K&n On 3.4

[ALLSPEED]

A couple of weeks ago I installed this K&N intake on my 99 996. I am more than happy with it. To me there is a very noticeable increase in power from about 4000 r's. I can feel it pull harder and the front end seems to lift more from the increased torque. K&N makes some dyno claims that are impressive for a bolt on upgrade. I don't know how exact they are but I think it was money well spent for performance. The K&N installation instructions are very thorough and it took me about three hours most of which was spent trying to get the heat shield as square as I could. The only thing I couldn't do was turn the connector for the MAF around because mine is molded. It cost $340 plus tax. For those of you who like a sports car sound it also adds that when accelerating hard. Very different than stock. Kind of throaty if that makes sense. Anyway, for you naturally aspirated guys, IT REALLY WORKS. Thread or PM if you want more info. Robert. P.S. The ends of the foam molding on edges of the heat shield need to be trimmed and that will make it look more square. I'm waiting to see if it shrinks any before I trim it.

Edited April 9, 2010 by ALLSPEED

[Loren]

Sorry - I do not agree.

Read my blog on Product claims and dynos -- and reality

[ALLSPEED]

I agree with you on claims that companies make. I'm not saying that I believe their dyno claims, just that in my feeble little mind I do feel an increase in pull from 4000 rpm. No horsepower or torque figures but a noticeable difference and I don't think it is just because I spent $340. I wish you could have driven it before and after for your honest opinion. I would like to see some honest test but all I am going on is my experience. Is that fair?

Edited April 9, 2010 by ALLSPEED

[Loren]

I am not saying you should not do it - I am saying don't believe the claims.

If you look at real world tests of many of these intake mods - you will actually lose mid range torque and have very little real HP gain.

As I said to each their own - but I would not spend money on this mod.

[ALLSPEED]

I guess this is one of those things that you have to try, to believe if you don't believe me. I believe in God and I've never seen him. It is a lot of money for the materials but I'm happy and just wanted to show others what it looks like. No, I did not get rid of my old air box because I wasn't sure either and if I didn't notice any difference I would have put it right back on because I'm not into dolling my car up with a bunch of crap. I prefer the stock look but this is under the hood and I think looks as clean as possible. I hadn't seen any posts on this and thought I would put it out. No written claims, just the hemmoraging veins in my cheeks from G-force. LOL I've got an idea, you've got the connection. I've got a 996 stock except for intake and I believe your motor is stock. Get one more and a dyno and I'll take my stuff to Roseville. I know you don't have free time with all your effort on this site and probably don't care about K&N but I would be willing to bet five Big Bens that if we could test it correctly there would be a noticeable gain in pull. I am not promoting anyones claim of amounts just some added power that didn't cost that much compared to some of the money spent on manifolds,headers,etc. In fact I will give you five Bens and you give me nothing if it doesn't. Get a dyno and some time to blow K&N out of the water or eat a little crow.

Edited April 9, 2010 by ALLSPEED

[ALLSPEED]

Do you think that $200 red silicone hose people are putting between their air box and throttle body has any merit? I think the K&N does. Look at all the money made on plenum's for TT's. Wrong thread but real snake oil. Let me ask Loren something else. If you tried this setup and you noticed a good difference, would you keep it?

Edited April 9, 2010 by ALLSPEED

[torontoworker]

The thing I notice is that you have kept the stock plastic intake which seems to dump air to only a small part of the filter area which is better then most of these set up's where people remove the OEM tube. In most K&N and other aftermarket air filter set up's they remove the tube. The issue I have with the open concept of these K&N type systems is that your engine bay is a dirty hot environment - it really is. All that road dust and grit gets up in there and has to go somewhere and with the intake suction, your going to have to be cleaning that filter quite often. I won't get into the oiled filters/maf issues but simply put; your going from a semi ram affect with the factory set up to a filter that is taking mostly ambient air pressure inside the engine bay.

I'm not sure if the engine cares about ram affect (some say yes, some no) but if you look at the 997 setup's with dual enclosed intake systems it must have *some* positive benefits - same with the RS and RSR's having small deflectors on the rear wing to direct a kind of ram air flow into the top wing vents.

It would seem to me that the key here is engine breathing and that maintaining some sort sort of ram effect while increasing the sq area of filter material while reducing it's restriction (two non complementary ideals) would be best.

If the two major aftermarket intake companies came up with fully enclosed housings and some sort of ram air effect then I could buy into these types of equipment upgrades 'easier'. I just think the factory by going with a narrow rectangular tube, (higher air pressure) and drawing air through the grill work of the factory wing would surprise people on how efficient the original design is.

I have a CAI tube after my factory air box - I did it for sound mainly. Does it *feel* better? Sort of - but would need to dyno a before and after and I'm not willing to spend $75 bucks to disappoint myself. LOL It was a cheap upgrade that makes the WFO throttle position wake up everyone around me when going up on ramps.

I've just put on a GT3 wing on my C2 and bodged up a diverter inside the wing to separate the warm engine bay heat from the engine bay fan. It was being drawn down into the second hole (only 3" away) inside the wing that leads to the OEM intake. Along with that I made an internal scoop just under the wing slot that grabs more air and channels it into the OEM intake tube. I was after *cool* air into the intake instead of *warm* air and these K&N type housings are grabbing warm engine bay air instead *cooler* outside air. We all know about O2 molecules/air densities and temperature right?

I think these aftermarket filters should be modified so that they are enclosed within a housing and not left open to the engine bay environments. Just my 2 cents.

[ALLSPEED]

I am in total agreement with the enclosed box concept and fresh air. They could have built the wall of the heat shield up higher around the throttle body but it would have made it harder for DIY'ers. There is some isolation with the deck lid closed and the filter sits directly below the engine cooling fan so it gets fresh air through the louvers also. Modifying the heat shield would not be that hard and I may play with that at the expense of having it look funky. Aerodynamics is the name of the game also. Isn't the object to get as much air (I realize the cooler the better) into the engine as possible. That's what turbos do. How come Porsche car bodys are so sleek yet the tunnel for air intake such a maze? Noise pollution! The stock air box is a compromise to performance because of noise, in my opinion. Why do people disconnect their mufflers at the track? Just for sound? High flow cats? I guess I could go on and on but since I have no hard facts so what the heck. I am happy with the system though it could isolate cold air a little better as toronto states. My reason for the post was to show others how it looks and what my opinion was. Does it feel better, sort of, how's that. Have a great weekend, Robert.

[torontoworker]

No worries Robert. I'm willing to bet that it does sound a lot better when you step on it. I wish I had access to injection molding equipment - I would love to try out some ram air enclosed housing designs for these cone air filter systems. The other thing is the design of the upper plastic grill work on the top of the OEM wing could be enhanced for better airflow into the intake. FYI: the engine bay fan draws air out of the engine area - not pulling it in. The idea is to cause negative pressure so that the heat is sucked out instead of pressurizing the engine bay which would stall out the cooling effect.

Most people do report a 'crisper' throttle response with the e gas and aftermarket intakes so that might be worth the money right there. I've got access this summer (I help out with tech inspection sometimes) to a portable dyno at the track (Mosport) that I might try out with a before/after test of the CAI against the OEM pipe to see if there is any HP gain.

Cheers - keep it shiny side up!

[ALLSPEED]

No worries Robert. I'm willing to bet that it does sound a lot beting that this is correct.ter when you step on it. I wish I had access to injection molding equipment - I would love to try out some ram air enclosed housing designs for these cone air filter systems. The other thing is the design of the upper plastic grill work on the top of the OEM wing could be enhanced for better airflow into the intake. FYI: the engine bay fan draws air out of the engine area - not pulling it in. The idea is to cause negative pressure so that the heat is sucked out instead of pressurizing the engine bay which would stall out the cooling effect.

Most people do report a 'crisper' throttle response with the e gas and aftermarket intakes so that might be worth the money right there. I've got access this summer (I help out with tech inspection sometimes) to a portable dyno at the track (Mosport) that I might try out with a before/after test of the CAI against the OEM pipe to see if there is any HP gain.

Cheers - keep it shiny side up!

Just checked the operation of the engine compartment fan on my 99 996 c2 and it blows" into" the engine compartment. Their is an arrow on the blade confirming that this is correct.

[Loren]

Allspeed is correct - the engine compartment fan blows air INTO the engine compartment.

[bmohr]

I had a K&N on my 3.4 for about 10k miles or so, no cells. Was louder indeed. Maybe a bit better throttle response. Not sure it increased any power or not, but I'll tell you the possible dirt/grit you are potentially subjecting your engine to with it on is not worth the benefits mentioned IMO. I took it off and reinstalled my original airbox. 340 bucks..wow. It should be less than half of that for some plastic tubing and a filter.

[ALLSPEED]

I am watching the filter very closely. i have been doing some experiments to it especially bringing cold air in through the fan motor hole directly above the filter. I need to buffer the air as it comes in the deck hole because after running at high speed it's great but when you stop the idle fluctuates. i guess it mapped itself with ram induction. You can go around the block with high rpm's and low speed and it will fix itself. I just don't want it breathing hot air.Who knows, I still have my stock box . Trying to make it work correctly, Robert