28 vs. 32 pin DME

[djnolan]

I have a M-tune MAF kit and need to convert my DME from 28 to 32 pin EPROM. It has been on the shelf for a while and now I have found the time.

Question I have is there a difference between a stock 28 pin and a stock 32 pin DME? Does the 32 pin version EPROM have any different operating characteristics than the 28 pin? Is it worth trying out as I do the conversion, if I can get ahold of one?

[DannoXYZ]

I think you mean 24-pin vs. 28-pin?

Once you convert your 24-pin to 28, there's no difference with factory 28-pin.

[djnolan]

Ooops, I can't edit the title but you are right...

So is there a difference between a 24 and 28 pin regarding horsepower, torque, fuel maps, etc?

[fiily]

Originally Posted by djnolan

Ooops, I can't edit the title but you are right...

So is there a difference between a 24 and 28 pin regarding horsepower, torque, fuel maps, etc?

Bin files are the same, difference is size of the chip storage is less on the 24 pin, and the 24 pin is only for 87 and below 944's, 28 pin = 88 and up 944's

If you have a m-tune, you need to have your DME sent in or do the 24 to 28 pin conversion. I think rogue tuning charges $50 plus shipping ~ $75 if you don't like messing with soldering, electronics, etc etc

[djnolan]

Originally Posted by fiily

Bin files are the same, difference is size of the chip storage is less on the 24 pin, and the 24 pin is only for 87 and below 944's, 28 pin = 88 and up 944's

If you have a m-tune, you need to have your DME sent in or do the 24 to 28 pin conversion. I think rogue tuning charges $50 plus shipping ~ $75 if you don't like messing with soldering, electronics, etc etc

This is very helpful, I looked all over the web for info on the EEPROM contents and couldn't find it. Am I correct in concluding only the turbo or N/A performance chips need the larger 28-pin EEPROM memory?

Yes I am planning to do the mod myself, and Rouge gratuitously provided the pins with the MAF.

[DannoXYZ]

No "need" really as they're identical. The internal chip-mappings of an '87 24-pin 951 vs. an '88 28-pin 951 is exactly the same. Same mappings and same performance. You can even swap entire DME boxes between the two and they'll work just fine.

The reason you need 28-pin is that in the earlier 24-pin DME, the program-code is stored in the CPU. That cannot be changed. With the later 28-pin chips, that program-code is moved to the chip. Rogue uses that shift to replace the original DME program-code with their own much improved version. Also incorporates new features such as MAP-based ignition-maps, MAF transfer-functions, temp-based ignition adjustments, multiple-maps, etc.

[djnolan]

Now I remember about the internal code in the cpu.

I just went looking for my MAF kit and found everything but the pins. Can anyone tell me where to source the pins?

And can the moderator please change the thread title, this is getting too embarrassing.