1984 3.2 ECU Questions

[Schubs]

I have a 3.2 out of a 1984 Carrera that needs an ECU. I found 2options locally, a 0261200078 and 0261200082.

Will either of these units work?
Is one more desirable then the other (slightly different mapping for more hp)?
Is one easier to tune (Steve Wong chip)?


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[Flat6pac]

Why don’t you send your old ECU to Steve Wong then you lol know what you have.
Bruce

[Schubs]

I don’t have an existing ECU :/

Bought a project car that came with the 3.2 on the shelf and a box of components, but the ECU was missing.

[Raceboy]

Might as well then buy VEMS Plug and Play ECU, works with stock sensors, offers much improved driveability and throttle response and also more power. Gets rid of AFM too

Check here: VEMS for Porsche and www.facebook.com/vemsporsche

[Schubs]

Looks like a nice system, but it looks like it’ll probably approach $2k Canadian by the time I get it here.

The manual shows the 078 as “high compression engines worldwide” and the 082 is for “USA, Japan, Canada (...etc.) cars with M298”.

The M298 code looks to be “prepared for unleaded fuel (catalyst, manual transmission car)” which sounds perfect as it matches the year of my 3.2.

It kind of leads me to think the 078 has lower emissions programming... and maybe more HP?...

[Raceboy]

Price for the kit is 1250 euros shipped to you, I have usually marked the value of the kit few hundred euros so that customs would be easier with import duties.
Note that kit includes wideband lambda and all the necessary wiring etc and is completely reversible, no need to cut or hack anything.
If original 3.2 DME's cost from 500 USD and up usually the price difference would be just several hundred and imo several hundred for modern system that offers great improvement is very reasonable.

[ischmitz]

Either will work. All these ECU are the same from an electronics point of view. Some very early Euro DME didn't have the O2 sensor electronics as this wasn't used in Europe. The part number ends in 51

By the end of the day it comes down to what software (chip) you will put in there. I'd use the latest U.S. spec chip since this has the most refinement from the factory.

Ingo

[Duc Hunter]

You could still call Steve Wong. I had an ECU issue with my 964 powered 75. He had some "known good" ECU's that he had completely gone through and checked out. I bought one and the car runs perfect. I could have bought it with a fan cowry chip, but as he is THE guy for doing chips in these cars, I got one of his chips in it.

I actually also carry a spare DME (as DME relay) in my cars....just in case.

At least call and talk to Steve, his customer service is always amazing. He can you the numbers, and what you need to buy, if he doesn't have one, or you don't want to pay for his.

[Schubs]

Thanks for all the help! I ended up buying both of the DMEs as the price was to good to pass up. I need to get the main harness still, and I see those are running north of a $1000.

And someone was kind enough to plant the idea of PMO’s for my project and THAT would be really awesome...

[Quicksilver]

To simplify this for people looking at this in the future.
1984 thru 1989 DMEs (Porsche 911 ECUs) are all the same with two main variations:
- 84 thru mid 87 have 24 pin chip. (Fixed program with various parameters controlled by the 'chip')(yeah there is a "no O2 version" but it is rare and you won't run across it in the US)
- Mid 87 thru 89 have 28 pin chip. (Updated basic program along with the various parameters controlled by the 'chip')

Any working DME is a good starting point for a replacement. All can be fairly easily updated to 28 pin chip. And all can be updated to improved table parameters (updated 'chip').

[mepstein]

Originally Posted by Schubs

Thanks for all the help! I ended up buying both of the DMEs as the price was to good to pass up. I need to get the main harness still, and I see those are running north of a $1000.

And someone was kind enough to plant the idea of PMO’s for my project and THAT would be really awesome...

I usually see the DME harnesses for a couple hundred. $1K is way too much.

[ischmitz]

Good summary: the one major difference between earlier code version (mostly found in 24pin chips but chip pin count is not synonymous with code version) and later code is the difference in idle speed. Earlier cars were set to 800rpm and this was raised to 880rpm later.

Often people ask: can I use XXXX DME in YY car. The answer is always yes. Any 3.2 DME can run any 3.2 engine. Idle speed might not be stable (needs adjustment of throttle stop) and subtle differences in running, yes but for testing it’s perfectly alright.

In other words the differences between all the DME Porsche brought out are very minor compared to the differences of any of these compared to performance chip.

And most any DME can be upgraded to the last code version with minor work.

[mepstein]

Originally Posted by ischmitz

Good summary: the one major difference between earlier code version (mostly found in 24pin chips but chip pin count is not synonymous with code version) and later code is the difference in idle speed. Earlier cars were set to 800rpm and this was raised to 880rpm later.

Often people ask: can I use XXXX DME in YY car. The answer is always yes. Any 3.2 DME can run any 3.2 engine. Idle speed might not be stable (needs adjustment of throttle stop) and subtle differences in running, yes but for testing it’s perfectly alright.

In other words the differences between all the DME Porsche brought out are very minor compared to the differences of any of these compared to performance chip.

And most any DME can be upgraded to the last code version with minor work.

Ingo is my go to guy for DME work. Super knowledgeable and easy to work with.

[mysocal911]

As has become apparent in the thread, there’re many who appear to be “knowledgeable” about the Porsche DME ECM
used in the ’84-’89 911 3.2. Credit is due, though, to one of the earliest Porsche DME ECM techs, a virtual pioneer,
Todd Knighton at Promotive. He started with "tweaking" the first Porsche DME ECM, the one used in the Porsche 924.
Most who get credit on Pelican Parts for their knowledge about the 911 3.2 DME ECMs, pale in comparison. Presently,
his work on the later Porsche DME ECMs starting with 993s, place the 911 3.2 DME technical knowledge attributed
to some, basically at the high school auto shop level. Todd developed one of the first PC apps for "performance tuning"
of the 911 3.2s. Todd is at the development level of being able to write source code for the Intel processors used
in the Bosch modules for the Porsche DME ECMs.

[mepstein]

Originally Posted by mysocal911

As has become apparent in the thread, there’re many who appear to be “knowledgeable” about the Porsche DME ECM
used in the ’84-’89 911 3.2. Credit is due, though, to one of the earliest Porsche DME ECM techs, a virtual pioneer,
Todd Knighton at Promotive. He started with "tweaking" the first Porsche DME ECM, the one used in the Porsche 924.
Most who get credit on Pelican Parts for their knowledge about the 911 3.2 DME ECMs, pale in comparison. Presently,
his work on the later Porsche DME ECMs starting with 993s, place the 911 3.2 DME technical knowledge attributed
to some, basically at the high school auto shop level. Todd developed one of the first PC apps for "performance tuning"
of the 911 3.2s. Todd is at the development level of being able to write source code for the Intel processors used
in the Bosch modules for the Porsche DME ECMs.

That all sounds great but most of us don’t know of Todd because he doesn’t seem to be on Pelican, sharing his knowledge with this group of enthusiasts. I’m sure if he does decide to share in the forum, his knowledge will be appreciated

[mysocal911]

Originally Posted by mepstein

That all sounds great but most of us don’t know of Todd because he doesn’t seem to be on Pelican, sharing his knowledge with this group of enthusiasts. I’m sure if he does decide to share in the forum, his knowledge will be appreciated

Here's a link to Protomotive; https://www.protomotive.com/home.html

If you have any questions about Porsche performance tuning, you can call him.

[Schubs]

As this looks to be a good post for DME info in the future, here’s what I found in the Service Manual for control unit numbers.

[larrym]

yes - any 3.2 ecu will work - several variants of chips & circuit boards

- you can find all about that by actually searching this site - or just googling it - i have about 50 links saved on the subject

i've used 3 different ones both 24 & 28 pin on my '89 & have a spare on shelf - currently have an 082 with Wong chip in the car

imho my 24pin ecu with the factory 383 chip pulls better at lower rpm & goes up hills like a locomotive, whilst Steve's chip is notably more spirited midrange accel & tends to be on the advanced side of the curve not liking to be lugged

since you are apparently in "early build stage" - just buy any one that fit your budget & try it out when the car is together - spend money on Steve's chip thereafter

now - i'm gonn'a be really kind & give you these

DME Compatible for '89 3.2 Carrera

http://rennlist.com/forums/911-forum/111318-carrera-3-2-performance-mystery-and-chips-long.html

84-89 DME Chart

Originally Posted by Schubs

I have a 3.2 out of a 1984 Carrera that needs an ECU. I found 2options locally, a 0261200078 and 0261200082.
Will either of these units work?
Is one more desirable then the other (slightly different mapping for more hp)?
Is one easier to tune (Steve Wong chip)?


Sent from my iPhone using Tapatalk

[mysocal911]

Originally Posted by larrym

now - i'm gonn'a be really kind & give you these

Doesn't really add much to this thread!