Sneak Preview: Boxster + Carrera Engine Swap / Upgrade Article...

[Wayne 962]

I just finished the coding of this article, and I have a preliminary version that has not been edited or gone over too much. But, I'd thought I'd toss it up here for everyone to see if they'd like.

Pelican Technical Article: Engine Swaps & Upgrades

Enjoy, and let me know if you have any comments. Again, I have yet to finalize the edits on it.

THANKS!

-Wayne

[Aron in Toronto]

Cool, Looks like a good read.

Hope there are still some 3.4s stashed away if the time ever comes for my '97.

[Doug&Julie]

Makes me want to buy a Boxster and put a 996 motor in it!

Very much appreciate the "which motor goes into which chassis" outline. As a future purchaser, this will likely weigh into my decision.

Looking forward to the book.

[Wayne 962]

Originally Posted by Doug&Julie

Makes me want to buy a Boxster and put a 996 motor in it!

Drove mine tonight. It's a rocket. In some ways, it's almost too much power for the five speed, I almost feel like a four speed with taller gears might be more useful. I run out of RPM very quickly.

-Wayne

[s_wilwerding]

Any details about reprogramming the DME? Thank you so much for the article - I've got the 3.4 sitting in the garage right now, ready to be swapped in.

Have you seen any issues with the transmission/clutch?

[Wayne 962]

Originally Posted by s_wilwerding

Any details about reprogramming the DME? Thank you so much for the article - I've got the 3.4 sitting in the garage right now, ready to be swapped in.

Have you seen any issues with the transmission/clutch?

The programming section is not in there yet. No problems whatsoever with the transmission or the clutch. They are perfectly fine...

-Wayne

[s_wilwerding]

Todd mention in his old article that he used 964 engine mounts for the transmission - it looks like you use 993 engine mounts. Any big difference between the two (other than price, which is significant)?

[tholyoak]

The 993 mounts are the same as the 996/986 mounts so you are accomplishing nothing by using the 993 mounts. Take a look at your stock mounts and you will see they are stamped with 996 and 993 part numbers. The 964 parts are taller and space the trans end down properly allowing the square fitting on the mount to fit properly into the carrier bracket.

-Todd

[Wayne 962]

I didn't actually take very good notes on this, and I didn't take very good photos on this either. I did order up a whole bunch of different mounts and compared them all to each other. If I remember correctly, the 993 mounts were indeed almost identical to the Boxster ones, but they had a longer stud sticking out of the bottom, which allowed you to space them down a bit. Oh, and yes, I thought that the cost of nearly $600 for a pair of mounts was a bit high, and I was looking for alternatives.

I will order up a set of each tomorrow and then bring them home and take photos of them.

-Wayne

[931GT]

What about swapping in an air-cooled 3.2? It seems that in a few more years there will be a ton of dirt cheap Boxsters on the road with RMS leaks requiring a new engine... but I'd bet there are a great number of folks who would prefer to plop in a bulletproof 3.2 instead of try their luck again with a ticking timebomb. Maybe the RMS failures are overstated but it seems that as the miles rack up it becomes more and more likely that the crankshaft will get tweaked. Thoughts?

[Wayne 962]

Originally Posted by 931GT

What about swapping in an air-cooled 3.2?

That would be prohibitively expensive, both on the engine front, and the installation. I heard of someone who put in a GT3 motor into the Boxster - the installation (not including the engine cost) was about $50K or so. The cheaper solution would be to install a big block Chevy, but that would also be very difficult to do, electronics-wise.

-Wayne

[s_wilwerding]

I'm starting to buy parts, and just want to make absolutely sure I'm buying the correct things:

97-99 Boxster flywheel 986-114-012-05
97-99 Boxster flywheel bolts 999-073-092-01
06-08 Cayman clutch disk 987-116-014-00
06-08 Cayman pressure plate 986-116-028-04
06-08 Cayman pilot bearing 034-105-313

Thanks.

[Wayne 962]

Originally Posted by tholyoak

The 993 mounts are the same as the 996/986 mounts so you are accomplishing nothing by using the 993 mounts. Take a look at your stock mounts and you will see they are stamped with 996 and 993 part numbers. The 964 parts are taller and space the trans end down properly allowing the square fitting on the mount to fit properly into the carrier bracket.

-Todd

I ordered a stock replacement Boxster mount and a stock 964 mount and compared them. The 964 and Boxster mount are identical in terms of how and where they mount the transmission, as you can see by the attached photo. The 993 mounts that I used for my conversion were identical to the Boxster mounts, but they had a longer stud sticking out of the bottom. I was able to place some washers in there and lower the assembly by about 1/2 inch using that technique. I don't see how the 964 mounts would work any differently than the stock Boxster mounts. At first glance, they look taller, because they are constructed differently. But when you measure them, they are almost identical. I made sure that the mounting planes on the two mounts were level as well (it doesn't look like they are in the photo, but they are at the exact same level when placed on their tops). Actually, I'll just take another photo.

-Wayne

[s_wilwerding]

So I probably still want to go with the 993 mounts.

Did you use a regular Cayman (not S) clutch in your conversion? I'm ready to start buying parts, and don't want to buy the wrong thing - I assume I want a Cayman clutch kit.

[Wayne 962]

Originally Posted by s_wilwerding

So I probably still want to go with the 993 mounts.

Did you use a regular Cayman (not S) clutch in your conversion? I'm ready to start buying parts, and don't want to buy the wrong thing - I assume I want a Cayman clutch kit.

I just used a brand new stock 986 Boxster clutch, because it was what I had, and I wanted to see how it would work. On the older 911s, unless you go Turbo, the standard clutches are typically fine. So far with mine, the clutch is not slipping at all. But I would probably recommend the later-style 987 Boxster/Cayman clutch package.

-Wayne

[tholyoak]

The 964 mount is slightly taller than the 993/996 mount. The installed height is lower than using the standard mounts. This is the only factory solution to lowering the trans end. As I stated above, I would highly recommend against using washers or spacers as the mount is no longer keyed to the carrier bracket. There are more elegant ways to lower the trans end if you desire it even lower than the 964 mount can provide, but the 964 mount is the only bolt on solution to get any lowering and keep the mount and carrier bracket keyed.

-Todd

[Wayne 962]

Originally Posted by tholyoak

The 964 mount is slightly taller than the 993/996 mount. The installed height is lower than using the standard mounts. This is the only factory solution to lowering the trans end. As I stated above, I would highly recommend against using washers or spacers as the mount is no longer keyed to the carrier bracket. There are more elegant ways to lower the trans end if you desire it even lower than the 964 mount can provide, but the 964 mount is the only bolt on solution to get any lowering and keep the mount and carrier bracket keyed.

-Todd

I agree that that not having the mount keyed to the brackets is not ideal, but I doubt it probably doesn't make too terrible a difference. The measurements of the mounting flanges on the 964 mounts show about a 1mm difference between the two, so that would result in a lowering of about 1mm. Maybe they are manufacturing the 964 mounts slightly differently these days?

-Wayne