Intake setup recommendation
 

Hey everyone,

I've been trying to do some research on what a reasonably priced intake setup would be for a 986 S from '00.

From what I have gathered:

a 987 airbox can be modded to fit (by cutting away part of the muffler and plastic-welding a hole), but there seems to be some issues with using the 3.25" MAF housing without reflashing. There has been some mentions suggesting either to cut out the 3" MAF housing from the 986 airbox and attaching that, but it seems like it doesn't work well since the filter screen would have to be modded as well. As an alternative to this, someone suggested using a Bosch 3" MAF housing, possibly sourcing it from BMW (I haven't seen any mentions of a part number for that though). Then there's the story about upgrading to a 996 or equivalent 74mm throttle body, and there are a couple of different options for plenums (IPD, 996, etc), Pedro's Garage seems to have discontinued their TechnoTorque2.

Does anybody have a recommended, end-to-end solution (airbox + maf + tb + plenum + tubing)?

Or, should it just be left stock?


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A quick cheap an easy way which gets results is 996 throttle body and plenum, a 1 foot circa 80mm alu pipe and 2 90 degree bends, a few jubilee clips.

I'm currently doing this mod and will be posting a diy video soon.
See my posts below concerning dyno etc. :)

I found loosening the intake runner and fuel rail/injectors to be helpful in extracting the 986 airbox. Clearance is very little and it can be a bear to get out. And don't cringe but the engine cover tabs had to be bent up out of the way. This all because the 987 is physically larger going in. The grafting of 986 Maf to 987 Maf housing is a lot easier. Get a 40 watt soldering iron and plastic wire ties to plastiweld the two. Yes, you will have to procure a new smaller screen for the Maf. Then follow up with hoses and elbows to connect the Maf to the TB. I followed a fellow member Kram who posted a excellent tutorial with pics! Do a search on his post for details on the specifics for this mod. Thanks Kram!

If you want to follow up with the further addition of 996 TB and 997 plenum Kram includes it all.

What is the Net gain in HP after all this work is done?

Hmmm, won't the alu pipe, given its thermal conductivity, heat up the air as it moves between the airbox and the throttle body? Most people seem to prefer silicone tubing.

You can use whatever you want. I originally mocked mine up using plastic drainage downpipe. This was cheap, readily available and gave results. For sure if you are after the ultimate set up with no cost concern there will be other ways to get a fraction more.

I'm pretty sure any significant intake mods will require remapping to get anything but more volume out of the setup. Might, in fact, degrade performance. Over they years of trying all sorts of intake "airflow" mods on many cars, usually they just made more induction noise. The ONLY time there was any really change was when the mods we accompanied by a remap that adjusted for the changed A/F ratios.

how do the a/f ratios change?

There's another link with some Dyno results but in my case 74mm TB and larger diameter intake gave circa 5bhp. This was after the exhaust and manifolds which gave just shy of 10bhp.

Is this mod currently on your car, or are your dyno results from your S?

Not saying it can’t happen that some minor change can be had, but to get the most out of any intake/exhaust mod, a custom mapping should be done.

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

Half day remap session on the dyno after all the mods gave another circa 10bhp.

why is that?

It’s not worth it....
 

...These cars do not respond well to half measures. Either build an all new engine and do EVERYTHING hi-po all at once, or leave it stock.

If you want some sound, delete the secondary cats and swap mufflers, but that is ALL you want to do.

All of these intake mods are a waste of time.

good info to know.

Well, maybe 10/10ths is right. However, I should have the proof of the intake mod pudding before the last snowflake falls! Watch https://youtu.be/tXx8GoTwATY for progress. :cheers: