Ever since I was young I've always had a passion for speed. I grew up dreaming of TR7s, MK1 Escorts and Lancia Stratos' etc... This passion led to terrorising town centres on Friday and Saturday nights in a procession of different bangers.

As I went through cheap thrill after cheap thrill I felt there was something missing, I was sure there was more to this game than just cheap cars and easy women. While all my friends were aiming for RS Turbos and Astra GTEs I had an urge to break away, to make a mark for myself. It was around this time my current floozy showed me a White Spitfire Mk4. It had a distinct look and feel like nothing I had seen before. This set the cogs wurring in my head. I started to research the car and the brand Triumph, I wanted to make sure I knew what I was letting myself in for. I joined the TSSC and had a few test drives in a couple of 1500 spits. The engine was terribly underpowered, it felt like it wouldn't pull the skin off a rice pudding. I still wanted the glossy exterior of the car just without the lagging performance.

Unwilling to admit defeat I ventured down to TSSC HQ to seek advice. The idea was brought up of using a GT6 but replacing its body with that of the Spitfire. During my visit the building started to rumble and everyone raced outside. At the time I didn't know exactly what it was but I could feel the power of it coursing through the floor. As I followed everyone outside my eyes were greeted by a Lilac GT6. It was love at first sight. It was like the Spitfire but on some crazed drug fueled rampage. With every note of its engine it seemed to be calling me. This made up my mind, I forgot my Spitfire ideas and went searching for a Mk3 GT6. One week later and £400 down I had the car of my dreams (or at least the rusty outline of it).

After an 8 year rebuild I got the car on the road and started on the serious business of getting ever greater power out of it. I had opted for a 2.5 engine from a saloon before even trying the 2 litre that came with it. The 2.5 engine was fitted out to race spec, carbs, exhaust, electronic ignition etc etc. Basically if it made it go faster I did it. This large amount of non standard power created certain "issues" such as 4 ruined drive shafts, one differential and finally ripping 3rd gear out of my uprated gearbox. This final drive train problem had me puzzled, I had the best GT6 box I could possibly have and yet it wasn't enough, what could I do to combat the problem? As I was mulling this problem over fate played its hand and I got chatting to Stu who lives up my road. Turns out he's a bit of a whizz with gearbox and runs his own company converting classic cars to modern gearboxes (www.classicconversions.co.uk). He talked me through some options and it seemed I could either have a Sierra box or a Toyota Supra box. But in his opinion, for the power I was kicking out the Sierra box probably wouldn't last long either and so it would have to be the Supra box and it certainly looked the business, dwarfing the GT6 box. I went for the W58 model as it had a longer 5th gear ratio.

Once I had decided on the Supra box we had to look at fitting it. Stu had never actually done this particular conversion before so it was a slight leap of faith. The conversion kit was designed for the TR6 to start with, the bell housing was built in Australia but for a TR6 so there was no guarantee it would fit when it arrived here. When it arrived we realised we needed a 2.5 rear engine plate instead of the GT6 rear engine plate I had put on the engine originally. I got out my little black book and started ringing people in a desperate search for an engine plate. Out of all those I rang the only one who came through for me was Chic Doig. He had an engine plate at my house in a day and the project could continue.

The first stage was fitting the 2.5 engine plate. Me and Stu then fitted the specially made friction plate with a Toyota centre and a TR6 outer. Next came the pressure plate from the GT6 and finally the bell housing. In order to get the bell housing to fit the chassis had to be trimmed slightly to make way for its girth. Once the bell housing was securely in place we put the gearbox in place and trimmed more off the chassis to make sure the gearbox fitted. After enough room was made we fabricated a rear mount for the box.

The clutch slave cylinder had to be moved position as well.

After all the gearbox installation was complete I got in touch with Prop shaft Technologies and had them make me a new, stronger prop shaft. Then all that was left was setting up the clutch. This took all of 15 minutes. A few test drives later proved everything was working as it should. To finish the project off completely I refitted the gearbox tunnel. It went straight back on bar 6 inches that had to be trimmed off the back end.
The car is quicker through the gears and extra gear on the Supra box is great for cruising. I also feel happier about letting the clutch up quicker as I'm not expecting to hear the sound of grating metal anymore. I would like to thank Stu who without this would have never happened.

By James Beaumont.

	Triumph Sports Six Club South Yorkshire Area Herald Spitfire Vitesse GT6 Bond Equipe Specials TR Stag 2000/2500/2.5 Dolomite Acclaim The Local Club For all Triumph Owners
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Home What's On Technical    Service Sheet    Gearbox    Gearbox1    Trunion Oiling Members Cars Past Events Tribunes Newsletters Contact us Edit Your Profile	James Gearbox Part 2 After installing the gearbox I could not get the car to run at all, I put this down to a fault on the ignition system so I sent it off to John Noble of Chesterfield to fit the 3d mappable ignition system. After a week at John's it was running sweet, Webbers set up right at last, tuned to be driveable around town and not cutting out at every junction. BHP 150 at 5250 rpm, trq 1lbft, max bhp 165 at 5500 rpm. pic of chart Now its the time for test driving the box and power, wow big smile all the way back to work with John my brother trying to keep up. This car pulls in any gear at what ever speed you are doing due to gear ratio, could do with six speed box not five,  1st gear very short 0-20/30, depending revs  2nd gear 50/60  3rd gear 70/85  4th gear 90/100  5ft gear 110/120mph this car would pull a lot more. On old GT6 box it would go past the light at the bottom of the speedo and still could do more but revving its head off and car shaking to bits at 7000rpm. The car was doing around 140/150 mph we guessed, so new box less top end but stronger and faster up the gears. If I change the  diff from 3; 89; 1 to 3; 63; 1, I should get some top end back too, the 3d ignition has made the run so sweet and it ticks over with out dying and still kicks out big flashes from the twin pipes. I am currently working on changing wheels before I do the diff to get grip.