I'm making a BPT miata
 

Bullshit to "everyone has done it search around" I've been looking my ass off and found fuck all other than bits and pieces of "its possible" so I'm doing it.

Not only am I doing it but I'm doing it in one or two days and racing next Saturday.


So far I've found that I have most of everything that's established as needing to be changed over, namely; oil pan, standalone ecu,mani's, flywheel and clutch, tranny, and the engine has a cas already so no need for me to swap mine in so bonus there.

I'm really hoping the the connectors for the electronics are the same but if not I get to freshin up my soilder skills.

So who thinks this is a great idea lol. Reason is I fucked my engine and can't find a cheap/close bp to swap, this one is only 500km away, ya that's close for miata parts.

I'm picking the engine up tom so I'll have pics up this weekend of the swap and the details that way in the future someone can see wtf needs to be changed as the info doesn't seem to be out there in great detail.

Oh ya this is that built 1.92 bpt that's been forsale forever in the classifieds. I think it will be fast if I can make mspnp work with it...Or use the standalone it comes with..

So, you're using the BPT from the 323 GTX? If so, that's pretty cool. Most would say unnecessary but if you need to replace the engine, why not eh?

Good luck!

I'm really not sure why and I could be totally wrong, but for some reason I want to say that Marc from M-tuned said he's put the BPT motor fromt he GTX in a Miata before, might want to get in touch with him for tips.

Nice thing is you can sell the parts you can't use (intake + exhaust manifolds, oil pan, turbo, oil feed line) to the Protege / Escort guys and make some money back.

Electrical connections should be the same, physically there's not a whole lot different, though how much depends on what "built" means.

Word Koto, thanks for the reminder kplafin I will get ahold of him if I run into any hang-ups.

Matt, ya the standalone and turbo and manis will be sold off for sure (along with my 99 head and custom 94 int mani made to fit the head) so I can recoup some costs hopefully. And most of what I've read suggests the connectors are the same, should help with the lack of time I have to do it.

I honestly can't think of any connections that would be different, if I get a chance tomorrow I'll take a look and compare my Miata to my GTR and GT/X hybrid motors to double-check.

What head are you planning on using? The BP26 head, or one from a Miata?

FYI, that 99 head will flow better than the BPT, IIRC.

hmmm

I'd hope so the BPT heads have restrictions on the intake ports, the NA protege heads flow better. Apparently the restricted intake ports increased torque at lower RPMs.

The only other downside I see is the lower CR of the BPT vs. an NA BP->NVM, I see it has been built

Those intake restrictors aren't as bad as you'd think, but either way, these heads just don't flow very well.

I've heard conflicting testimony, but you have a GTR so who am I to say. ;)

Well the head is fully built and flowed (increase of 20percent, which is enough to put it on par with the 99 I assume) so I imagine those intake bumps are long gone lol. Although my 99 head is semi-built (oem parts but worked over pretty throughly) and the int mani is a 94 modified to fit with lot of porting and extrude honing so either one will work fine I'd say.

Or if I can swap over head parts and cams I can slap on the 99 head and sell the gtx one. Not sure if valves ect as interchangeable there though.

Thanks Matt that would be cool if you could re-assure me that the wiring will be pnp bacially.

The cr is 8:1 which is low for a time attack car, but I'm never out of boost or below 4k so it shouldn't matter.

you won't be able to use the stock GTX manifold... not unless you want to severely modify your sheet metal and/or subframe.

I was thinking the same thing....if you put the motor in there with the GTX manifold on the throttle body will be right at the firewall won't it?

^^Where does it say I'm going to use the gtx mani's???

MIATA MANIFOLDS on the gtx head yo.

Plus my turbo manifold/turbo is way more baller than the oem gtx shit;)

The intake restictor argument is about as conclusive as the exhintake argument.

What you believe depends whose side you're on.

Use one head or the other. If you use the GTX head, you'll either have to plug the stock t-stat opening and remove the coolant plug (I'm sure you know this, but just in case :p) or run a coolant reroute. You *could* swap over head parts, but it's a lot of effort for not much gain, if any. The BP26 head uses HLAs still, which means you'd have to swap the cams, lifters, shims, and all that nonsense over from your 99 head. Not worth it, IMO. Valves should be interchangeable; the only head that I can think of at the moment that has different valves is the BPD variant of the BP26 head, which had sodium-filled exhaust valves. I know that between the BP05/BPZE/BP26 and BPD, the valves are all the same size. Since your BP26 head is built, it may have oversize valves.

Right now it's raining pretty hard, so let me see what I can come up with for being different as far as electrical plugs from memory... TPS/MAF are different, but you're using Miata parts. The BPT has an oil pressure switch, not sender, so just use a Miata sending unit. It should have a knock sensor, if you don't have a knock control box you can get one from a 626/MX6/Probe GT with the F2T. I really can't think of any other connectors that are physically different, so I'll have to wait until the weather clears to look. I know that the coolant temp switch that bolts into the T-stat housing on the BPT can change based on the year (I've had at least two different ones now).

Yeah, the exhintake debate never gets old.

so what you are saying is that you are putting a miata motor in a miata... I don't see why that justifies a whole new thread. besides the manifolds that motor is identical. The only exceptions are the dip stick location (in the pump instead of the pan) and the casting on the rear of the head not having provisions for the coil packs.

Seriously... wtf dude.

So, will the motor run on a megasquirt for a miata?

Or will it need alot of custom work in order for it to function correctly?

If the latter, than sounds like a waste of time.

Stock for stock, there's quite a bit more than that for differences between the two motors...

Fireindc: No reason it shouldn't, with conversion to Miata use.