Engine replacement
 

I have a '99 2.5L Boxster

If I had to replace my engine (god forbid, IMS issues or whatnot), I would love to go bigger. What engine would be ideal for me? By this, I mean what engine will be the most efficient in terms of cost and power? I would like to go bigger than a regular 3.2 S engine. I know that my car uses a non-e gas system, so I heard that 996 3.4L non-e are ideal? Would I need to purchase anything else? Third radiator upgrade?

I'm somewhat new to the car scene and would like guidance. A comprehensive list on what needs to be done during an engine upgrade to a bigger engine would be grand.

Cheers

You are correct a 99 996 3.4 engine is a direct replacement & gives the most bang for your buck. You should have the 996 injectors pressure cleaned & tested for spray pattern & install a new 160 degree thermostat & water pump. This should be sufficient for street driving.

Thanks for the fast reply. I'll probably upgrade the clutch too while I'm down there.

Will my base transmission hold up the new engine? Do you recommend the third radiator that the S uses?

Yeah new disc with a 987 pressure plate & probably a new flywheel. Stock trans is strong enough. Since you are in AZ you will probably want to add the 3rd rad. & Box S coolant pipes.

Here is a good general info article from our forum owner: Pelican Technical Article: Boxster Engine Conversion Project - 986 Boxster (1997-04) - 987 Boxster (2005-08)