CR gearbox

[Andy_mr2sc]

No it was from John Readman. No idea what make it is. There is a Company in the USA that makes a beefed up 5th gear with stronger teeth. I'm sure it was discussed on this site before and found not to fit.

[Jhonno]

Andy_mr2sc said:

No it was from John Readman. No idea what make it is. There is a Company in the USA that makes a beefed up 5th gear with stronger teeth. I'm sure it was discussed on this site before and found not to fit.

Ah, possibly not comparing like for like then..

CR 1234 and standard or even a slightly longer 5th would be perfect.

[aide]

The Quaife CR (and WR) upgrades that Gearboxman/CTS offer are (I'm told) manufactured by Quaife for Berine at CTS.
I asked for a CR with std 5th but I was told that 5th on their CR/WR offerings aren't interchangeable.

[Andy_mr2sc]

I've just had a recce on their site and the pic shows a new input shaft as well as the two 5th gear ratios. That explains the price difference over John Readman's.

[chris watton]

Andy_mr2sc said:

I've just had a recce on their site and the pic shows a new input shaft as well as the two 5th gear ratios. That explains the price difference over John Readman's.

yes, Mine is Readmans too, and the original TVR CR ratios were the same for 4th and 5th. I really cannot speak for aftermarket variants. I just know that on my Tuscan S CR box I had in my first Tam, and the CR box I now have in my latest, both have the same ratios, with the last two gears the same as the standard box.

ETA - I always thought that if people wanted to change the way 5th spins up, they change the final drive ratio in the diff...

Edited by chris watton on Friday 17th March 15:38

[Jhonno]

chris watton said:

Andy_mr2sc said:

I've just had a recce on their site and the pic shows a new input shaft as well as the two 5th gear ratios. That explains the price difference over John Readman's.

yes, Mine is Readmans too, and the original TVR CR ratios were the same for 4th and 5th. I really cannot speak for aftermarket variants. I just know that on my Tuscan S CR box I had in my first Tam, and the CR box I now have in my latest, both have the same ratios, with the last two gears the same as the standard box.

ETA - I always thought that if people wanted to change the way 5th spins up, they change the final drive ratio in the diff...

Edited by chris watton on Friday 17th March 15:38

That would effect the whole box of cogs though..

[chris watton]

Jhonno said:

That would effect the whole box of cogs though..

I know - but it is mentioned when people are concerned about the noise/revs when motorway driving in 5th.

[umeerw]

Based on above it seems nobody regrets getting a car box fitted so will def book it in !

[Willfin]

I've just had the CR box upgrade done on mine along with the engine rebuild. Looking forward to stretching it's legs once all run in.

Apparently it works best with a 3.73 diff, which would be next on my list ifs not quite right on my 3.46 diff.

Go for it!

[Incognegro]

I'm so split on this. I'm gonna wait til my car gets back and see how standard arrangement works. With the added torque I'm thinking I may try launching from 2nd and never use 1st anyway.

Had a small test of the Readman Racing (big tooth quaife internals into standard casing) on standard ratios (it was Gruffs 4.7ajp though) and all felt fantastic. Never needed anything lower than 3rd, changes were solid and everything felt strong, I mentioned to him how lazy it made me feel, like driving an auto

I may even go that route... after estimating/dreaming my figures of car after build and using the data on Harry's LapTimer the projected power and ratios I have would see 206mph on a flat road (where conditions allow like a hurricane behind me lol)