Vitesse Gearbox Swap on a TR6

[BIGRED]

I'm a new member and acquired a (1969) TR6 about 18 months ago. I've decide to carry out a few upgrades and one of which is to swap the original gearbox with OD for a Vitesse ( MX5) conversion. As it's been a while since I tinkered with a transmission, any help or suggestions would be gratefully appreciated.

[John Morrison]

Well welcome, 'Bigred' to our forum, a name would be nice?

Can I ask why on earth would you contemplate going down this route, you are going from 7 to 5 speeds, and devaluing your TR at the same time?

John

[BIGRED]

Hi John, luckily I have the same name John, so less confusion and thanks for your opinion

I want to swap the gearbox because the one in current use is bit clunky, long shift throws and I have enough money to swap for a MX5  5 speed and address the aforementioned issues.

I intend to keep the original should I decide to sell so I don't see the car losing value, if anything it would increase in value if offered with 2 x gearboxes.

John

[John Morrison]

Ah understood, as I always say - its your car.

John I'll move your post into our TR6 section, see if we get you some more info, 

regard's, 

John.

[PodOne]

Hi John

Welcome.

Having had long experience of using lots of MX5 boxes both 5 and 6 speed its a great box to use and lends its self to many other applications but from using the TR6 albeit for only a short period of time with OD I see no advantage as the ratios are long enough coupled to the torque you have. The OD just adds to its flexibility. First gear on the MX5 was too short I found in some situations. 

Your going to have to remove it anyway. Why not just have the box/OD rebuilt which will be I suspect a cheaper option plus you keep the driving character of the car.

Up to you in the end but you risk removing the appeal to some if you come to selling her.

Andy   

[Spit_2.5PI]

Hi John. I've no experience as to whether the MX5 box is a good idea or not, but I do have a 6-cylinder engine mated with a GT6/Vitesse Triumph box in my Spitfire. This was built for me by Picton Sportscars (sadly no more) about 20 years ago. I seem to remember being told that there were "small boss" and "large boss" cranks on the 2.5-litre engines and - if memory serves - it was the TR5/early TR6 small boss crank which mated directly with the GT6 box. I forget if the GT6 back plate was needed too or perhaps they are the same as the TR backplate. I think you also need the lighter 2-litre flywheel, which should be easy to source if you haven't already got one, along with the clutch for the Vitesse/MX5 combo. My thinking is that, if your Mazda box has all the mods required to fit a GT6/Vitesse engine, then it should be an easy fit in your early TR6. I'm happy to be corrected as my memory was never my best point.

Whatever you decide to do, good luck!

Cheers, Richard

[PodOne]

The early TR6 has a "long (large) back" crank at least it was on mine which had matching engine/body numbers.

I'm sure someone else will chip in and confirm.

Andy

[cp25616]

John as Andy recommends above stick with the normal Triumph o/d box, just get it reconditioned if you are not happy with it in its present state. The MX5 gearbox is certainly something I would not be considering .

Alan G

[BIGRED]

13 hours ago, John Morrison said:

Ah understood, as I always say - its your car.

John I'll move your post into our TR6 section, see if we get you some more info, 

regard's, 

John.

Thanks,

regards

John

[John Morrison]

Hi John, 

 

IF you are set on going down the MX5 route, then one of our regular contributors had a look at this

some time ago, thread titled;-

my new gearbox? (Mazda MX-5 to TR)

 

John

[FatJon]

The MX5 box works fantastic on the TR6 and is absolutely slick in its action. I tried one for a day and it’s the very next thing on my list. It is night and day better than the TR box/pudding stirrer, with or without overdrive and the ratios are perfect.

[RobH]

Why not just buy an MX5 then instead of trying to change a TR into one ?

[FatJon]

11 minutes ago, RobH said:

Why not just buy an MX5 then instead of trying to change a TR into one ?

I have, and the MX5 is great in every way but one, it’s doesn’t look like a TR6. 

I will also not be returning to hub assemblies that knock the pads back, 1960’s tech mechanical injection, a fuel pump that whines and packs up on hot days etc.

 

 

 

[PodOne]

Just saying having had a few MX5's the last one modified to the limit that the boxes in both 5 and 6 speed versions are good to use but still breakable to the point I always had a spare or two as they were cheap then!

But I wouldn't describe the TR box as a pudding stirrer if it is then it most likely needs a rebuild/service.

Up to you in the end and get some people just like to modify their cars. Some more than others!

Andy

[BIGRED]

13 hours ago, FatJon said:

The MX5 box works fantastic on the TR6 and is absolutely slick in its action. I tried one for a day and it’s the very next thing on my list. It is night and day better than the TR box/pudding stirrer, with or without overdrive and the ratios are perfect.

Thanks for your vote of confidence, really good, particularly against all the other naysayers. Have you installed he MX5 gearbox as of now or is it a future project

[Malbaby]

The price of the Vitesse conversion is a killer.

 

[TRTOM2498PI]

Whilst I have no experience of the MX-5 transmission in a TR6, I am all for modifications.

A Triumph Stag derived gearbox in a TR6, with quality bearings, and a competition o/d unit, is hard to beat.  Going from second gear, to o/d second, on flat chat at 6500RPM is similar to that of a VW Golf R (DSG) or Porsche PDK gearbox !  The gear change is riffle bolt sharp, too.

The orignal road testers also noted, the precision & accuracy of the TR gearbox gear change, so anyone who thinks they are sloppy, or use other adjectives, have probably not used a well sorted/rebuilt one.

My other TR6 has a Borg Warner T5 gearbox, with Cosworth YBT engine. Again, TR gear change is superior in every regard.

 

Cheers.

[TRTOM2498PI]

A short clip of my TR6 at Blyton Race park, with use of o/d in second gear at flat chat.

Edited September 18, 2023 by TRTOM2498PI

[FatJon]

12 hours ago, BIGRED said:

Thanks for your vote of confidence, really good, particularly against all the other naysayers. Have you installed he MX5 gearbox as of now or is it a future project

I drove my friends for a day and I’m about to but the conversion from Vitesse to go in with my new engine. 

[BaulyCars]

The MX5 box is pretty much one of the nicest manual gearboxes to use and cropping up in lots of classic conversions, mk1, 2, escorts, I think also now used by Caterham rather than the old Type 9's etc etc. 

Any weight benefit or its a wash?

I'd also be quite keen to know if it gives anymore or any less leg room vs the original box with OD.    

[BaulyCars]

6 hours ago, TRTOM2498PI said:

A short clip of my TR6 at Blyton Race parkm with use of o/d in second gear at flat chat.

....and yet that sounds immense!

[TRTOM2498PI]

7 minutes ago, BaulyCars said:

....and yet that sounds immense!

Thanks, it's a great package !

[Z320]

Hi John,

I use a MX5 gearbox in my TR4A for 3 years,

bought for 100 Euro from a scraped MX5 NA and cut in shape (not that easy).

My friend Jochen (not Jochem) bought a Vitesse set for a real good price about 5 years ago and fitted it 2 years ago on his TR4.

He has been at the Euromeet at Wales with the car!

Both we always have a fat smile in our face driving it.

I never wanted to buy a risky OD with all the multiple possible troubles,

he wanted to get rid of the GB + OD because all the troubles he had and will come up.

What you mentioned above, the long way if travel for shifting the gears, is same-same on TR and MX5 gb.

For me the 5 gear was real surprising long to shift with the MX5 gb!

The „impression“ by some guys could be different,

because they see a short lever on the MX5 gb (give the impression of short ways)

and a long one on the TR (give the impression of long ways),

comparable with the „moon close to the horizon / high in the dark sky issue“.

For more questions please ask.

Ciao, Marco 

Edited September 20, 2023 by Z320

[Z320]

Btw,

what is the money value of a hobby (equipment)?

The memories of someone who spends his money on traveling?

An old horse in the last quarter of his life - or dead?

A beautiful garden around your house?

A camper, bought new, now 20 years old?

All the cigarettes you have been smoking?

If you can afford the money, don’t do anybody a harm with it and want it, do it now and not later.

My opinion 

[BaulyCars]

That's quite lovely, Marco - I will immediately spend lots of money on new car parts...

I'm sure someone makes a 'short shifter kit' for the MX5 box to reduce the long throw, given the aftermarket support for that car?

My only other question was whether it is worth buying the Vitesse kit (does it make it much easier), or whether it is cheaper to buy an MX5 box and work it out yourself.