Who's made the change to an K&N air intake filter on their xj8?

thinking of picking up a "K&N 33-2190 High Performance Replacement Air Filter" and wanted to get second opinions/ suggestions.

notice any difference in gas milage or power?

 

There is no improvement in power or economy. Save your money.

 

And, if the filter is not oiled exactly right you can bugger your MAF!

 

I would suggest adding a secondary inlet into the airbox, a tube down to behind the grill area to allow more air in than just the fender. I didn't dyno my car before and after, and I went to a cone intake anyway, but even if it does gain you some, it's not going to be noticeable, especially if it's the drop in replacement. The cone filters give you more sound but can't swear that it's power and not noise. Mileage won't be affected much either, you'd be better off doing the routine stuff (plugs, keep oil fresh, good gas, clean the MAF, etc) to keep mileage up to a premium. The filter won't really make a difference, even if it does give you a hp or two bump (again, I haven't seen a before/after dyno run with like conditions for both runs, so I can't speak to that. I've seen some videos where the K&N does do some, but each car is different)

 

Gains/losses on a dyno of a few HP cannot be automatically attributed to any changes made to the car. There's always scatter and inconsistency on any dyno runs.

K&N, like any manufacturer choose the most flattering curves for their product.

 

+1 buggers the MAF.

Put a KN in one of my LR3s: was cleaning MAF sensor constantly.

 

Mine came with one. It was the first thing I changed. I sold that POS on eBay and just do paper filters once a year ($6-8). I have bought enough MAFs on cars that had those things, I think I'm now part owner of Bosch.

 

Odd you say that, my Infiniti is giving me my 1st problems since ownership. It was recently switched over to K&N as well. All symptoms/codes point to the MAF sensor I cleaned it & still get idle issues , now I'm waiting on a new MAF sensor to arrive & I may just go pick up a paper filter lol.

 

I owned an XJ8 and wanted some more go. So I saved and bought an XJR. I drove the XJR for a while and wanted more go. I saved and bought the XFR. For now, I have all the go I want and then some.
I suspect that I have actually invested less money, and certainly less time than the guys whop have truly gotten significant HP gains. But I have missed out on the fun and bragging rights and the chance to lie about my improvements.

 

I like modded cars, and they can be a blast. That said, I love a factory high horsepower car. I also feel that good value is to be found in moving to another car rather than the modding route. No offense to modders and hot rodders! I know a lot of guys with old school hot rods (think 30s american chopped, channeled, rodded out stuff!), and it's a blast.

 

Just "bolt a supercharger on it" and be done with it.

Just kidding!

Really, get an XJR instead!

Some of my Ferrari buddies run the K&N with NO OIL, believe it or not, because they want the extra air flow, are not afraid of the extra particles not filtered by the unoiled K&N, but ARE terrified that the oil will mess up their expensive F car MAF. We are talking about cars that get driven a hundred miles a month sometimes though.

I think that speaks volumes about the danger of an oily K&N.
Vector

 

ratgawd,

There's an easy way to test for any perceptible improvement in performance that could be gained by using a K&N filter. Simply drive your car with the air filter removed. It's best to do this after a rain when the air has been washed of dust and insects.

Whatever performance difference you can perceive is the maximum improvement a K&N filter could provide. But in reality, the actual difference will be less, because any air filter must, by its nature, restrict air flow. The biggest difference you'll probably notice is a little more induction noise, as CharlzO mentioned. Any performance difference you notice will be mostly or entirely placebo effect.

As Vector mentioned, an air filter that can allow more air flow can also allow larger airborne particles to pass, so I use OEM style paper filters in our cars.

Cheers,

Don

 

It's strange that noise can affect your 'butt-dyno'???????

Maybe try the filter/no filter with EAR PLUGS?????

bob gauff

 

Thanks for the advice guys!
Went with the oem paper style filter, price difference was the final 'nail in the casket'.