987 Airbox-Worth it?

[The Radium King]

also, as you note, the original maf holder and new tb will be same ID so good there; thing is that the tubing you are using to join the two units fits to the OD which is 1/4" or so larger (the thick lip on the tb is 1/8" or so) so that the air compresses from airbox to maf holder, then expands, then compresses at tb again - wasted work. also, a decreasing radius intake system (ie, airbox larger than maf holder larger than throttle body) will tend to accelerate the intake airflow and facilitate cylinder fill for low rpm torque. small gains overall, and not worth the work of modifying the programming on your car when you can just use the original maf housing. i did it for (a) oem look, and (b) i have a pst2 and wanted to run a 996 tune on my car.

[Robert986]

Thanks boys, maybe I´m starting to understand.. So, my car is the 2003s ROW as I understand it it should as standard be sporting a 986.606.125.01 MAF-sensor attached to the narrower housing. The 987.606.125.00 would then be the larger housing complete with a 986.606.125.01 sensor inside.. Did I get that correct?

So do I want the larger or the narrower MAF housing..
I believe that I should strive for a air-path with a smooth but slightly decreasing diameter all the way from the airbox to the plenum. Thus I take it that the larger MAF is the way to go, just ensure that the piping gives a good decrease in diameter downstream, and since I will be using a custom tune I guess the cost won´t be too overwhelming just for the MAF-tune part.

Please enlighten me if I still got it wrong!!!


Some more thoughts.. I am starting to believe that the theoretical dimensioning to strive for should be:
1) Go from wide to narrower in the airbox, MAF, Throttle body, to accelerate air and give good cylinder fill at lower rpm (as stated by TRK). By keeping the whole chain larger than oem, it will still give more flow at WOT, thus more power.
2) Here comes the strange part.. I believe I have read somewhere that the plenum, or (maybe the chamber between the plenum and the intake runners) should be basically as large as possible, to act as a "air-reservoar" with enough air to provide the runners with enough air. (Have I got this 100% wrong???)
3) Then the runners.. I guess the runners must me "wide enough" but not least quite long.. The length to achieve some momentum in the air (more air mass accumulated) to provide cylinder fill at lower rpm:s, thus the 996 intake / runners are preferred.

All in all I´m sure I got at least some part of the above bullets 1-3 wrong. Let´s discuss! :dance:

[maytag]

Originally Posted by The Radium King

.....small gains overall, and not worth the work of modifying the programming on your car when you can just use the original maf housing. i did it for (a) oem look, and (b) i have a pst2 and wanted to run a 996 tune on my car.

So I'm moments shy of buying a PST2 for this same purpose.
I understand from other threads that I'll need a 996 VIN and associated password, in order to load that 986 flash to my 986 DME. (Correct?)
In anticipation of this, I called my dealer today to see what it'd take to get them to help me with that VIN and password. No joy. They basically mocked me, that I'd think they'd just hand that out. They're kinda dicks over there.

So, question: some of y'all who've done this (TRK?) Do you have a VIN and associated pass code you can share? And if not, do you know a dealer who is supportive of this, who I could contact?

I'd sure like to know I've got a clear pathway before I pull the trigger on the PST2.

Sent from my SM-G970U using Tapatalk

[itsnotanova]

Originally Posted by maytag

So I'm moments shy of buying a PST2 for this same purpose.
I understand from other threads that I'll need a 996 VIN and associated password, in order to load that 986 flash to my 986 DME. (Correct?)
In anticipation of this, I called my dealer today to see what it'd take to get them to help me with that VIN and password. No joy. They basically mocked me, that I'd think they'd just hand that out. They're kinda dicks over there.

So, question: some of y'all who've done this (TRK?) Do you have a VIN and associated pass code you can share? And if not, do you know a dealer who is supportive of this, who I could contact?

I'd sure like to know I've got a clear pathway before I pull the trigger on the PST2.

Sent from my SM-G970U using Tapatalk

Your Dealer in Utah is the worst in the country. I've heard multiple stories from 986 owners. I have a 996 ROW tune on my street boxster but my DME and immobilzer came out of a 996. Pretty simple switch, but I'm not sure about putting a 996 tune into a 986 dme. The immobilizer will still know it's a boxster (I think). I just put a 996 intake on my 2.7 rallycross boxster and was going to also switch over to a 996 tune. Give me a few days and I can tell you what happened

[maytag]

Originally Posted by itsnotanova

Your Dealer in Utah is the worst in the country. I've heard multiple stories from 986 owners. Try Porsche of Plano. They're pretty laid back there and might give one to you. I have a 996 ROW tune on my street boxster but my DME and immobilzer came out of a 996. Pretty simple switch, but I'm not sure about putting a 996 tune into a 986 dme. The immobilizer will still know it's a boxster (I think). I just put a 996 intake on my 2.7 rallycross boxster and was going to also switch over to a 996 tune. Give me a few days and I can tell you what happened

Ha! You're a stud.

Yeah, I'm quite disappointed with the dealer options we have in Utah.

I'll watch for your update! Thanks!

[itsnotanova]

LOL. I haven't been called a stud in awhile. Text me your vin at 512-925-9171. I'll get you a code when I get one. I have a source but I normally only ask him for codes for myself. It's a source I don't want to wear out

[maytag]

Originally Posted by itsnotanova

LOL. I haven't been called a stud in awhile. Text me your vin at 512-925-9171. I'll get you a code when I get one. I have a source but I normally only ask him for codes for myself. It's a source I don't want to wear out

Do I need the code for MY VIN? Or for the VIN of a 996 whose flash I want to load? How does that work?

[911monty]

Hey Maytag; I notice no one has brought up something that should be mentioned here. I believe you have said that Utah smog for your year, like Ca. consists of OBD interrogation. Since the diesel gate saga, Ca. smog test checks that the OBD program has not been altered as this will be a fail. You might want to check this if you license your car for street duty.

PS Dealers especially VW/Porsche dealers in an "enhanced smog inspection" state will be far less likely to supply info to alter the OBD programs which could open them up to litigation. Unlike a State that does not do smog testing.

[itsnotanova]

Originally Posted by maytag

Do I need the code for MY VIN? Or for the VIN of a 996 whose flash I want to load? How does that work?

Your vin to start. I've never installed a 996 tune into a 986 dme so it's new to me. I don't think getting a 996 vin will work but I'll ask when I get the codes.

[Newsguy]

Reflashing to a 996 tune is possible.
I got a ROW done to eliminate the secondary cats and the air pump.
Alas, I never got to experience the result. The replacement engine I bought seized after a mile.

[Nitro V8]

I wonder if a re mapping session on a rolling road can tune for the 987 maf rather than having to get an actual 550se tune put on the DME?

[Robert986]

Originally Posted by Nitro V8

I wonder if a re mapping session on a rolling road can tune for the 987 maf rather than having to get an actual 550se tune put on the DME?

That´s not the way to do it.
What you actually need is a new MAF-table for the larger MAF-tube, thus the DME can understand the MAF-signal again. Then if you really want you may map it on the rolling road, but I think the DME will manage this by it´s own with such small changes.

My tuner made me a new MAF-table just for this, you may inbox me for contact info to my tuner, I´m sure he can help you with this table.

[Nitro V8]

Originally Posted by Robert986

That´s not the way to do it.
What you actually need is a new MAF-table for the larger MAF-tube, thus the DME can understand the MAF-signal again. Then if you really want you may map it on the rolling road, but I think the DME will manage this by it´s own with such small changes.

My tuner made me a new MAF-table just for this, you may inbox me for contact info to my tuner, I´m sure he can help you with this table.

Thank you very much.
I will pm you
Cheers