M97 3.8L X51 motor in a 996 (2002+) car?

[itacud]

First, please let me apologize to those who will ask me to search... I've done no work for a while now and have just searched and read continuously! =) But, I'm down to the wire now. I must make a decision on what engine to replace in my 2002 996 by tomorrow. I'd love to put the 3.8 X51 motor in it if there is a good electronic solution that allows all original systems to function correctly. Otherwise, I'll have to use a standard 996 X51 replacement motor. Tough, I know. =)

I know a few people have put the 3.8 X51 into their 996's... I was wondering if it can be done with the stock 2002+ 7.8 DME, and stock wiring harness, with something like a softronic software reprogram... Also wondering how much additional hardware would need replacing, in the form of control modules, sensors, etc... Or, physically, is it only a matter of merging some mismatched hoses?

Again, thanks in advance to anyone who can help answer these questions! I promise to keep searching in the mean time. =)

[phillipj]

I know that Todd (username THOLYOAK) Put a 3.8 in his Boxster. He has more knowledge than anyone regarding these conversions. He has posted many threads and has helped others with their conversions.

I also considered putting a 3.8 in my 996. The engine cost was too prohibitive mostly because I didn't have a 3.8 core to exchange.

From what I understand you may have to beef up the driveshaft with the 3.8. You are putting a lot more power to a drivetrain that was not designed for it.

As far as the electronics I have no idea. From what I have read you should be able to use the 7.8 DME. I know there are other issues but I'm not knowledgable enough to discuss them. Todd actually took the time to figure out all of these obstacles (plumbing and electronic) and make it work.

It's not plug & play that is for sure.

Good luck with whatever you decide to do and please update the forum on your progress!

Succes!

Edited May 28, 2009 by phillipj

[itacud]

Thanks for the reply! From what I could find, the last engine swap Todd had posted about was the 3.6 X51 that went into his boxster. The work he did to integrate that properly, including the upgrade to a full DME 7.8 system was impressive! What I can't tell however, is if putting an M97 3.8 motor in the 996 which already uses the 7.8 DME, can be done w/o replacing the wiring looms. It seems like a "simple" software program of the engine control is all that would be needed, but I don't know. Hopefully someone who's done it might be able to share. Thanks!

I know that Todd (username THOLYOAK) Put a 3.8 in his Boxster. He has more knowledge than anyone regarding these conversions. He has posted many threads and has helped others with their conversions.

I also considered putting a 3.8 in my 996. The engine cost was too prohibitive mostly because I didn't have a 3.8 core to exchange.

From what I understand you may have to beef up the driveshaft with the 3.8. You are putting a lot more power to a drivetrain that was not designed for it.

As far as the electronics I have no idea. From what I have read you should be able to use the 7.8 DME. I know there are other issues but I'm not knowledgable enough to discuss them. Todd actually took the time to figure out all of these obstacles (plumbing and electronic) and make it work.

It's not plug & play that is for sure.

Good luck with whatever you decide to do and please update the forum on your progress!

Succes!

[tholyoak]

Putting a 3.8 into a 2002+ car that already has a 7.8 DME is quite straightforward. Very few differences between putting a 3.8 and 3.6 in those cars. The 7.8 DME can be programmed to run the 3.8.

-Todd

Edited May 29, 2009 by tholyoak

[phillipj]

Itacud,

Sounds like you are cleared for take off :jump:

:cheers:

[itacud]

That's great news... Thanks very much for the reply! Unfortunately, I'm not sure who can sell the correct software. I can't get a clear response from Softronic as to what "conversion file" they sell is the appropriate one to use for a 3.8 installed in a 996 3.6 chassis, and FVD refuses to sell their 3.8 -> 3.6 software anymore, insisting that they will only do the conversion in house.

Putting a 3.8 into a 2002+ car that already has a 7.8 DME is quite straightforward. Very few differences between putting a 3.8 and 3.6 in those cars. The 7.8 DME can be programmed to run the 3.8.

-Todd

[phillipj]

Most places that do conversions will not sell their software. They figure that they have done the R&D and their not going to provide it unless they do the conversion.

Todd should be able to guide you on this..

Edited May 29, 2009 by phillipj

[itacud]

Yup, looks like you are correct. I've heard back from both FVD and Softronic on this issue, and neither will sell their conversion files for this particular conversion. It's a little odd, since Softronic sells many other conversion files for a reasonable price (almost double the price of a simple ECU tune), but won't do it on this particular conversion. It seams it would be fairly difficult to pull off the install on one's own, without the ability (or knowledge of how) to write the correct M97 engine control maps into the stock 996 ECU?

Most places that do conversions will not sell their software. They figure that they have done the R&D and their not going to provide it unless they do the conversion.

Todd should be able to guide you on this..

[phillipj]

Take a look at this post.. He is putting a 3.8 S motor in his 99 996. Much bigger job than yours would be. Maybe he can answer some questions for you.

http://www.renntech.org/forums/index.php?s...rt=#entry134936

[itacud]

I love to see that people are working on this swap! =) I do wonder if he has a software package ready to program, or is just giving the '04 996 DME programming a try with the 997 motor? The latter seems to be the case.

Take a look at this post.. He is putting a 3.8 S motor in his 99 996. Much bigger job than yours would be. Maybe he can answer some questions for you.

http://www.renntech.org/forums/index.php?s...rt=#entry134936

[tholyoak]

I helped a fellow do this conversion, he was able to have GMG do the remapping of the 7.8 DME to run the 3.8

I find it strange that Scott (softronic) will not provide the ecu mapping.

-Todd

[itacud]

Hi Todd. That's interesting to know... I did actually originally speak to GMG about helping figure out this install, and they told me it would be new R&D for them, and weren't quite sure what would work right away, and what would need to be tried out first. I may give them another call. Thanks!

I think the issue with Softronic stemmed from the fact that all communication went through an intermediary, as opposed to Scott directly. There may have been some facts that were lost in translation.

I helped a fellow do this conversion, he was able to have GMG do the remapping of the 7.8 DME to run the 3.8

I find it strange that Scott (softronic) will not provide the ecu mapping.

-Todd

[Terje Gronlie]

Question for Todd.

I have recently bought a 1999 US 996 with a 3.8l 2007 model and understand it needs to be tuned properly as it does not work well over 2000 rpm. 

Who can I contact about this for hardware and software requirements etc. 

I am located in Norway, thank you.