K&N air filter on supercharged engine
 

Good or bad? I'm new to Jaguar ownership and want the beauty to last my lifetime.

Personally I prefer the stock air filter, change it regularly, or sooner if I've had to drive thru some dusty weather. My last air filter element only has 5,000 miles on it when I was on a long road trip that entailed a pretty bad dust storm in western Oklahoma panhandle. As soon as I got home I put on a new filter.

i have never trusted the K&N air filter element system to do as good of a job as a conventional paper element. My engines have always outlasted the rest of the car on every car and motorcycle I've owned. So why switch ?

Z

K N Filers are reusable but need special cleaning oil
 

Not sure if you are replacing the OEM paper filter or are planning a performance upgrade. Lots of people have done it on the XKR.

The KN filter are re-usable but require cleaning with KN Oil.

You may get marginal better performance and MPG, but on a X100, the OEM paper filter is a cheap easy swap out. On my base 1999 XK8, if I hit a bad sandstorm, I just use a hoover on the filter element when I get home. Always change it out as part of my regular service schedule.

yeah, the K&N's are reusable indefinitely and have a 2 part regimen for cleaning, then oiling, preferably with the K&N proprietary spray cleaner and spray oil.

When the K&N's first were introduced they were just for motorcycles, especially marketed to racers, probably for the exposure. At the same time I was a full time motorcycle mechanic at theTriumph dealership in OKC, and serviced many motorcycles that were using the K&N's. Without exception, the engines wore prematurely, even when K&N's cleaning regimen was followed to a T.

I learned then all I wanted to know about the K&N "miracle" filter. Will they flow more air than a similarly sized paper element ? Yes they do. But at the same time they are flowing more dirt into your engine. I won't use them, or put them in a customers vehicle.

Z.

This right here. More engine wear and possible fouling of the MAF. All for some negligible performance gain that you won't even notice.

If you want a real decent performance mod for peanuts on a XKR, get a different upper supercharger pulley. If you're shy about machining, just get the bigger of the two and still get more than the filter change with a remove replace operation. It somewhat moves the torque a bit lower too, so it does feel a bit more gutsy.

I'm not a fan of K&N filters as I have seen a lot of people just don't get the oiling right and sling onto MAF sensors, and that's before the debate on filtration and wear. I just buy a stack of paper filters and check every oil change; I replace about every 6-12k.

I totally agree. To me, and I have my flame proof suit on when I say this, K & N filters would be a waste of time, money and energy fitted to out cars.

As just mentioned first off upgrade your pulley to a smaller one. 29bhp? Gain. Next change your MAF buy the exact OEM one though do not pay Jaguar prices. Change your current air filter for a new one. I think any gain you get from air filters, of any kind, is from them letting more air through. The problem with that is what else do they let through with more air? More dust? You can imagine what damage dust particles can do to your shiny piston walls. If your not bothered about that sort of damage simply remove your air filter, not advised. That will get you more gain than ANY air filter no matter how expensive or clever.

I installed a K&N filter on my 911.. for a while . Saw no change in performance and as others have said you may get oil fouling on your MAF if the cleaning, reoiling of the filter is not done properly. Threw it away after about 5000 miles and went back to stock paper filter. If looking for performance I would start elsewhere first.

My 98 XK8 has a K&N type filter, its blue and they threw away the top housing. Just makes more noise underhood, see no performance difference.

As stated..............
Something that can mess with your maf readings is not a good thing,

I was looking at K+N but decided to stay with the paper air filter because of the possible maf fouling problem..

A true story. I took my XKR along to a tuning station and wanted a before/after comparison on their rolling road. So the stuck it on there but came back shortly after telling me they had a problem. The car would not rev above 3000. Odd. I knew when the car is at a standstill you cannot get it above that, the revs sort of 'bounce' at that point. Try it. So I was at a loss as to what the problem could be. I had cleaned the MAF have a read click me to read Then found I had cleaned the wrong spot, though the first clean did help too. Again click me to read . So I bought a new one and changed it. Make the mistake though of paying over the odds for a genuine 'Jaguar' one when a OEM one is exactly the same for 1/3rd of the price. Changing the MAF is one of the easiest jobs on the car. Click Me .

Did it make a difference? After fitting I visited a friends farm and as you leave their gateway the road outside has a sharp bend on the left and a sharp bend on the right. So when you leave their gateway you cant hang about as they can come around those bends at high speed and you wont see them coming till they are almost upon you. So I looked left, looked right. Windows down I could not hear anything. Put my foot down to come out sharpish. ............... Nearly planted the front bumper in the hedge opposite. I had forgotten about the MAF and expected the same response but instead the response was rapid and more powerful than I was expecting. Had to reverse fast and get out of there. I was lucky. Not saying yours will change as much but mine certainly did.

I never did get the car re-tuned etc. This MAF change and the new smaller pulley got me more power than I need.

You don't need an K&N to get your MAF dirty, so far I have enjoyed the K&Ns for almost 300Kmiles on my XKR, they have been very supportive for my needs.

The intake is already restrictive as it is on a stock car, so you can imagine that increasing airflow by spinning the blower faster only increase that, and that is costing power..

So if the stock XKR is good enough, the small increase in power is not worth it to go to a K&N Panel filter.

If you want some more power, than the intake is definitely an easy way to add some more power, and these gains go only up when you spin the blower faster. With intake best is to do all (ideally with TB), but less restrictive tube, bigger MAF and large K&N Cone filter will do the job vey well. Just a K&N panel filter will also help of course, just not so much.

Of course when you tune, always make sure that you start with a good base, as over time items can degrade like the MAF/Throttle cable adjustment/Fuel pumps etc etc, which all have an effect.

Can't remember when or which Car I had when the K&N came out, but I bought one of the first ones. That was year's ago and continue to use them today....I made a rule to clean it every other time I changed the Oil or at 10,000 miles....Never had any MAF Sensor problems either! Of course, back when I started using them the Cars didn't have MAP Sensors! They were Carbureted! It seems like I had one on my 1970 454 Corvette Coupe, I think that was about the time they were getting to be "The New Big Thing"! Anyway, I still use them!

I remember now! Seems that all the cars back then used the old "Oil Bath" Air Cleaner and when K&N came out it was the thing to do as the Oil Bath thing was just a Mess and didn't work very well either!

Billy Clyde in Houston