Air intake and throttle body mod, Part 1

[NewArt]

The first instalment of my Airbox/TB mod is now available on YouTube!
https://youtu.be/tXx8GoTwATY

I'll post the next episode before too long (he hopes...).

[The Radium King]

nice. some tips ...

i didn't have to remove the oil cooler or intake runner (just loosen) but yeah, it was hell to get in.

you shouldn't need a 987 engine cover to fit the larger plenum, etc., but there is a metal tab on the engine bay that should be sawn-off to make room - you'll find it when you do the install.

i was able to stretch and use the existing boots when fitting the new plenum, but some use silicone adapter couplings instead.

remove the bracket that attached the old throttle body to the transmission - not needed any more.

get under the car and look up - there may be a fuel vent line that has to move slightly to properly fit the airbox.

if modifying a 986 maf housing to fit the new airbox you will not have any clearance issues. if fitting a 987 maf housing, you may wish to consider 'massaging' the engine bay in the area around the housing to ensure proper clearance. there is also a tab on the housing that could be filed off, and bend one of the retaining clips.

if you are super-ocd like me, consider:
- bevel the leading edge of the throttle body lip
- trim the filter hanger in the airbox
- trim the rubber lip on the side vent

[dsallean]

Nicely done video. Look forward to episode 2.

Thanks

[NewArt]

Thanks for the tip TRK! I’m still waiting to hear from my guy at Porsche to see if he will upload the special edition flash. He seems positive but wants to research it all before going ahead. Very Porsche engineer style as opposed to my Ah, what the hell, what could go wrong? attitude!

[eicheldp]

Nice job on the video, I'm looking forward to the next installment. I installed Ben's 3 printed plenum with the 74 mm TB and I'm extremely pleased with the performance. I ended up using the stock air tube with the muffler removed to make everything fit.

[dijinn]

Fantastic! This is the next project I'll be tackling on my 986 so, I anxiously await Part 2.

[Boxstard]

I have a 97 with 2.5 motor so not as much choked down with 68mm throttle body as 2.7 or S cars and 987 airbox is probably just overkill, so planning to install 74mm TB from 996 but leave the rest intake stock, still snorkeled. Some suggested noticeable gain at higher rpm from this simple mod but if anyone going through this thread has experience let me know.

[The Radium King]

Originally Posted by NewArt

Thanks for the tip TRK! I’m still waiting to hear from my guy at Porsche to see if he will upload the special edition flash. He seems positive but wants to research it all before going ahead. Very Porsche engineer style as opposed to my Ah, what the hell, what could go wrong? attitude!

no sweat. sorry i can't be more help on the flash bit. what i do know is that the tool used by the porsche techs currently is more evolved than my decade-old pst2; same functionality i presume, but different interfaces so i can't give a step by step.

it will, however, be easier for you than it was for me, as you are using a 986 flash. in my case i am using a 996 flash, so i actually had to go in as a 996, get a bunch of errors, then go into the dme programming module and push the new tune (ie, the computer will only offer 996 tunes if it thinks you are a 996). now when i want to look at engine stuff i go in as a 996, and when i want to looks at perhipherial stuff (gauge cluster, abs, etc.) i go in as a 986.

the basics of your process will be to go into the program as a 986, find the dme programming module, enter your dme programming code, and select from a list of available flashes. 5 minutes later you are faster. don't expect your tech to know anything about this as it is not something they are trained to do. i'd forward you the manuals i have on the process, but again it is for my old pst2 and will most likely have no applicability to what the tech is using now.

note that you will also have the opportunity to chose a NA or ROW version of each flash. ROW gives you the ability to pull the SAI off your car (you'll need two inexpensive oem blocking plates) delete secondary o2 senors (ie, run test pipes) and drive your car into the garage door when you try to start it in gear. ROW also only reads deviation for one bank, so harder to set timing later on if you need to. i guess it depends on what they do for emmissions testing in PQ.

[NewArt]

Emissions testing in Québec? Hahaha, ain't no such thing! It really is the wild west of the east!
I've got everything but the air tube (silicone elbow etc., to source yet). I'm editing the video of Part 2 now and should have it up shortly.

[thstone]

Nice video!

[The Radium King]

for my tube i used the oem cayman part 987.110.222.01 at the maf holder, a 3.25” OD aluminum coupler, and a 3.25” ID silicone elbow. both found on ebay or siliconeintakes.com. need to trim the elbow to fit, and bevel the leading edge of the coupler if ocd.

[986bsdriver]

Originally Posted by The Radium King

and drive your car into the garage door when you try to start it in gear.

Didn’t realize that the clutch interlock would have been controlled by an ecu. Those Germans are rather sneaky

[The Radium King]

Originally Posted by 986bsdriver

Didn’t realize that the clutch interlock would have been controlled by an ecu. Those Germans are rather sneaky

probably an american safety requirement not reqd in the rest of the world. if you are into it, there are actually two clutch interlock switches - one when the clutch is pressed all the way in (this is to allow start of the vehicle) and a second that activates when the clutch is initially pressed - this triggers a timing retard to depower the engine so shifts are easier. try zip-tying it so that it doesn't activate - see what you think.

[jaykay]

Originally Posted by 986bsdriver

Didn’t realize that the clutch interlock would have been controlled by an ecu. Those Germans are rather sneaky

The starter will engage if activated ..from the engine bay irrespective of tune loaded.....and clutch position don't ask me how I know this.