XJS V12 Manual Conversion & ITB's & Maybe TWR Rep

XJS V12 Manual Conversion & ITB's & Maybe TWR Rep

Author
Discussion

urquattroGus

Original Poster:

1,264 posts

146 months

Monday 18th February 2019
quotequote all
I've been plotting and scheming about buying an XJS for £10-15K and then modifying it tastefully.

I'd love a Lister XJS but that seems to be a little out of budget, £60K for a good one now it seems. I'd need to sell two other cars I like to get close to that.

These guys do a manual conversion:

https://simplyperformance.com/v12-5-speed-conversi...

I was then thinking of fitting individual throttle bodies and a fruity exhaust, no doubt at considerable cost. Perhaps run it using something like and Omex 710 ECU.

I have some experience with this as I fitted an Omex 600, Throttle bodies and twin coil packs to my 1966 Alfa Giulia, it's been great over the last three years.

The TWR rep bit I'm not sure about, I do idolise the 1984 TWR XJS, but I don't want to look too naff.

Has anyone driven a manual V12 XJS conversion?

I want to create something that looks and sounds mean but in a well thought out form.

Biggest question is, which car would be the best to modify? Engine wise there seems to be the Pre He 5.3 (too old and scarce?) HE 5.3, 6.0 TWR or the later Jaguar 6.0 unit?

Then there are different models over the years, eg the Le Mans special edition etc. Do some of them have a LSD?

Thoughts?

tortop45

434 posts

116 months

Monday 18th February 2019
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Hi.with the engines the pre he has more power than the he engines.dont now about the 6 litre ones.as for the gearbox ive fitted a manual to my daimlar doublesix coupe which has the same running gear as the xjs and it goes like a rocket and well worth the convertion.simply performance use a 5 speed box as far as i no and quite expensive.i got hold of a 4 speed from a pre he xjs.have a look a harrys garage on you tube hes done a good review on his one.

300bhp/ton

38,783 posts

146 months

Thursday 21st February 2019
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Quoted HP was higher for the HE engines. As was mpg.

Ultimately there are very few pre HE cars available, so might be easier to find a latter one.

The factory 6.0 with the 4 speed auto is a lovely engine however and a much quicker vehicle than any of the 5.3's with the 3 speed. But these too are rare.

They should all have LSD's as far as I know.

For "looks" I wanted to do something to my XJ-S when I had one. I was thinking more the wide arch Group44 look, but not in racing colours.




My other thoughts on the XJS was why about fitting the supercharged AJ16 from the X300 XJR.

lukeharding

1,409 posts

45 months

Tuesday 26th February 2019
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This sounds like it has the beginnings of a great thread. I've got a few XJS, both auto and manual, including a V12 manual. The gearboxes can be a bit agricultural but it really is transformative for the car. It becomes so much more responsive than an auto and drags out the sporting pedigree whilst retaining the GT heart. Even the manual 3.6 cars are huge fun and surprisingly rapid. There are a couple of converted cars coming up for auction soon I believe (different auctions).

There is a huge amount that you can do with these cars to modify them, its just that you don't see it done much yet.

urquattroGus

Original Poster:

1,264 posts

146 months

Tuesday 26th February 2019
quotequote all
Thank you for the encouragement guys smile

Thinking about things more, It needs to be 1992 or prior as I don't want to have to run cats; performance and sound wise.

I quite like the Pre HE cars, but I think realistically a good HE might be the best bet and with the most cars to choose from.

I also found this (look at the price but wow!)

https://store.jenvey.co.uk/jaguar-v12-e ... ckjr04-kit

Whether that would fit under the low bonnet of the XJS I'm not sure, but imagine the sound a throttle response!

Simply Performance have a demo car so once I have sold my other car I'm going to go and have a look at that to give me an idea.

_I'm a little all over the place at the moment as the range is so broad, but the options seem to be_

Bag a nice He 5.3, actually prefer the interior of earlier ones, for example, I've spotted a nice 1982 one for sale.

XJR-S 5.3 - I actually quite like the bodykit.

XJR-S 6.0 Pre Facelift Attracted by the 6.0 engine but scarce and the price etc. Difficult to repair Zytek engine management, probably would replace anyway.

XJR-S 6.0 1992/3 Facelift - A couple that look good value but I don't like the rear lights as much and they look like the heaviest version.

Also what is the actual cut off for running a car with no cat's legally?

I thought it was 1992? Would a facelift 6.0 be legal with no cats?

Confusing things is whether you "pass an emissions test" with cats or not.

lukeharding

1,409 posts

45 months

Tuesday 26th February 2019
quotequote all
urquattroGus said:
Thank you for the encouragement guys smile

Thinking about things more, It needs to be 1992 or prior as I don't want to have to run cats; performance and sound wise.

I quite like the Pre HE cars, but I think realistically a good HE might be the best bet and with the most cars to choose from.

I also found this (look at the price but wow!)

https://store.jenvey.co.uk/jaguar-v12-e ... ckjr04-kit

Whether that would fit under the low bonnet of the XJS I'm not sure, but imagine the sound a throttle response!

Simply Performance have a demo car so once I have sold my other car I'm going to go and have a look at that to give me an idea.

_I'm a little all over the place at the moment as the range is so broad, but the options seem to be_

Bag a nice He 5.3, actually prefer the interior of earlier ones, for example, I've spotted a nice 1982 one for sale.

XJR-S 5.3 - I actually quite like the bodykit.

XJR-S 6.0 Pre Facelift Attracted by the 6.0 engine but scarce and the price etc. Difficult to repair Zytek engine management, probably would replace anyway.

XJR-S 6.0 1992/3 Facelift - A couple that look good value but I don't like the rear lights as much and they look like the heaviest version.

Also what is the actual cut off for running a car with no cat's legally?

I thought it was 1992? Would a facelift 6.0 be legal with no cats?

Confusing things is whether you "pass an emissions test" with cats or not.
You'll probably get more for your money by buying a HE car rather than pre HE to be honest, and a later HE too as they get a revised bonnet with more of a bulge that gives you a little more under bonnet clearance. You could always find an earlier interior if you really wanted, I agree they look better.

The link doesn't work but I think I know what you're referring to, and yes it does look fun! I'd love to compare a 5.3 with that against my 6.5 car. Yes it is tough to find a 6.0 RS but there is an overpriced one for sale at the moment, but there are definitely 5.3 RS cars cropping up now and again as projects.

urquattroGus

Original Poster:

1,264 posts

146 months

Tuesday 26th February 2019
quotequote all
lukeharding said:
urquattroGus said:
Thank you for the encouragement guys smile

Thinking about things more, It needs to be 1992 or prior as I don't want to have to run cats; performance and sound wise.

I quite like the Pre HE cars, but I think realistically a good HE might be the best bet and with the most cars to choose from.

I also found this (look at the price but wow!)

https://store.jenvey.co.uk/jaguar-v12-e ... ckjr04-kit

Whether that would fit under the low bonnet of the XJS I'm not sure, but imagine the sound a throttle response!

Simply Performance have a demo car so once I have sold my other car I'm going to go and have a look at that to give me an idea.

_I'm a little all over the place at the moment as the range is so broad, but the options seem to be_

Bag a nice He 5.3, actually prefer the interior of earlier ones, for example, I've spotted a nice 1982 one for sale.

XJR-S 5.3 - I actually quite like the bodykit.

XJR-S 6.0 Pre Facelift Attracted by the 6.0 engine but scarce and the price etc. Difficult to repair Zytek engine management, probably would replace anyway.

XJR-S 6.0 1992/3 Facelift - A couple that look good value but I don't like the rear lights as much and they look like the heaviest version.

Also what is the actual cut off for running a car with no cat's legally?

I thought it was 1992? Would a facelift 6.0 be legal with no cats?

Confusing things is whether you "pass an emissions test" with cats or not.
You'll probably get more for your money by buying a HE car rather than pre HE to be honest, and a later HE too as they get a revised bonnet with more of a bulge that gives you a little more under bonnet clearance. You could always find an earlier interior if you really wanted, I agree they look better.

The link doesn't work but I think I know what you're referring to, and yes it does look fun! I'd love to compare a 5.3 with that against my 6.5 car. Yes it is tough to find a 6.0 RS but there is an overpriced one for sale at the moment, but there are definitely 5.3 RS cars cropping up now and again as projects.
Link from Above:

Throttle Body Kit etc

https://store.jenvey.co.uk/jaguar-v12-e-type-sf45-...


You have a 6.5l? Bored or stroked? Sounds expensive!

There is a 7L Lister for sale at the moment for £45K, it's not the usual wide body type with supercharger.
https://www.ebay.co.uk/itm/Jaguar-XJS-Lister/16356...tongue outf:0

lukeharding

1,409 posts

45 months

Wednesday 27th February 2019
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Give me a day or two and I'll write up a bit of history on it for you. It was converted a long time ago and has been through most of the big names in the process so the history is great. My goal is to better it with one of my own smile

HeWhoDaresRoy

371 posts

172 months

Thursday 28th February 2019
quotequote all
I've got a 1991 V12 LeMans, that's been converted to manual using the 5-speed 'box from a 3.6 litre car.

Currently running a 3.54 diff, so shorter that the usual 2.88 fitted to HE V12s, plus all the AJ6 Engineering tuning bits. It's actually quite a fast car, but I've got half an eye on buying this kit from Rob Beere to bring it up to 6.1 litres (or sourcing a 6 litre, which gives you a 6.8 litre using the kit, I think):

http://www.rob-beere-racing.co.uk/engine.html

My gearbox is starting to complain a bit now, so it might be worth spending the extra and going for a Tremec 6 speed, I think it is.

sjc

11,300 posts

226 months

Thursday 28th February 2019
quotequote all
urquattroGus said:
There is a 7L Lister for sale at the moment for £45K, it's not the usual wide body type with supercharger.
https://www.ebay.co.uk/itm/Jaguar-XJS-Lister/16356...tongue outf:0
15 grand more on their website than the classified advert on Ebay!

urquattroGus

Original Poster:

1,264 posts

146 months

Thursday 28th February 2019
quotequote all
sjc said:
urquattroGus said:
There is a 7L Lister for sale at the moment for £45K, it's not the usual wide body type with supercharger.
https://www.ebay.co.uk/itm/Jaguar-XJS-Lister/16356...tongue outf:0
15 grand more on their website than the classified advert on Ebay!
Bought for £40K at auction in November 2018 smile

Latest online temptation is a British racing Green Sept 1992 "Facelift" XJR-S 6.0 but the drawbacks might be the weight of the facelift car and the fact I think I would still need to run cats....

The pre facelift XJR-S looks better from the back but the facelift one does have a few things going for it maybe...

Edited by urquattroGus on Thursday 28th February 16:06

lukeharding

1,409 posts

45 months

Thursday 28th February 2019
quotequote all
urquattroGus said:
Bought for £40K at auction in November 2018 smile

Latest online temptation is a British racing Green Sept 1992 "Facelift" XJR-S 6.0 but the drawbacks might be the weight of the facelift car and the fact I think I would still need to run cats....

The pre facelift XJR-S looks better from the back but the facelift one does have a few things going for it maybe...

Edited by urquattroGus on Thursday 28th February 16:06
Thats the Historics one right? It failed to sell on the day, but might have sold afterward. I know the owner (not very well, admittedly) and was curious when I saw it for sale with a dealer.

urquattroGus

Original Poster:

1,264 posts

146 months

Thursday 28th February 2019
quotequote all
lukeharding said:
urquattroGus said:
Bought for £40K at auction in November 2018 smile

Latest online temptation is a British racing Green Sept 1992 "Facelift" XJR-S 6.0 but the drawbacks might be the weight of the facelift car and the fact I think I would still need to run cats....

The pre facelift XJR-S looks better from the back but the facelift one does have a few things going for it maybe...

Edited by urquattroGus on Thursday 28th February 16:06
Thats the Historics one right? It failed to sell on the day, but might have sold afterward. I know the owner (not very well, admittedly) and was curious when I saw it for sale with a dealer.
I saw the historics one, not that one, at least I think...

The historics one was a Japanese market 1993 5.3 that had been converted to manual, XJR R1 wheels etc. Looked interesting. DO you know much more about it? Think this is the one you mean??

lukeharding

1,409 posts

45 months

Friday 1st March 2019
quotequote all
urquattroGus said:
I saw the historics one, not that one, at least I think...

The historics one was a Japanese market 1993 5.3 that had been converted to manual, XJR R1 wheels etc. Looked interesting. DO you know much more about it? Think this is the one you mean??
Well the one at Historics was the only narrow bodied Lister ever built apparently, and I moved it for the owner last year to get some work done, so it couldn't be another one surely?

urquattroGus

Original Poster:

1,264 posts

146 months

Friday 1st March 2019
quotequote all
Oops oh sorry you meant the lister, I was talking about non lister cats that have been up for sale. Yes, I think it’s that one. Do you know much about it’s history? Purports to be an narrow body ex directors car but with the 7 litre engine. Did it look and sound the part?? smile

alabbasi

1,121 posts

43 months

Saturday 2nd March 2019
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There's a guy in the US called Robert Hall who runs a company called 'The DrivenMan' who does 5 and 6 speed tremic conversions. His kits are supposed to have everything needed for the conversion. I bought a 75 XJ12C from him and we discussed the manual conversion. He said that it completely transforms the car.

lukeharding

1,409 posts

45 months

Monday 4th March 2019
quotequote all
alabbasi said:
There's a guy in the US called Robert Hall who runs a company called 'The DrivenMan' who does 5 and 6 speed tremic conversions. His kits are supposed to have everything needed for the conversion. I bought a 75 XJ12C from him and we discussed the manual conversion. He said that it completely transforms the car.
Yep, a manual XJS is a completely different car to an auto one. Both are nice but the manual just makes the car so much more alive

lukeharding

1,409 posts

45 months

Monday 4th March 2019
quotequote all
urquattroGus said:
Oops oh sorry you meant the lister, I was talking about non lister cats that have been up for sale. Yes, I think it’s that one. Do you know much about it’s history? Purports to be an narrow body ex directors car but with the 7 litre engine. Did it look and sound the part?? smile
Yep sorry there were some crossed wires there! Apparently the history of that car is true, though I didn't hear it run. It doesn't quite have the presence of a wide bodied Lister and I believe originally the wheels were different (which I would prefer), and a flat tyre didn't help. It is a bit of a confused car since a Lister is a lot to do with its looks, but it would be a fantastic sleeper I imagine.

craigjm

10,788 posts

156 months

Monday 4th March 2019
quotequote all
I have driven a manual XJS and a manual XJC using both of the gearboxes common in use. The tremec T5 and the Getrag 265. They change the character of the car quite considerably. I have to say that the tremec in the XJC made it a totally different car and actually quite annoying after about 20 minutes of fun. It really took away the luxury cruiser style. In the XJS and the getrag, which was a simply performance conversion it was a different story but the clutch was quite heavy and again on a long distance drive I found myself wanting that bit more of an ability to just waft.

So for it XJC restomod I went down the route of a 6.0 TWR engine linked to a GM700r4 4 speed auto box using a Johns cars conversion and then fitting all of the AJ6 engineering modifications like the throttle bodies etc, quick cat air filters and by the time it’s finished it will have a switchable Emerald ECU and a ProFusion switchable stainless sports exhaust.

With this setup you can lock it in gear when you want to really hoof it and access all the power above 3000rpm and when you just want to waft lock it in drive, turn off the exhaust and take it out of sport.

Edited by craigjm on Monday 4th March 14:37


Edited by craigjm on Monday 4th March 16:56

alabbasi

1,121 posts

43 months

Monday 4th March 2019
quotequote all
lukeharding said:
Yep, a manual XJS is a completely different car to an auto one. Both are nice but the manual just makes the car so much more alive
I have an XJ-SC 3.6 which I believe has a Getrag 265 transmission, a 75 XJC with a 700R4 which I hate because it seems to never shift when I need it to. I suspect that the cable is out of adjustment. I also have a 94 XJS V12 which has the 4L80E which is fantastic.

Good info on the tremic. The problem here is that getrag 265's are pretty hard to come by. The only cars that had them which were sold in the US were early 80's BMW's and everyone wants them.