JDM BP-Z3 you want this motor
 

This motor has a couple of hot parts that only the jdm market recieved. I'm looking for a source for the motor, trans, harness, and ecu. Anyone know an importer that can get a hold of this combo? Just as an FYI the motor has a hot cam, better intake mani, higher comp, and better exhaust manifold. I'm seeing jdm Miata combo's pop up on ebay in the 1200 range just not the vvt version. The trans is not important but a nice bonus.


Someone find an importer!

Where did you get info about that motor? The wikipedia page says its just the VVT engine from 01+. I know wikipedia isn't always right, thats why I ask.

I dont know if there is a difference in engine codes, but it appears that there is a significant performance difference between the USDM BP-Z3 and the JDM BP-Z3.

13hp is pretty significant if you ask me. That could be 30hp difference on a typical aftermarket turbo setup.

My only concern is the compression ratio, I wonder if its high enough that most people wouldnt want to turbo on a stock bottom end.

I believe the comp is .5 higher.

so 10.5:1?

Yup, with the cam, intake, exhaust, and probably a little more aggresive ecu tune. Is the USDM engine also code bp-z3? I thought it was different?

10.5:1 is quite high for a turbo setup, unless you plan to run build the bottom end I would avoid. The hot cam and mani really isn't worth the price and work of a built bottom end. For the price of lower comp pistons you could probably buy a better mani and nice set of cams.

Unless I'm missing something, I don't see the point.

I saw a 90-97 motor go on ebay for 795 buy it now shipped. I have a buddy in japan, i wonder if he could hook me up....

I'd rather run lower boost and higher comp on this application. The intake is the one discussed in this thread.

https://www.miataturbo.net/forum/t42779-3/

It seems like all of those enhanced features might be appealing to a person wanting to run NA.

We don't need a hotter cam since even on non JDM engines, it's just a matter of turning up the boost until we are in rod bending territory. It's not like these JDM motors can magically spin to 8500 RPM. The exhaust manifold just gets tossed out or sold for a turbo manifold. Higher compression is the opposite of what we want and the ECU is useless since it can't be reflashed. Seems like a lot of trouble for a slightly better intake manifold.

You fail to realise that cams lower dynamic compression, which can allow for more boost/power safely.
Its amazes me how many people in the miata world dont realize this aspect of cam tuning.
People make 300+hp on 15+ psi on big turbos in hondas all day long, with stock rods that are weaker than the stock BP rods. Its not magic, its because they have better cams.

Personally, Im wouldnt be interested in a while engine, but if you could source the Intake manifold and cams, I would certainly be interested.

I bet a a JDM z3 exhaust cam with a MSM intake cam would make significant gains in a 99 head.

Plus when your tracking a boosted car the less psi the better. I'd rather have 220whp @ 8psi than 220whp @ 10psi any day.

Fixed.

I'd rather run high comp/low boost and have a nice solid powerband. I'm sure it could make 300rwhp and that's all I would want.

True, but the cam is a huge factor

This is a good point, but consider the changes in ignition timing you have to make to avoid detonation, especially at about 5K RPM.

Cam can lower DCR, sure, but then you have to look at overall TQ.

There is no free lunch. Personally after bashing my head into a wall periodically regarding detonation on my last project, I would rather have a well setup turbo system and mid to low 8's static compression and higher boost to make a given power level than 10:1 comp and less boost. The tuning is more forgiving.

Good reading (links) on SCR versus DCR, and a damned good site for those who are considering LS swaps too:

Static Compression vs. Dynamic Compression Ratio - LS1TECH

"Dynamic compression ratio" does not exist. There is only one compression ratio, and that is "compression ratio." There is no "static compression ratio" either, because that would imply that another type exists, which is not the case. There is only "compression ratio," and that is determined geometrically.

Bigger cams improve VE. VE affects cylinder pressure. CR affects cylinder pressure too, but that does not make them the same thing. They are different.

Just needed to get that off my chest.

Oh, and again, "dynamic compression ratio" does not exist.

Neither does HP, but its pretty damned relevant.

You can have two engines with a 10:1 absolute universal truth cmpression ratio, identical heads, displacements, boost, fuel, AFR, and timing, and one will blow up and the other will not. I have not seen a DCR particle, yet DCR matters.

Dynamic Compression - Hot Rod Magazine

Sparetire, what you and the Hotrod article are referring to is VE.

Nothing fucking exists.
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