Hi
has anyone got any recommendations and/or experience with any K&N Filter kits (including the air-pipe - not sure this is the correct technical name), to replace the XJ-S' standard air-filter & housing?

Does it actually give more power?

I've got a 1979, doing an engine-out decoke/overhaul.
If anyone has got any tips / do's / don'ts for that job as well, I'd be grateful.

Cheers

Ronnie

 

I used a K&N filter on a truck a few years ago. I found very fine dust accumulating on the inside of the air cleaner. If you are religious about checking and re-oiling the filters, that may not happen. I went back to paper, I've got enough chores to do already.

 

Ooooooh Nooooooooooo! (running for cover)

 

Google will show you a fair number of results from independent people with small but repeatable gains, in other vehicles. Unless the XJ-S has a particularly restrictive filter, you won't feel the gain.

 

Not sure how "religious" I am about oiling filters, but if that's what it takes....

Did some googling, and came up with AJ6 engineering in the UK, which is closer to home. They apparently have one or more kits, including the air intake. Bolts on, apparently.

Thanks for the insight

 

go for an aftermarket cone filter to replace the airbox. youll see a small gain in itself, but that will make room for more gains with other mods like cat delete, larger TB, etc.
**** K&N

 

Hi Ronnie,

One of the problems with the stock XJS intake is the extremely small diameter inlet pipe, I remember reading somewhere that the inlet air speed hits mack 1 (the speed of sound) before redline, what this means is that no more air volume can get into the engine. There are a number of ways to tackle this problem and it depends on what you want from the car.

1. The most unobtrusive modification that will still allow the engine to breath better. Add an additional inlet to the OEM airbox underneath, similar to the AJ6 here is a link THE JAGUAR V12 ENGINE / AJ6 Engineering

2. Enlarge the intake to 2.5" this was done by both Lister and TWR and will give slightly more engine growl than the AJ6 version. I have also seen similar mods but with a flex hose to behind the headlight.

3. Replace the OEM airbox with something like the Growler, a cone filter on a pipe. This will give you a tremendous throaty roar at full throttle.

If you are planning on modifying the engine further and don't mind the additional roar 3 would be my choice. If you are not going to do more than an exhaust I would look at 1 or 2 as it will help the car rev a bit better but only approaching red line.

cheers
Warren

 

well i did mine,one for each side V12, 3" 90* bends, already have 6MM oversize TBs, K&N filters, works fine got some full throttle roar, but its part of the character of my car.

more power,i dont know made to many changes all at once!

dynod around 325-340WHP, depending on whos dyno.!

 

just remembered,DUH.

tried dyno setup with hood closed,filters on.

then open hood ,no filters at all, overhead fan blowing down, made 3hp more.

 

Ron, i really like your 90* HAI's
what other mods have you done to your XJSC?

 

Thanks a lot

I'll go for option 3 - I really want a more throaty roar; the XJ-S original sound is very refined and gentleman-like, which in itself isn't a bad thing. But a bit more sporty sound does more justice to the car.

Again, thanks for the tip

Cheers

Ronnie