987 v 986 Air box

[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

[mikesz]

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

[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]

http://986forum.com/forums/performance-technical-chat/47555-tuned-modified-2000-boxster-s.html

[jaykay]

Originally Posted by edc

http://986forum.com/forums/performance-technical-chat/47555-tuned-modified-2000-boxster-s.html

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

[edc]

It's the regular cheap eBay stuff. It's all from alibaba ultimately. Over here it's branded as Toyosport, Topgear, Direnza etc as they place large enough orders to have their label put on or stamped on. Over your side I think this is the same as Topspeed but also resold as various other "brands". Remember only 1 pair of cats for UK and European cars ie no cats in headers. I kept the standard cats which are 400 cell. You call them the rear cats.

[Qmulus]

So, I ordered up the '04 Boxster S 550 50th Anniversary SE MAF sensor to throttle body hose, along with the "stopper" that was listed, but not shown in the diagram. The stopper was over $25 and just ended up being a plug for an unused port on the hose. IMO, it is NOT worth it if you want to do the same.

Here are a couple of pictures. In the first I have the 987 airbox, the 987 MAF sensor and 986 SE MAF sensor to throttle body hose. In the second picture I also included the 987 throttle body tee, 987 MAF sensor to tee hose, and tee to AOS tube for comparison. As you can see, I have not yet modified the airbox to fit in the 986 chassis.

While it is possible to use the 987 tee, from testing by another local shop shows that it difficult to install due to interference of the throttle body to oil cooler if clocked as on the 987, and also interference with the engine cover if you clock the throttle body so it does not hit the oil cooler. The tee also does not play nicely with the tuning if you actually connect up the vacuum operated flapper, so you would probably just use the tee without hooking up the flapper.

I plan on installing the airbox with the 986 SE plumbing after doing a baseline dyno test, then repeating the dyno testing after installing the airbox, plumbing and 986 SE tuning. The tuning will only work on an '03 or '04 S as they have the M 7.8 ECU. It is also possible to use these parts on earlier cars with stock (or whatever performance tune you have) if you sleeve the inside of the MAF housing to match the original, and use the MAF element from the original air box.

[P_Carfahrer]

Originally Posted by Qmulus

So, I ordered up the '04 Boxster S 550 50th Anniversary SE MAF sensor to throttle body hose, along with the "stopper" that was listed, but not shown in the diagram.

Qmulus, do you have the part number for the SE Maf to throttle body hose? I am having a hard time finding it and I like the OEM look and may look at using it in my install.