986 Porsche Boxster to 981 body update conversion

[Beaker77]

Hi Ph'ers,

I am a big fan of the 986 as an affordable, good all round mid-mount sports car. However, probably like many of you, I think its looks have become quite outdated and could do with a refresh to give this great platform a new lease of life, so I have decided to start a project to create a 2015 981 Boxster body conversion update for my 986 Boxster S. I thought it would make for an interesting build diary so I will be chronicling my build journey here.

I am starting with all OEM factory body panels and will be striving to minimise the modification of these panels as much as possible to fit the 986 to maintain as close as possible to the 981 OEM dimensions. As you can see from the pics below, even 15 years on, dimensionally they are still very similar but do have some differences in panel heights, bonnet scuttle panel areas and roof covers etc. that will need to be addressed.

986


981


Rather than butcher my Boxster S while I work through the conversion, I have bought a bare shell to fabricate the conversion onto and then will be creating composite panels off this to fit to my Boxster S.

The donor


I have also collected most of the OEM body panels now, including a complete 981 rear end which will be very useful for keeping the rear of the conversion true as this will be done in sections. I also picked up some 981 Cayman roof/rear end panels with a view to creating a hardtop for the Boxster at a later date.





You might have noticed an Audi S8 in the background with the front end removed ready for the 340HP V8 engine to be taken out...that gives you a hint as to what the next phase of this project will be tackling! ;-)

I have started mocking up some of the panels and am getting a good sense of where the new 981 panels will be re-located on the 986 shell and there will be quite a bit of fabrication work to keep all the original 986 panel mounts, but it will be seamless in the new composite panels created from these.





This should be an interesting project (probably for all the wrong reasons!), so I would be interested in any comments or ideas as the build progresses.. I will keep the diary posted with my progress. I hope you find it interesting too.

Edited by Beaker77 on Monday 11th January 19:23

Edited by Beaker77 on Monday 11th January 19:43

[Beaker77]

80sMatchbox said:

You nutter!!



...but in a lovely PH way. Bookmarked!

LOL, I do like the road less travelled...

[Beaker77]

Yes, I have been told these things once or twice in the past, I just cant help myself, these things are there to be done!

[Beaker77]

fridaypassion said:

Looks awesome. If you want some composite tooling/production done let me know.

Thanks, will do.

[Beaker77]

Thanks for the feedback guys, always good to hear your opinions and no doubt there will be many more to come before this project is completed!

[Beaker77]

W12JFD said:

Absolutely tremendous idea - my only thought is that perhaps some more power may be appropriate!

Agree W12JFD, all part of the plan in the guise of an Audi V8 engine conversion, but that will be another story...

[Beaker77]

griffter said:

At first I thought "oh no, some deluded optimist is going to ask where he can buy the 'bodykit' and then get torn to shreds". Cost would exceed that of new 981, 'updating'-all-the-rage-in-the-80s-on-911-horror-stories, it'll never be worth what you paid for it etc. And the lone sympathiser agreeing that the 986 drives better and the 981 looks better, so why don't porsche offer a drive in, drive out service etc.

But your proposal, your progress and the background in your photos convinces me you are crazy, in a good way!

Good luck. Spyder conversion next? 986 coupe?...

LOL, classic! Funny you mention 986 coupe because if you think this is crazy, I have something a little less 'subtle' lined up for when this is finished which will evolve this into a 981 Cayman body with a few other 'enhancements'...still early days though but should be fun.

[Beaker77]

Hard-Drive said:

Wow...that's batst mental, and absolute fair play to you if you can pull it off!

I have to say the slight deal breaker for me is the Audi engine...any car that's been re-engined with a different make somehow doesn't "work" for me. Rover V8 in a Series 1 Land Rover, VW Beetle with some madly modified flat four pushing out hundreds of horses, 996 turbo in a 986...all good. As soon as it's a Subaru in a Porsche, or an Isuzu in a Range Rover Classic, the car loses a bit of "soul" IMHO. Or if it's an iconic engine config, e.g a flat 6 becomes a V8, or a Cobra kit car is built with a V6 rather than a V8.

But as I said, fair play to you, and do please keep the build thread updated as it's an awesome project nonetheless!

Hey Hard-Drive, I actually agree with you in many respects. My plan is to stick with the 3.2 for the Boxster project, however the upcoming Cayman project will definitely not be a mild Sunday driver so needs something more dramatic (plus I do love the sound of a V8!).

In an effort not to be totally sacrilegious, I choose the Audi V8 over the (heaven forbid) chev LS2 (which is actually an easier engine to work with with 400HP out of the box), however in the spirit of the point you raise, the Audi engine feels more appropriate as it does come from the same family (VAG) and the transaxle is actually an Audi unit so does that count ;-)

[Beaker77]

Escy said:

Hard-Drive said:

I have to say the slight deal breaker for me is the Audi engine...any car that's been re-engined with a different make somehow doesn't "work" for me. Rover V8 in a Series 1 Land Rover, VW Beetle with some madly modified flat four pushing out hundreds of horses, 996 turbo in a 986...all good. As soon as it's a Subaru in a Porsche, or an Isuzu in a Range Rover Classic, the car loses a bit of "soul" IMHO. Or if it's an iconic engine config, e.g a flat 6 becomes a V8, or a Cobra kit car is built with a V6 rather than a V8.

There are plenty of family ties, they share lots of the same components. The V8 in the Cayenne is basically an Audi engine.

What transaxle are you planning on using with the V8?

Our posts must have crossed Escy, using the Boxster S transaxle.

[Beaker77]

Hi guys,

Have made some progress with mocking up the doors, side skirts and rear end now. Next steps will be fixing rear bumper and lights, then after some more work on the doors it should be ready to start building out the internals on the panels for a nice factory type fit onto the 986 shell ready for final finishing and mould creation.

[Beaker77]

Trev450 said:

Beaker77 said:

In an effort not to be totally sacrilegious, I choose the Audi V8 over the (heaven forbid) chev LS2 (which is actually an easier engine to work with with 400HP out of the box), however in the spirit of the point you raise, the Audi engine feels more appropriate as it does come from the same family (VAG) and the transaxle is actually an Audi unit so does that count ;-)

Speaking of which, don't know if you've seen this:
http://www.planet-9.com/987-cayman-and-boxster-mod...

Thanks Trev450, haven't seen that one, interesting read.

[Beaker77]

Dan911 said:

Beaker77 said:

Hi guys,

did I hear something about LED rear lights are a problem to retro fit?

Looking good..

Yes, LED lights are a challenge because they have their own CAN bus controller and requires some creative 'reverse engineering'.

[Beaker77]

Ozzie Osmond said:

Escy said:

What transaxle are you planning on using with the V8?

Beaker77 said:

Our posts must have crossed Escy, using the Boxster S transaxle.

Surely the V8 torque will rip that transaxle to pieces? I would think it might be 25% above the transaxle's rating. Lotus always had dreadful trouble trying to find transaxles for their V8 Esprit and had to restrict engine power for that very reason.

I think it will be ok, there are a few I know of in the states running around with more powerful chev LS engines using these transaxles. That being said though, it does have a lot to do with how you drive it! I will fabricate a decent oil cooler which will help too. I suppose proof will be in the eating...

Edited by Beaker77 on Friday 22 January 16:45

[Beaker77]

Digitalize said:

I'm honestly shocked with how well this has gone so far.

Yes, it's coming along nicely Digitalize and I'm happy with how it's looking so far, but building out the internals and final fitting and fettling will take some time to do it properly as I want a factory type fit.

[Beaker77]

scotty_917 said:

As I have one of the first 986 3.2's delivered in the UK, I'm not looking to chop or change anytime soon. However, similar to earlier posts, I wish your project all the best and I too am very surprised with how well the conversion seems to have gone, thus far! Bookmarked!!

Thanks scotty_917, I can understand that as we want to keep some nice original 986's on the road and there will likely develop a good market for these over the longer term, but there are a lot of unloved 986's out there that are being out of their misery so I feel I am just giving them a second life!

[Beaker77]

So I have been assessing the options for the LED lights. As @Dan911 previously alluded to there are significant challenges with retrofitting factory LED lights (which are controlled by the CAN bus) to the older analogue systems. There are two options I am considering. Either use a programmable micro-controller with an analog-to-digital converter to convert the analogue signals coming from the 986 to simulate the digital CAN bus signals to the 981 lights, or replace the internal LED drivers in the 981 lights to an aftermarket driver with analog control. In an effort to explore the second option I needed to disassemble a tail light to investigate if this was feasible. Not wanting to butcher my nice new shiny 981 tailights, I had a Panamera light (which uses the same systems) that had a crack in the lense so I pulled that apart to see what might be possible. I thought you might me interested in what these look like inside.







Long gone are the days when you could just replace a light bulb!

Edited by Beaker77 on Thursday 28th January 07:33

[Beaker77]

Escy said:

Beaker77 said:

I think it will be ok, there are a few I know of in the states running around with more powerful chev LS engines using these transaxles. That being said though, it does have a lot to do with how you drive it! I will fabricate a decent oil cooler which will help too. I suppose proof will be in the eating...

Edited by Beaker77 on Friday 22 January 16:45

I'm planning on putting 500+bhp through a similar 987 3.2 transaxle. You might find you want to use the same transaxle, the 986.20 isn't a direct bolt on to the Audi V8 while the 987.20 is pretty much.

I actually considered that Escy as the 987 transaxle does fit without any modification because it has a starter motor housing on the side like the Audi engine, however the 986 bellhousing bolt pattern does match the Audi engine (7 of the eight bolt holes in the transaxle line up, the eighth lines up but is a blank on the engine block that could be tapped out if desired). The issue is that the 986 bellhousing doesn't have the starter motor housing on the side like the 987 bellhousing. The Audi starter motor doesn't actually stick out to far so a small cut out of the 986 bellhousing will fix that with a little fabrication/welding to cover it over. Bit of extra effort, but saves £700 for another transaxle! I will set up a separate thread for the engine conversion with some pics. What are you building? Sounds interesting...

[Beaker77]

cirian75 said:

holy crap !

so its a whole unit job if too many fail.

anyways, you Sir are mad and I salute you.

Yep, whole unit replacement as they are sealed units, but we have ways! ;-)

[Beaker77]

cardigankid said:

I am astonished by the professional looking results you are achieving in such a short space of time.

The 986 is a beautiful looking car in its standard form, simpler than the 981 but more classic. I'm not sure that I wouldn't rather make a 981 look like a 986. To that extent you are gilding the lily, but the interesting aspect of it is going to be how you get the Audi V8 into it. That on its own would be exciting, with updated gearbox and seats (the 986 was a tight fit for the taller motorist) . You would end up with a 986 that could tan a 981.

Thanks cardigankid, I am pretty happy with the results so far, but still a long way to go.

[Beaker77]

Escy said:

Here is a photo of an Audi V6 (same as the V8) spacer plate on the 986.20. You can see which holes line up as i've put bolts through them. The bigger issue for me was the crank sensor pickup. It's mounted on the bellhousing on the V6 and there is no casting for it on the 986.20 and as i'm using the standard management I decided it's worth going for the 987.20



I'm putting an Audi S4 2.7 bi-turbo in a Boxster S 986

Thanks Escy, I have added pics of my test fit below too.









You can see in the pic below the issue with the starter motor housing, but as mentioned I think this can be cut out and a cover fabricated.



As you stated, the bigger issue is the crank sensor location. You can see the reason for this in the pic below. The reluctor ring on the 986 is behind the flywheel (hence the engine block mount) and the Audi reluctor ring is in front of it (hence the bellhousing mount). Once I have decided on the flywheel/clutch combo I will be using, that will determine where I need to mount this. Have you decided what you are using yet?

Edited by Beaker77 on Wednesday 3rd February 13:35