Stock Air box Replacment

[VMAX1]

What would be a good replacement for the stock air box. I looked at this one, AireTEK High-Performance Intake and just wondering what the experts thought.

[McLovin]

Why do you need to replace the stock airbox?

[Por_sha911]

Originally Posted by McLovin

Why do you need to replace the stock air box?

+1 The stock air box can handle more volume than your system will allow. Unless you are doing mods to the intake and exhaust, the stock system is great.

[Jammo]

Hi,
stock airboxes are great and balanced. The only thing that is missing (rectified in the later models) is getting the intake out of the heat sink of the engine bay and sometimes counter productive air demands of the cooling fan.
Cold, uncontested air is what we need in the inlets, denser and as cold as possible. I have carried out some experiements with this 'theory' and come up with the following - as in pictures. I will be making the mods out of aluminium later but I wanted to find the best place for uncontested cold air - it seems to work.
Regards

Jammo.

[john walker's workshop]

and water injected too, or is there a drain?

[Geronimo '74]

Jammo,


taking in your air 4 inches closer to the grill does NOT increase hp!! You wil notice no difference.

When driving, the air in the engine bay is being refreshed at such a rate that the temperature inside the engine-compartiment barely exceeds outside air temperature.

With this setup, all I see is a more difficult intake of air due to lack of smoothness of the tube you used to extend the plastic tube of the airbox.
If water (rain) is not drained properly, you will get it in the intake, which is bad.

@OP

instead of replacing your already more then adequate setup, you could try and drill holes in the airbox lid (do a search for pics)
or trim the lid so that you are only left with a rim/edge to keep the airfilter in place (RS style, do a search for pics). You will gain a nice deep throaty sound, not noticable HP

[Jammo]

Originally Posted by john walker's workshop

and water injected too, or is there a drain?

Hi John,
All Carrera airboxes have a drain hole in the rear, lower corner of the cover. However, I have slightly enlaged the hole and fitted 'one way' rubber outlet. So far, very little water has gone in there as the spoiler grill does 'disrupt' a droplet into a mist, no different from original really.
Regards

Jammo.

[Jammo]

Originally Posted by Geronimo '74

Jammo,


taking in your air 4 inches closer to the grill does NOT increase hp!! You wil notice no difference.

When driving, the air in the engine bay is being refreshed at such a rate that the temperature inside the engine-compartiment barely exceeds outside air temperature.

With this setup, all I see is a more difficult intake of air due to lack of smoothness of the tube you used to extend the plastic tube of the airbox.
If water (rain) is not drained properly, you will get it in the intake, which is bad.

@OP

instead of replacing your already more then adequate setup, you could try and drill holes in the airbox lid (do a search for pics)
or trim the lid so that you are only left with a rim/edge to keep the airfilter in place (RS style, do a search for pics). You will gain a nice deep throaty sound, not noticable HP

Hi Geronimo,
Not really interested in throaty 'soundalike' intake noise - the engine and exhaust sytem give the 'tell tail' signs to the ear - but functional. Not that I will argue about HP gains, I am mistified how you could even know what I can feel from the other end of a computer - I will admit that all the mods (including intakes) is a massive difference from stock, just one of the building blocks of the car rebuild.

Engine bay air temeratures drop due to the demands of the cooling fan and forward motion, and so can the pressures drop that are trying to be replaced by the air rushing in trying to 'top up' the depression caused in the bay by the fan - most later cars now benefit from trying to get 'outside air' uninterupeted, into the inlets, take a look at every F1 car, later Porsches, even a basic Fiat Panda.
Regards

Jammo.

[Geronimo '74]

Jammo,

The advice of drilling holes in the airbox was for VMAX1 (@OP = @ original poster) It's cheaper than dashing out for a new airbox, and just as good.

I am not feeling what you feel from this side of the computer at all. But I do know what you will not feel when you draw air 4 incher closer to the grill, and that is an HP gain. ( you're not the first one to try this.)
But if you by any chance succeed where many before you have failed (by trying to gain HP with only extending the intake tube of the airbox), I will, most respectfully, stand corrected.
But for that, you will need dyno sheets to back your statement up.

Last but not least, let me congratulate you on a very clean looking engine bay!! Must be the result of a well executed rebuild.

[VMAX1]

The bottom back tab is broke and I can't snap the clip. I haven't checked on a price, but my guess would be $$.

[Oh Haha]

What year 911 are we talking about?

[Geronimo '74]

Originally Posted by Oh Haha

What year 911 are we talking about?

+1

Look on this site, our host sells them, but CIS airboxes ain't cheap.
Because you are looking at the AIRTEK stuff (which our host also sells) I'm guessing you have a post CIS Porsche.
You could look for a used item on ebay or in our For Sale section. Or you could go the AIRTEK route, but make sure you do regular maintenance on the filter, and do not excpect more then a deeper sound and a little more room in your engine bay.
You'll gain not real HP with this new setup.

"Average gains are 6-12 HP depending on vehicle and level of other performance upgrades. " --> believe me, a 12 HP gain will depend on the level of other upgrades.... Not on the type of filter you use
The stock setup our cars have is already very good!!

[VMAX1]

1987 Carrera. That is one Nice Clean engine in the pics.

[JJ 911SC]

VMAX1

Here is what it look like with the AIRTECK.

Not sure it give me more HP as I put a SW Chip at the same time but the Red did add a few MPH....

I droved in the rain and no water in the cab or on the filter.

[Cherry Bomb]

When purchased, my 911 was equipped with a K&N drop in filter. I drove it around for a few weeks and then decided to cut open the factory airbox cover, RS style. I left the airhorn in place with the idea it would still draw cool air as designed. The famed intake noise was minimal, but apparent (read bordering cool).

I am not sure if it was the airbox mod or the host of tune up parts/procedures that brought my 911 to life. I should have done the mod after the up keep. ;-)

When I was performing this lid mod I had noticed my airbox base was cracked in three spots. Each crack was no less than two inches long and when the lid was secured with all four clips, one crack would open wider and the entire lid/filter sat slightly off from perfect.

I found out that factory MFI airboxes aren't really easy to find in excellent shape, or at all. Luckily, the other day, I scored a NIB factory airbox assembly complete with Porsche filter.

Here's the cool part......I drove with the stock unmodified box with a drop in K&N filter. I drove with a stock box, modified lid and same K&N filter. Then I replaced the cracked factory airbox assembly, with a brand new factory airbox assembly with Porsche filter. I drove with the K&N filter over the last 5000 miles, cut open lid for 4657 of those miles and just replaced entire airbox/filter yesterday.

I can now see why Porsche designed the airbox as it is. I have much better throttle response and way more torque feel all around in comparison. I drove no less than five hours, one two hour trip and then a three hour trip one hour later. It was a rewarding experience that transformed my car to what I thought it should've been from the start. Did I gain HP with the factory set up, probably, but I have no Dyno time to prove, so I won't claim it. I am basing this excitment on feel and actual performance on the road. A road that I frequent multiple times a day, nearly every day. I know my car's character by now and it has changed for the better, just yesterday.

It was the feel of the car as it ripped down the road with what appeared to be less effort. It was the tire spin that was more than usual at same or less throttle. It was the harmonious whine of the flat six as I approached rev limit in what seemed to be a slightly faster amout of time.

My conclusion is that Porsche knew what they were doing and I stand corrected in thinking that a stock 3.2L wants more air without giving it more intake, exhaust or computer enhancement.

I do not miss the "sound" of a K&N and RS/hack lid, rather I missed the sound of the quiet, humble six from the start.

FYI: I stem from a Hot Rod background and 99% of my daily drivers had to be loud and proud as a result. This is the first performance daily driver I have owned that sounds better as is....I think I am getting older, no, it's just my Porsche. (enter corny music here)

Dear Santa, please cross the B&B header system off my list. I just want an M&K pre-muffler now.

Merry Christmas and Happy New Year!!

[dshepp806]

I've a broken piece on my stock 89 airbox (the rx'g part of the clip process-that is, the rx'g end of the equation). I've a plan to drill some holes to insert a pin length-wise so that the clip has something to grab, then epoxy in place). No way will I mount ANY hardware to gnerate a clip point,...worried about stuff coming loose and heading into the intake....can't believe people do that....I think I can pull this one off easily....no boxes aren't cheap.

Agree with Geronimo "74.

BEST!

Doyle

[4495]

I know that a lot of people on here aren't fans of aftermarket air filters but I did see a positive response in favor of the cones and it was in Panorama's Tech section and they said that they saw a marginal gain in HP and had had good success using them....but that's just a bunch of Porsche techs though.

[RWebb]

Originally Posted by VMAX1

1987 Carrera. That is one Nice Clean engine in the pics.

ok, as per above there is no good replacement for the stock air box - the stock air box is just fine

add noise by drilling holes in the top

to add a few hp, address the exhaust and get a chip set up for what you have - e.g. the Steve W. chips

hundreds have worked this all out before and a search will be educational

[rwingnut1]

Any of you guys cutting replacing up your 3.2 air box lid want to sell your trumpet/snorkel?

[VMAX1]

I bought a cone filter, K&N, and went back with the stock air box. Will let go of the cone,cheap. Noises, for my taste.