How and why I chose the base car: I am a sucker for innocuous looking saloon cars with indecent performance, and have had a few. My E60 M5 was great, apart from the poor ride quality, and the fact that it was so troublesome. I think that E39 was peak M5. With the knowledge that forced induction engines are much easier to screw more power from, than naturally aspirated ones, having an intense dislike for fragile mechanical components, and lazy throttle response, left me few options for an everyday car which I could develop into (for me) the ultimate Q car (sleeper to anyone under the age of 60 ). Immediately after the M5, I had considered an X306 XJR, but although I liked the ride, handling, looks, interior, and especially the rock bottom pricing, felt that it would be too difficult / expensive / possibly impossible even, to improve the power to the point where it would equal, or beat the BMW's performance, and even if it could be done, it would very likely be as troublesome as the BMW. Not that there's anything inherently wrong with the X306; it was the world's fastest production 4 door saloon when announced, but it was 1,000cc down, and 10 years older than the BMW. The X308 was a bit closer, but Jaguar's first V8s had their own troubles. I did buy a 6.0 litre X305 XJ12, and look at the practicality of supercharging, but reached the conclusion that I would spend a lot of money, and probably ruin a good car. When my wife wanted to dispose of her 2004 XJ6, I took it over as my do everything car, and began to appreciate its agility, and very respectable performance given its modest claimed 240 bhp; all it needed to make a great car was twice as much power, and probably sharper brakes to match. An X350 XJR, with its now sorted timing chain tensioners, 400bhp straight from the factory, and weighing (depending on whose figures one reads), up to 400kgs less than the M5, seemed to be a good place to start. It took me 5 years of research and test drives to find "the one". I never spent that much time choosing any of my three wives. 😎 I looked at really cheap high (200,000+) mile examples from 2003, to late low mileage ones at pie in the sky prices from chancer "classic" dealers, discovering along the way that from 2006, in exchange for the extra fiver per week VED, one got better electrics, better brakes, VVT, a few extra bhp and more bottom and mid range punch.
I was a little unconvinced by the 2007 X358 facelift, finding it not as subtle as I would like, although that is what I bought, partly for the black / black colour scheme, the very full yet no sunroof spec, but mostly for its full ownership (Jaguar cars, followed by an aerospace design engineer) and maintenance history, contained in a two inch thick folder, complete with receipts for almost everything bar fuel and screenwasher fluid from day #1.
As purchased on 14/10/2017
found a comment on a Jag forum you made in 2017 regarding a 3.8 e type which I bought 50 years ago as a doner to build a d type, It was incomplete In a sad state But it was a 3.8. I still own the car and use it regularly.
My prior experience of tuning had mostly involved the removal of material from cylinder head faces, reprofiling camshafts for lift and duration, altering ignition advance curves, adjusting mixtures via jet and needle changes, exhaust modifications, fitting uprated components to take increased stresses etc. All old school stuff, much of it unsuitable for a quad cam supercharged V8 with variable valve timing and everything controlled by a programmable ECU. I asked trade and racing contacts for advice which boiled down to forget tuning boxes and off the shelf maps, get the ECU settings optimised on a dynamometer, preferably by someone running a successful racing team. East Anglia is reasonably well served by such businesses, although two of the companies I had used had recently closed owing to retirement with nobody wishing to take them over, a shame; a lot of expertise lost.
Phone calls eventually produced someone who seemed to know what they were doing, actually called me back when he had all the info he needed from Jaguar, and booked the car in for a whole morning of dynamometer and laptop for £250. Bargain. He suggested that for best results I should arrive with a tank full of the highest octane fuel I could find; Tesco Momentum 99.
After the first run, as he was perusing the downloaded data on his laptop, I asked him to remove the 155 mph limiter while he was at it. "No problem but I doubt there is one; I just ran it past 170 mph in fourth, and I haven't touched anything yet." Run #2 after some adjustments via the OBD port produced an additional 10 bhp, and the comment that it was pretty well set up to start with, able to self adjust to the increased boost and high octane fuel, but there could possibly be a little more to come, further investigation showed that there indeed was no speed limiter, just an engine revolution limiter set well beyond the red line on the tachometer. Curiouser and curiouser. The little more was another 7.4 bhp, and an impressive 37.2 Nm. Road testing revealed responsiveness improved far beyond what the figures suggested, and an ABS fault apparently caused by the front wheels having been stationary whilst the rears had touched 2.75 Castles at one point. That I considered highly satisfactory, although of course there was no air resistance to overcome on the dynamometer, so it probably couldn't achieve that on the road. An ABS reset cleared the fault and extinguished the warning lamp.
During a visit to Abbott Racing in Manningtree, where son #2's Saab was being attended to, Ed Abbott (a former Jaguar Development Engineer) approached me, having peered at the VIN at the bottom of my screen: "Ha, a Jaguar Cars car;- that will have some odd features.", but wouldn't, or couldn't be drawn further, so I am none the wiser; was this car used for development by Jaguar? Was it delimited and messed around with for somebody important to use and then sold (as approved used!)? Or, given my experience with my old XJ12, and various road testers' comments of "What speed limiter?" when at Millbrook etc are Jaguar speed limiters a figment of somebody's imagination?
Several months on, the EML began to occasionally illuminate, but could always be extinguished with a cheap code reader which told me little. My Delphi system however, indicated a failing catalytic converter.
A £60 afternoon session at the Old Which Test Track** in Gosfield,
theoldwhichtesttrack.co.uk/
with a borrowed data logger suggested that whatever the problem was, it had no adverse effect on performance.
**If you're tempted to go there, watch for the fault at around 500metres from the start; it had me airborne on my first run.
Satisfied with the performance, and the very modest costs to get there, I did nothing more than remove some of the under bonnet and supercharger insulation to aid charge cooling, try a couple of doses of Cataclean in the hope that would solve the occasional EML, service it, fit new pads, another set of rear tyres, and drive it for a year and a half. I decided that a supercharger oil change was a good idea, using the oil bought way back when the smaller pulley was fitted.
If anyone is interested:
jagchat.net/thread/1420/supercharger-oil-change-v8-engine
The old supercharger oil wasn't that bad, considering the 137,626 miles behind the car.
A routine check in March 2019 revealed that the plastic intake was slightly distorted, and chafing against the charge cooler hoses, so I ordered an aluminium intake tube from the USA. Yes, you'd think such things would be available in Britain for a British car, but apparently not.
The fettler in me couldn't resist the old school action of port matching, probably because the Jag was almost tediously reliable, and I wanted something to do. Although I will always be convinced that clean intakes and exhausts increase power, and the intake manufacturer claimed a 15 bhp increase from their product, I didn't feel the need to spend money on more dynamometer time, and couldn't perceive any performance difference on the road, but the supercharger sound effects were improved, imo.
Expressing boredom with reliability caused the radiator to start weeping, not too expensive to buy, but a pita to change owing to having to discharge the a/c to remove it. I added a new main water pump (XJRs have three), new belts, new auxiliary idler and tensioner pulleys, new supercharger idler pulley, and coolant hoses to the parts order. There was nothing apparently wrong with any of the foregoing, but they were all relatively inexpensive, 143,000 miles old, and very easy to access while the radiator was out. The supercharger coolant pump had been replaced with an uprated one by the previous owner.
The EML illumination became ever more frequent to the point where it came on every fourth ignition cycle, so new downstream oxygen sensors went in, and had no effect whatsoever, until suddenly the performance fell off to the point where the car could barely manage 1.6 Castles, and the EML could no longer be extinguished.
Out with the recently replaced sensors, to reveal that the internals of the left bank catalytic convertor had let go, wiping off the end of the sensor.
The left converter was clearly beyond salvation, and reasoning that the other probably wasn't far behind, I checked prices for a new pair;- the best I could find was just over £1k, each. A whinge about that to mate James, something of a wizard with exhaust systems, resulted in less restrictive 200 cell aftermarket "universal" jobbies, adapted to a reworked system including an X pipe, for about £450 in total.
I think that it sounds nice on acceleration,
but remains unobtrusive when ticking over, and drone free when cruising. And full performance restored.
The last change was just over a year ago, when I finally stopped procrastinating about the silver painted (fake) wing vents, which considering them a bit Gerald, I had never really taken to, and got my bodywork mate Paul to bring them in line with the solid black paintwork, which I feel makes the car look more subtle.
Looks absolutely stunning - If there are any issues with uploading images etc, please do let me know and I can look into it!
This is the easiest historical thread to update, ever. As well as the meticulously completed service book and the weighty file of receipts, the previous owner had created and maintained an Excel spreadsheet of every repair and maintenance item on a CD, which my wife transferred to my laptop for me, and fixes when it crashes. I have kept this up to date "just because", including modifications and notes where appropriate. The first job was to hand the car to a bodywork mate to sort out a depression and stonechips to the front bumper cover, and three tiny areas of electrolytic corrosion, to which aluminium Jags seem prone. The rear tyres were quite worn (a recurring problem ), Winter was approaching, and I had a full set of 255 35 20 Dunlop Winter tyres doing nothing, so these were fitted to the Callisto wheels supplied with the car, a TPMS valve kit used to repair one with a damaged body, and a set of secondhand staggered Kalimnos bought to carry Summer tyres.
Well shod for all seasons, work began with a replacement supercharger pulley in stainless steel offering a claimed 40 bhp increase, This required machining of the supercharger snout, which was done by the supplier, as they have made a tool to carry this out in situ. Because power output wasn't measured prior to this, I can't comment on the claim, except to say that what was already the quickest XJR I had driven, was now significantly quicker. Possible reasons for the car being so rapid emerged a few days later when the software was examined.
I do like the look of these. The big problem for me is that every time I sit in any era of XJ they feel so small; no head or legroom in the driving seat. I do wonder if Ive been unlucky to always sit in them after a short person has set the seat for their size 🤣
Absolutely stunning: I'm a huge fan of X350s and X358s and that's pretty much my perfect spec. I've noticed some of the nicer X358s are going for serious money nowadays so the ship has probably sailed for me.
They're great looking cars. A chap 3 doors down from me has got one he imported from Japan, it sounds lovely when he fires it up.
Lovely
Looks awesome, I worked at Jag when the 358 was launched, great