987 v 986 Air box

[Qmulus]

You can find the part number in post 269 by The Radium King, or is it pretty easy to find in the online parts breakdowns. The part number for the "Stopper" is also in one of the later posts by me, but I wouldn't bother getting it. I am sure that you could find something that would fit that is far cheaper than the expensive factory plug.

[scottmaggie]

Finished my 986 to 987 airbox and 3.4 throttle body & plenum upgrade. Here's a ton of pics and a write up including part numbers. My car is a 2003 Base Tiptronic but this should work for all 986 models. USE AT YOUR OWN RISK!!!!!

NO NEED TO BEND CLIPS OR TAKE APART TOP OF ENGINE - Easy to do if you have access to a lift & engine jack...















USE AT YOUR OWN RISK!!!!!USE AT YOUR OWN RISK!!!!!USE AT YOUR OWN RISK!!!!!USE AT YOUR OWN RISK!!!!!USE AT YOUR OWN RISK!!!!!USE AT YOUR OWN RISK!!!!!

[edc]

You need either the 996 plenum or the larger one from Cayman 3.4 if you want to go to the 74mm throttle body at the same time.

[hotdawwgman]

Has anyone done this to a 2002 Boxster S? I have a question about the tune used.

[Newsguy]

I would also like to confirm the tune for a 2002 S: the 7.2 DME will work with the 996 tune?

[Nitro V8]

Thank you for the reply.

I have looked at the 987 airbox and before the maf but after the filter there is a 90 degree turn that constricts air flow to less than the 83mm id of the 987 maf tube. Difficult to judge exactly what it is due to its angle and turn but I would suggest around 70mm.

With the above in mind what is the point of the larger 987 maf tube over the 986 maf tube? All that is happening is that the restriction is moved closer to the air filter.

Any thoughts/comments?

[CGT919]

For all those who wants to use the 987 MAF housing on the 986 S ...

I have used this reducer which fits after a bit sandpaper exactly in the 987 MAF housing
cutting out a hole for the MAF

https://www.pvc-welt.de/PVC-U-Klebemuffe-ECO

AL107

[CGT919]

For all those who wants to use the 987 MAF in the 986 you can just implement this into the MAF housing to reduce it safely

AL107



https://www.pvc-welt.de/PVC-U-Klebemuffe-ECO

[hotdawwgman]

So I was able to add the 987 Airbox, 987 MAF Tube, 997 Throttle Body, and T-Plenum in. All parts were slightly used, but looked decent. Fired her up. Drove her around for a tad, and now I have 3 codes. P1119, p1126, & p1133. I need a tune which should happen this week. Is it possible I need a new Throttle position sensor? Or should I try to do the throttle relearn procedure first?

[Robert986]

Originally Posted by hotdawwgman

So I was able to add the 987 Airbox, 987 MAF Tube, 997 Throttle Body, and T-Plenum in. All parts were slightly used, but looked decent. Fired her up. Drove her around for a tad, and now I have 3 codes. P1119, p1126, & p1133. I need a tune which should happen this week. Is it possible I need a new Throttle position sensor? Or should I try to do the throttle relearn procedure first?

You don't need a new throttle position sensor, what you need is a tune with a updated MAF-table to reflect the larger MAF tube area.

[ike84]

Originally Posted by Robert986

You don't need a new throttle position sensor, what you need is a tune with a updated MAF-table to reflect the larger MAF tube area.

Hey robert! speaking of tunes, how is your car doing? Any updates?

[Robert986]

Originally Posted by ike84

Hey robert! speaking of tunes, how is your car doing? Any updates?

Hey Ike, thanks for asking! Car runs really great, just wish the summer was longer! Next mod will be coilovers I guess.. 😎

[preppyr6]

For anyone looking for a 987 MAF housing adapter sleeve (3.25" OD 3" ID) I found this on eBay that might help. The pvc-welt link wont work for us US folks (AFAIK).

https://www.ebay.com/itm/16mm-200mm-PVC-Inner-Diam-Equal-Water-Supply-Pipe-Fittings-Adapter-Connector-/174808609002

Hope this helps someone. Im in the process of sorting parts for this upgrade now.

[Coaster]

Originally Posted by preppyr6

For anyone looking for a 987 MAF housing adapter sleeve (3.25" OD 3" ID) I found this on eBay that might help. The pvc-welt link wont work for us US folks (AFAIK).

https://www.ebay.com/itm/16mm-200mm-PVC-Inner-Diam-Equal-Water-Supply-Pipe-Fittings-Adapter-Connector-/174808609002

Hope this helps someone. Im in the process of sorting parts for this upgrade now.

Initially, looking for a non-tune solution.

Does the 987 assembly come with a MAF sensor installed? I think that is what I understand.

I assume the 987 MAF and fitting comes off (with the special security bits) and the PVC sleeve slides in to reduce the ID to 3". A hole is needed in the reducer tube, and the 987 MAF and fitting is reinstalled? Assuming the 987 MAF assembly comes with a MAF installed, the connector plugs right in?

Later, I assume I can remove the reducer and push a 986SE tune on a 2003 986 S?

[Drewie]

One done also here

Used the best from from two posts:

987 v 986 Air box
from The Radium King and
987 v 986 Air box
from scottmaggie

We have started according to the instruction in The Radium King's post, but we didn't bend the engine lid tab.

Rather we lower the engine a little bit according to the instructions from scottmaggie.
But again 6" or 15 cm is impossible to lower, the hoses start to "dislike" it after 3" or 8 cm. We unscrewed only 4 bolts in the front mount of the engine. It was enough for me.
I can't imagine to insert the 987 air box there with the left air distributor still mounted.

Don't forget you need longer bolt as mentioned in step 17 in scottmaggie's instruction, and also insert the blue rubber grommet from 986 air box instead of the 987 black plastic grommet for tucker before trying to fit the air box.

We were able to fit the Air Mass Flow tube when the air box had been bolted. No need to mount it on the air box in advance.

The K&N filter was also little pain to fit.

The rest slightly differ to the other posts here since I was fitting GT3 throttle body not the 987 one. The T-shaped intake plenum and the elbow part was 3D printed. Designed by Ben006.
More info here:
Intake plenum and 911 throttle body

After all mounted and 3 times checked all is connected back, I turned key to position ON for approx. 1 minute. Then OFF for another minute.
Then with fingers crossed we started the engine. The engine was able to idle without engine light and any fault code in the ECU. Strange...
The AF ratio was definitely too high because the engine was "shooting" to the exhaust. Unfortunately our multibrand diagnostic tool was not able to start the basic adjustment of the ECU and engine components.
ECU started to learn at the third start when I didn't let the engine idle but rev it just under 2000 rpm.

After 5 minutes there was standing perfectly idling Porsche Boxster S 986 with 987 Air box with K&N filter, 987 AMF, silicone hump hose, custom 3D printed elbow, short silicone hose, GT3 Throttle body, custom 3D printed intake plenum, OEM air distributors and OEM 3,2l engine . In addition long exhaust manifolds, OEM CATs, and sport mufflers. At that time without engine light or any fault code in the ECU.

All took 12 hours. Everything in the engine bay is super tight, nearly no room for hands and tools. Many times we got stuck because the hose refused to connect back or were finding from which spot and which kind of wrench from wchich direction to use to screw some of the bolts.

BUT Engine light came up after ca. 50 miles / 70 km on my way to tuning company. No limb mode just orange engine light.
Unfortunately they were not able to dyno the car because even switched off PSM the car refused to rev over 4000 rpm without massive loss of power.
Need to find someone with 4x4 dyno which can rotate also front wheels during measuring.
So confused I forget to ask what fault was there. They just done small adjustment to "fix" this error.

No special tune so far...

Anyway looking for any Porsche specific diagnostic tool because readiness for emission test is still not green. So I don't believe to these multibrand diagnostic tools anymore. Because they probably show only emission relevant DTC not all of them.

[Pololo_Boxster]

Reviving this thread, if it's OK with members..

I am going to start doing this upgrade with my 2000 Boxster 986S..

So far I have the following:
1) 987.1 Airbox with the MAF section
2) 74mm TB from the 997
3) Plenum from the same 997

Still a bit confused if I either need to use the 987 MAF or the 986 MAF along with these upgrades?

If I go with the current 986MAF, do I need to have it tuned?

When do I need to have it tuned? if so, what's the best way to do this?

My apologies if this has been covered already... I read through all 16 pages, but still a few questions left..

TIA,
Regards
CB

[The Radium King]

is up to you.

first, some nomenclature.

the maf is the sensor. the 986 maf is the same as the 987 maf.

the maf housing is the tube the maf mounts to. on the 986 it is part of the airbox. on the 987 it is a separate tube that attaches to the airbox.

the 986 maf housing is a smaller diameter than the 987 maf housing. the computer multiplies the maf reading by the cross-sectional area of the tube to determine flow. so, change the tube diameter and confuse the computer.

if you do not wish to do a flash then saw the maf housing off of your 986 airbox and plumb it all together. the 987 maf housing is not required.

otherwise, if you plumb it all together using the 987 maf housing then you need a flash that will work with this larger diameter. for a 2000 the solution is a 996 flash. the 996 of the same year had the larger intake tract and the 3.2 runs just fine with this flash. your dealer should be able to provide for you, or anyone with a piwis or pst2 contraption.

the benefits of the latter option are twofold; using the larger diameter maf housing removes a restriction to airflow. second, the thinking is that porsche neutered the boxster so as to not compete with the 996. otherwise a 3.2 should not be 50 hp down on a 3.4. there's only 3 places that can happen - exhaust, intake, ecu (fuelling, timing). so, an ebay exhaust, clean up the intake as much as you can (pro tip - bolt an intake manifold from a 3.4 onto your car) and 996 tune.

Originally Posted by Pololo_Boxster

Reviving this thread, if it's OK with members..

I am going to start doing this upgrade with my 2000 Boxster 986S..

So far I have the following:
1) 987.1 Airbox with the MAF section
2) 74mm TB from the 997
3) Plenum from the same 997

Still a bit confused if I either need to use the 987 MAF or the 986 MAF along with these upgrades?

If I go with the current 986MAF, do I need to have it tuned?

When do I need to have it tuned? if so, what's the best way to do this?

My apologies if this has been covered already... I read through all 16 pages, but still a few questions left..

TIA,
Regards
CB

[ike84]

That's great to hear man!

Coilovers are phenomenal. My car has less than 40k when I switched over, and the OEM struts were toast. The coilovers made a truly remarkable difference in handling characteristics.

Sent from my SM-G970U1 using Tapatalk

[Robert986]

Btw, as stated previously I put in the 987 airbox & MAF with great results.. My tuner made a new MAF-table so if anyone needs a MAF table for the 987 MAF with Motronic 7.8 let me know!

[The Radium King]

every time you compress air (force it through a narrow opening) you do work. and heat the air. i would rather do less work and have cooler air.

but make your own choices. to quote yoda - do or not do.