That's as much tire as I can get for now.. (9" wide)

I'll get pics as soon as anything important happens!

KeloidJonesJr.

iTrader: (8)

RiGHT ON, man right on! Long live rotaries!

fast13b

There was no good way to fit the hotside stuff all in there as-is. So, I had a pow-wow with my fabricating buddies and we decided the only good way to go will be just to tube frame the whole front subframe. We removed it tonight and built a jig for the chassis and suspension mounting points. I went and picked up some steel tubing today as well.

This is getting fun

trainwreck517

iTrader: (1)

Man this looks like its going to be one hell of project, make sure to take plenty pictures of fabricating the front subframe.

Can't wait to see the progress.. good luck man.

fast13b

Yeah, the plan is not only to document everything here and on the Miata forum, but also to set up the jig so I could make more.. *cough*

Thanks

KeloidJonesJr.

iTrader: (8)

Wow you got so muchspace in your garage. My garage just has junk in there.

mycarisolderthanme

Looks like it's gonna be some project! Looking forward to seeing the progress.. I'm a new resident here in CO, just moved to Denver for college. I've heard a lot about FM and would love to stop by the shop just to check things out sometime!

fast13b

Sure, feel free to stop by any time you're on this side of the hill..

Got lots done this weekend. Finished the jig. Sat the subframe and the engine back in the car to begin marking things up with chalk and getting an idea for some initial cuts. I think I have the idea in my head for the way I'm gonna tube the suspension mounting points. The actual cross member portions and steering rack will hopefully fall into place. There is plenty of room on the drivers' side. The space crunch is on the passenger side: trying to fit a DP and a WG in there. I might even have to make an up pipe from the manifold to the turbo if there is not enough room between it and the frame rail.

The good news is that I may be able to get it low enough that I will not have to do any surgery (or maybe just a little) to the transmission tunnel. An initial cut will bring it down about 3". I may have to get rid of some lips around the engine bay and seam weld it up to clear the oil filter and such- no big deal. The bad news is that the more I bring it down, the more I'm going to have an issue with the WG clearance.

The steering rack may need to be moved quite a bit forward. This concerns me since I do not know what that means for the Ackerman angles. (Is that right?)

Oh well, I'll have some time to think before I start cutting anything.

dantheman

iTrader: (4)

I love builds like this. Good luck!!

xrotaryguy

It looks like you have gone the rout of modifying the chassis to accomodate the motor and its oil pan. I wanted, though that if you wanted to change oil pans that you switch to an S5 Rx7 front cover. That way you could use any 13b oil pan from 74 to 92 and still have the electronic oil metering pump. The timing setup is defferent on the earlier covers. Just a thought though. Have fun.

tom tim

fast13b

The FD oil pan puts the drain plug between the front of the Miata cross member and the steering rack. I'd rather just make the frame fit around it and use the FD pan than use the FC pan and still have to modify the cross member.

I'm eliminating the oil metering pump so that doesn't matter.

I feel from experience that crank angle trigger wheels like the FD are more precise and make more power than distributor type setups like the FC.

So I got a turbo, but it has a weld on V band outlet. That sucks. Looks like I'll be making an up pipe for the HKS manifold as well due to frame rail clearance. (spending too much money here so I'm gonna start out basic since I have a stock engine anyway).

Going to have to relocate the underbody wiring loom and fuel lines to the other side of the chassis. Oh fun.

Decided to just build a rotisserie and seam weld the whole thing since I'll have it stripped anyway. Might as well do it right.

fast13b

Made the preliminary cut to the subframe today to get the engine suspended and level so that I can take some real measurements and figure out this whole subframe thing. Honestly, the only thing I'm hung up on at this point is how to tube the subframe in such a manner that I can make room for the turbo and the WG. Making a structural frame and keeping the A arm mounting points in the right place will take some thought.

The engine/ tranny mounts don't look hard. The oil filter mount and slave cylinder clear now no problem. The engine might sit about a half inch or so on the drivers side, but there will be all that weight from the turbo and manifold hanging out over the passenger side as a lever arm. Between that and coilovers I'm not concerned wth getting it balanced. The tight clearances however may be dictating solid mounts since I don't want to cut into the frame rails and I do want a decent sized turbo

The shifter mounting is ideal- centering it puts the engine as far back as it can go with the oil filter in the stock location. Looks like all I'll need to do (since the FC tunnel is taller than the Miata) is take the BFH to this one hump underneath. It clears now but only by a finger width and I'd like to extend that a touch. Oh, and not much luck of pulling the tranny w/o the engine attached from what it looks like. All of this will put the engine at a slight nose up tilt, but I suspect that this is ok. Oh, and I will need to remove the frame lip around the engine bay in a couple spots and weld the seam to box it in (such as where the oil filter is).

Now I just wish I had the motivation to clean things haha