Spitfire - Best exchange diff supplier

Spitfire - Best exchange diff supplier

Author
Discussion

FLAT 6

Original Poster:

480 posts

229 months

Friday 23rd March 2018
quotequote all
Any recommendations based on actual experience?

I spoke today to Andy at TD Fitchett and he seemed a good guy and sensibly priced but I'm sure there are other options?

In terms of the actual diff choices - my car is a Mk4 with a 1500 engine but still has a 1300 gearbox and diff. I am fitting an overdrive setup so I was thinking of going to a 1500 diff since I don't need such long gearing, although I suspect I wouldn't really notice the difference.

Presumably the 1500 gearbox had a longer top gear to compensate for the smaller ratio diff? So a 1300 gearbox with a 1500 diff might be too highly geared and have me going for overdrive more often than I'd be used to? I'm really only putting in overdrive for long runs - planning trip to Le Mans Classic in July.

Cheers,

Al.

//j17

3,719 posts

192 months

Friday 23rd March 2018
quotequote all
Mike Papworth is generally considered the master of Triumph diffs and gearboxes. A one man band so no website so you need to either call or email him - 07768 775170/mike.papworth1@btopen-world.com

FLAT 6 said:
Presumably the 1500 gearbox had a longer top gear to compensate for the smaller ratio diff? So a 1300 gearbox with a 1500 diff might be too highly geared and have me going for overdrive more often than I'd be used to?
More down to the greater torque of the 1500 engine over the 1300 and a spot of standardisation of gear sets with the switch to the singel rail gearbox across the Triumph range triggering a change in rear diff ratio.

In the real world you probably won't notice much difference. MintyLamb.co.uk used to have a really good wheel/tyre/gearbox/diff comparison tool but looks to be offline at the moment. In reality is only makes a few hundred RPM difference.

Edited by //j17 on Friday 23 March 13:30

FLAT 6

Original Poster:

480 posts

229 months

Friday 23rd March 2018
quotequote all
OK, thanks. I'll contact him.