E36S50

I am looking at a 1998 Boxster with the intent of dropping in a 996 911 engine. I think RUF performs a similar conversion, but I am wondering how plug-N-play this swap is? Ideally I would go for the 320HP 3.6L, but the standard, pre-'02 296HP 3.4L would be okay. Any info would be appreciated!

****Update**** I just did a better job of searching the archives and found more info. I now know it CAN be done, but I'd like to know, other than the obvious, what parts are required and if there are any major tricky areas.

Thanks

Boxster 3.4

The tricky stuff (just what immediatley comes to mind)

I would not call a 3.4 swap true"plug and play". The parts alone are very expensive and you do have to do significant rework to make them fit perfectly and work together. Having said that, if you want to know what I learned in the process of doing this here goes:

The 3.6 will be more complicated to get into a 98 because of eGas. If you go with a 3.4 you just need the engine & complete intake system. You can reflash your motronic.

Airbox rework / refitting. Even with spacer and bolt kit the boxster airbox will probably need to be reshaped to fit with the 3.4.

Rework of fuel rail system on 996 engine to mate with remaining 986 system and retrofitting fuel line. Keeping all out of hot zones.

Rework/retrofitting of air intake on 996 from "rear" breather to front.

Engine installation/lowering using a spacer/long bolt kit (FVD).

There ware a few electrical "changes" that I did not get specifc deatails on.

New Clutch (will need a Sachs Superclutch)

Exhaust/cats(if you have them)/muffler tweeking. Get it all to fit with heat sheilds perfect.

Reprogramming motronic for 996 3.4 - FVD did mine.

Must have parts: (minimum)
3.4 with complete intake
FVD 3.4 spacer/bolt kit
tools and resources to handle fuel rail work
clutch
tools and resources to redo the airbox and intake
motronic reprogram resource

get some drilled rotors

Geoffrey

Actually, the 3.4 996 conversion is quite easy. It takes us about 5 days to do and costs roughly 13k which includes a brand new 996 engine from Porsche. We use the Boxster motornics which are reprogramed with the 996 X51 power kit program using the Porsche programming tool and yields about 340hp with a GHL stainless exhaust all included. We use the factory Boxster harness and run a separate wire to make the varioram work. All-in-all it is a nice package.

HBacura

Geoffrey, can you PM me with more info. on this upgrade. I will be looking into upgrading to the 3.4 in late March, early April next year

Gundo

Geoffrey,

Send me an email please..I am close by in CT and have some questions for you about the 3.4 conversion.

Gundo

Boxster 3.4

Geo,

13k is too good to be true. How can you do it for that? Engine alone is $9,000

Dave

Geoffrey

Well, ok, it is $13.9k and the new engine from Porsche is much less than $9000 from the dealer. All-in-all, it takes about 5 days from start to finish including a dyno session to make sure everytihing is operating properly. It truely is a very nice conversion. We've been seeing early Boxsters go through the auction for $15k and this upgrade is perfect for that scenario. It makes a car 'S' fast for less money.

Boxster 3.4

I agree that it is a NICE conversion.

Wish I had known about you two years ago.

Steve Wilwerding

I have a few questions for Boxster 3.4.

Did you upgrade anything else besides the engine (another radiator, tranny, etc.) If not, does the 5 speed seem to work OK with the 3.4? Do you ever have cooling problems?

Thanks.

Dwayne Williams

Wow - that's pretty impressive. A Boxster with 340 would be quite a bit stronger than an 'S' - they only have 250ish depending on the year model you have. Do you happen to have any dyno charts for one of these conversions? I'd love to see one.

Boxster 3.4

Steve,

NO problems. It seems the 5 speed is up to the task. I did not add another radiator and I have driven a lot in 95+ humid, traffic without issues.

Dave

Geoffrey

The only nonPorsche parts on the conversion are the cone air filter and stainless exhaust which is required because the 2.5l Boxster exhaust is too restrictive for the 3.4l 996 engine. If you track the car, I'd install the extra radiator in the front. One of the conversions we did we actually installed a complete Boxster S trans and subframe which was not as easy as one might think. I think the 5spd works just as well as the 6spd. Now, if you could regear them, then I'd want the 6spd and the car would simply rock.

On the 6spd conversion, we also installed 'S' brakes and GT3 seats. The car is silver with the Boxster red interior. Very nice car.

I do have dyno sheets off of a Dynapack dyno which is a chassis dyno and will show RWHP. I will get one put together in the next day or so, but I'll have to FAX it to someone who can take a picture of it and upload it here on Rennlist. And I was mistaken about the HP, it is 320, not 340 as I was thinking about the 3.6l 996 engine at the time.

Dwayne Williams

320 at the wheels is still quite impressive. You can fax it to me and I'll scan it. I'll send you a PM with my fax number.

Geoffrey

I searched the dyno for results from one of the Boxster conversions and didn't find any that we saved. The claimed 320hp from one of these conversions is from a 300hp rated 3.4l Carrera engine, and the 20 extra is from the more aggressive X51 Motronic ECU code, nice flowing stainless steel headers and exhaust, and a cone style air filter.

We actually did a conversion on a 996 from the standard engine package to the x51 package which included new heads, cam, etc. Porsche claims 35-40 hp additionall with the X51 and we saw 15hp on the dyno. The customer spent about 15k for that 15hp.

Jeremy Cottrell

Can you elaborate on what neds to be done to the fuel system. Do you run the 996 fuel rail and injectors with the Boxster intake manifolds?