Marc is correct, the 3.4 intake will work, at least on a MY 99

Regarding the intake system, can you substitute a 3.2L intake out of 986 instead of the 996 3.4L intake?
I ask since It's my understanding the additional height of the 996 setup might cause some problems in a 986 installation.
If the 3.2L setup won't work, are there alternatives?
thanks for any help.

Also, (IIRC) the 3.4l (or 3.6l) intake can be reversed to make connecting the intake with the air box easier.

I used to have a copy of an article from one of the UK published Porsche mags that detailed a 3.6l engine installation into a 2.5l Boxster but I think I threw this out a move or an office cleaning or two above.

The Boxster water pump is used which puts the water pump hose connections at the right locations and so on.

Pelican Parts (or whatever the name is) I think has some web pages that detail the well details of installing various engines into various Boxster models.

Sincerely,

MarcW.

There was a guy at BRBS that has done this to his 1999 Boxster. He originally had the engine 'lower' in the bay, but recently raised it, and I believe put a Cayman 'cover' over the top, to handle the difference in height of the intake. I don't remember all the details, but I'm pretty sure he frequents the board, so should pipe in on this installation. I tell you, the car definitely moves faster, especially in the higher gears.

The guy who did mine kept the 996 plenum, but used a Cayman airbox. The engine is mounted lower in the car.

987 engine cover makes it fit just fine. There are other modifications to install the motor but if clearance is what is in question here, just get a 987 engine cover. That is what has worked for me.

thanks Jaay--how much more room do you gain by going with the 987 engine cover?

I've never heard of anyone using the 3.4L 996 intake on a Boxster. It's totally the wrong size and shape. That is unless you're referring to the throttle body, which fits fine. I don't recall there being any substantive differences between the 2.5L intake and the 3.2L intake so it's neither impossible nor valuable to swap in the 3.2.

to the new engine, the new engine's intake will work as long as the engine is mounted lower and the new engine's intake is rotated 180 degrees.

This is my memory of this. I looked for a copy of the article and didn't find it so I'm working from memory.

There is a Porsche online parts site that has a colllection of articles/write ups on the various engines that can be swapped into various Boxsters that covers this swap and others in more detail. I thought is was at the Pelican parts web site but I didn't take the time to search/confirm this. I'm on vacation...

Sincerely,

MarcW.

I self performed a factory remanufactured 3.4 into a '99 2.5 after my Boxster's engine blew (slipped sleeve). I can't speak to other years as the e gas is probably different deal. Yes the intake will work, in fact you want the 3.4 intake because as part of it's horspower it has the vacuum valve switch on the intake which has to be wired to the ECU with a spare wire. Then of course the ECU has to be reprogrammed to make the vacuum switch work. I had to fabricate a new pipe from the intake to the airbox but the Boxster airbox worked. . The front of the engine is lowered a bit, using spacers under the front mount. It's tight but it fits with the 986 cover. The cost for all of this, including custom exhaust, was around $12 K so it's not for the faint of heart and wallet! But an awesome car was the result and not a day goes by that I regret that I sold it to a friend. At least I get to see it every now and then! And I bought a Cayman S which helps ease the pain!

The airbox and intake tube from a 3.4L will not fit. The throttle body and everything else downstream will work fine.

Sure it will. Mine did. If you don't use the 3.4 intake you don't get the resonance chamber. You do have to hang the engine 1" lower on the front mount with spacers to get the cover on but that's no big deal.

Edited 1 time(s). Last edit at 06/19/2012 12:55PM by Laz. (view changes)

and tear on the half shafts, their bearings anyhow, and the CV boots.

Not sure how much a half an inch drop of the engine affects the amount the half shafts are out of parallel with the road.

Sincerely,

MarcW.

... it's a 1/2" drop of the front of the engine, at the front engine mount.
There is a negligible difference in the angle of the half-shafts, since they're in the opposite direction of the "engine drop".
The engine pivots on the two tranny mounts which are almost over the half-shafts.
Happy Boxstering,
Pedro

... The airbox, air filter and air tube which is completely different from the 996 to the Boxster.
The engine's intake Plenums, tee and throttle body are basically the same and useable.
Happy Boxstering
Pedro

jeeeez.. Just put a 987 engine cover on. Stock height motor and your done.