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Old 03-11-2010, 05:15 PM   #1
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DME 7.2 vs. 7.8

DME 7.2 vs. 7.8...

I have a 2002 Boxster S (3.2L). I am swapping a 3.4L from a 06 Cayman S into it.

I know that I have DME 7.2. I also know that the new engine has 7.8.

Here is my question: Are these DME's different hardware or just different programming (maybe with different pins connected)?

If it is only software, can our 7.2 computers be flashed to 7.8?

Also, has anyone on here done this particular swap?

Thanks in advance
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Old 03-12-2010, 07:41 AM   #2
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You will need to swap to a 7.8 DME, as they are different computers, add the wiring to control the VarioCam Plus valve lift solenoids, and change a few pins in the harness, then program the proper 3.4 map into it with a PST2 or PIWIS. Your car with the 7.2 DME has VarioCam, the 3.4 has VarioCam Plus, which is a totally different system and is controlled differently.
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Old 03-12-2010, 08:16 AM   #3
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When did Porsche make the switch

from 7.2 to 7.8? Were any 986s 7.8?
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Old 03-12-2010, 08:45 AM   #4
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Quote:
Originally Posted by mikefocke
from 7.2 to 7.8? Were any 986s 7.8?
Yup, 03's and 04's have the 7.8 DME.
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Old 03-12-2010, 09:46 AM   #5
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tell us more about your swap plans...

where did you get the motor?
is your 3.2 toast? or are going to re-sell it?

any mods to the 3.4 before it goes in?

do you need a new tranny or anything else to accommodate the new motor?

who's going to do the swap and how much is it going to cost you?

I'd be interested in any info you can share as I'm considering a similar project.

thanks
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Old 03-12-2010, 03:02 PM   #6
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Quote:
Originally Posted by cheetah

Here is my question: Are these DME's different hardware or just different programming (maybe with different pins connected)?

If it is only software, can our 7.2 computers be flashed to 7.8?

Also, has anyone on here done this particular swap?

Thanks in advance

Yes, different hardware and programming (you will need 7.8 986 DME flashed to teh cayman's engine system).

It's just not software like I said.

yes I have and so have a few other people, but not many... and the real info is hard to pry from some people.

like the above posters said, you will need to re-pin quite a few pins on your DME/wiring harness plus add the variocam plus controllers... and probably lengthen two others... Im not familiar with the small items on a cayman engine, my experience is just with the 3.6 from a 996.
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Old 03-12-2010, 03:27 PM   #7
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I got the motor from someone doing a swap themselves. Motor is in perfect shape, low miles.

The 3.2L is in pieces (literally). Both halves of the engine have sleeve damage, and the entire engine is pieces on shelves right now. It was the one that was shown in Jake's thread in the fall:

Engine Carnage

The 3.4L already has the Porsche deeper sump mod, and I will be buying the 160 degree thermostat, oil pump pin, and IMS bearing from LN. I already have an underdrive pulley and headers. I am waiting on my T-body / plenum also, and that should be here soon. So the power will be quite a bit more than I have now.

I already have the 6-speed in my car, and doing the math, first and second gear are almost identical to the Cayman S. I have slightly higher numerical gears for gear 3-6. But it bolts right up.

I am doing all the work myself. The current state of the car can be seen here:



Doing it myself, the cost will be much less than a shop, of course. But there is still a lot of little things that I will be doing to make it as stock as possible. I am really excited and can't wait to get it back on the road.

I will be documenting the swap as I go...
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Old 03-12-2010, 03:29 PM   #8
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I am working through the pin-outs right now, so any notes or help that you have would be appreciated.





Quote:
Originally Posted by easyc
yes I have and so have a few other people, but not many... and the real info is hard to pry from some people.

like the above posters said, you will need to re-pin quite a few pins on your DME/wiring harness plus add the variocam plus controllers... and probably lengthen two others... Im not familiar with the small items on a cayman engine, my experience is just with the 3.6 from a 996.
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Old 03-13-2010, 11:56 AM   #9
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its rather straight forward if you have the porsche pin numers for the 7.2 and 7.8 to compare and contrast... but fyi the bentley manual isn't complete... I will be happy to looks your pin changes on say an excel sheet once you have them to see how they compare to what I did with the 3.6, but I'd rather not send out my sheet... this is one of the harder parts of a swap shops charge 10K+ for... lol

just pm and I will send you my email address
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http://i187.photobucket.com/albums/x...s/DSCN0406.jpg
2001 986S... 3.6 swap (yep 7.2->7.8), PSS9's, GT3 seats, OEM 986 Carrera 5-spokes, and much more http://i187.photobucket.com/albums/x...me/burnout.gif
1987 928 S4 white on red and... dead
2004 Chevy Surburban... drinks gas like its cheap or something
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Old 03-13-2010, 01:48 PM   #10
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I just tried pm'ing you and it said that I can't because you are past your limit.

Just pm me with your email address and we will go from there.

Thanks
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Old 03-13-2010, 02:02 PM   #11
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no problem
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http://i187.photobucket.com/albums/x...s/DSCN0406.jpg
2001 986S... 3.6 swap (yep 7.2->7.8), PSS9's, GT3 seats, OEM 986 Carrera 5-spokes, and much more http://i187.photobucket.com/albums/x...me/burnout.gif
1987 928 S4 white on red and... dead
2004 Chevy Surburban... drinks gas like its cheap or something
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