Steve Dallas

In its highest output version, that engine puts out 175 BHP. Even if miracles are possible, and you can bump it up 25% to 218 BHP, you still have to factor in 23% drive train loss, and you are back down to 168 WHP. A healthy stock Renesis puts down 200 WHP. Sure, the torque curves are different, and just maybe Granny won't beat you off the line in her Camry anymore, but why?

Packaging may be a concern, but why not a Honda K24A2 or a GM LE5? At least those engines are actually capable of putting down 200 - 240 HP at the wheels, and there are kits available to bolt them up to Mazda transmissions.

I've heard of putting an RX-8 engine in a Miata, but I've never heard of putting a Miata engine in an RX-8, and thought I never would.

I wonder where the OP is on this project? Update?

NotAPreppie

The initial appeal comes from being able to mount pretty much any MZR/Duratec/EcoBoost I-4 to the NC Miata subframe and to be able to mount the NC Miata subframe into our cars with zero/minimal fabrication. Similarly, the I've read that NC Miata gearbox will mate up to almost any MZR/Duratec/EcoBoost I-4 engine.

I'd be surprised if the SkyActiv-G engines differ significantly in the arrangement of the mounting points. If that's the case, you could probably mount up the SkyActiv 2.5T with a ND Miata gearbox.

Honestly, I'd love to see an L3-VDT or Ford 2.3L EcoBoost from the Mustang. Or go crazy with a L5-VE with a race cam, intake/ITB, high-compression pistons (which will allegedly do 240whp when installed in an NC Miata).

All that said, I think the best bang for the buck is still going to be a LS swap. Given how well documented they are now (the LS Powered RX8 FaceSpace group is full of active and helpful people), a half-decent LS swap will probably cost less AND make more power than any 4-banger.

Bwek

The NC miata guys with cams and header make 200+whp and 200ftlbs

It quite normal for them to make those numbers with the 2.5, Bosworth has a whole selection of mzr/duratec 2.5s that make 300+ crank.

My Mzr swap is in storage till the winter when I have time to work on it again.

I've been tempted to try the ecoboost mustang engine in my car, I'd only need to be the standalone why available from Ford racing

9krpmrx8

iTrader: (46)

I highly doubt that, my buddies 2006 with a tune, header, lightened FW, catback, intake, etc makes just under 150Hp and 130ft/b. I highly doubt a cam would get him 50WHP and 70ft/lb.

Bwek

Was that with a 2.5? Was it tuned? Moto-east has consistently tuned stock engines to around 190-200 with no cams

It's no different than a Honda that makes 200 at the crank from the factory and 230 and the wheels with full bolts and a tune.

I fellow time attack NC miata has made 200whp on her 2.5 swapped car even though her header is choking her car.

Steve Dallas

230 at the crank amounts to 177 at the wheels, assuming 23% drive train loss, which is typical of RWD Mazda cars. Even if we are charitable and assume only 20% loss, it still only amounts to 184 at the wheels.

Bwek

Sorry you misunderstand me the civic made 230whp with bolt on and tune came off the line making 197 crank stock

Yes there are 2.5 swap miatas making 200whp and 190 torque

Or you can go ecoboost but that requires even more space in the cabin

TeamRX8

iTrader: (25)

No, that’s with cams and a whole lot of other parts

http://www.moto-east.com/main/moto-e...ifold-results/


The answer to the thread title is simple; because it makes no sense.

.

bwilk

iTrader: (1)

Isn't there a 260-275HP DISI Turbo version of the MZR? I agree that there's no reason to do this over an LS or a REW/20B, but it's at least a small upgrade in HP.

NotAPreppie

https://en.wikipedia.org/wiki/Mazda_...o_.28L3-VDT.29

georonimo@gmail.com

Great swap! Any updates on the electronics/management compatibility?
I've been thinking about doing this exact same swap since these cars are all over the marketplace for practically free once the garbage rotary blows up.
I love the idea of a solid roof Miata and those NC's handle like nobody's business!

TeamRX8

iTrader: (25)

your diapers need changing, pee-yew〜〜