Many of you may have seen this online over the weekend, but I wanted to share it here as well. We've spent the last 18 months developing a new swap that uses the 2009+ K24 engines in an effort to bring a lower cost K24 swap kit to market that can be used with the stock NA/NB subframe.

The full write-up with pictures, all details, and dyno graphs can be found here:
https://kmiata.com/blogs/news/game-c...3-swap-is-here

This swap still gives you over 200whp N/A, saves you about $2k over the cost of our current K24A2 swap, and thanks to the stock subframe it can be legally run in NASA ST4/TT4, and more. We think it has really broad appeal and will become a really popular option for lots of race cars and street cars alike. And yes, we will be turbocharging one ASAP. Making an easy 500+whp from a $350 junkyard longblock sounds like a good time.

Check out the link, looking forward to hearing your feedback!

 

Just when I commit to my BP! Looks interesting.

 

Great write-up.

*stares at K24A2 in garage wondering if a Z3 should happen instead*

 

Well for your power goals I'd stick with the A2, but if you decide that 200ish whp will do the trick then the Z3 will be be less expensive and easier to swap.

 

Very nice! Interested in seeing final oil pan pics.

 

This is awesome. Keep up the good work, guys!

 

I wish I would have had time to grab a ride in the car you were running around in at AMP. Do you plan to reduce price when the cast timing cover comes in?

 

welp, that 2k subframe was about the only thing preventing me from this swap.

 

I like that you keep working on making this swap easier and more affordable. Personally I like the idea of turbocharged cars for the street, but if I end up building a N/A for track use this swap will be a serious contender.

 

The idea was to have a swap for everyone. Glad we have something that better meets your needs.

Next time!

I don't expect pricing to be reduced, we just won't get killed on machine time on the billet covers anymore. We are pricing them too low for the time being. Once we know the volume is there then we can justify the tooling expense for the cast covers. And keep in mind if you're going with a standalone you probably won't even need it because you should be able to make the stock crank sensor work.

 

This is pretty epic. I can't wait to see what happens when you slap a turbo on it.. it's just begging for one and should be really easy to do.

Really makes building a monster BP sound silly if these really do hold 400+whp in stock form.

 

*Kicks BP to curb*


My body is ready.

 

Any issues with slave cylinder placement if running the BMW transmission?

 

From memory, on my old e30 the clutch slave was on the driver's side.

 

It's the ****! Here's my little write-up I posted on Trackable Miatas.


I had the great opportunity to drive KMiata's latest K24z3 swap kit at Miatas Before the Gap at AMP last Thursday.....and now............ I'm ruined.

My initial thought was that it delivered power like my miata, but with 70+ more hp. It was surprisingly torquey too. I purposely put it in higher gears, sub 4k rpm, and it was still responsive. I giggled several times while taking the tach to 8k(7800 limiter I was told).

David basically made this kit for me......

I need a swap that retains OEM subframe for ST4/TT4, ST5/TT5. Which this one does, plus one less expense on not needing the tubular subframe.

Able to make power from 160rwhp-210rwhp reliably. Easily done with a k24z3, even with the weird head with the exhaust "manifold" cast into it. I'll just need to figure out how to tune for each map I want.

Low running costs, so ideally no $2k engine rebuilds every other season. I just found a localish k24z3 with 42k for $400 at car-part.com. That's cheaper than a fuggin BP4W.

And of course doesn't break the bank upon initial setup. This kit does not require the tubular subframe, as mentioned before, nor does it require an expensive header. Also, inexpensive donor engines.

I have a feeling we'll see this swap become really popular within multiple groups/series/etc.

Here's the official write-up of this swap including target costs: https://kmiata.com/…/game-changer-the-new-k24z3-swap-is-here

Now I just have to put together my plan get this swap done in my car.

 

BMW slaves are on the other side of the bellhousing so a 3" downpipe clears just fine without the trick hydraulic release bearing.

These things can do 400whp at like 10 psi without much effort at all. I had a discussion with our tuner about them, and he told me he had a 9th gen Civic Si on the dyno recently (k24z7, exact same thing as k24z3) and he made 580whp on 100% stock internals. We'll be machining our own turbo adapter for the head soon and I'd like to do a basic 500whp setup in a shop car to explore the potential. $300 engines and transmissions that can handle that kind of power reliably is exciting so we must do it. For science.

 

 

It still blows my mind that stock Honda engines can handle as much power as certain swap-tastic American V8's.
I'm sure this has been beat to death in another k-thread, but why run a kpro/modified ecu instead of something like an ms3? It seems like you could skip the machined cover altogether and use the built-in crank trigger, run a relay to power the VTEC solenoid... what else is special about Honda engines that nobody runs them with a megasquirt?

 

Hondata = $650

MSPro = $1200+

???


Thats probably you’re biggest driver...?

 

David, any concerns with early Concentric Slave Cylinder failures? I have seen 370Zs with this issue, but I don't expect the engine-swapping Miata community to be as sensitive to failures.