Socketing '93-'95 NA8 ECU

93_Clubman · Postby **93_Clubman** » Fri Aug 28, 2009 3:01 pm

see: viewtopic.php?f=57&t=37873&p=494711#p494711

green_comet · Postby **green_comet** » Sun Aug 30, 2009 10:43 am

So basically you pull the standard chip, and solder in a 28pin socket. Then you can swap in and out the modded and stock chips you have?

Where did you get the modded chips from? this bloke? mpheinitz

I wouldnt mine getting a couple and playing around with the ecu.

93_Clubman · Postby **93_Clubman** » Sun Aug 30, 2009 12:59 pm

Yeah GC - as Mike says - you get a stock chip (with what ever rev limit you want) in case the one you remove to replace with a socket isn't reusable. Then you can swap between stock & race chips, or even the aftermarket chips like Fueltronics or Powerchip. I have a Fueltronics chip from a socketed ECU of Lightyear's, & Mike's chip is way better than the Fueltronics chip. Btw, probably worth mentioning that Mike recommends factory timing of 10 degrees BTDC, so this mod doesn't factor in any gain from bumping timing to 14 or so degrees BTDC. I believe Mike also has complete socketed ECUs or socketed ECU PCB & components, so it's up to you how you want to do the mod.

Btw, if any Australian delivered '96-'97 NA8 or '98-'00 NB8A owner is interested in this, please post a photo of the inside of your ECU components so it can be determined if a flash ROM is used as opposed to the EPROM of the '93-'95 cars. From late '95 US Miatas went to OBDII, however in Australia we didn't get OBDII until the NB8B, but we did get at least a partially revised ECU (plug etc), hence the uncertainty of applicability here.

green_comet · Postby **green_comet** » Sun Aug 30, 2009 1:19 pm

Just sent you an email Mike.

manga_blue · Postby **manga_blue** » Sat Oct 10, 2009 8:51 pm

Just giving this thread a bump while I'm waiting for a burner to arrive. Just for a bit of interest here's a plot from gibsonconsultings's map of a standard ecu from a '95 California NA8.

California Fuel Map.jpg

The high load figures are virtually identical to what I read off the dyno on mine when it was totally stock a couple of years ago. This means that someone in Mazda actually specified it to run like wet porridge at WOT above 3,000rpm! What were they thinking???

93_Clubman · Postby **93_Clubman** » Sun Oct 11, 2009 12:28 pm

from memory they apparently found the JDM & USDM '93-'95 NA8 maps are identical, & I understand we pretty much got whatever revisions the JDM got.

how did you go socketing the ecu?

manga_blue · Postby **manga_blue** » Sun Oct 11, 2009 6:23 pm

Haven't socketed yet. I have all the bits except the Willem burner which is on the slow boat. I've got 32 pin ZIF adaptors to take either 28 or 32 pin EPROMs. Both my ECUs are 32 pin. I might go the 32 pin route first if I can find the definition files. The chips are only around $7 locally. Knowing that the original A/F maps matched the dyno results so closely is a good point to be starting from. A son with fluent Japanese is helping with some queries too.

I've gotta say thanks very much again for the ECU. It's turned out to be a really good upgrade, even in stock form. My old one was a BPF6A, the one you gave me was a BPF6E (or is it an BPF6H?? :oops:

). More than just a minor version upgrade - there's a whole lot of stuff which now works far better with this one. There's more power through the range delivered more smoothly. Little engine control things for cold idle, slow driving and air conditioning are so much better.

93_Clubman · Postby **93_Clubman** » Mon Oct 12, 2009 12:03 pm

manga_blue wrote:I've gotta say thanks very much again for the ECU. It's turned out to be a really good upgrade, even in stock form. My old one was a BPF6A, the one you gave me was a BPF6E (or is it an BPF6H?? ). More than just a minor version upgrade - there's a whole lot of stuff which now works far better with this one. There's more power through the range delivered more smoothly. Little engine control things for cold idle, slow driving and air conditioning are so much better.

No problem ref BPF6C ECU - it's good to know there's improvement to be found there. I think this would have been the last or near last ECU revision prior to the introduction of OBDII in Japan & the US in the Aug '95 built cars. I take it these improvements would be due to the ECU map as opposed to components, as component-wise the BPF6A is very similar, just a few minor parts as per below.
BPF6A

CIMG0218.JPG

BPF6C

CIMG0219.JPG

BPF6A & BPF6C

CIMG0215.JPG

Fluent Japanese would be a very handy skill, as would fluency in ICT!

manga_blue · Postby **manga_blue** » Mon Oct 12, 2009 1:19 pm

So it was a BPF6C, was it? I'd forgotten. Anway, as you said, the boards are almost the same - just a few resistors moved around and later revisions of the processor and ROM chips. I assume that someone in Mazda decided to clean up the code.