Mobeck Tekniske are building a complete historic racecar for a customer. This will be a replica of Tom Walkinshaw’s 1984 Jaguar XJS TWR Gr.A car and I put all my effort to make it as thrue to the original  and correct as possible in all details and spesifications. Follow this project page to the details witch is uniqe to this racecar. In Historic racing the cars has to be built just like the originals and no modern equipment must be used, this means I have to do a lot of research and special work.

An XJ-S with a good body and without an engine was found in Stockholm. The car was stripped for all parts and the whole body was dipped in acid bath to get rid of rust and paint. After acid dipping its so much easyer to see the state of the plate and do the work with cutting, modifications and welding. The weld quality will be soo much better and you dont get any contamination in the melting pool.

A big part of the work makeing a racecar like this is the research aorud witch modifications they did to make it a racecar in 1984. I have traveled and wisited the original and taken measurements and hundreds of photos of most parts and I ahve also been reding books and written to some of the guys who worked with this at that time. A Gr.A car are supposed to be mildly modified as they should have no body widening, original suspension, std valvelift and std manifolds. This class was like this to see “std” cars compete on the track, a good idea. But as I get deeper into the project I discover that the TWR Jaguar must have bee one of the most modified Gr. A cars that was built. They where pretty good at bending the rules, and because of this I end up with a lot of work. The suspicious and on the edge modifications has to be done also, to make a correct replica.

On racecars is standard procedure to seamwled all plate joints for extra strength. It will also be a lot of modifications to make room for wide wheels, air jacks, special suspension mounts, totally 4 oilcoolers and a bigger radiator. I have the homogolation papers for XJS Gr.A and I find a lot of pictures and details there I can work by.

The suspension is strengthened and new mounts are made like I see them in old pictures. The rollcage is also made to look like the original but at the same time it has to be FIA aproved.

Now most the mods and tricks are in place and I work with removeing brackets for interior and such.  Then makeing mounts for motorsport equipment and aerodynamic aids before its shipped for painting.

Karosseri ferdig preppet. Lakk neste

We use a epoxy primer and solid paint with a clear coat, white underbody and trunk like some of the originals. Its easier to work at night and also easier to spot cracks and damages when things are white.

So now its for some sponsors and race livery

Here we take a quick jump to the complete finished car for the looks of the body. You can read abot the suspension, brakes, driveline and engine in another chapter on this website.

  1. Nice work on the XJS TWR Project.
    I’m a big fan of the original car, and its great to see somebody doing a replica build.
    I’ve been rebuilding my xjs 87 for a couple of years . Just keeping it a stock car have not got the talents that you have to upgrade.
    cheers from Vancouver BC

  2. Looks fantastic, doing a less detailed build myself.
    Looking forward to seeing more of the mechanical detail, engine exhaust suspension etc.
    Did you make the call centre lock hubs or buy them?. Where did you get the brakes ?

    • Thanks Robert.
      More pictures will come, I have just been so busy in the workshop and the website suffer.
      Calipers are made from billet aluminium as a copy of the Endurance AP caliper from 1984.
      Wheels and hubs are custom made for the project also.
      Ole M

  3. So nice:)
    I am hoping to build a race XJS from a bare body, however, not to group A specs!
    I have a Jaguar wrecker whom has a bi turbo ex racer (body not good) may make the job easier.
    Do you have any panels or items to reactivate for sale to builders such as me…?

    • I have a lot of parts Reginals, but I try to focus on special parts that you cannot get elsewhere, like special engine tuning parts as cams, valves, manifolds, and such. Also Shock absorbers for racing, adapted to the customers need and skills.

      Ole M

  4. Great project, so interesting to read. So much detail. Thanks for publishing this. Wonder how you got along with the whole drivetrain. Must be very impressive. Thanks.

  5. hello,

    we have the intention to buy/build an XJS group A for the Peter Heritage Cup
    is your car for sale?


  6. Cool build on the jag, definitely a lot of work and skill in it, have an old 78 xjs i’m rebuilding for road and to do some track days. Was wondering if i would be able to purchase a copied set of the Homologation papers you have from you. Would be good to have them for my collection. One of our customers through work is friends with Alan Scott who was TWR’s engine man from here in New Zealand, Alan now runs a bed and breakfast in the South Island and hope to catch up with him sometime next year and pick his brains on making a decent baffled sump for mine.

  7. Weren’t the original cars ‘chopped’ by an inch or so to reduce their frontal area? I seem to remember a YouTube video with an Australian guy who owns one of the original cars. He talked about some of the ‘secret’ modifications that scrutineers didn’t check. Fantastic project by the way. Shame that Speedline couldn’t reproduce the wheels for you.

    I have car No. 2 on my screen saver with photos pinched from Duncan Hamilton’s website!

    • Hi, the cars was not chopped like at the roof, but there was a secret modification up front witch is hard to find.

  8. Can you confirm the final tire sizes? I see three different ones mentioned for the rear, so am confused.

    1) In the picture description above of the rear tire, a 315/35R17 Hoosier race tire is pictured, which has an overall diameter of 653mm.
    2) The description below this picture refers to a 300/620-17 tire being fitted, which has a much smaller 620mm overall diameter.
    3) On your website, it says that a 300/625-17 rear tire is being used—625mm overall diameter.

    Are the final sizes given on the twr-tribute page the actual sizes being used? And were these the exact tire sizes used in 1984, or just the closest available modern race tires to the exact sizes used in 1984? Thanks!

    • Hi Seth, You have really been scrutininizing this well. So, there is a difference betewwn tyre dimention description between DOT road legal tyres and motorsport tyres. The tyre I use during build is a DOT tyre and dimention 315/35-17 as you say. This is the closest dimmention I find at a reasonable price to build around. If you want to buy a motorsport tyre close to this it will be called something like 295 or 305/640-17 But it is very limited availibility in slicks in this dimention. So we will maybe use a Dunlop 290/645-17 for racing witch is available. But also when it rains we may use another dimention. But originally the Gr.A was a bit staggered with larger diameter at the rear. It all depends on what kind of race we will attend, sometimes DOT R-tyres, sometimed Dunlop slicks, maybe some hillclimb tyres and then rain. And in 84 they had Bias ply, now we must use Radial as its the only type available. Avon has Bias ply but for much lighter cars, they will overheat on the XJS.

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