Opinions on conversion to manual gearbox and other mods...

[Philp1965]

I know its a lot of expense, and I'd be spending money which I would never recoup, but I'm having thoughts about converting my a '90 V12 to a manual gearbox. A friend of mine has a 3.6 manual and it seems a lot quicker off the mark (but then again, so does my '91 Le mans V12, although not by much). I'm also thinking about putting the AJ6 engineering kit on it - manifolds, plus torque conversion and exhaust.

The question is, what does anyone else think about carrying out work like this? I've had mixed responses from other XJS owners some say sacrilege others say good idea. Me? I'd like to think the mods will enhance the car

[Hosier77]

well its a very expencive option, you will need a flywheel, spigot bearing, clutch, gearbox (obviousely one man enough for the job), gear stick, centre console, pedal box, clutch pedal and master cylinder, gearbox mounting and a speedo drive.
Bear in mind that the 3.6 manual is quicker off the mark because the diff ratio is much lower, 3.54:1 rather than 3.07:1 (from memory, something like that anyway). so thats 23% more torque at the expence of 23% lower top theoretical speed. Thats why we use them in our race cars. Its a cheaper mod, makes the V12 very quick off the mark but means the engine is spinning faster for a given speed, so fuel consumption gets worse!
There are more diff ratios available in between too, which give a more subtle change.
Which ever option you take, have fun and enjoy a splendid motor car.

[Patfallon]

Hi. I think if you've got the money, why not. you probably didn't buy the car thinking of it as a way of making money so make it what you want it to be. But try to make sure it still feels like an XJS. It should be fantastic if you do it. As for the engine mods I'm starting off with the AJ6 Tuned exhaust and super-duper ECU which should be sorted in the next two weeks. also a cross-brace (mines a convertible), bushes, adjustable shocks and slightly firmer springs. I want to try and retain the cars civilized style. Manifold etc when I can afford it. When my three speed auto has had enough I'll have a four speed auto fitted. Sorry I got carried away, we were talking about your car, Yeh go with the mods.

[Philp1965]

I like the idea of the mods myself. Hosier77 - thanks for the advice - I don't expect I'll get much change out of £2k for the gearbox and other bits. If I do do it, I'll probably go for a Tremec TKO or T5/T56 and get it shipped over, unless I can get it cheaper in the UK. Didn't know about the 3.6 diff having a different ratio - its a thought and a cheap alternative but as much as I love the car, do I really want 6-8 mpg?

Pat - I like the AJ6 kit - it will go well on your car. I've got it on the Le Mans.. hang on, the brain cells are beginning to work and I'ver just had a thought...change the gearbox on the Le Mans and leave the other as it is. That would save me a few quid. Hmm...

I'll keep you posted....

Phil