View Full Version : A couple Triumph questions

Webb Sledge
05-15-2004, 05:25 PM
First off, does anyone have the 0-60 specs for a pre-73 1/2 TR6? If I'm not mistaken, the power dropped from 125hp to 105 hp in the second half of 74.

Also, can an overdrive be fitted to an originally non-overdrive TR4, or any TR for that matter? What would have to be done, and about how much would it cost?

05-15-2004, 07:55 PM
No US spec TR6 was ever 125 horses. Maybe the 69 had a little over 100, then went down from there, all the the 100 range. The UK injected models cranked about 150 horses.
Yes, you can retro-fit the stock 4-speed with either the A-type or the J-type (later overdrive).
I just had mine changed over to the J-type at a vendor that advertises his work in this area of expertise. The cost is big. 1600+. I still can't get it to work right and have to remove it and ship it back to make it work. Not a happy camper. If you can, get someone within driving distance to do the work so you can take care of problems. This guy is 1000 miles from me (or maybe a million). I am really p****d off.

Good luck.


Webb Sledge
05-15-2004, 10:50 PM
Wow, that sucks. I imagine I could do it myself if I could get an overdrive, along with the help of the guys at the shop.

What's the difference in the J-type and A-type overdrives?

05-15-2004, 10:59 PM

Power of TR6 was 104 gross hp. The TR6 is a little torquier than a TR4, but the hp ratings are pretty similar. As for 0-60MPH ratings, Road and Track got 10.7, and Motor got 8.7 for a PI (150hp) Euro-spec version.

TRs are definitely not cars for 0-60 lovers. Even the TR8 is a 8.5 0-60 car.

05-16-2004, 03:46 AM
Hello Webb,
to fit an overdrive to a non overdrive gearbox you need to get a different output shaft. That and the overdrive unit and it's electrical control.

Alec graemlins/thirsty.gif

Webb Sledge
05-16-2004, 02:41 PM
How hard is it to change the output shaft? Also, what's the difference in the A and J type overdrives?