Boxster Project Advice

[1990C4S]

I have this project: 1999 Boxster in very good shape, complete car, with the original engine on a skid/pallet. This engine has damaged valves, it looks like one of the chains failed, I have not dug into it, and I do not want to spend the time and money on a 2.7 engine.

I temporarily connected the engine to the harness and powered up the car, everything seems to work, the immobilizer is happy, and the engine will turn over. I assume I have spark etc. If this was a good engine, I could be driving in a couple of days.

Included with the car was a 2004 S engine, which is not compatible with the 1999 ECU. Compression is good, it looks like it's worth installing. S0 I want to get the newer S engine into the car.

I see three options:

1. Run two ECU's. I need some of the 1999 ECU/immobilizer for door locks, widows, etc. I would need a 2004 ECU (7.8 DME I think) with the immobilizer bypassed to run the engine.

2. Run the 3.2 engine from a Megasquirt ECU. Megasquirt 3 can run everything, including the variable valve functions. Keep the original ECU for auxiliary functions.

3. Sell the 3.2, buy a slightly older compatible S engine, plug it in and drive. This is my least preferred option, I would be selling an unknown engine and buying an unknown engine. And it's boring, this is supposed to be a more fun/challenging project.

Assuming my electrical and software skills are 9/10 or higher, what would you suggest?

I just want a fun car that performs, resale value is zero concern. I am up for the challenge of 1. and 2. above.

[obthomas]

I have a 2003 Boxster S to go with my experience with engine swaps. There will be several significant issues trying to marry a 2004 ecu engine control to a 1999 car. In those years Porsche moved things like engine temperature and tachometer to CAN Buss. Your cluster and engine control will give you challenges. Good news is that starting and immobilizer are separate from the ECM and if you have the car key you should be able to start any engine you put in the car. Good Luck

I had your problem and went LS3. Now I don't have a problem.

[1990C4S]

Those are good points about the CANbuss and the speedo, I need to do some more research.

I have considered other swaps, Audi 2.0T, LS, Honda, etc. For most of those swaps (if I buy a kit) the cost is about five times what I have into the car so far.

Still pondering...

[tonythetarga]

I think the only ‘easy’ swap for the ‘99 2.5
Is a Gen 1 996 3.4 engine from ‘97 to ‘01.