986 vs 987 MAF tube

[The Radium King]

Originally Posted by P_Carfahrer

I have performed this mod in the last weeks. I had planned on using the 987 MAF tube and getting a tune from either a local tuner or Evo motorsports. My car is a 2001 S with the 7.2 DME. Both tuners said they can't make the 987 MAF tube in the 7.2 DME work as the map table size in bytes is larger for the 987 7.8 dme and they can't compress the map to work properly in the byte size table allotment in the 7.2. Enlarging the byte size map would change other addresses and cascades into an mess.

I cut the 986 MAF tube off and grafted it onto the 987 tube like in the thread. The id of the 986 MAF tube is still larger than the 997 Throttle Body. You just need to install larger hoses as the 986 hose restricts it even more.

If you have 2003-2004 with the 7.8 dme then the 987 tube can work.


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you can use a 996 tune on your car if you want to keep the larger maf tube.

[NewArt]

Originally Posted by The Radium King

you can use a 996 tune on your car if you want to keep the larger maf tube.

Cool, thanks for the information!

[witko999]

I thought that the 987 MAF tube was 3.25" diameter, against 3.5" for the 996?

Or do the 3.4 987's use a 3.5" MAF?

[The Radium King]

Originally Posted by witko999

I thought that the 987 MAF tube was 3.25" diameter, against 3.5" for the 996?

Or do the 3.4 987's use a 3.5" MAF?

987 and 996 are same ID. i’ve been running 987 airbox, 987 maf and tube, 997 plenum and cayman tb (or 996? can't remember) for several years now no problem. using a 996 tune and monitoring trims. low load trims have been perfect, and idle trims a bit higher but still well within spec.

[The Radium King]

Originally Posted by NewArt

Cool, thanks for the information!

here is more specific info ...

a number of variables - year, displacement, variocam. porsche moved the 996 from the 7.2 to 7.8 dme in 2002, but didn’t move the boxster until 2003. unfortunately, porsche also put the variocam+ system into the 996 at the same time, whereas it didn’t introduce it into the boxster until 2008 (the box kept the standard variocam timing). so, a 2003 or 2004 can’t run a 996 tune. fortunately (and pls verify, as i have no direct experience) the 2004 Special Edition anniversary edition boxster runs the 987 airbox and maf housing on the same engine as a standard 2003/04, so that is the tune i would use in that case. if you have a 99 or earlier i am not sure how well the 3.4 tune would work on a 2.5 (ditto and 2.7 or 2.9). a 996 tune to 01 works great on my 2000 S, and should work no problem on a 2001. if you have a 2002 you should be ok with an earlier 996 tune as well.