K&N Air Filer for the later 3.6

[SimonR]

My previous XJ-S (a 1985 car with earlier induction system) had a glorious induction sound. It had been to TWR early in its life and although I never found out exactly what they did to it, it seemed to have a lot more power than others I've driven and the growl to go with it.

You can hear it in this video (just about - apologies for the terrible quality from 12 year old camera!)

https://youtu.be/g-d7GNiL4UM

One thing that helped was a K&N panel air filter, and I was surprised that there isn't one listed for the later cars with the circular air filter element - I even called K&N who confirmed that they don't make one. Undeterred, I measured the existing standard element and see if there was one that would fit. It looks like K-2350 which is: 165mm (Length) x 89mm (Inside Diameter) x 135mm (Outside Diameter) is a little too long, even though it's specified for some Jags, however It occurred to me that my MG Maestro has a K&N Filter so I compared the size of that and it fits the XJS Airbox perfectly. Part number is K-2360.

E.g. https://www.ebay.co.uk/itm/130472327446 ... Sw~AVYpFMw

Unless anyone can think of a reason why using one of those would be a bad idea I'm going to give it a try and see if I get a slightly more engaging engine sound out of the old thing - and yes, I know that Jaguar probably spent a lot of money and time trying to remove exactly what I'm trying to add back...!

While I'm at it - has anyone else modded their AJ6 / 16 car to add a bit more Jaguar Growl back?

[ptjs1]

Simon,

Great post! I've searched for years to find an exact fit from the K&N catalogue for my AJ16 engine! I'm going to wait until you've tried it out and then I'm in the market for one also!

Paul

[SimonR]

I think this is more or less spot-on Paul - here are some comparative pictures, with the OEM filter next to it:







And installed:



When the OEM filter is installed there is about 11 mm of thread above the nut - with the K&N it's about 7, mainly because of a higher lip around the inner part of the K&N filter. The OEM filter is fatter, i.e. has thicker walls, but I imagine that's to do with its construction and the K&N filter can get away with a thinner wall as the filtration medium is different.

I'll report back on if it makes any difference to the noise and performance in due course - although at the same time I'm also replacing quite a few consumable items (fuel filter, plugs, oil etc) so it's not a hugely fair test!.

[davidr]

That's very interesting. Like Paul, I've looked before to see if there is a K&N filter for my Celebration. I guess that so long as it fits in the canister and seals properly then all is fine.
Please do report back on the noise. If it makes the car sound like I'm the holder of a Halfords loyalty card then it isn't for me!

[poprivet]

Just a thought, as it's the same physical size and is less restrictive, is the filtration compromised?

[ptjs1]

Pop,

I guess that's the constant challenge for sports air filters - the ability to flow more air whilst not compromising on filtration efficiency? I'd like to know how they work the calculations?!

And David - as a Halfords Trade Card holder, I'll be happy to lose just a little bit of the noise refinement of the car! I'm even thinking of fitting some straight-through middle pipes as well!

Paul

[SimonR]

If it makes the car sound like I'm the holder of a Halfords loyalty card then it isn't for me!

Oh I don't know - if it's loud enough I'm thinking of going the whole hog and fitting a full TWR body-kit with spoiler, gold alloys and tinted windows

[SimonR]

I finally managed to drive my car on the open road today, and can report back a bit about the difference the air filter has made.

First-off, it's difficult to say whether it's more responsive than before as a result of the filter. The 4 extra BHP that K&N say you get is probably not all that noticeable in the first place, and I've also given the car a pretty comprehensive service and unstuck the brakes since I last drove it, so although it certainly felt a lot more lively, that could be any number of things causing it. It's possible that a new standard filter would have had a similar effect when replacing an aged and pretty dirty original one.

The engine sound, however, (and this was the object of the exercise) was definitely louder, and the detached almost silent induction sound that I got with the old air filter is definitely more of a growl and sounded pretty good on acceleration, as the revs rose.

I'll stick a video on YouTube and link to it when I get the time so you can see what it sounds like - it's not as brash as my TWR-modified previous car but I think that may also have been because its early style air box had been modified with a large-bore trumpet that opened into the engine bay.

[greeban]

I'm very interested too - thanks for taking the time to post here.

[SimonR]

It's taken a while, but I finally remembered to ask my S.O to take a quick video of the Jag accelerating so you could hear the engine sound.

https://youtu.be/3LmIqtIp1Yc

Apologies that the microphone on my phone isn't all it could be, but you can hear a bit of a growl. I'll make a better one when I can.

It also show how quickly you can get from 30 to 60 in an XJ-S - I could really do with a bit of private road or race track to give it a proper exercise!