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-   -   K series Miata swap (https://www.miataturbo.net/engine-performance-56/k-series-miata-swap-71588/)

Fireindc 05-26-2014 10:52 PM

looks pretty awesome to me. props.

k24madness 05-27-2014 12:23 AM


Originally Posted by emilio700 (Post 1134203)
That car was going to have the 2.0L Whammy motor but maybe not now. Other idea is putting it into the 95R.

I will have my lawyer draw up the adoption papers ASAP. I have references the can vouch for me. The Whammy will have a good home and be adequately fed by E85 and a Rotrex C30-74. I have the resources to ensure a happy full life in a comfortable chassis.

KMiata 05-27-2014 12:49 AM


Originally Posted by ctdrftna (Post 1134547)
it actually looks like it will make good power, there isn't much room to fit a conventional looking manifold, this keeps the runners nice and long, they look stepped and its a 4-2-1 design with 3" collector and v bands

Exactly. except its a 2.5" collector and then we are stepping it up to 3" exhaust. Typical setup for all but the crazy high hp N/A builds.

Here was our criteria:
1) be able to actually get the header in and out of the car without moving the engine (hence the V band)
2) good ground clearance
3) put exhaust to the left side of the car so you can run it in the stock location (since we are still using the PPF)
4) Proper running lengths
5) 4-2-1 if possible

Car hits the dyno this week. We will see how it does. If I'm not satisfied we will look into other designs, but honestly there is only so much we can do to stuff a header in that space. Car is gonna be nutty either way.

emilio700 05-27-2014 01:25 AM


Originally Posted by k24madness (Post 1134562)
I will have my lawyer draw up the adoption papers ASAP. I have references the can vouch for me. The Whammy will have a good home and be adequately fed by E85 and a Rotrex C30-74. I have the resources to ensure a happy full life in a comfortable chassis.

Its 13.0:1 and cant really be reduced. $11k and its yours

TurboTim 05-27-2014 08:07 AM


Originally Posted by ctdrftna (Post 1134547)
it actually looks like it will make good power, there isn't much room to fit a conventional looking manifold, this keeps the runners nice and long, they look stepped and its a 4-2-1 design with 3" collector and v bands

I've been all hateraid on this project mostly out of jealousy but I must say this header looks well done.

Midtenn 05-27-2014 01:42 PM

Definately making it hard not to save my pennies and do this in a few years [starts searching craigslist for more wrecked Miatas to part out]

noname4me 05-30-2014 08:44 AM

Will this conversion kit work with the (OEM NB) 6spd transmission? I saw way earlier in the thread that the 5spd was the original choice for developing the prototype parts, but was wondering if everything will work with a 6spd.

ctdrftna 05-30-2014 09:20 AM

Should work perfectly fine with 6speed.

Sparetire 05-30-2014 02:18 PM

One of the cool things about this is that the extra headroom RPM wise could make a 6 speed more effective - might be able to get away with a lower gear on some corners. And higher top speeds in every gear relative to most BPs. 5 speeds will see bigger benefits, as this will help compensate for the greater spread between gears relative to a 6 speed.

The not so cool thing about this is that it has become my latest excuse not to do a reroute, Mazdaspeed motor mounts, and other maintenance type items.

ctdrftna 05-30-2014 02:32 PM

From what I read is that in stock form you don't want to rev a k24 past 7800-8000. Now that's what my BP revved to so there's no difference in head room. How ever the drag guys rev them to 9k plus.

Sparetire 05-30-2014 04:39 PM


Originally Posted by ctdrftna (Post 1135457)
From what I read is that in stock form you don't want to rev a k24 past 7800-8000. Now that's what my BP revved to so there's no difference in head room. How ever the drag guys rev them to 9k plus.

I always just respect my stock 1.8's 7000 RPM redline. I guess I am really conservative there.

Yeah, the k20a.org boards are a bit unclear IMHO on how high you can really rev them safely in stock form. I think 'safely' means different things to different people. Some people post up that they rev K24s a bit past 8 on DDs and see years of reliable use, then others who think that's insane. I think of a K24 as an 8K RPM engine stock and a BP as a 7K RPM engine stock. Now k20s seem to universally get reved well past 8 and that's considered OK.

concealer404 05-30-2014 04:40 PM

That's not the point, though... the point is that it wouldn't take much to rev one to 9k, and that would be super win for a 6spd/4.3 combo.

ctdrftna 05-30-2014 06:52 PM

Yeah modified you can rev them high, for me i will rev it as high in stock form as my built 1.8l so no gain unless i build the k24

motormechanic 05-30-2014 07:03 PM

if there's more power in the 0-8000 rpm you're limited to for the k24 than your 1.8 BP, then who cares how high you can rev?

emilio700 05-30-2014 08:45 PM

After talking with Oscar Jackson Jr about it I have decided to build mine was a K20. He tells me 250 wheel on E85 is is just a good header, intake and tune. the k20 will survive all day long at night. With just aftermarket pistons. The K24 really wants to stay below 7600-7800 really heavily modified. this is assuming sustained full throttle like you would see on the track not a short burst up a freeway on ramp like most street guys do.

I want 9k and I am willing to give up some midrange torque for that.

ctdrftna 05-30-2014 09:28 PM


Originally Posted by emilio700 (Post 1135529)
After talking with Oscar Jackson Jr about it I have decided to build mine was a K20. He tells me 250 wheel on E85 is is just a good header, intake and tune. the k20 will survive all day long at night. With just aftermarket pistons. The K24 really wants to stay below 7600-7800 really heavily modified. this is assuming sustained full throttle like you would see on the track not a short burst up a freeway on ramp like most street guys do.

I want 9k and I am willing to give up some midrange torque for that.


Did hell freeze over, a MT member just said he was willing to give up torque for more top end!!!!

ctdrftna 05-30-2014 09:29 PM

Emilio, this is for you


4 Piston 2.5L Road Race Engine - K20A.org .:. The K Series Source . Honda / Acura K20a k24a Engine Forum

Splitime 05-30-2014 09:59 PM

I just remembered that there are some guys across the street running a direct drive K20 on methanol in a circle track car. Power number was around 400 NA I think? Maybe 3xx.

emilio700 05-30-2014 10:01 PM


Originally Posted by ctdrftna (Post 1135534)
Did hell freeze over, a MT member just said he was willing to give up torque for more top end!!!!

actually the same ~250whp top end. I just want to rev to 9k and I like the way it sounds. I'm doing this for fun. No specific goals or races that I'm going to do with it.

ctdrftna 05-31-2014 04:55 AM


Originally Posted by Splitime (Post 1135545)
I just remembered that there are some guys across the street running a direct drive K20 on methanol in a circle track car. Power number was around 400 NA I think? Maybe 3xx.

a lot of sprit cars run these motors.

A friend of mine just dyno'd his k24 yesterday
its stock crank and bore size, 13.7:1, full head work and drag cartel 4.5 cams
skunk2 ultra manifold with 90mm tb and a hood exit race header

366whp and 236 ftlbs on M5 methanol


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