Triumph Sports Cars

Hi my first post, i pick up the first of my 2 64 spits tomorrow, first one will get original type resto and the second im told is for mechanical spares but doesnt look too bad? and could be used for a hill climber etc with engine swap. I want to keep it light as possible and the engine options are plentiful as are transmissions, my preferrred options at the moment being a rover v8 or holden (aussie gm) V6 and toyota celica 5 speed but have not been able to find much info on differential swaps/strenghtening. I was wondering what others have done, i want to keep the irs, not fussed on brand though. power with the stock v6 (fuel injected) is around 200 to 250 hp (dependant on year) v6 weighs about 170kg. but can probably be kept under the original bonnet as it is fuel injected, also cheap here, can get low milage units for about $700 (350pounds) abit more for computer and loom. the differential has me stumped though, it would appear to be the weak point from my research.

Thanks in advance

Mark-The stock Spitfire and GT6 differentials are weak. You can do a Quiaffe limited slip but with that your stuck with weak u-joints and wheel bearing. You might be better off with a modified Datsun 240/260 or newer unit. I am sure they can be done for better money then building a spit rear end. Good luck!

Thanks Mike, that is what i was thinking, but wasnt sure which other diff to start with, have people had success with this swap.

I think if you go through the forum and project cars you will find some TR6s and Spitfires with alternative rear IRS units.

Mark, I've heard that there is a Datsun/Nissan third member that will adapt fairly easily to the Spit chassis and should be strong enough for the engine you describe, but I don't have any details. The main problem on adapting a new third member is that the spring attaches to the top of the original unit and you'll have to fabricate something to replace that or make mods to the frame to accept coil over shocks outboard. It's definitely going to take some fabrication either way. If you want to keep the stock size wheels and wheel wells I think I'd look at GT6 outer hub carriers adapted to take a Nissan half shaft which would match the rear diff assembly.

Spit/GT6 rear ends and suspension are exactly the same and both cases are far too weak for even the stock engine, gear ratios are 4.11, 3.89 or 3.27 so gearing is limited, the simple thing to do is run a solid axle like a ford 8.8 and 4 link, the spitfire rear outer bearings are weak and really the whole set up is not very easy with the cross leaf to adapt any other rear end

Hi Mark, IRS is the one of the hardest modifications for a spitfire. I used an RX7 differential. See my writeup.
[www.britishv8.org]

I had to make my own A-arms and add to the frame. If I had to do it again I would use the same design but with an early 90's Ford T-Bird IRS. There are many gear ratios available unlike the RX7.

Whatever you decide its a major fabrication effort.

Cheers,
Max