... and that is all we're going to say about the K&N air filter. Please make it so.

 

Sorry H20Boy but I cannot resist. I had used a K&N filter on my Corvette for 14 years without a problem. I currently have one in my XKR. The company has been around for quite some time selling hundreds of thousands of these things (I assume). My impression based on reading posts on other forums (some of which had included dyno comparisons between stock and K&N filter) was that there could be some essentially negligible improvement in horsepower and torque comparing a K&N filter with a new stock filter. However, the real benefits are that as time goes by, a dirty K&N filter would flow air much better than a dirty stock filter. Even so the improvement will probably not be seat-of-the-pants noticeable. K&N has a very detailed procedure for cleaning and re-oiling their filters and following the oiling procedure should not result in any problems (and NO I do not have stock or any other interest in K&N).

Doug

 

^ forgiven Doug. I do have one on my xk8 also, only because I didn't want to buy paper filters as frequently as owning this. I've put 60,000 miles on it and it barely looks used, so I have yet to do a clean n re-oil.

 

Sorry to chime in so late especially after being told not to. But with that being said, I am in the industry and have seen many times over the results of oil on MAFS, and its not pretty. It usually only occurs only after someone has cleaned one and did not follow directions to a "T". I also run them on personal cars as well. But I also have not seen any hp gains from one that I have had on a dyno. So it boils down to if you like intake noise or not.

 

There's no debate...nothing to see here...just move along now....

 

you crack me up steve... I'm going to change your title.

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Crap, this just will not do! How can I be moderator and have no privileges to change member 'titles'? Think I'll head over the Moderators Forum (yes, its hidden from you 'normals') and see if I can get some more power. <-- that may be the only power we can increase Sam.

 

My concern with K&N is not the MAF oiling issue, since that can be corrected, but all the dirt it lets in.

Here's some interesting info:

http://www.autospeed.com/cms/A_111486/article.html

 

One would think that, and for the most part it's probably true with other cars, but I picked up .6 second improvement in the 1/4 mile after exhaust and intake mods. Pretty significant. But this is on a 4.0 SC which responds much better to exhaust and intake mods than the NA. Think about it: the NA cars have the same exhausts and intake as the supercharged cars.
This means either the NA cars have more than enough exhaust and intake or the supercharged cars are terribly restricted.

 

Yes .6 second in the 1/4 is very significant but since I have not gone to the drags with any of the cars I have owned (and I suspect maybe at most 1% of XK8/XKR owners do so) it would really not have much of an impact on my daily commute which is mostly on slow city streets. Nevertheless, I am interested in the details of how you achieved that with just intake and exhaust mods.

Doug

 

Seismic Guy, if I may interject, I can remember, way back to the '60s when I actually did go to the drag races. (I was a teenager, not a participant) I read a lot of information about getting more power out of engines, and, fundamentally, the notion was that you had to consider an engine as an air pump. Essentially, the more air that you could get into and out of it, the more power that it would develop, since more air meant more gasoline. Back then, you could put a better carburetor, a better intake manifold and some headers on a car and get a LOT more power out of the big engines of the time. I am talking about a two second or more difference in the quarter mile. I had a Barracuda with a 318 cubic inch engine, which was considered a moderate engine, and there were 383 and 426 ci engines available. By comparison, a 4 liter XK8 engine is somewhere around 244 ci. Modern engines are much more highly engineered, especially engines such as in our Jags, but, still, getting it to breathe better is the ultimate way to develop more power.

 

Hey Kev--we are somewhat kindred spirits. I had a 383 Roadrunner back in the 1970s and was also lucky enough to have a 1967 Barracuda fastback with a 318 for a few years (boy would I love to have either of those cars now). Anyway, the Cuda was really my wife's and it only had a 2 barrel carb but I did convert the exhaust from single to dual (glass-packs of course) and that was the extent of the tinkering. With my Roadrunner, of course, it was another story. Mods over time included larger carb, single-plane intake manifold, headers, cam, electronic distributor, etc. And you know what? With each mod I did the car ran crummier but this was before the days of the onboard computer that could compensate for changes. Years later when I "grew up" I finally figured out that you needed to have an overall plan for the mods you did and they needed to be compatible with one another.

Doug

 

What kind of details? The only mods were a Macleod X-pipe II and my own intake. 10 year old bald Pirellis. This is a 99 XJR. Ran a 12.996 @ 107.05 mph. The fastest stock time I've seen was 13.6something. The published stock numbers are like 13.7-13.9 sec.

 

Doug, you are right. I saw a lot of guys try to do too much to their cars without really knowing what they were doing, and usually it ended up with a car that did not run well at all. The surest and quickest way to get some more performance was to put some headers and a better exhaust system on a car. That alone, ALWAYS gave a performance boost. When guys started putting carburetors and intake manifolds on, they often put too big a carburetor that drowned out the motor. We would see a lot of guys show up at the drag strip with all sorts of things done to their cars, and they would run pretty well for certain parts of the power curve, but just did not run all the way through it, as would the guys who knew what they were doing could get them to do. My Barracuda was a 1968, and I followed it with a '74 340 Duster. That was one sweet running car! I had a few friends who had 383 Road Runners. One guy, down my street had a 1967 GTO, and when another guy got a 383 Road Runner that could beat him, he bought a Camaro Z28, and still could not beat the guy in the Road Runner, so he bought a 454 Chevelle. Another guy down the street had a GTX 440 and he had the engine sent off to Keith Black Motors to have balanced, blueprinted and fully race prepared. He didn't take it to the strip, he street raced it, and after just a few races, no one would race him any more. The development of those muscle cars were a very exciting period in American Auto history. I guess you may know that what Chrysler did was to take the heads off of the 440 and put them on the 383 block (the 383 was not really a performance engine) along with a better intake manifold and cam, and created the Road Runner 383. Chevrolet took the crank out of the 283, put it into the 327 block, along with some Corvette heads to make the Z28 302. Wild times!

 

Wild times indeed! Those were the days where I was lucky to get about 13mpg and gas cost $0.25 a gallon. Also, engines in those days were lucky to go 40,000 miles without needing a valve job or rings. I guess I like it better today.

Doug

 

Alright Doug and Kev you are taking me down memory lane with you! I too was a Mopar man and my desire to get something that was as exciting as my 70 `Cuda 340 is why I ended up with my XJR! And what a stupid young fool I was for selling that absolutely exquisite car, it would be worth $70K plus in it's form at the time I sold it. I think that the 340 was the best small block engine Detroit made and the A body `Cuda was the best Mopar ever.

 

LOL! Another Mopar dude here. in the 1980's when I first got my license I had a 72 Charger with a 318. I'd love to have that car again. At the time it was just used beater that my dad found cheap. But I got a job and did a lot of work to it. When I finally sold it it was a nice car. If I could only get it back...