www.jec.org.uk

Just wanted to say hi, seeing as I now have another XJR to play with. Its a 2002 Model in Black with the 'oatmeal' interior

I used to run a lovely silver blue X300 XJR which I wish I had never sold then recently I stumbled across an X308 XJR at the right price with very good provenance and I knew the previous owners. Mechanically it has been played with and has a number of upgrades that make it even more fun albeit removing its originality.

It carries the following modifications:
supercharger pulley upgrade
custom built intercooler
air filter upgrade
engine remapping
slightly lowered suspension
Free flow catalytic convertors
Full big bore sports exhaust

It also has the usual faults:
sagging headlining
slow returning seat belts
a slightly scuffed drivers seat (now restored)
the alarm doesn't 'chirp'

Next steps are to machine polish all the paintwork, replace the headlining and detail the engine bay which is too grubby for my tastes.

Cheers

ChrisC

sounds superb , welcome back, enjoy

Chris C It Sounds good, on paper but i would like to know from someone (obviouslyyou) with the experience of having the vehicle, what physical difference is there from standard, a lot of changes have been done, does the lowering of the suspension change the balance of the car going into corners ect.
The normally great 308 basics (for me an old wotsit owner) are quite sufficient.
Does it include any CATS suspension items,bigger brakes ect.....im not being picky im just trying to establish first hand from actual guys that have the same standard model then upgraded to the vehicle again.
A lot of younger guys who could not afford 308s originally, are now buying them and like your model are trying to better the standard set up, which after running mine i find them very adequate in all the upgrade items.......Joe

with regard to the seatbelt, i think they are only 100 from jaguar, and well worth the effort

i always felt better putting on my new seatbelt in my 308 rather than the ' pre-owned ' one

sounds a good car
BB

Hi Vince how's things, still got the XJS........haven't seen you since Southern Day. ...Joe

Huh? This is weird I wrote a fairly lengthy reply to Joes questions and the post is not showing. Please excuse this test.

To set the scene - I have owned XJ's for about 30 years and raced a manual series 1XJ for a few years so my opinions on modifications to these wonderful cars is a little biased as I like them to perform and handle. I will confess to not being an expert on any of the modifications...

To be fair, the X300 XJR I owned was kept 100% standard and i simply enjoyed the powerful surge of luxury BUT it didn't go round corners to well and they famously tramline which was certainly true for my car.

The X308 XJR I purchased was owned by a well known Jaguar specialist and had all the modifications I listed when I bought the car so I cant speak to being able to say what changes were instantly noticeable but below are my personal views

Lowering:
No performance gain and I believe you should adjust the suspension settings to maintain the factory geometry (something most people forget). To be honest the car does look better as the wheels fill the arches nicely. But on the downside, I cant slide my trolley jack or ramps under the front valence... My car has CATS suspension so it flows through corners nice and flat so the handling is lovely on the slightly stiffer springs. Personally I feel there is no real point in lowering the car by 1.5" unless you like the more aggressive look - so consider it as cosmetic.

Sports exhaust:
I am aware that there is *some* improvement in performance especially with the free flow catalytic converters. The bigger bore of the exhaust extracts the gasses bester and sound wise produces a deeper tone. But you have to be so careful when choosing a system as most sports systems introduce a 'drone' about 1500-1800 revs. I have played with my system in an attempt to remove that drone but it is still there (for a minute). The system came with the car and I dont want to replace the whole system but I am pretty sure there is a solution out there - possibly a crossover pipe just before the first silencer box.

Supercharger Pulley:
Smaller size = faster supercharger = more boost = faster acceleration.
This is an upgrade that would provide a noticeable improvement but it means the supercharger has the potential to run hotter (due to a faster rotation)

Intercooler:
Basically keeps the compressed air from the supercharger cooler so goes hand in hand with the smaller pulley, apparently adds a few BHP but probably not noticeable on its own.

Engine remapping:
Definitely noticeable as a modification. The throttle has a crisper response and acceleration is instant, allegedly it also improves MPG. Engine re-mapping has a few flavours, the cheap version is a simple software update, the more expensive remapping is done on a rolling road and adjusted to suit your car. The 2nd option is naturally better but more expensive.

Replacement air filter:
Worth changing as it allows more air to flow and never needs replacing so cost effective in the end.

When you add up all the changes - and you can see this advertised on the Arden or Paramount site (for instance) - its quite easy to lift the engine performance from 370 BHP to around 450 BHP - its just not cheap... but if you can buy a car with all this work done already... well why not have that extra power and performance?

My XJR is lovely to drive, very fast when needed, corners beautifully and is feels like a limousine when driven gently

Wow a nice write up there Chris, very detailed, and you seem to know what you are talking about......great post
Joe

Any pics?