A couple Triumph questions

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?

Webb,
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.

Bill

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?

Webb,

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.

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

How hard is it to change the output shaft? Also, what's the difference in the A and J type overdrives?