I haven't seen it done yet, although I've seen an LS1 swap, Ford 302, Nissan motors, Rotary's, etc. Wondering if anyone has done this with a 4G63 yet. Saw a Miata on Pinks the other night that had a swap done that was just totally badass to me.

Figure the only obstacles is finding a manual tranny that'll work, flywheel and clutch setup, driveshaft, and then getting things like the gauges to work if a wiring harness from a dsm is used. I have a 91 Eclipse fwd that I'm tired of cause of traction issues so all I'd really need is a Miata shell, and then whatever it takes to convert everything. Any ideas or good leads into the right direction? Thanks.

I've seen it done before. I think the best swap is the 1.3 turbo rotory. Reduces weight and doubles, nearly triples the bhp.

Anyhow a dsm wire harness and ecu is a must. For the gauges you just have to get the wire schematics for both cars and splice/hard wire where needed. Fabricated mounts, exhaust/manifold, bracket for the transmission and engine. I don't know about the flywheel, I'm thinking custom with miata clutch? Suspension and brake bias have to have some changes.

..and prob the CAS getting in the way with the firewall if doing a 'north/south' motor install...

If you're doing the RWD install only, then you'll need the transmission used in the truck or van with a 4Gxx engine. Also you can have a driveshaft made or possibly find one the right length and just have the ends changed to fit your needs. The shop I work for (part time) has turned out custom drive shafts for projects and we've never heard of anyone bending, dropping, or blowing out their shafts.

I'd go with a MegaSquirt ECM also, it would be simple to wire it up and get it going that route (but I support MegaSquirt so of course I'd say that)

Mighty Max trans.

What about a t4 trans with the bellhousing adaptor. They put thoughs tranys in everything back in the day.

I have a Miata I have the plans of doing exactly this. Being a long term DSMer I need something new and different if I was going to get back inthe game. I couldnt find anyone who had done it either. I will be "building" my own wire harness to make things work. Will go aftermarket for all the gauges. Figured that would be the easiest way to do it and it would look great as well. As for the CAS at the fire wall, either mod the fire wall or go with a cam/crank trigger set-up on the front of the motor. I havent descided yet. I will figure that out once I am installing things into the car and see how things look. Drive shaft can easily be made. I am in Dallas and there are tons of drive shaft shops that can do somthing like this. I am going to upgrade my '91 Miata rear with the '99 Torson rear end which will hold up better and there are plenty of gear ratios to choose from. As for the final and most important questions, what to do about the tranny. Here are a couple of links that will give you plenty of choices to go with. I am going with a Toyota tranny. They can handle the power and have a strong aftermarket following and are very popular that finding parts and "builiding" one wont be a problem. So heck out these links and descide what route you want to take.

:: Project Zero G :: - Transmissions

Bill's Auto Fabrication - Toledo, Ohio

I long thought about a 4G63 swap in my s-10 for a bit there... LS2 sounds better though. When I planned it all out, I was thinking of going with a modified EVO mani to point the TB to the front, rather than the back. I think the CAS will be okay, so long as you don't tuck the motor back too far. As for the EVO mani, there was a guy that got around all that, but he cut the ends of the stock DSM mani off and swapped them. It looked pretty ugly...

I'll just get a JM fab manifold and have them swap the direction. Planned on stock ecu and wiring to make that simple and use Dsmlink. Wanna keep things for tuning as easy as possible and as much like a dsm as possible....just in a Miata. Thing about the tranny that's hard is getting one that'll bolt up the same, have a good clutch that'll hold, and have the shifter fit in the same location thru the console. I think that's really the biggest challenge. Everything else would be pretty easy to figure out or fabricate though other than just make sure all the electrical stuff works properly. I've seen a 4G63 swap into an RX-7 and supposedly used the TII tranny so maybe that'll work since some guys do rotary swaps into Miata's.

I've heard that the tranny's out of a mighty max truck are weak. Not really sure. I'd like to be putting down around 400hp or so at least. My car ran a 7.7 in the 1/8th (guess that's around an 11.9-12.0 in the 1/4) in a fwd Eclipse so can only imagine what that'd do if that same motor was in a Miata. Hoping for much quicker than that though. I watched some vids on Streetfire and they had one with a LS1 swap that ran an 11.9 in the 1/4. Couldn't believe that's all it ran. Hate the V8 swaps in import cars. It just doesn't sound right. Like putting in a Honda motor into a Mustang Cobra. Lol.

A couple of my buddies from MD are doing a swap in an old RX7. I think the total investment for the job is somewhere in the $300 region....free car, junkyard engine, and some misc items.

The giant truck turbo sitting on the manifold in the first pic is definitely for laughing purposes only.





They wired up a 2G ECU and harness, and are tuning with DSMLink. They MADE an adapter plate to mount the 4G63 to the stock RX tranny.

The car runs and drives, and will hopefully make a pass down the track before the end of the year!

The original plan was to put the engine into a late '80s or early '90s S10 truck, but you can't beat a free car.

That thing looks beast^^

But for the other guy that is going to be ALOT of work..... but im pretty sure it will work with alot of midding. The only thing i want to know is, why a miata?

I wouldn't think it'd be much more work than an RX-7 swap like the one above. I mean there's gonna be fabricating to do regardless.

Why a Miata? For one, they're very light. They're also very fun to drive but in stock form they're slow as hell and wouldn't even waste my time trying to mod the stock motor with a supercharger or turbo. There's a turbo Miata here in town and I'd wax it's ass all day long. Everyone does LSx swaps and that's old to me. How many people throw in 4g's in these cars? Not only that, but people don't expect these cars to be fast. I know I NEVER see a Miata and think to myself, "man, I bet that car is fast". I like having a fast car but love being underestimated. But also want one that's nice as well as fun to drive. And this car would pretty much do all of that....and you can also make them look pretty sporty at the same time.

Sounds like a pretty cool build to me, a sleeper miata......

Why so quick to dismiss the stock motor on a miata? Are there no ways to make the engine faster outside of a turbo? Bigger pistons, head, etc. Just curious.

Also, what is the weight difference between the motors? Asking cause I would think a swap that involves more weight will screw with the handling.

Well for me, it'd be more money to mod a Miata motor than to take a motor out of a dsm that I'd already have. I mean to make 400 horsepower on a dsm is pretty simple and cheap when compared to a Miata motor and getting mods for it that I don't have. Look at the cost of a supercharger for a Miata and the measley power output you'd get compared to a 4g motor. If I didn't have a motor already, it'd be different and I'd maybe "consider" it. But even still, there's enough guys selling dsm parts or motors to where I'm sure it'd be cheaper to throw in a dsm motor. I already have an eprom ecu, wiring harness, etc. I could sell some of my parts to get some of the things I need such as the intercooler for example. Remember, I have a fwd dsm already but I'm not driving it. I was considering looking for an awd dsm shell to swap all my parts into. But the lighter weight would make it much easier to go faster I'm sure. Not to mention the cornering ability of these cars.

Only things I can think of (at the moment) that I'd need to make the swap happen is to buy another tranny, flywheel, clutch, driveshaft, engine and tranny mounts, and intercooler. Sure some things would come up that I haven't thought of but can't be too much more.

Why a Miata?

The handle very well, light weight, and have plenty of aftermarket suspension parts and body/chassis parts available to make them even better. They have a great following and a great set of groups who are actually very open to guys who do swaps on them allthe time.

Why Not Build The Bp Motor Instead of The 4G?

Although the Mazda BP motors are good motors, they are not known for lots of horse power. Even buit, force inducted BP motors put out that much. IT takes a lot of money to build a 300+ motor. But a 4G6* motor is stong, and easy to push 400+ out of and cheap to build.

What About The Tranny, Flywheel, anbd Clutch?

If you look at the links I supplied you can get an idea of what to use for all of these. I do think the RX-7 tranny would be the easiest to use in a miata and shoudl line up with the shifter hole without problems. Here is all you would need to make one work with a 4G motor... :: Project Zero G :: - RX7 Transmissions

The RX-7 pictured by jusmx141 and all and being a low budget car is gets the job doen nicely. But I want a nice car and a nice build that puts down nice power taht handles nice. It will be NICE! Seriously though, I think a 4G Miata can be done very well and be very cool. I always wonder what Mitsubishi would have built if they descided to build a roadster and I think a 4G Miata is about as close aas we can get to building something like they would have.

In short, it should be a fairly simply build with most of the needed parts available and fun to drive once complete. I say, why not?

Yeah, I don't see many high horsepower Miata engines around. Don't wanna sink tons of money to be struggling to make 300 horsepower.

As for the build, I've seen some 4g swaps that just look Ghetto. I wanna do it and make it look nice. Like everything was made to just bolt in. Or lemme say that if it has to be fabricated, I want it looking nice. Not look like stuff was cut with a hacksaw and thrown together with some jb weld. It's something I'd be able to take my time with and when I ever get around to maybe getting this done, I guess I'll have to make a post. Looked on miata.net and all I see is people wanting to do it but no one actually doing it. So looking like I'm doing a bunch of research on my own.

My parents have an old B2200 truck and it doesn't run right now. They've just used it as an old work truck and I guess the clutch went bad on it. I'd sure like to get my hands on that transmission though. Just wish there was a page for a Miata that was like, "get this part from this and it'll bolt right up. And get this and it'll bolt in." I found this link Miata Drivetrain Interchange Guide but they do a lot of babbling and trying to read thru it all to see what's best to use. Sigh, I have a lot of homework to do again. Would be much easier if I already had a Miata shell laying around but don't have one just yet. Really wanting to sell my Jeep to make this happen but I'd need another car to drive around.

Hey, I saw this post and I have been looking into a 4g63 miata myself. Anyone have any updates?

Nah, I decided to buy another dsm cause I didn't wanna wait around forever to have a running car to make fast. I still like the idea but if I ever make it happen, it won't be for years before it happens.

The best transmission you can get I my mind would be a t350 or a t400 there cheap and there parts are to. buschur make a Adapter Plate here.
https://secure.buschurracing.com/catalog/product_info.php?cPath=21_312&products_id=1520

Holy cow! $400 for a machined plate???

Update on my Miata Swap... nothing. I have been focused on getting my shop up amd running over the last couple of years. Now that it is getting off the ground I am about to start spiyting out some sick builds. The 4G63 Miata has not been forgotten about either. Infact, a lot of thoight and planning has gone into the design proccess of it. There will be nothing like it, thats forsure.

I hate to say this but, the BP-ZE in my opinion, for what it is, is a better motor than a 4g63... Power... 4g63 wins hands down. But

BP,

Non interference, 1.8L DOHC, Looks pretty good under the hood. Pretty much a turbo engine without turbo. Just add turbo and fuel, ud be happy. But yeh, not a high HP engine. I've torn into them, such a simple design, surprised there so robust...

Had a couple beat TO HELL and back.... I mean 7k + all day day long.... 250K miles and still have good compression... tear it apart and not have any notable traces of wear...

g4ebguy90 said:

I hate to say this but, the BP-ZE in my opinion, for what it is, is a better motor than a 4g63... Power... 4g63 wins hands down. But

BP,

Non interference, 1.8L DOHC, Looks pretty good under the hood. Pretty much a turbo engine without turbo. Just add turbo and fuel, ud be happy. But yeh, not a high HP engine. I've torn into them, such a simple design, surprised there so robust...

Had a couple beat TO HELL and back.... I mean 7k + all day day long.... 250K miles and still have good compression... tear it apart and not have any notable traces of wear...

Click to expand...

I have to for the most part agree. I've been playing with turbo BP's for almost as long as 4g63's. They really are a ridiculously hardy engine. They'll make power all day long reliably right up until 300/350whp at which point the wimpy little rods let it down. I had several Escort GT's and a turbo BP Tracer with 200,000 hard miles making 220WHP and damn near ZERO issues. Hell I put a tiny hole in a radiator with a poorly placed intercooler clamp and drove the thing home with zero coolant sitting in traffic for 20 miles. Got rear ended and shoved into a truck with a hitch, it put the radiator cap IN the valve cover, and again drove it home spitting oil everywhere no problem. All this on the same engine. I finally got rid of it after the second shell rotted out around the drivetrain.
Anyways, if I was going turbo 4 in a miata I'd just use the BP or B6 it came with and do something like this.......https://www.youtube.com/watch?v=kG9KmJjZNF8

He doesn't have many details on the conversion, but running dsmlink, DSM throttle body, ECU, and I'm guessing most of the engine harness.