Mazda Rotary Club

General => General Technical => Anything Engine/Performance/Tuning related => Topic started by: dom187 on April 17, 2012, 10:01:55 AM

Title: 16Bit Vs 8bit ECU\'s
Post by: dom187 on April 17, 2012, 10:01:55 AM
Hi All,

I am looking to buy a rex in the very near future and I understand the 1996+ cars come with a 16bit ECU which has various benefits. I plan to put a Apexi ECU + the commander in what ever car I get. My question is if you have two cars, one with a 8bit ECU an one with 16 bit ECU then put in the Apexi ECU in both is there any difference between the setups? Is having the Apexi ECU in there negating what ECU was originally there as I understand the looms are different and there where other changes?

Thanks for any help.

Dom
Title: 16Bit Vs 8bit ECU\'s
Post by: Prof on April 17, 2012, 11:13:08 AM
You\'ll have to adapt the loom in the car that had the 8 bit ECU, as the connectors to the ECU were different - the 16 bit ones have 4 plugs, the 8 bit only 3. But all the ancillaries should work ok if memory serves me right.
Title: 16Bit Vs 8bit ECU\'s
Post by: dom187 on April 17, 2012, 11:17:31 AM
Thanks, I think I might not have phrased my question correctly :)

What I am trying to work out is there any advantage to me buying a car with a 16 bit ECU vs one with a 8 bit ECU when I plan to change the ECU with the Apexi one at a later date?
Title: 16Bit Vs 8bit ECU\'s
Post by: BlitzBoy on April 17, 2012, 11:33:38 AM
No advantage, as the Apexi is 16 BIT anyway .

But I would say the 96 plus cars, the looms will be in better shape, pre 96 most of the looms are failing apart due to age, plus the Rats nest with the solenoids are in a black box on the 96 plus , better design. Just seems the 96 plus cars are bit more reliable in my experiance
Title: 16Bit Vs 8bit ECU\'s
Post by: lockwood77 on April 17, 2012, 03:09:49 PM
You will need to make sure you get the right Apexi PFC for your car too, there are 6 versions for the FD! Three "8-bit" era and three "16-bit" era I think. I\'m not sure if they are interchangeable within the 8-bits, e.g. if you can use version 1, 2 or 3 on the same pre-96 car (I think you can), but you definitely need one of the later versions for a 96+ car.
Title: 16Bit Vs 8bit ECU\'s
Post by: dom187 on April 17, 2012, 05:25:23 PM
Cool, thanks for all the advice guys. So a 1996+ car is the ones to go for?
Title: 16Bit Vs 8bit ECU\'s
Post by: lockwood77 on April 17, 2012, 05:30:53 PM
Not necessarily, depends entirely on the condition of the car! :) But all things being equal, you\'d have to assume a newer car will be in better nick, at least as far as wiring goes. Bodywork, engine, turbos etc. are all down to mileage, maintenance and how careful previous owners have been of course.

You might find later Apexi PFC models harder to come by, as there are fewer 96+ cars around and hence fewer PFCs floating around. You can still get them new though (I think - there was an issue a while ago with Apexi, they went into administration for a while but are still going as far as I know).
Title: 16Bit Vs 8bit ECU\'s
Post by: Furb on April 17, 2012, 11:36:04 PM
The 16bit pfc\'s may be a bit more rare, but on the other hand, people cant get rid of them as easy as the commonly used 8bit.
I got my almost new 16bit pfc 4 years ago pretty cheap because the guy couldnt get rid of it.
Bought a knightsports 16-8bit converter harness and i was set!
Title: 16Bit Vs 8bit ECU\'s
Post by: jpo on June 17, 2012, 01:13:30 PM
Sorry for the late thread-bump, do the 96+ PFCs work on the 99+ models or was there another change in ECU/loom after 99?