Question for the JDM experts

DRFT MX5 · 07-19-2006, 01:47 PM

I have heard this time and time again from many people in the MIATA community (especially my fellow autocrossers) "There is no difference between a USDM and JDM motor for the Miata"

I recently read an post today on M.net saying that the BP-ZE motor (01+, aka my motor) in Japan had a 10.5:1 compression ratio giving it 160ish at the crank stock.

Also last night I was watching a BMI video the with the New NC Roadster vs the NB Roadster, and I could have sworn that NB roadster rev'ed to 8K??

Am I going crazy? and how do I make mine do that!!!

timallen · 07-19-2006, 01:51 PM

From what I have heard, they are the same motor, but are tuned differently for different regions/countries to meet regulations and other factors.

One can change the rev-limit by changing the crystal in the ECU that controls the "clock".

Let me dig up the link on Miata.net, but a friend here in Tampa has done it successfully.

DRFT MX5 · 07-19-2006, 04:59 PM

How "dangerous" is it to bring the rev limit up to 8K from 7.4K? I know a friend who autocross' with me has a BP motor (2000) which he's running on a Link ECU and he's running it to 8K. Do you think there would be much benift?

timallen · 07-19-2006, 09:39 PM

Well, my friend did some dyno runs with and without the rev limit raised, as well as the Bipes unit on and off, including a combination of both.

The resulting differences were minimal. Maybe a few HP; that's it.

There's a thread about it on m.net

the blue potato · 07-19-2006, 09:44 PM

Chris - when you and Kylee show up - I will introduce you to Todd Kawana who will have an Aizawa engine with a bit more compression and pick up.

DRFT MX5 · 07-20-2006, 07:19 AM

Thanks guys! See you at the Gap...

Phatmiata · 07-20-2006, 08:15 AM

Keep in mind they also run a higher pump gas in Japan. Also, my buddy was station in Japan and he says that his 91 (B6-ZE) would not allow him to go over 100mph. Some kinda speed controlled fuel limiter? But yeah, i would have to say the motors are all the same, just differet computer controlled thingamabobs on the ECU.

PhatMiata

DRFT MX5 · 07-20-2006, 08:34 AM

I had a friend with a NA8C which wouldn't go over 100mph either... but for a completely different reason

(bad rings which lead to hitting a deer, blowing the motor and nearly burning the car to the ground, which he then fixed and sold two weeks later for an S2k... traitor!) NO I'M NOT BITTER!

Sriracha · 07-24-2006, 09:27 PM

Quote:

Originally Posted by DRFT MX5 @ Wed Jul 19, 2006 10:47 am

Also last night I was watching a BMI video the with the New NC Roadster vs the NB Roadster, and I could have sworn that NB roadster rev'ed to 8K??

Am I going crazy? and how do I make mine do that!!!

I just rewatched the clip, that NB was actually redlining @ 7500.

But agree w/ others JDM NB's are most likely tuned differently for the better gas and such.

DRFT MX5 · 07-25-2006, 07:12 AM

I guess they must have a different gauge face then on the late model NB, because though mine will tack up to 7200 or so... my red bar starts at 7. Hmmm... it would even be nice to raise my rev limit 500rpm's. With as much autocross as I do that would help...

Bryan · 07-25-2006, 09:30 AM

Quote:

Originally Posted by DRFT MX5 @ Tue Jul 25, 2006 8:12 am

I guess they must have a different gauge face then on the late model NB, because though mine will tack up to 7200 or so... my red bar starts at 7. Hmmm... it would even be nice to raise my rev limit 500rpm's. With as much autocross as I do that would help...

On NA's, it's an easy fix on the ECU, but I don't know about NB's.

07-19-2006, 01:47 PM	#1 (permalink)
DRFT MX5 Member Join Date: May 2006 Location: Virginia Beach, VA Posts: 454	Question for the JDM experts I have heard this time and time again from many people in the MIATA community (especially my fellow autocrossers) "There is no difference between a USDM and JDM motor for the Miata" I recently read an post today on M.net saying that the BP-ZE motor (01+, aka my motor) in Japan had a 10.5:1 compression ratio giving it 160ish at the crank stock. Also last night I was watching a BMI video the with the New NC Roadster vs the NB Roadster, and I could have sworn that NB roadster rev'ed to 8K?? Am I going crazy? and how do I make mine do that!!!
	__________________ Chris Samulski Virginia Beach, VA http://i98.photobucket.com/albums/l2...nnoproblem.jpg

07-19-2006, 01:51 PM	#2 (permalink)
timallen Administrator Join Date: Mar 2006 Location: Tampa, FL USA Posts: 4,623	Re: Question for the JDM experts From what I have heard, they are the same motor, but are tuned differently for different regions/countries to meet regulations and other factors. One can change the rev-limit by changing the crystal in the ECU that controls the "clock". Let me dig up the link on Miata.net, but a friend here in Tampa has done it successfully.
	__________________ Tim (Toolman) Allen Owner/Administrator http://TampaBayMiatas.net Administrator http://ClubRoadster.net http://V8Roadsters.com http://V8RSpec.com 1993 Mazda Miata Limited Edition #790 of 1500 Black with Red Interior Coming soon: 1.7l with 45mm Jenvey DCOE IRTBs

07-19-2006, 04:59 PM	#3 (permalink)
DRFT MX5 Member Join Date: May 2006 Location: Virginia Beach, VA Posts: 454	How "dangerous" is it to bring the rev limit up to 8K from 7.4K? I know a friend who autocross' with me has a BP motor (2000) which he's running on a Link ECU and he's running it to 8K. Do you think there would be much benift?
	__________________ Chris Samulski Virginia Beach, VA http://i98.photobucket.com/albums/l2...nnoproblem.jpg

07-19-2006, 09:39 PM	#4 (permalink)
timallen Administrator Join Date: Mar 2006 Location: Tampa, FL USA Posts: 4,623	Re: Question for the JDM experts Well, my friend did some dyno runs with and without the rev limit raised, as well as the Bipes unit on and off, including a combination of both. The resulting differences were minimal. Maybe a few HP; that's it. There's a thread about it on m.net
	__________________ Tim (Toolman) Allen Owner/Administrator http://TampaBayMiatas.net Administrator http://ClubRoadster.net http://V8Roadsters.com http://V8RSpec.com 1993 Mazda Miata Limited Edition #790 of 1500 Black with Red Interior Coming soon: 1.7l with 45mm Jenvey DCOE IRTBs

07-19-2006, 09:44 PM	#5 (permalink)
the blue potato Moderator Join Date: Mar 2006 Location: South Posts: 4,431	Re: Question for the JDM experts Chris - when you and Kylee show up - I will introduce you to Todd Kawana who will have an Aizawa engine with a bit more compression and pick up.
	__________________ The Blue Potato / 1995 NA8C Pitcrew #001 / R.S. Aizawa IRTB / RS Watanabe / KG Works www.thebluepotato.net \| http://www.thebluepotato.net/blog/

07-20-2006, 07:19 AM	#6 (permalink)
DRFT MX5 Member Join Date: May 2006 Location: Virginia Beach, VA Posts: 454	Thanks guys! See you at the Gap...
	__________________ Chris Samulski Virginia Beach, VA http://i98.photobucket.com/albums/l2...nnoproblem.jpg

07-20-2006, 08:15 AM	#7 (permalink)
Phatmiata Rare Parts Hoarder Join Date: Mar 2006 Location: Tampa, FL Posts: 8,938	Keep in mind they also run a higher pump gas in Japan. Also, my buddy was station in Japan and he says that his 91 (B6-ZE) would not allow him to go over 100mph. Some kinda speed controlled fuel limiter? But yeah, i would have to say the motors are all the same, just differet computer controlled thingamabobs on the ECU. PhatMiata
	__________________ No Roadster, No Life!

07-20-2006, 08:34 AM	#8 (permalink)
DRFT MX5 Member Join Date: May 2006 Location: Virginia Beach, VA Posts: 454	I had a friend with a NA8C which wouldn't go over 100mph either... but for a completely different reason (bad rings which lead to hitting a deer, blowing the motor and nearly burning the car to the ground, which he then fixed and sold two weeks later for an S2k... traitor!) NO I'M NOT BITTER!
	__________________ Chris Samulski Virginia Beach, VA http://i98.photobucket.com/albums/l2...nnoproblem.jpg

07-25-2006, 07:12 AM	#10 (permalink)
DRFT MX5 Member Join Date: May 2006 Location: Virginia Beach, VA Posts: 454	I guess they must have a different gauge face then on the late model NB, because though mine will tack up to 7200 or so... my red bar starts at 7. Hmmm... it would even be nice to raise my rev limit 500rpm's. With as much autocross as I do that would help...
	__________________ Chris Samulski Virginia Beach, VA http://i98.photobucket.com/albums/l2...nnoproblem.jpg

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