I know it's of lower importance, but any feedback on fuel economy?

Empty quoting this :party:

It's basically the same as the BP. Its hard to say for sure though because I've been beating on this thing non stop, plus I think the tune is a little rich. I'll know better once I do some long, boring highway driving.

In for vid of stock long block K24a2 Miata with decent header and intake and tune v basic 225ish WHP 1.8 turbo Miata.

Yes, I know the turbo will have 35ish more WTQ.

Yes, I know the basic 1.8 is cheaper.

But it will be interesting to see how another thousand RPM allows the K24 car to use gearing more effectively. 5 or 6 speed on either car.

I bet its closer than one most are thinking. And the whole not-having-to-source-badass-hot-side-parts-to-keep-it-together-on-long-track-stints has be tempting for a fairly substantial contingent of people here. Imagine Crusher with a K24. Jesus. Lots of classes where that's not OK, but still.

My buddy has a Civic with a K20A2 that made 220whp on a heartbreaker dyno with a kludge intake, Hybrid swap header, 3" exhaust and a street tune on 93 octane. I want this in my life.

magicdc2, I need you to either finalize the swap parts or let me test a prototype kit. Like, right now. professional engineering insights and professional install photography can be provided. Serious.

I haz the same feels.



But sadly I'm a college student, and my car is in the garage until the snows gone.. In a few months.. :sad2:

Almost there, thanks for being patient. Official pricing to be released really soon. I'm in Chicago, come on up and I'll let you drive it (also serious).

That's what this swap is about - just good, cheap OEM power that stays nice and cool after lots of track abuse.

Just for kicks I looked around online a bit.

If someone did end up roasting 5 speeds using a K24, S2000 6 speeds run at like 600 bucks and a K series adaptor plate to run one is about 300 bucks.

'Why not just get a 6 speed?' Because they are a pita to find and expensive and they break sooner than S2000 boxes for the crazy power people. Stripping 4th because TQ on a road course in a 350WHP 2400LB car is sort of lame.

So basically this has possible transmission solutions that are sort of interesting. PPF and cross member issues aside, 1000ish for a 6 speed with useable ratios for a K that's pretty strong and shifts well is neato. S2000s run 4.10 gears, so the whole package should work pretty well.

Contrast this with finding one of those 'affordable' and 'common' T-56s I keep hearing about.

U need a custom flywheel as well.

Custom drive shaft

And adaptor to go from pff to s2000 trans.

Yeah, as natedawg mentioned, here are the reasons I did not consider an S2000 trans:
-this setup is mainly designed to be used with an N/A K series setup, thus making less torque than you turbo BP guys, and fits within the power limits of the Miata trans
-S2000 trans is one more thing to buy
-doesn't bolt to PPF, so needs custom mounts or PPF adapter?
-custom drive shaft is needed
-VSS won't work, which means you'll probably have to run an S2000 cluster (my setup has 100% functional miata gauges)

Its certainly a good option for people wanting to make over 350wtq out of a K miata, but for me and probably 95% of potential buyers, the Miata trans will do nicely, keep costs down, and keep it simple.

So far my 5 speed trans is handling the K24 torque like a champ, and gearing feels good with the 4.3. I don't see much reason to make the setup any more complex.

What is different about the k-series engine that would require a custom k-member? Is it the oil pan and pickup?

Just wondering.

Its for clearance everywhere. header, oil pan, oil pump, etc.

Our first k member was a chopped OEM one, and we had to hack it up pretty drastically.

copied and pasted from k20a.org thread, in case anyone is interested:

"I also have some important updates on the final production version of parts:

I have a revised version of the adapter plate, this time made in steel.

I have also revised the intake manifold adapters to be 3/4" thick, allowing customers to run a full OEM k series pulley setup with the EP3 idler (there was previously interference with the pulley and TB). Also, I have a version for a PRB head as well as a RBC head.

The subframe and mounts were shipped out this week to my supplier, and I will have the first final production versions in a few weeks, including powder coating.

I have contracted with Moroso to produce a custom baffled pan for me based on my specs. They already have my prototypes and will also be sending me a unit to test fit in the next few weeks."

I just came.

However, wtf is a PRB and RBC head?

Also, I saw you like to PM people the guys on that other site the ballpark pricing. I would appreciate the same!

Head casting codes:

PRB : 02-04 RSX Type S - 200HP
PRC : K20A (JDM Type R) - 220HP
PNA : CR-V
PND : Base model RSX
PNF : "EP3" Civic Si
RBB : TSX
RRB : 06+ Civic Si


PRB and PRC are good ones.
The PND/PNF head is really common and also really awful. It was rated at 160hp at the crank, but Im pretty sure that was an exaggeration since they struggle to make 120 at the wheels.

pretty much. and between all those heads, there are two basic designs for the coolant ports on the intake side.

TSX and Si use the RBB/RBC/RRB style, and the Type S/Type R uses the PRB/PRC heads (identical castings).

People still make 200whp out of the weak 160 hp k20a3 with OEM internals, so its not that hard to make power. I've never understood the point of using that motor, unless you are power limited in a specific class.