2002 996 3.8 into 2000 986S

[black_box]

I've come across a 2002 996 engine that's been resleeved and received the 3.8 JE Piston kit that LN sells. Drove the 996 that it's currently installed in -- motor is a beast, but the car is ready to be parted due to other issues.

How hard would it be to put this engine into a 2000 986? Simple as bolting it in and swapping intakes? Or would I need to get more involved with the fuel systems and DME I would want to keep the current Boxster transmission, as it was rebuilt not too long ago, and of course I'd probably reflash the fuel maps as well after building, 'specially if I go w/ headers. If horsepower scales proportionally to displacement, I'd be looking at 340 hp without considering exhaust or ecu mods. That would be a very fast Boxster.

[BYprodriver]

Originally Posted by black_box

I've come across a 2002 996 engine that's been resleeved and received the 3.8 JE Piston kit that LN sells. Drove the 996 that it's currently installed in -- motor is a beast, but the car is ready to be parted due to other issues.

How hard would it be to put this engine into a 2000 986? Simple as bolting it in and swapping intakes? Or would I need to get more involved with the fuel systems and DME I would want to keep the current Boxster transmission, as it was rebuilt not too long ago, and of course I'd probably reflash the fuel maps as well after building, 'specially if I go w/ headers. If horsepower scales proportionally to displacement, I'd be looking at 340 hp without considering exhaust or ecu mods. That would be a very fast Boxster.

You have to run the 996 DME also because your car has 7.2 DME & 2002 996 engine uses 7.8 DME.

[The Radium King]

read the pelican technical article on engine swaps. that's the start. for your specific swap you have some other things to deal with ...

- some people are getting away without lowering the engine by using a cayman engine cover instead (more clearance)
- your car has a fuel return supply system; the engine you want to put in doesn't. you'll have to update the fuel pump or rebuild the fuel system
- you'll have to build a new intake, as the news engine requires a larger maf housing
- the engine you want to use has a 7.8 dme; your car has a 7.2. these are entirely different beasts. you have two choices - update your car to 7.8, or run the variocam+ on your new engine with some other method (like a jegs window switch that triggers on rpm). the 7.8 conversion requires that you get the ecu and wiring harness with the new engine, convert to a newer dash cluster, hvac unit and abs system.
- you'll need new exhaust to flow enough air for the new engine.

too much work; sell the engine to me instead.

[Wayne 962]

Ultimate guide to the swap here: Pelican Technical Article: Boxster Engine Conversion Project - 986 Boxster (1997-04) - 987 Boxster (2005-08)

From that guide:

The Boxster 2000 chassis can accept any Carrera 996 3.4L engine, or can use any Boxster engine from 1997-2002. In 2003, Porsche switched to a vane-cell adjuster mechanism to control the variable camshaft timing, and this system requires the later DME running Motronic 7.8. Unless you upgrade the car to use the later DME (very difficult), you cannot use any 2002 or later 996 Carrera engine or any 2003 or later Boxster engine. You can swap in any replacement engine of the same displacement from 2000-02 without having to remap the DME. (I.E. a 2000 2.7L Boxster with a blown motor can accept a 2002 2.7L engine with no remapping needed). Installation of a 3.2 Boxster ‘S' engine would be an easy installation, but would require an updated map for the DME.

So, it would be quite difficult.

-Wayne

[black_box]

Jeez, that's a shame.... Sounds like just getting a 2003+ roller 986S is a better idea. My car's engine is good anyway, would only be swapping for MOAR POWA! I got spoiled driving my Dad's '08 987S. Having an NA 3.8 would give me 100 more hp over stock, but more importantly another 75 ft-lbs of torque.

[tonythetarga]

It might be cheaper to find an '02-'04 996 with a bad motor and do a transplant.

[black_box]

Originally Posted by tonythetarga

It might be cheaper to find an '02-'04 996 with a bad motor and do a transplant.

No, definitely sticking with a boxster body. I've driven 996's and 997's and for me, it's boxster all the way for handling - plus you get a lot more trunk.

[tonythetarga]

I am just awaiting delivery on my 1st Boxster after having owned 4 911's over the years. With your enthusiasm, I am now really looking forward to my next DE to see how the Box handles!
Thanks

[Wayne 962]

If you refer to the article I wrote (link above), you'll see that anything 2001 and later should work well for you. 2002 and later would be ideal, but the 2001 cars can be reprogrammed too.

-Wayne

[Ray_s]

I would not worry about swapping the DME.

I've spoken some folks who changed the variable valve timing mechanically so valves simply stay with max clearance, which is around 11mm at higher revs as compared to around 3.5mm at lower revs. Trade off is a little more consumption and emission.

Add-on switches which open and close the valve vent depending on revs only may lead to a little rocky behaviour of the engine..

Fuel system is an extra effort as described. I coached a friend in Austria on same conversion by phne and email and he succeeded :-)

[black_box]

I've got an '02 Box S roller in my sights now....

[Bfan]

Very interesting project. Keep us posed on your progress.

[BYprodriver]

Originally Posted by black_box

I've got an '02 Box S roller in my sights now....

You need a 2003 or newer Boxster if you still are set on a 3.6 996 engine.

[Wayne 962]

Originally Posted by BYprodriver

You need a 2003 or newer Boxster if you still are set on a 3.6 996 engine.

You can still do it - you just need the 7.8 DME. From my article referenced above:

To install a Carrera 996/997 3.6/3.8 engine or a 2003-08 Boxster/Cayman engine into one of these cars, you need to purchase a new 7.8 DME, and then slightly modify the pinouts on the DME connector. In addition, you need to modify / extend the Boxster engine wire harness, as the camshaft position sensors are located on the opposite ends of the engine than on the 5-chain early motors (also the new camshaft adjusters have different connectors). All of the systems on the car should work normally with the later-style 7.8 DME (2002 has ABS version 5.7 so it does not have the same issues with the cruise control as the 2001 model). If you are installing an engine with Variocam Plus (all Carrera 3.6/3.8 and Boxster 2007-08), you will also need to add in the wiring to control the variable valve timing.

-Wayne

[black_box]

Ok, tell me if this is insanely bad idea, or just crazy:

I have a complete '02 C2 Cab with a big, nasty 3.8 pistoned motor and 6 speed trans. I am looking at a 2002 Boxster S Tip with a bad immobilizer (and other possible electrical issues).

How hard would it be to drop the entire 996 drivetrain into the Box? Can I get around the DME / Immobilizer / key / gauge cluster issues by just swapping all of those things over from the carrera?

Will the 6 speed 996 transmission and axles switch over directly? I know I'll have to swap intakes and exhausts. Is there anything else crazy to worry about?

[Ray_s]

Why don't you read the excellent swap article first????

The gearbox will have to stay the Boxster gearbox, else you'll end up with 6 reverse gears, 1 forward gear , LoL...

Converting from tip to manual transmission is a project by itself.

Immobilizer - you will have to buy a new one and teach it to the car with a PiWIS.

Again, I would not swap DME, cluster etc etc but mechanically make the valves stay max open, a fairly easy task and much much easier and cheaper.

All in all your project sounds rather expensive, 3.8 with small tiptronic, not a good combination to start with...