smotch789

How is the 2.5 getting 300 h.p?? I have a 3.0 durtec which from my understanding is same engine. This seems like the easiest swap to do. Either get Miata subframe or 2 RH engine mounts from an Rx8 ??? I love this swap because from bellhousing back nithnot changes. I plan to follow this swap & use megasquirts as soltion.?

John V

iTrader: (1)

The 3.0 is an ancient V6. The 2.5 is a modern 4 cylinder.

There are many changes required to make it fit with the stock firewall. The stock transmissions from the RX8 and MX5 don't work.

NotAPreppie

Work work due to firewall/shifter location or bellhousing bolt pattern?

John V

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Shifter location mostly (too far forward). But neither one is strong enough to hold up to the torque that this setup will make.

NotAPreppie

I read somewhere that the Mustang Ecoboost gearbox will mate up to any MZR. Is that the way you're going?

John V

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No, I have something else planned but need to make sure it'll work first. Waiting on parts to make that happen.

John V

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MZR 2.5L turbo first fire up.

It's worth noting that the firewall has not been cut or hammered at all in this installation unlike the other MZR installs that I've seen.

https://www.youtube.com/watch?v=PNg43DdwjYA

NotAPreppie

Well that's just kind of sexy.

olddragger

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John V

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The MZR is a great engine. The 2.5 was installed in hundreds of thousands of cars in the US and it's very strong internally, very light, relatively compact and has a strong aftermarket following.

NotAPreppie

How much power are you hoping to make with this, John?

John V

iTrader: (1)

Eventually, ~ 450 at the wheels.

Until we get the chassis sorted out and learn to drive the thing, probably around 300 to the wheels? I don't really think it needs that much power to be competitive.

NotAPreppie

Well now you have me doubting my desire to do an LS swap if an L5-VE with a turbo can make that much power...

UnknownJinX

No replacement for displacement.

I don't doubt it can that make much power, but do you like a lot of lag as well?

You also know a lot about LS already and how to make reliable power out of it.

John V

iTrader: (1)

The power delivery will be a lot different. If your goal is to just make a lot of power, LS is your answer. LS will likely end up cheaper than going the direction I went, and you won't need to do any real fabrication. LS will also end up quite a bit heavier. It largely depends what you want to do with it.

If I were just building a track car with no rule set guiding the decisions, I probably would have gone the LS route.

NotAPreppie

Yah, I'm still a couple of years off on starting my swap so it will depend where I'm at.
It's just nice to know that there's another option that's been done.

John V

iTrader: (1)

https://youtu.be/qLjZ7kc9Mwo 402hp / 370lb-ft of torque at the wheels. Pretty happy with that.

John V

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Not the most up-to-date pic of the engine bay, but I'm pretty happy with how the engine fits in here.

John V

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I just realized I updated the thread in the Track forum but not this one. Car runs pretty well. Still some stuff to sort out but the engine runs like a champ.

Soravia

Really nice fit. I want to do NA modded and cam 2.5L MZR swap on S2 car. Is it possible to move the engine more forward to not cut any metal on body?
I plan to do OE looking swap and keep FSTB etc.

For those wondering, NC Miata supercharger kits are out of production. Soon the ND Miata kits will follow to extinction. Good-Win Racing is selling the last of ND supercharger kits for $3880 shipped on discount until Noon PST 30 AUG 19. When they are gone they are gone. Many are envious of my NC with FMSC kit.
I recommend getting the ND kit while there. ND makes more power than NC with 181 HP on 2019+ stock.
Who knows, ND SkyActiv-G might just swap right into the RX-8 as well! their 2.5L version makes 185 HP and 185 FT-LB right out of factory at 6,000 RPM. Bump the cams and springs, you'll see over 7,500 RPM and more at the wheel before boost with the supercharger.

NotAPreppie

I'd bet the high pressure fuel pump will be something that has to be worked around.

TeamRX8

iTrader: (25)

Envious??? He’s making a highly responsive 400 rwhp easy with a 7163 EFR turbo. An ND is a lot lighter than an RX8 too. Take your tinker toys and dinosaur SC ideas and go get petrified already. You noobs crack me up.

Soravia

Oh, really? But how much can you put down on the tarmac on DD car with DD tires? I'm already breaking traction all the time and have to stay below 65% throttle on my SC car with ONLY 225 wHP. Everytime I go full throttle, the rear hops and DSC kicks in even on dry pavement, 1st through 3rd gear. There's no wait for boost, comes on as soon as throttle is pressed. I have to be careful with clutch to not dump it when I shift mid corner.
Each their own purpose.There's ND, NC turbo kits out there for people who want dyno charts and 0-60 numbers. They can dole out lots of power for sure. SC are for DD people who want throttle response.

I want 2.5L MZR (NOT the DISI from Speed) in the RX-8 for the DD reasons. Much more lower to mid torque to push the car with people in it. I can rev all the way to 7,500 RPM with OE springs and more if I upgrade springs and destroke to 2.3L for reduced piston speed, for the sports car feel. Stock 2.5L will run out of breath at 6,000 RPM.

And of course, I can swap the RENESIS over with sub frame, wiring, and all the ECU parts over to the NC Miata (minus steering , to get the high revving feel in it without so much torque for the tires. Imagine a 400 lb or so lighter Honda S2K.

As for SC power limitations, just saw a CTS-V coupe dyno at 875 wHP with Flex-Fuel (about 70% mix I bet). Probably smaller pulley, too.

John V

iTrader: (1)

I haven't been paying much attention to this thread and I probably won't continue with regular updates moving forward but I wanted to respond to this.

1) Yes, you could probably move the engine further forward and reduce the amount of cowl cutting, but I think you would still have to cut the cowl. And then finding a gearbox solution would be much harder. I didn't do that because it defeats the purpose of this car, which is to optimize the weight of the drivetrain for handling.

2) I contemplated a supercharger setup, but none of the off the shelf ones were remotely appealing. Why? Well the Roots-type SC kits don't make nearly enough power, first of all. Second they are tremendously inefficient and put a lot of heat into the charge. Third they are heavy. If I were to go with a supercharger setup, a custom manifold with a Whipple (screw) type supercharger would work. But another downside to superchargers is they are very hard on the engine. They put a huge radial load onto the crank which is hard on bearings.

In the end, the turbo has worked out very well. With a set of cams the 2.5L easily breathes to 8,000 RPM, which is okay for brief periods with valve springs and stronger rods. I've been revving the stock motor to 7,400, with a set of mild aftermarket cams. The powerband and power delivery of the turbo is great for autocross, because of how responsive the turbo is with this engine. And yes, 400+whp is very driveable off of corners, at least with the big sticky Hoosier tires. You simply cannot approach the powerband of my setup using a supercharger. It will make half the torque at 4,000 RPM compared to my setup.

As I move towards a more racing-oriented gearbox for next season I will have my existing setup just kind of sitting on the shelf. Bellhousing, clutch, release bearing, FD gearbox, mount and the driveshaft. I have contemplated more than once building an emissions-compliant clone of this car with a smaller turbo and around 300hp at the wheels and this driveline setup would be perfect for that. If someone was interested in purchasing it from me I'd strongly consider that, to help fund the next phase of this car.

Brettus

iTrader: (2)

My Renesis makes almost double that power and probably double the torque from about 4000rpm on up . What you describe never happens on my setup unless I nail the throttle half way through a corner or when it's wet . Are you running crossply tryes from the 70s?