987 v 986 Air box

[edc]

Originally Posted by Qmulus

I pretty much assumed that was the case, but I can't find the where in the intake threads that this was discussed. I guess I need to have a look in the 987 diagrams to see how it was set up. I have a feeling that even if the late 986 M96.24 and 987 M96.26 are almost identical and use the same ECU hardware, the later 987 software may not work in the 986. I may have to go play with a local shop PIWIS II to see...

I haven't seen any posts where someone with a '03 or '04 adapted the 987 air box. I would like to see if they found the 550 edition MAF to throttle body hose.

In the UK at least the 987 has a different AOS arrangement with an extra clip.

Why would you need the 550 MAF to TB tube? If you upsize the TB it won't be of any use anyway.

[10/10ths]

....so I have a 986 with a 987 airbox from the factory.

If you need photos let me know.

[mikesz]

You will have to let us know how you make out. BTW haven't forgotten I still owe you $$ for my gauges!

[Gelbster]

For those interested in upgrading the "T", the Thread linked may be useful& cheaper than the plan mentioned in the quotes:
Intake plenum and 911 throttle body

Originally Posted by Qmulus

I just picked up the parts to convert my '03 S to the 987 airbox. I was able to find an airbox with MAf housing and rubber connection hose, which would mate with a 987 throttle body T. The interesting thing is that from the pictures that I have seen the '04 550 edition looks to use a different throttle body to MAF hose to match the 987 MAF housing to the 986 throttle body, but I don't see it listed anywhere. Odd.

I also found the split intake T from an '05 987 S with the vacuum flap and PCV hose. With these parts I THINK I will be able to bolt everything in using all factory parts. I haven't yet checked the vacuum control diagrams to see if the vacuum valve was control separately from the other intake flap.

Has anyone tried the either the early or later 3.4L 987 throttle body T on a 986? It does move the throttle body down and back closer to the MAF housing. Hopefully this won't have clearance issues on the 986.

[BYprodriver]

Originally Posted by 10/10ths

....so I have a 986 with a 987 airbox from the factory.

If you need photos let me know.

I would like to see that, especially the throttle/body area

[edc]

The throttle body area part itself look very similar to a regular 986. What you do have is a more solid plastic MAF to TB pipe with a smoother curve. From memory the neck of then plenum is the same length as the regular one too. The MAF is also further ER away from the airbox almost next to the TB.

[Qmulus]

All of the parts arrived yesterday and today. I have the 987 airbox with snorkel, 987 MAF housing, rubber hose from MAF to throttle body, and 987 "split" T that the throttle body mounts to and the matching hose to AOS that goes to the ports on either side of the T. I went over to a shop today on a break from shopping and mocked it up on 986 engine and everything looks like it will mount right up. The only question is what to do with the vacuum controlled flap in the T.

I did find a picture of a stock 550 edition '04 engine compartment a few days ago (a UK site maybe?), but I can't find it again. As we all know, it uses the 987 airbox, but with the 986 throttle to intake T. There is no different part listed for the throttle body to MAF hose, but it is obviously different than both the "normal' 986 and 987 parts. I have seen it before where Porsche will have parts on cars without showing the part numbers in the parts breakdowns. So, I would like to see the actual 986 550 throttle body to MAF housing hose and its part number if possible.

I did also noticed that in the parts diagram they have a part 98711026000 listed as "Stopper" that is not in the diagram, but goes with the 550 edition in the Throttle Body diagrams, which is not used on other cars. I would be interesting to see what that is as well.

[edc]

Here's the 550 Anniversary arrangement

[The Radium King]

so, a quick look at the parts diagrams shows a 987 part number for the duct on the SE car - 987.110.220.01. a check of the 987 boxster (not cayman - it uses a larger TB for the 3.4) parts diagrams shows that the intake duct is 987.110.222.01 - different part number. so, that first part number is what you would need to join a 987 airbox to a 986S 67mm TB and plenum.

[jaykay]

...is there a specific 550 se MAF housing or is it just the larger diameter 987 piece ? What diameter is it? It needs to be the right size for your tune.

[edc]

From memory the 550 uses the same MAF as regular 986.

[cornholington]

Originally Posted by edc

From memory the 550 uses the same MAF as regular 986.

How would that work, since the 550 uses the 987 airbox?

My reading of the parts KATALOG indicates that the 550 uses MAF with part number 987-606-125-00...

[The Radium King]

and the 987 maf comes w the housing, unlike the 986 part.

to Q, you have a 2003 so 7.8 dme. you want a flash for a car w the larger maf holder and the improved variocam (but not variocam +). you are limited to the se flash or *perhaps* a 987 boxster flash. 987 boxster would be excellent as it would have the programming to drive your new flapper, however i am uncertain if it would work well on a 986 car - i *think* the 987s have other programming built in to the dme such as traction control; it may not function properly as all systems are not connected (i've asked this question before on several forums and never got an answer).

otherwise, i had done some research previously that had indicated that the plenum flapper was controlled differently than the resonance valve (worst case, check the wiring diagrams for the 987 - seperate wires for each would indicate different control - or get someone with a 987 to have a look). you could delete it altogether, or use a solenoid triggered by the same signal as the resonance flapper, or use an rpm signal to trigger (if you new how it was supposed to function, you could build an rpm-triggered window siwtch to actuate it).

[Qmulus]

Good information! I knew that the MAF to throttle body hose needed to be different. Thanks EDC for the picture confirming that, and thanks to The Radium King for the part number. I must be looking in the wrong place, as I could not find a different number for that part.

Now a harder question concerning the 550 edition, that won't be so easy to verify. Did the factory modify the airbox to remove the resonance chamber, or did they modify the chassis (I kind of doubt that)? Also, for those who have fit the airbox, are the mounting points identical? That is, do you just bolt it in with the existing hardware, our do you need to modify or add things like bolts or washers?

Personally, I am not sold on the bigger throttle bodies until I see dyno data, not just "butt dyno" impressions. From experience, bigger throttle bodies need to be mapped properly to match the flow characteristics. Just bolting a larger one in and running it can lead to odd part throttle behavior. That probably wouldn't show up on the dyno, but would be felt in real world driving. I am not a fan of something that might give me 5 hp on the top end at the expense of drivability.

[Lapister]

Just my personal experience, the 987 airbox mounts to the original location. At least 3 and yes you will loose the Hemholz chamber the 986 had as there is no space. Impressions to me driving it is that I lost a bit of low end just around 2.5-3.5k rpms but by 4k you are really booking and linear all the way. Just a bit of trade off but that push from 4K is really nice and looking back with the smaller TB it just felt slower between 4K and redline. By Butt Dyno it really feels like there's more than the numbers suggest.

[jaykay]

Not that I am good at stopping and testing, but we could just go back to a standard stretch of road and stop watch or timing / dyno software to gauge performance changes.

[edc]

I've posted dyno data before of mods on my first Boxster. Base line, exhaust and manifolds then throttle body and intake, then lastly remap. All on the same dyno.

[cornholington]

link, please?

[edc]

Tuned/modified 2000 Boxster S

[jaykay]

Originally Posted by edc

Tuned/modified 2000 Boxster S

Very nice thank you....would like a visual on your exhaust components