3.4 engine swap Q&A

[soccerties]

Originally Posted by itsnotanova

1) What flywheel/clutch do I use? The 3.4 had a really good clutch on it and I'm hoping to reuse it.

This is dependent on which transmission you use. I foolishly ordered a 996 clutch but was using the 5 speed trans from my 99 Boxster. The teeth didn't line up so I had buy a regular 986 clutch which to my knowledge are fine to use with the increased power of the 3.4.

Originally Posted by itsnotanova

2) I have the cluster, immobilizer and DME from the 996 cab. Besides running another wire to the cluster for the oil pressure gauge, it's just plug and play right?(using the 3.2 engine harness). There shouldn't be any reason for getting the 996 DME reprogrammed. The 3.4 DME will still think it's in a 996 cab?

I don't believe you'll need to reprogram the DME. I'm not sure about your MY but with my 99 harness I also had to route wires for the resonance flap in the intake.

Originally Posted by itsnotanova

3)I have a 987 aluminum engine cover. I won't need to lower the motor any to clear the 996 intake?

I also bought a 987 engine cover. However the intake was making contact with the car and not the engine cover. I had to use a couple inches of spacers on the front engine mount. Try to lower the engine as little as is necessary because the engine lowers your ground clearance.

Originally Posted by itsnotanova

4)Is there a verdict on which fuel rail is better/easier? 3.2 or 3.4?

I used the original rails because the 99 Boxster has a return fuel system, but the 99 996 did not. Your MY will be different than mine so you'll have to decide which one to use.

You've probably already seen it, but this pelican article was the most helpful resource I came across.
Porsche Boxster Engine Conversion Project - 986 / 987 (1997-08) - Pelican Parts Technical Article

[Paul]

Originally Posted by soccerties

This is dependent on which transmission you use. I foolishly ordered a 996 clutch but was using the 5 speed trans from my 99 Boxster. The teeth didn't line up so I had buy a regular 986 clutch which to my knowledge are fine to use with the increased power of the 3.4.

I have about 30000 miles on my 3.6 with the 2.5 5 speed clutch and tranny, no issues.

[itsnotanova]

I was at COTA today and ran into Brad Roberts. He's a car chief for one of the Cayman GT4's racing there and use to be big in the boxster scene. He's done a few swaps and said that because I'm using a 6 speed I shouldn't have any problem using the 3.4 clutch and flywheel. He also said that the 987 engine cover isn't normally enough to clear and I would either have to lower the motor a little bit or make some clearance in the sheet metal. He suggested I use the 987 airbox and that the dme, immobilizer, cluster, locks and keys from the 996 should work fine. Thanks for all your imputes.