KN CAI unit question

Does this unit retain the ram air tunnel to the airbox or does it remove the airbox? or add to it like the Evo kit?

The K&N kit requires the air tunnel from the stock intake. Unfortunately, there is no bracketry to secure the tunnel, so it will not align with the inlet and you will have practically no fresh air. It really is a bad design. The air filter is also poorly positioned just below the fan inlet, so you have to replace the system with the factory equipment if you intend to drive in the rain. Do yourself a favor, get the EVO intake. Or go the long route like I did; buy the K&N, throw it away, then buy the EVO.

I would agree w/TT's assesment, and add also be prepared for a possible check engine light with the K&N.

TTJunkie, have you ever seen one? Because you have no idea of what you are talking about. The original inlet air duct (tunnel) mounts to the heat shield and does line up perfectly with the scoop in the lid. You have to drill 2 holes in the upper side of the duct to mount it. I would recommend getting some additional hardware and added a 3rd hole through the heat shield and duct on the bottom to make it more rigid. I would also recommend making an additional braket to stiffen the left side of the heat shield. I did both mods when I installed mine about 5 months ago and there are no issues. I have driven my car multiples times in the rain (even heavy rain, mutliple inches per hour) and made many trips to the car wash (using a pressure sprayer) with no issues of water contamination to the filter. Porsche designed rear lid and vent is to channel water to sides of the lid for drainage. Keep in mind that the EVO intake also places the filter exposed under the vent and has no water contamination issues. The CEL light issues seem to be common on the 99-02' cars with the old style MAF. The MAF was changed on the 02' to the 00'+ Boxster style. I've never had a problem with driveability or CEL issues. The K&N 63 series with a pair of Fabspeed mufflers made 22 hp at the wheels on my car on a dynojet.

02 Carrera: Though I appreciate your enthusiam, you should know that you have voided your K&N warranty by driving in the rain. This is not however, a problem with the EVO system, because the filter is NOT in the same exposed position. Yes, I have installed and fully evaluated both systems on my own 03 C4S (a 375 hp screamer that can really put these systems to the test).

3k miles on my K&N CAI, and loving it. The cone is right under the fan that sucks air.

Junkie, I suggest you also read the warranty statement from K&N. This is yet another incorrect comment you have made in this thread. There is no restriction from driving in the rain in the warranty statement. The kit includes a sock to be used over the filter, but it is completely unnecessary. I severely doubt you ever installed or seen one in person based on the incorrect comments posted on this thread. To be honest, I didn't take much into making gains with simple bolt-ons on these cars, until I saw it on the dyno. Unfortunately, I never dynoed the intake and exhaust separately. I have still NEVER seen an independant dyno sheet on an EVOMS intake. No, my car certainly did not make the gains shown on dyno sheet K&N enclosed with the kit, but it wasn't far off. I am still curious about what the real gains are from the EVOMS intake. Anyone got a before and after dyno sheets they can post?

The K&N CAI is a piece of junk, you will need to add bracketry and fiddle a lot to get it to work properly. This includes intake plumbing, acceleration rubbing, CELs and additional support to augment poor materials and workmanship. The K&N is also poorly designed; you will void the warranty if you drive it in the rain, sock or no sock. This is clearly stated in the warranty. The EVO CAI is a high quality system. It is well designed and well implemented. I have installed and used both systems. I threw away the K&N system (I would have felt slimey reselling it to someone else). I love the EVO system. I am a software engineer and have absolutely nothing to do with auto part sales or marketing. This is simply owner input posted as a warning to others considering the same mistake I made.

If I recall correctly from another thread....the warranty issue doesn't deal with the K and N warranty...it deals with a Porsche warranty that may be voided if you drive with the K and N in the rain. The explanation dealt with the fact that the K and N filter was positioned such that it would suck up water from the roadway due to the forward motion and water being thrown up from underneath. The comment was made that Porsche wouldn't fix an engine that failed because it had been subjected to water in the intake due to a design deficiency on the part of K and N. So the warranty issue comes from Porsche not K and N. Given that discussion, I don't think I'd want to try and test Porsche's position for the sake of an aftermarket filter that doesn't seem to do much more than a stock one. The argument also cited the fact that the EVO CAI didn't have any of those problems or issues, so why risk it with a K and N? That seemed reasonable to me, and I bought the EVO.

The K&N installation instruction is in front of me and I quote: If I'd have done more research on this forum, I'd have bought the EVO, but I now have the K&N (got it installed by a garage) and got the CEL after 100 miles (C2 2000 Cab), so the EVO can't be worse. If you compare both systems, it's clear why the position of the K&N can suck water more likely than the EVO.

I have the K&N and haven't had any issues. Take your time installing it and you'll be fine. I rarely drive in the rain so that isn't an issue for me. fwiw - it seems as though most of the issues with K&N have been on pre 02 cars.

K&N has the CEL issues with P-cars. I was told by a shop I trust tha K&N foul the MAS

another thread confirming why I will not buy a CAI. I am scared of the CEL and MAF going south. If there is an CAI system that can GUARANTEE NO CEL or MAF issues, I will consider/buy that one. EDIT - even more reason I have an 01.

If only there were a way to tell the Porsche community how bad some aftermarket products really are. Even Panorama advertises the K&N system! It's like those cheap, resonating B&B exhaust systems, it doesn't matter how bad something is; if it's marketed properly, it will sell. What we really need is a warning section for the junk that we've bought, installed, uninstalled and thrown away!

Actually it doesn't get water sucked in. This is true for both heavy rain and pressure washers at the car wash. I've had it on my car for over 7 months and this has been well tested at least 20 times. Why? Simple, just look at the design of the rear deck. The rear lid is designed to channel water to the sides of the lid. In fact, you don't have a straight path at all where you can get to the filter other than the OEM scoop. The only way I have been able to get even a drop on the filter is by opening the lid after washing the car. A few drops may drop on it as they do across the entire engine bay when opening the lid wet. This isn't by any means new in design for Porsche. I have a very similar setup in my 79' S/C. The filter snorkle is directly under the grill in the lid. Again, the lid is designed to chanel water to the sides. I have no problems with water contamination in my 79' either. Last, not everyone has problems with this intake. I have never had to deal with a single problem with this intake in over 7 months on my car. I've never had a CEL light come on, rubbing issues or any driveability problems. I've even cleaned and re-oiled the original K&N filter with absolutely no issues. The only thing I did different from putting it out of the box was adding 2 additional mounts: 1 for the bottom of the scoop and 1 for the left side of the heat shield. Considering that it made 22 rwhp on my car in combination with a used Fabspeed exhaust, it is far being "junk" that needs to be thrown away. I was also one of those few who got it for $247.95 shipped, as advertised in Panorama, and it was worth every penny. Given this, I could never justify paying $350 more for an EVO intake.

FWIW, even your stock airbox will cause CELs now and again. Indeed, in my Boxster S, I had them intermittently. It used to drive me nuts. The MAF sensors seem to be especially ornery little fellows. However, an air filter or freer flowing air filter should not cause trouble per se, but poor design, implementation, or installation of a CAI certainly could do so.

Indeed, but somehow you manage to justifiy paying thousands more for a Porsche over a Corvette (which is ostensibly faster, stoppier, and your favorite keyword: cheaper)?

... just to let you know: My indie confirmed that the reason for the CEL I reported yesterday after installing the K&N CAI was a cat signal and not the CAI. It's gone now. According to him, the MAF is fine. Remember I have a C2 MY 2000. Cheers, Harold

I own a K&N CAI & have asked before but never got an answer....What is the code one will get that is caused DIRECTLY by the K&N? I have had my K&N several months & am having no problems on my 1999 996. However, when I go to a car wash I put a towel over the filter & when I remove it it IS fairly wet. I have had NO problems in the rain, but I try not to drive my P car in the rain. Just my .02. - Cam

Porsche has known that there are issues with the design of the MAF Sensor in the early 996's. In 2002, they changed the from the single path design to a dual path unit that was first installed in the 00' Boxster.

I've heard that the K&N filter is sometimes over oiled from the factory. Would it be wise to clean it and then re-oil it before installing it? Also, would it be possible to just get an 00 Boxster MAF and put into a 99 C2 w/o any issues or modification?

I asked my mechanic last week before the K&N CAI was installed if we should dry the filter overnight because I read about it on this forum. He didn't think it should be done and as the CEL is (at least for now) not coming from the CAI/MAF, I guess he was right, so no need to dry it. What I'm wondering is why some folks are not using the net on the filter (better performance?). I heard it should help to keep larger particles out of the airway and therefore avoid the MAF issue? I'll try the thing with the towel at my next car wash; I was already fearing that I need to hand-wash the car from now on.

Its possible but not adviseable, the ECU expects a certain voltage level to correspond to a certain level of air mass. The updated MAF (image 1) has an angled air-measuring port that skews the sensor readings compared to the standard Bosch MAF (image 2). Your car will not run properly unless the MAF voltage compensation table inside the ECU is also updated. One of the reasons Porsche gave for the update was water contamination. With zero engineering going into the aftermarket clean-air intakes the situation can only be worse.

Thanks.