Hello from Newbie and quick question on air filters
Discussion
Hi All,
Thought it was about time I introduced myself having recently purchased a 996 Carrera 2. I've come from a forum that deals in fire breathing mythical beasts from Blackpool. Having got over the fact that to look at the engine I have to go to the back of the car and having 6 cylinders in stead of 8 etc I wanted to ask a quick question on K & N air filters.
The car I bought came with a K & N filter fitted and my issue is a combination of aesthetics in that I like to keep things original and also I'm sure it would be better for the engine to be breathing in purely cooler air as per the original set up than air from the engine bay. I've attached a pic of what I've got fitted and the filter does have a black cotton jacket which I am not sure if it is designed to restrict air flow from the sides of the filter and thus draw more from the nose of the filter than is in line with the duct that comes draws clean air in.
I've also read mixed reviews on K & N's potentially increasing oil traces on the MAF.
Sorry, that is a long winded way of saying who has had experience of K & N filters and the original set up ? Is there any detrimental reasons of running one that should make me change back to the original set up and install a Piper cross or equivalent filter within the original housing ?
Pics of car and engine bay below. Many Thanks. Jeremy![](http://thumbsnap.com/sc/PIpHd2XG.jpg[/img]</a> <a href="http://thumbsnap.com/Nji9TlMK" Target="_blank" rel="nofollow">[img]http://thumbsnap.com/sc/Nji9TlMK.jpg)
Thought it was about time I introduced myself having recently purchased a 996 Carrera 2. I've come from a forum that deals in fire breathing mythical beasts from Blackpool. Having got over the fact that to look at the engine I have to go to the back of the car and having 6 cylinders in stead of 8 etc I wanted to ask a quick question on K & N air filters.
The car I bought came with a K & N filter fitted and my issue is a combination of aesthetics in that I like to keep things original and also I'm sure it would be better for the engine to be breathing in purely cooler air as per the original set up than air from the engine bay. I've attached a pic of what I've got fitted and the filter does have a black cotton jacket which I am not sure if it is designed to restrict air flow from the sides of the filter and thus draw more from the nose of the filter than is in line with the duct that comes draws clean air in.
I've also read mixed reviews on K & N's potentially increasing oil traces on the MAF.
Sorry, that is a long winded way of saying who has had experience of K & N filters and the original set up ? Is there any detrimental reasons of running one that should make me change back to the original set up and install a Piper cross or equivalent filter within the original housing ?
Pics of car and engine bay below. Many Thanks. Jeremy
This takes me back a bit! I used to own a 996 3.4 several years ago and still remember it being a lovely, communicative, raw, driver's car - very old-school (in a way even my current 997S can't hope to match) despite the new-fangled water-cooled engine. I'm sometimes very tempted to buy another....
Anyway, enough reminiscing, let's get to the point of your post. Unfortunately the pic of the K&N hasn't attached itself (Edit: it has now, just to prove me wrong!) but I'm sure I know the kit in question. This is the one that completely dispenses with the factory airbox and replaces it with some curvy tubing and a cone filter with a slightly home-made-feeling surround? Please let me know if I've got this wrong. I've NEVER liked this design for the very reasons you state - it allows hot air to be drawn-in from the engine bay. Having once spent very many hours with Mr Chip Wizards (Wayne Schofield - you can search him on here) experimenting with maps for a water-cooled 911 (albeit in this case, a gen-1 997) I can promise you hot intake air is the last thing you want. The control units for the M96/7 engines pull timing VERY rapidly as IATs rise, lowering power output right across the rpm band. I'd therefore recommend the K&N thing is relegated to the bench and the factory airbox reinstated.
But......
Now you'll unfortunately find that the factory airbox completely removes all the luvverly intake noise (and the 3.4 does have a particularly good intake yowl when opened up). Thankfully there is a remedy available, that also allows you to retain the factory, cold-air-breathing airbox. The noise-abatement culprit is a Helmholz resonator that sits in the top half of the factory airbox and is joined, externally, to the main intake hose by a pipe at right angles to the main intake. To get your induction noise back, you buy a replacement intake pipe (without the link to the Helmholz resonator) and remove the Helmholz resonator itself from inside the top half of the airbox. A specially designed stopper that comes with the intake pipe kit closes up the hole in the top of the airbox that's left by removing the Helmholz horror. As the standard factory air filter is somewhat restrictive, you can usefully replace it with a BMC-F1 panel filter at the same time as fitting the Helmholz-removing kit.
The result is a proper cold-air intake that breathes better than the standard factory airbox (better-flowing filter and the bl**dy great big plastic Helmholz canister out of the way)! You'll also notice a small-but-consistent performance improvement over standard.
If you really like your sports cars to sound like sports cars (as an ex TVR owner, you MUST do!) then I'd also recommend replacing the far-too-quiet side silencers (under each rear wing) with factory Porsche Sports Exhaust (PSE) units. When installed from the factory, these came with vacuum lines, electronics and a quiet/loud switch on the dash. The good news is if you just install the silencers and forget all the rest of the complications & nonsense, they're in 'loud' (it really isn't compared to anything TVR) mode all the time. They also sound particularly good on the 3.4. No performance gain this time, but the car will sound so good you won't care!
Induction kits and filters can be found in the UK here: http://www.design911.co.uk/fu/pt697_703_-cma81-cmo... (it's the one with the code 'INDUCTIONKIT2' with the blue intake hose) but unfortunately, this one doesn't remove the Helmholz resonator - it just disconnects it. Even better is this one: http://www.fabspeed.com/996-carrera-cold-air-upgra... that allows you to dispense with the Helmholz altogether and free-up space inside the airbox for air to flow. Fabspeed ships to the UK and I had the exact-same item fitted to my 996.
Exhaust cans can be found here: http://www.carnewal.com/products/P96/p96059/PSE-Fa... I think Gert will supply them without all the vacuum and electrical bits if asked.
Hope this helps.
Ian
Anyway, enough reminiscing, let's get to the point of your post. Unfortunately the pic of the K&N hasn't attached itself (Edit: it has now, just to prove me wrong!) but I'm sure I know the kit in question. This is the one that completely dispenses with the factory airbox and replaces it with some curvy tubing and a cone filter with a slightly home-made-feeling surround? Please let me know if I've got this wrong. I've NEVER liked this design for the very reasons you state - it allows hot air to be drawn-in from the engine bay. Having once spent very many hours with Mr Chip Wizards (Wayne Schofield - you can search him on here) experimenting with maps for a water-cooled 911 (albeit in this case, a gen-1 997) I can promise you hot intake air is the last thing you want. The control units for the M96/7 engines pull timing VERY rapidly as IATs rise, lowering power output right across the rpm band. I'd therefore recommend the K&N thing is relegated to the bench and the factory airbox reinstated.
But......
Now you'll unfortunately find that the factory airbox completely removes all the luvverly intake noise (and the 3.4 does have a particularly good intake yowl when opened up). Thankfully there is a remedy available, that also allows you to retain the factory, cold-air-breathing airbox. The noise-abatement culprit is a Helmholz resonator that sits in the top half of the factory airbox and is joined, externally, to the main intake hose by a pipe at right angles to the main intake. To get your induction noise back, you buy a replacement intake pipe (without the link to the Helmholz resonator) and remove the Helmholz resonator itself from inside the top half of the airbox. A specially designed stopper that comes with the intake pipe kit closes up the hole in the top of the airbox that's left by removing the Helmholz horror. As the standard factory air filter is somewhat restrictive, you can usefully replace it with a BMC-F1 panel filter at the same time as fitting the Helmholz-removing kit.
The result is a proper cold-air intake that breathes better than the standard factory airbox (better-flowing filter and the bl**dy great big plastic Helmholz canister out of the way)! You'll also notice a small-but-consistent performance improvement over standard.
If you really like your sports cars to sound like sports cars (as an ex TVR owner, you MUST do!) then I'd also recommend replacing the far-too-quiet side silencers (under each rear wing) with factory Porsche Sports Exhaust (PSE) units. When installed from the factory, these came with vacuum lines, electronics and a quiet/loud switch on the dash. The good news is if you just install the silencers and forget all the rest of the complications & nonsense, they're in 'loud' (it really isn't compared to anything TVR) mode all the time. They also sound particularly good on the 3.4. No performance gain this time, but the car will sound so good you won't care!
Induction kits and filters can be found in the UK here: http://www.design911.co.uk/fu/pt697_703_-cma81-cmo... (it's the one with the code 'INDUCTIONKIT2' with the blue intake hose) but unfortunately, this one doesn't remove the Helmholz resonator - it just disconnects it. Even better is this one: http://www.fabspeed.com/996-carrera-cold-air-upgra... that allows you to dispense with the Helmholz altogether and free-up space inside the airbox for air to flow. Fabspeed ships to the UK and I had the exact-same item fitted to my 996.
Exhaust cans can be found here: http://www.carnewal.com/products/P96/p96059/PSE-Fa... I think Gert will supply them without all the vacuum and electrical bits if asked.
Hope this helps.
Ian
Edited by Ian_UK1 on Tuesday 24th May 20:20
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