So having just finished up the valley hose happiness, there are a few things I have noticed about my 2008 XKR Portfolio Coupe.
-One of the intercooler hoses had already been changed out.
-When changing the air filters, I pulled K&N filters, well used ones, from the air boxes. Just thought that was interesting. Replaced with WIX units.
-Exhaust has been modified. Resonator and mid muffler has been removed, X-pipe put in place. Not sure how I missed this before, but ya. I thought 'Neat!'. Still have the factory rear box however, which I am leaving for now, it is still fairly quiet and reserved, until I choose it not to be by depressing the loud pedal lol
-Duckbill has appeared to have been trimmed already, which is a huge plus!
-IPod dock retrofit has already been done. This I have known for a while due to me jamming off tunes from my old IPod Nano 8GB haha

Anyway, just some interesting observations and finding out about the history of my car.

 

Good job on the kn replacement!, I dont like to sacrifice filtration. Get her ECU tuned lots of safe power available on that car!

 

Bad job on the K&N replacement, now you will have lower airflow and inferior filtration. Plus you just lost $140 worth of filters.

 

Hope you're not serious cuz no way in hell KN filters as good or better then stock paper filter
Also hope you realize then if you take filters off completely your car will run with the same power or less just because of all the limiters in place in the ECU

 

Tested or just referring to any sort of urban legends?!

As an analogy - old, stuck air filters should not reduce power, correct?

 

Alex empty your private message box.
Been trying to get ahold of you.
Cee Jay the OP tossed the KN's and installed Wix.
I think??
KN's are garbage.
I know!

 

Yea I test these cars while developing my ECU tuning and spent hundreds of hours doing it. Its the same story on 4.2 and 5.0 cars, ECU with limit power on any modification made to hardware
Either way back to KN , even with the ECU tune, gain from the kn filters will be miniscule and not worth the extra dirt and increased wear you will get. If you want to let more air you have to do it right and increase the surface area of the filter and leaving filtration Factory, this is what I have done for the XKR cars..
Just FYI our record setting XF supercharged ran with stock paper filters pushing over 700hp , on my fully stock 2013 XJ SC at around 620 with ECU tune only

 

Done , go ahead sent

 

I will have my ECU tune updated in upcoming days, after a full exhaust change done in recent weeks. I'm on KNs, but have a set of brand new standard filters too. If I only not forget - will ask my tuning guys to check on KNs vs standard filters.

If there is no difference - I'm with you - paper are safer. But I would bet some money that KNs will give a couple of ponies...

 

Can tune it for you, not many tuners in the world actually tune these properly.
Look if you want to test k&n versus stock filter on a dyno I would like to see that test . I predict there will not be any difference in power.

 

So Alex how will the new Ca. law affect your tune .

 

Good question 😥

 

first off I do not think their equipment is able to tell the aftermarket programming unless things like o2s and emissions related things are turned off, but we will see. If anything can be just programmed back to stock for emissions testing in California..

 

Interesting discussion on this Forum from 2014 - 2015 about K&N air filters:
https://www.jaguarforums.com/forum/x...ilters-119498/

My opinion is still the same.

 

Yeah, the oiled medium if too heavily oiled makes a mess of the MAF. If too lightly oiled, equivalent to removing the screens on the windows but hanging sticky fly strips to collect the impurities.
Related, I also use very fine clean filters on the house furnace and air exchanger… https://www.consumerreports.org/furn...nd-central-ac/
Same theme. not oiled yet high flow and exceptional filtering.

 

Thanks! ECU tune is next on the list. Been in touch with you already, will be again as soon as funds allow 😁

 

I kept them actually, stuffed them in the WIX boxes lol. Actually I'd sell 'em to ya for $120, low mileage lol 😜
Honestly they seemed quite old and dirty, but I'm too much the car parts hoarder to bin them so on the shelf they went. Nice clean filters, even OE paper style had to be an improvement.

As a side note, no MIL regarding MAF sensors since I've had the car with the filters, and I've no idea how long they've been in place.

 

I watched a k&n rep work for 6 hours (in the early 90's) with a 900 Honda RR. It was on a dyno the entire time and the rep could never give as nice a power curve as oem. He did get more peak but the map was all over the place and in real life it ruined the power delivery most of the time.
I used a K&N in a turbo'd '88 chev truck, but...BUT...the filter was behind the front bumper and the only reason I used it was the fact that in wet conditions the turbo was sucking so hard that a paper filter would have been saturated and collapse. Paper for me!

wj