X300 colour and Sport question

[Jaguar steve]

thejpster said:

a8hex said:

The guy who headed up the development of the AJ16 engine wrote an article in the JEC rag a few years back where he said that in hindsight they could take more advance on the ignition, and he'd developed a spacer to put in to effect this. I should try and dig out the article again some day. But I've never felt the need really.

The chap's name is Andy Stodart. I have the aforementioned bracket, for economy reasons, but I haven't gotten around to fitting it yet. Adds a constant 5 degrees.

Even without it I haven't found my 3.2 Sovereign LWB Sport to be particularly lacking in the performance department. The ZF four speed might be old but it's reliable and you can lock it into 2nd or 3rd using the left side of the J-gate. Pressing on you'll see the on board trip computer read < 10 mpg, but you are shifting two tons of leather and walnut.

A four litre gives you a ZF 4HP24E (rather than a 4HP22), which gives you a gearbox ECU and a sport button. I bought a 3.2 for the rarity and to avoid the limp home gremlins which seen to afflict the 4.0, but people say the 4.0 in sport mode has less slurry shifts. The 4.0 also has a taller final drive and 245 bhp instead of 216.

I'd considered this mod too on my AJ16 engine but felt that a 5 deg advance over the entire ignition map was pushing the envelope much too far, especially under very light loads/lean mixtures. Couple that scenerio with a few tankfulls of minimum spec fuel and the potential detonation from doing so could end up costing you a replacement engine.

Possibily a less crude approach would be to have a rolling road session coupled with a remap with the view of increasing torque not ultimate power. I don't know if anybody machines alternative profile cams for the AJ16 but that might be a route worth exploring too.

[cml]

Jaguar steve said:

The 3.2 6 cyl XJ is a extremely heavy car. I found both mine OK as motorway cruisers but considered them almost embarrassingly underpowered when heavily laden, driving in hilly areas or trying to get a move on. The 3.2 six is hampered further by a 1980's design 4 speed gearbox that only has torque converter lock up in 4th gear and 4th only engages at speeds over 50MPH - effectively you're driving round in third gear at any speed below that.

The penalties of driving one sufficiently hard to make reasonable progress under less than ideal conditions is sub 20's MPG.

I'd suggest you take a couple of big heavy mates along for a test drive, find some hills and see how you get on.

Spot on that, which makes the rash of new 50mph limits around here a right pain, gently drifting just over 50 to pop it into 4th, then easing back and hoping you don't meet any uphill bits. Getting it to move means holding it in 2nd and getting the revs to the sweet spot (4,000ish). Nice, but it destroys economy utterly. It is a little heavy, but not that far off the curve, a 7 Series is about the same. It doesn't look heavy though, for such a big car it manages to look small, if you know what I mean.

[naki]

if anyone is interested, there is a discussion on the revised cps bracket here

all 17 pages, but on page 4 Andy explains it.

http://www.xj40.com/viewtopic.php?f=23&t=2976&...