Sorry, I'm a K-series Noob. Brand new info to me.

Has anyone considering trying to run that exhaust manifold and turbo with a custom DP on a k-swaped miata? It looks like intercooler routing for a front mount IC would be a pain.


Insight to the k23a1 engine - K20A.org .:. The K Series Source . Honda / Acura K20a k24a Engine Forum

https://www.miataturbo.net/attachmen...ine=1421423902

https://www.miataturbo.net/attachmen...ine=1421423879

Or...

02 06 Acura RSX K20 K20A T3 T4 Cast Iron Turbo Manifold | eBay

https://www.miataturbo.net/attachmen...ine=1421424535

touche sir... Damn that's cheap.

We may or may not have a k23a1 on an engine stand right now. It could be made to work, but will need some other custom parts since it is very different than all other K series engines. Jury is still out if it will be a cost effective option.

Is that manifold aluminum? Wat?

test drive = success.

https://www.miataturbo.net/attachmen...ine=1421509573

My understanding is the K23 is a taller motor, so swapping into a miata would probably be problematic.

That may only be if you're keeping the stock intercooler, but anyway, it's much more cost effective and easy to just turbo a K20/K24.

And yes, the RDX has an aluminum turbo manifold with integrated water ports to keep the manifold "cool".

K23 looks interesting on paper but in the real world I don't think they make a lot of sense.

This is a very interesting feature. I am no Honda OEM engineer but why would you want to cool an exhaust manifold. Doesn't this just reduce the efficiency of the exhaust gasses by dissipating additional heat? I could see it maybe as a reliability feature I guess but other than that I am left wanting. Does anyone know the reason this is done?

I used to be a Honda OEM engineer... :wink:

The water cooling is necessary to keep the aluminum at a temperature that won't negatively effect the material properties...like staying solid...

Most aluminum casting alloys have a melting point around 1100F.

Compare that to common EGTs seen in a turbo manifold and I think you'll see why they needed water cooling in the exhaust manifold.

I'm not sure what alloy they used for the RDX exhaust manifold but I'd be willing to bet it was one with a higher melting temperature than normal casting alloys.

I think the question is really why bother using aluminum? What's the point? Lowering underhood temps and weight?

I would think primarily weight.

As further evidence of how light the Honda motor is, here's the final product. This is now a manual steering car with no a/c. The nose is so high that max camber is still slightly positive (.5 degree). Can't wait to get some suspension on this thing...
https://www.miataturbo.net/attachmen...ine=1421538571

Yeah, three Mazdas...

http://i875.photobucket.com/albums/a...psdvgskidl.jpg

Very nice, good work.

how does she drive?

that header looks beast. nice work!

Any plan for a heat shield between the header and that washer bottle? Or a relocation of the washer bottle?

Got my subframe/mounts this week and I picked up the rest of my parts (minus flywheel) from David today. I need to do some engine bay cleanup still but things are moving.

The latter, if it becomes an issue.

I'm more worried about underhood heat issues overall with that header...

It feels like what a Miata should have always had for a motor. Big fat torque (for a 4-banger), but not excessive.

The stock suspension is comical, though...especially with no front camber.

-anybody have exact weight savings vs stock engine?
-for the non-DIY types like me, what would this setup cost turnkey at 200whp (assuming that's stock output) and 250 ish whp ? assuming I drop off the keys to a stock NA, for example.

This swap has not been out long enough to answer this question accurately. And it will depend greatly on your location and the reputability/ labor cost per hour of the shop you use. Maybe a good estimate is to take the v8 swap kit cost estimates at shops for labor and add it to the price of a k24 and the kmiata kit and all other nic nack parts.

Based on some rough numbers I came up with, weight is about the same. Not enough to be a deciding factor IMO.

Andy, what were your before/after numbers?

So is the elevated front end merely a factor of no PS or A/C?

Doesn't seem like that would be enough.