turtlekingmaster

I have a 2jzge, that I want to build. I also have a 1992 Miata that I want to make fun. I've always loved both things, and was wondering what you guys think about doing it? My power goal is 600-800 hp, which is a pretty big gap I'd think. BUT, I do need it to run off pump gas so I'm ok with a more reasonable goal like near the 400-500hp. I do want to boost it with a turbo. I plan on rebuilding the 2jzge completely from the ground up.

What are some things I could do?

Suggestions?

Should I even do this? I know a lot of people don't, but I'm not sure why. Could I get a little guidance?

I will have to change out the trans, diff. What else should I change on it, subframe maybe? Anything else I should change out and/or strengthen to handle the power goals and what trans and diff should I put in it?

I just would like to make a plan before I execute.

I really want to do this so please help!

der_vierte

Thats a massive task, but not impossible. The inline 6 is very long and I would say you have to at least modify subframe(s), firewall, transtunnel, some other **** in the bay.
On a 2j at those power levels you can either run the v160 (expensive) or a GS6-53BZ (widely available) with an adaptor. If you stay <600whp then a ZF 310/320 will work, too. At this point you can also go auto...
Custom shifter linkage, custom big drive shaft.
Diff mounts/axles/hubs (v8 roadsters kit), Getrag diff from a V8.
I would start with a used 2J loom and build a new one from there with an ECU master or equal.
Big fuel pump and lines (walbro 525 powered directly from the battery).
Think about some chassis reinforcements.
Custom oil pan.

Twin scroll (maybe) custom manifold and if you can fit a 3,5" downpipe. Use 62mm turbo or bigger. For your higher goal on pump use a PT6870, g42-1200 compact or equal.

This will be a looong and hard journey and very expensive. Better think about an e30 or e36, e46 chassis, so much easier to put a 2J in.

There is *** loads I didn't mention!

Do you have a VVTI (weak rods) or non VVTI 2j? The earlier can survive 500whp no problem in stock form.

Good luck!

turtlekingmaster

What do you mean modify the firewall and transtunnel? Do you mean I'll have to indent the surfaces to make room for the engine and trans? I really want to make it work! And this mockup will be able to run on pump gas?
I have the vvti 2jzge motor, so it does have the weaker rods but I am planning on a complete rebuild of the engine for stronger internals and so that its clean and ready for the power

Gee Emm

First up buy a tape measure.

Then measure the engine.

Then measure the engine length forward of the firewall. That will tell you what it will look like when installed with no mods to the firewall. From that, you will also tell how far it will need to be recessed into the firewall. Then think about the bellhousing, and shifter location.

Just because you have two things and would like to make one out of them, does not mean that this is a good idea.

turtlekingmaster

Yeah, that's what I was most scared of. I really did want it to work. What engines do you recommend for a build of the same power goals?
Maybe a k24A? or a k24/20 Frankenstein build? I scratched the surface of that kind of build but haven't dove into that yet.

der_vierte

Built k24 will get you to 600hp WAY easier.
And cheaper.
If I wanted a stupid fast miata, thats what I would do.
If 450-500 is enough, stick with the BP and a 7163 or g30-660

turtlekingmaster

What kind of trans should I mount on a k24? I do want to change out parts of the car like diff and ofc handling mods, like suspension and frame structure support

Gee Emm

Man, stop asking dumb questions - save that for the bookface.

Use the search function, DV has thrown you a bone, go chew on it. Read some build threads. Read what people do to these cars to make them go fast, there is a massive amount of info here if you are after info. Pro tip: we don't do hand-holding here.

Use the search function. There are numerous engine swaps here if that is your thing,

Did I mention that this site has a search function ...

curly

iTrader: (25)

Also keep in mind that 400hp in these chassis is WAY over kill. Just did the math on a 420hp BP I tuned yesterday, it's equivalent if not better to a Hellcat Redeye, and "faster" than an R8, AMG GTR, Model S, GTR, etc. Now look at the tires/drivetrain of those cars, a lot are either AWD or 325+ width tires, or both. You're going to struggle to get over 245s on a NA.

The 2J is an awesomely capable engine, but outdated, large, and heavy. As others have said, consider a cheap E46 for your 2J, or the N54/N55 in 2007+ BMW 335/135 is the modern 2J, easily 600 with some bolt ons and proper tuning, plus a chassis to handle it.

der_vierte

It will be a death trap, that's for sure

turtlekingmaster

So got it. I shouldn't do a 2jz swap because its heavy and it won't clear the areas in the car. Can the BP platform handle 500? Or will it need some new internals.
Is a K24 turbo with a power goal of 600 overkill, can the miata even put down that power?

SpartanSV

If you don't figure out how to use the search function you're going to have a bad time.

patsmx5

iTrader: (16)

You can check my thread or youtube channel for a high HP BP Build.

A miata with 300whp is actually very quick and very doable to build and be reliable without redoing a ton of stuff.

A 400whp miata is also doable these days, but does require more swaps and work to make reliable. But it's been done and all the parts are available. IMO, 400whp is about the limit of a miata chassis without chassis mods like a cage or some other things to really stiffen it up and get the suspension working well.

A 500whp miata, if you want to do that, it's a project, you got a lot to learn. Check out build threads and vids of miatas that have done it to get idea of the scope/cost/work.

der_vierte

All internals, main caps, rods, pistons, oil pump, dampener, fully built head with cams. only the crankshaft can stay.

You'll have a hard time putting down 400whp on 245 100tw tires. First and second useless, third useless most of the time, but will hook in 4th

Newaza

The first thing you should ask yourself is what is your intended usage be it street, track or drag. The intended usage will tend to dictate what you should consider for power limits. Second is what is your level of experience in a high powered, short wheelbase rwd vehicle, and you need to honest with yourself on this one.

500hp or more in a miata is a real hand full on the street, even with very sticky drag radials on a good road surface. With anything approaching normal tires or just ok road surface it is flat out dangerous and will get you in trouble real quick in a short wheel base rwd vehicle. It is not just dangerous for you, but others around you should you attempt to use that power in a traffic situation. When I test mine on the street I only test on a very secluded area with no one around so I only put myself in danger. Unless you have experience handling a high powered short wheelbase car you need to lower your goals a bit for your safety and others.

SlowTeg

As others said, it sounds like you're in way over your head to be honest. Even an "easy" swap like a K swap where you can buy all the necessary parts off the shelf is a lot of work. A 2JZ.. I'd say buy an old Supra and stick it in that.

It sounds like you don't have too much experience wrenching (you likely wouldn't have chosen this swap). If you really do want the 2JZ, just find a reputable shop and a giant pile of money and I'm sure they can get it to work.

codrus

A 2JZ is a minimum of 8 inches longer than a 1.6 Miata engine, just from the bore spacing, and there's a good chance that once you add the accessories/etc it's going to be more than that. Look in your engine bay -- is there 8-12 inches of extra space between the front of the engine and the radiator? No, there isn't. To make the engine fit you either need to lengthen the car so that you can move the radiator forwards or set the engine further back. Lengthening the car is not really practical unless you don't care how it looks afterwards, so most people go with the second option.

Moving it back means that the back of the engine is going to be inside the transmission tunnel, which isn't wide enough. Moving the motor also back means you'll be moving the transmission back, and since the tunnel gets narrower as you go back that means that the transmission won't fit either. This is made even worse because a transmission that's strong enough to take that kind of power is going to be physically larger than the one Mazda designed that tunnel for. This isn't the small amounts of clearance you can make with a hammer, you'll need to cut out the sheet metal and fabricate a new tunnel from sheet metal. Doing that means stripping pretty much everything out of both the engine bay and interior. Motor, subframe, wiring harness, all the little things attached to the fenders and firewall, seats, dash, heater core, carpet, all the electronics -- everything. The transmission tunnel is a major structural part of the car, it's what keeps the chassis from bending in the middle. You're going to need to cut it out and fabricate a new one, keeping the front and rear parts of the car in their same relative locations during the process, and hoping that the car doesn't break in half when you're done.

Then you need to paint it and modify the interior parts to go back in -- hopefully the seats still fit! Design and fabricate a subframe to hold the new motor, make a custom oil pan for it (the 2JZ is taller than the B6 as well), hood modifications, a transmission cross member (the PPF is long gone by this point), and a new driveshaft. The shifter for the new transmission is probably now too far back to be easily reached, so you'll need to build a linkage to move it forwards. You can probably use a V8 roadsters differential kit to mount a stronger diff in a modified subframe with stronger axles and uprights, so that part is relatively "easy". Custom driveshaft to go between that diff and the Toyota motor, though.

Maybe you can use a stock Supra turbo manifold, but the Miata engine bay is probably narrower as well, so maybe not. All the rest of the turbo plumbing is definitely custom, and lots of work in the nose to fit a 600 hp intercooler and a big-enough radiator for that much power. Fitting a 4 inch exhaust under the car is going to be fun too. Hopefully the new motor fit with the existing steering rack, because moving that involves a huge amount of work to get the car to drive properly again (bump steer).

So now that it's all mechanically installed you just need to make it run! Install the ECU, build a complete custom wiring harness, adapters for the various other electronics in the car that are still Mazda (gauges, for example). You're replacing the entire fuel system to support that much power too.

Google for "Flyin Mata V8 build diary" and you can find YouTube videos and blog posts about the process for swapping an LS into a Miata chassis. Doing that is a couple of hundred hours of labor, and that's with pre-fabricated "kit" parts for the subframe and exhaust and no engine setback. I expect a 2JZ is probably 400-500 hours of labor.

And for what, bragging rights? Nobody builds 600-800 hp Miatas because there's no point, you can't use that much power in the chassis. You can't fit tires big enough to use that much power under the car, and even if you did then the short wheelbase makes it unstable. Miatas are great cars at speeds up to 100 mph and a little bit more. Mine (350 rwhp) will do 130 or so over turn 1 at Laguna Seca and it's a bit scary. Doing 160-180 in a 600-800 hp Miata would be, frankly, terrifying.

You are making the classic newbie mistake of "I have X and Y and I want to put them together" without any real goal. What is that you want to do with the car? Drag racing? Top speed on airport runways/land speed records? Autocross? Track days? Road racing? (please don't say street racing). Or just a fun mountain roads car? Answering that question will point you at a power goal, and once you have that you can figure out the best way to achieve it.

--Ian

turtlekingmaster

Thank you guys, I get it. I am new to this platform and just had a few questions. I do realize it won't work, so please just try to be helpful. For those giving me some information, thank you. I'm learning as I go.
Sounds like my plan is to reenforce the car as it is now, so suspension and handling. Then find a 1.8L to swap in for some extra punch.
Yes I am new to building cars. But I am not new, not a pro, in wrenching on cars.

der_vierte

At least you learn fast, have a cat.
With a std built BP (rods, pistons, oilpump, arp's, dampener, refreshed head) and a properly sized turbo (2860-67, EFR 6258/6758, G25 bla bla), you can have MAD FUN.

I can only suggest to try to go for a drive in a higher hp turbo miata, I think you will quickly change your mind about hp goals in these cars.

ChrisArter

OP I can tell you it took about 30 minutes down the google rabbit hole to realize it's the same destination but a much harder path. Outside of Miatas I'm an admitted Toyota Fanboy (Sequoia / 2UZFE gang) so to combine a Toyota motor with a Miata sounded like heaven, but it's not worth the squeeze from what I can see. I like other people's 2JZ Miatas though! haha. And not to discourage wild swaps either. But cost analysis vulcan logic, there's better ways to do it.

This is it. Power in these chassis goes very far. A friend's 250HP turbo Miata felt like being strapped to a rocket, so that's the direction I've gone also with my turbo NB.