DME part numbers/years for 1987 911

[superpilot27]

I need a spare DME for my 1987 Carrera.

My 1987 has a refurbished DME:
Bosch part # 0 261 200 082
Porsche part # 911.618.111.14

I have been told 1983 - 1987 DMEs will work in my car and 1987 - 1989 will work in my car. I also heard that 1989 DMEs will not work in a 1987.

Does anyone know what DME's will actually work on a 1987 911?

[DonMo]

The 84 to 88 will work. The 87 - 88 have a 880 rpm idle while the others have a 800 rpm idle. I am running a 28 pin Motronic in my 84. 28 pins were the 87-88 version. I believe the 83's did not use a Motronic. http://www.programainc.com/doc/Porsche.html is a link to what DME fits what year Porsche.

[kidrock]

I didn't know that different DME's had different RPM's. That's a great piece of info.

[rick-l]

I bet this guy would know.

http://www.pelicanparts.com/gallery/Steve_Wong/

[dw1]

A detailed description is available at :

http://www.911chips.com/dmeconvr.htm

Lots of other good info on that web site as well.

Courtesy of Mr. Steve Wong.

[rick-l]

If you go here https://techinfo.porsche.com/techinfo/pdf/en/catalogues/E_911_89_KATALOG.pdf page 408
I think you shoud have as original equipment in an 87 a 911 618 111 20 or a 911 618 111 16 if you have a Club sport (but I have never figured out for sure the model codes).

To figure out what a 14 comes out of you would have to download previous pet files and go through the MSP and V pages to figure out a model code.

[Steve W]

any .082 or .050 dme will work fine in your car - year doesn't matter . . . but why would you need a spare dme?

[superpilot27]

thanks DoMo, DW1 and rick-l,
I looked at the previous pet files 84-86 and couldn't find the .14 so I don't know what my DME is from.

Steve,
I replaced the DME last year with a refurbished DME because of an intermittent no-start condition at a shop in CA. (I suspect now that it had cracked solder joints.) This replacement/refurbished DME just failed with cracked solder joints, which I identified from info found here and PP and repaired myself Thursday. I wish I had taken the time last year to research the issue, (there was no time for DIY though)
I spent $3k at the shop who threw parts at it until it seemed to work, and now I had to fix the 'refurbished' DME myself.
So to answer your question, it seems that having a back up in the trunk might be the right move at this point. Or is this cracked solder joint/DME issue rare?

[superpilot27]

Steve,
I am now concerned if I am getting everything out of the engine as I could with a stock chip. I am curious what 'map' my DME chip actually has and if it is suited for my '87. It is numbered 1267355236.
I read what you wrote in the link from DW1 about adjusting the idle with this chip.
My board has the three jumpers B704, B705, B706 shown in your left pic [FIG. 3 - Already a 4K DME]. The car idles just below 800RPM on the stock tach, warm, with outside air temp 34F.

I want the car to be as efficient as possible. (It seems to run good, I smoked a buddies '08 Cayman S up into 3rd gear yesterday morning on my test drive.)
I have read in other posts that getting the AFR dialed in makes a big difference so my thought is to do the idle adjustment if it needs it and then adjust for 14.2 AFR next.
Any ideas?

[Steve W]

The cracked joint problems are not rare, but they have taken several years to reach that state, and don't happen with all cars. They are also expensive to keep as a spare, unlike a DME relay. The 'refurbished' DME that was installed may have been on the verge of failure when it was put in your car, and if there was a guarantee, I would have told you to send it back to whoever rebuilt it. If you fixed your unit properly, I really think it's overkill to keep a spare. If you still have your car 15-20 years from now and it happens again, well you know what to do.

There were basically two different 24 pin chip programs used in the U.S. 87 model year, the 1267355236 and 1267355302. The .236 program is the earlier one and idles lower at 800 rpm and rougher like the 84-86 cars. The .302 chip idles a little higher at 880 rpm. Power derived from the .236 chip would be equal to the 207 hp of the 84-86 cars, with the .302 chip at 217 of the 88-89 models. A good chip makes a significant difference to the drivability and everyday usability of your car, along with a smoother idle, more low and mid end torque, more throttle response, better highway fuel efficiency, and a 16-18 hp gain without any detriment to your car.

With regards to AFR adjustment, there's only the idle mixture you can adjust, and if you have a wideband AFR sensor, you want to adjust it to around 14.5-14.7:1 at idle. Since most people don't own one, then a shop can adjust it to 0.6-0.8% CO with their gas analyzer (measured before the cat) or you can do it yourself watching the voltage switchpoint off your O2 sensor. Adjusting the AFRs everywhere else, such as at full throttle and acceleration loads, can only be done by chip reprogramming.

[PorterF]

Originally Posted by Steve W

There were basically two different 24 pin chip programs used in the U.S. 87 model year, the 1267355236 and 1267355302. The .236 program is the earlier one and idles lower at 800 rpm and rougher like the 84-86 cars. The .302 chip idles a little higher at 880 rpm. Power derived from the .236 chip would be equal to the 207 hp of the 84-86 cars, with the .302 chip at 217 of the 88-89 models. A good chip makes a significant difference to the drivability and everyday usability of your car, along with a smoother idle, more low and mid end torque, more throttle response, better highway fuel efficiency, and a 16-18 hp gain without any detriment to your car.

I know this is an old old thread, but thought it was better to reply to this rather than start a new one.

Is there a difference in performance between a chipped .236 car and a chipped .302 car? Assuming they both have the same Steve Wong "program" they will have the same performance, correct?

For example a .302 car will gain 6-8hp and a .236 will gain 16-18hp from the chip? or is it 16-18 and 26-28 hp? It seems like the 84-86 cars would get more out of the chip?

If Porsche decided an 880 rpm idle was better for whatever reason, why don't the 24-pin aftermarket chips run the 880 idle? (I installed the 24-pin Steve Wong SSI chip, and my idle didn't change) I know half of the program on the 24-pin cars are on the 8051 chipset, is that the reason?

Does anyone know the rationale behind the 880 idle? Was it higher oil pressure, G50 made it stall easier, just idles better?