1997 Jaguar XJ8

curse word me ive never seen so much work go into a modern car as a diy project before. Madness!

There were quite a few landaulette conversions made of XJ Jags over the years, presumably for the wedding car business. Cabriolets International in Blackpool made many of them.

Here is an XJ40 they converted.


The XJ8 in this thread is an altogether more ambitious undertaking.

David

Time for an update! Structural work now complete.

MX5 (mk3) seats mounted: (get you low for seatbelt routing and wind buffeting reasons, get the weight down for axle weight limitation/IVA reasons)

Fully forward:


Small ( 5'7" ) person:


Fully rearward:


Normal (6' w/34" inside leg) person can't touch the bulkhead


Normal (6') person in driving position:


Minimum floor length between front and rear seats is 18" or 450 mm; minimum distance between rear seat face and the back of the front seat is 36" or 900 mm, so you should be able to sit with your legs straight out in front of you even if there's a giant in the front! ;D



Interior and electronicals test fitting:




Dash still fits even through the gap is 16 mm narrower (3 mm overplate plus a 3 mm overplate gusset each side and welds/not quite following the OE curves)




Stuffing wires and ECUs and lord only knows what:




Christmas tree:




SRS system happy:




ABS and powertrain happy:




Initially, only hazards, sidelights, and the carphone/radio worked.

The instrument cluster said...

Drivers door open
Passenger door open
Gearbox fault
Electrical fault
Suspension fault
Failsafe engine mode
Incorrect part fitted

Oh lord.

Cue much head scratching. What the instrument cluster meant to day is "You've triggered the inertia switch whilst installing the harnesses you fool"

Reset that, and we have:

Engine coolant low (it is empty)
Driver's door open (it is)
Passenger's door open (it is)
Failsafe engine mode (err what...)
Incorrect part fitted (err what...)

We also have 'Er' and beeps from the climate control unit, and no brake lights.

How they were sorted, just in case some future Google user cursing an XJ8 needs help. (note to future self?)

Source of the "err what" messages turned out to be the unpaid help (dad). When removing the A/C compressor he forgot to reattach the crank angle sensor wiring (engine failsafe mode) and he hadn't plugged the ABS unit back in (plug partially inserted, but not locked down) You can spoof wheelspeed sensor presence with 1k ohm resistors FWIW.

SRS - SRS system can be fooled into thinking its working by replacing the airbags with 2.2 ohm resistors. This will be refitted with the pre-tensioners only, no airbags, because of the IVA test rules.

Belt warning - Eliminate the seatbelt warning is the black/pink and green/black wires under the driver's seat. (join them)

Climate - at the switch you join the black/pink and purple/green wires to tell it that the refrigerant is between 2 and 30 bar. Don't join the others, else fans run needlessly. I powered the unit before doing this and it stored the fault code. Hold recirc and auto then turn ignition on to put the climate into diagnostic mode and you can read/clear stored codes from there. All gone now! :-)

Door open warnings - shoot Jaguar's software people. "Driver's door open" actually means "driver's door courtesy/puddle lamp is blown or not fitted" (it shows a bulb failure signal from the door ECU as a door open on the instrument cluster) Looks like I'll have to fit all the door ECUs to make that warning go away; don't need the seat ECUs (that are also coded to the car!) though.

Brake light switch was broken!

It doesn't appear to care that its alarm sounder has been removed. Still need to sort aerials for the car phone and the key fob. Discovered a pre-wired trailer socket in the rear fusebox that does bulb failure warnings, rear foglight disconnection when trailer connected, and split charge control - from the factory!

Now for a drivebelt, fuel, oil, and coolant and it'll turn a wheel under its own steam for the first time in over a year... :-)

I love the work going into this! Really being done properly, hats off to you.

This is perfect. The idea is pure genius and the quality of the fabrication is incredible! Can't wait to see it with its leather interior, makes you want to marry a random girl (which is very likely anyway) just for the wedding car.

edit : out of curiosity, is the white car in the first pics of the thread an Alvis ? I never see too many of these

This is epic! The car really suits being a convertible too so its a wonder Jaguar didn't do one out of the factory.

Will enjoy watching this progress!

Cheers all!


Its not tonybmw/oldbus/victor levels of properly by any means, but it shouldn't fall to bits and we've tried to make all the visible fabrication/modification easy to hide with trim...

(C-pillars/parcel shelf all get hidden by a mock hood; door tops just need some of the furry 'interior grade' Jaguar door apeture trim over them, plus a few bits of 'space board' foam wrapped with vinyl and hot glued into plate to cap the edges; B-pillars are the OE trims made slightly deeper and wrapped in vinyl, with a vinyl wrapped block of foam to top them off)

Screen frame is the only tricksy one. That's just going to get keyed and buttered with filler, then either primed/stonechipped/painted. Sills too - should hide a multitude of sins on a budget. The 'presence' of the vehicle lets you get away with murder too to be honest - most are too busy gawping to notice details provided they aren't offensive.


Funny you should say Alvis - he did have a TA-21 before the 420


Pillars you'll have to give credit to Jaguar for - we haven't moved them at all! (but did spend a lot of time agonising over how/where to chop the frame, then had 3 goes at making it, skinnier each time...) Original A-pillars are complete, but the rear seam was removed and the inner 2 sides of the triangle are 3 mm plate now. Top rail was cut away except for the outer skin and the screen flange, and made up in 30x30x3 box. Gives nice rounded corners, and you can curve it by cutting short sections and, err, filling the gaps with weld. (Might be 0.5 mm at the bottom, but 2 mm at the top. Pulls a little but workable) Gussets sit where the door seal flange is and hide behind the door mirrors - these really stiffen up the frame. Will get photos when nearer completion.


Why no factory one? Jaguar's budget was 20 pence throughout the 90s. The XJ40 had a lot of money and engineering put into it. The X300 they stripped out all the advanced systems and facelifted the interior/exterior slightly, but mainly spent about 5 pence on engineering. The X308 got a new engine design, and rather a good one save the Nikasil and the idiot who specced a plastic waterpump impellor/thermostat housing/cam chain tensioners. They spent 5 pence facelifting the rest of the car though, with the result that the bodyshell of an X308 is almost identical to that of an XJ40. Fairly bendy 80s stuff. An S-Type, or the aluminium bodied X350, is built like an absolute tank by comparison. To get a convertible done properly - with Jaguar levels of refinement - you'd be adding lots of weight anyway (2dr XK weights nearly 1900 kg, a 4dr XJ8 is 1710 kg) and the XJ shell just can't take it without significant retooling - out of budget. We're cheating by not having a roof at all and losing some of the other refinement that's useless with the roof off. (A/C, soundproofing etc)

In hindsight, a X350 would have been a better option, aluminium and all. (quite fancy alloy and glue/rivets rather than more bloody welding!) You couldn't buy them for scrap value though!


That Sierra works rather well! 2dr hatch as a base I assume? What structural mods, or do the doors open/close without?

Not sold on the screen frame chop (rather vertical/as if it has just been sawn) but I can't see any other way to do a DIY roof to be fair - that's one of the reasons we decided not to bother with one from the outset. (that's where the towbar comes in; tonneau in the boot and marquee in a little trailer for long trips, heh)

This might be a very stupid note, but I'm going to mention it anyway..
This conversion will add a lot of weight due to the added stiffness required, which will abuse the stock suspension. But didn't Jag do armoured versions of the XJ8, which are calculated for this added weight ? This way you might be able to install the stock interior and options.

I am saying this without having a clue of what this suspension upgrade might even cost...

Magnificent.