996 Airbox Mods and BMC Air Filters

[dbookman]

I'm new to this forum and was wondering if anyone has any recommendations on whether 996 Airbox mods (particularly the Fabspeed mod) and BMC Air Filters are worth going for. I heard that Excellence magazine wrote something up on this topic a while back, but I can't seem to find out which issue.

[Loren]

IMHO... both add some intake noise but have never been proven to add much if any HP. Nor because they don't but because no one has done good before and after dyno runs. With that said, I use the BMC and am very happy with it. I did some of the Fabspeed mods on my own (like removing the two screens) and I am have with that also. YMMV

[clord]

There has been, and continues to be much difference of opinion about the possible performance effects of BMC, K&N pleated cotton type air filters. They are an easy mod to do to today's "sealed" engines. They may, or may not flow more air (have a smaller pressure loss across them at a given flow rate), they may, or may not allow more of the finest grit through in doing so. They generally do allow more intake noise back out to the listener.

The most important fact is that if the user over oils them (easy to do) the oil can migrate on down stream to the mass air flow sensor and cause a CEL fault. PCNA has replaced many MAF sensors on warranty and is now hesitant to do so if the owner has an oiled cotton type air filter. You don't want to pay for a MAF sensor replacement yourself.

That said, I ran a K&N replacement filter in the stock airbox of my '99 C4 for 4 years with no problems, but, I was very careful about over oiling the thing.

I'm planning on running the stock paper filter on my incoming GT3. It's the same one that PAG installs on the TT and GT2. I figger if it flows enough for those engines and keeps them clean enough for PAG, it'll be fine for a NA GT3.

[dbookman]

Thanx guys. I had very good luck with a Euro airbox with a K&N filter in my '88 M3, but obviously that's a different animal altogether. And I hear you about the over oiling issue. That's is all too easy to do and unfortunately, I did just that with my Boxter. That MAF sure was expensive! On the other hand. I do wonder if the element inside the MAF could have been made serviceable by using some electronics contact cleaner.

I guess I'm still in a quandary about whether to go with either of these mods. I'd be happy with more throttle response and sound. I just don't want to loose any checks on the computer. B)

[Scouser]

I am real happy with my airbox mods. I don't know if I can honestly feel any increase in horsepower but throttle response does feel much better at take off. But I am not sure if that's from the added feel good factor you get from the extra sound.....which I love to hear with the top down.

[alter_schwede]

hey,

just bringing up on old theme, I've just got a quote for a BMC CDA Airbox with MAF adapter for 399,- euro incl. install and the price is also incl. VAT.

is the price reasonable?

cheers,

Tony

[alter_schwede]

just an update, the CDA airbox is now installed and it gives great sound and I can already see the gas consumption are also improved.

cheers,

Tony

[911 fly'n]

Installed Fabspeed cold air kit, $224.00, and K&N filter, 75.00, can't notice power improvement but sound is great low and high RPM,

[dbookman]

I went ahead and took the plunge, purchasing the Fabspeed kit and the K&N air filter. Previous to this I had installed a modified exhaust, which by itself made a very noticeable difference in throttle response and a huge difference in character. This car NEEDS sound, and I found it kind of embarassing that the bone stock E46 M3 BMW has a better exhaust sound than my 911. I had to change that! Anyways, the Fabspeed kit further improved on my throttle response (it was definitely noticeable) and I can finally say that I am happy with the mod.

[mdillian3690]

Question, why would you oil the air filter?

[alter_schwede]

it is for the airfilter to catch the smallest particles so the engine gets as much of clean air as possible and result with a better ignition.

[mdillian3690]

that is the first time I heard of that, thanks! Is this for Porsche only or other vehicles as well? and do you have to oil the filter?

[alter_schwede]

oiling the filter is only intended for the metall/cotton sportfilter, e.g. from BMC, K&N, GreenFilter etc.

see example from K&N Filter

[Tim W.]

One thing to consider is wraping your new filter in newspaper overnight to absorb any extra oil. ON my fist 996 there was a bit of extra oil and it fouled the MAF. I cleaned the MAF with electronics cleaner and cleaned the filter and had no more issues. I wrapped the filter before I put it in the current C4S and have had no issues.

[dbookman]

I was wondering if electronics cleaner might solve the problem. I had this issue with my Boxter and they told me they had to replace the MAF. They gave me the old one back and I kept it just in case. Now I have a spare for my 911, just in case!