6 speed gearbox

[dannyt172]

Hi, looking at getting back into a Clio sport had a 172 thinking a 182 this time. Does anyone know of a direct fit gearbox that can replace the 5 speed with a 6 speed? Thanks

 

[Tav]

Why would you want 6 speeds?

 

[mikeh]

Why would you want 6 speeds?

This.

There is nothing that is direct fit.

Some people have fitted VAG gearboxes, but its quite a task and I'm not sure if anyone has done a six speed one - space is pretty tight!

 

[Chip-mk1]

There is nothing that is a trivial fit and has 6 speeds.

It will cost you quite a lot more than your car in the first place did to swap to anything 6 speed I suspect.

 

[Dr HMS Derv Destroyer]

Standard jc5 boxes are strong enough if treated properly.

people run them on boosted clios without problems ( generally a refresh is done for peace of mind )

 

[Timmsy]

Why would you want 6 speeds?

I know of one very good reason to want a 6th gear!... While on the way to work on dual carriage ways or motor ways sitting at 60 or 70 the car seems far to high up the revs and would be lovely to have a 'motorway gear'

 

[tom172cup]

This.

There is nothing that is direct fit.

Some people have fitted VAG gearboxes, but its quite a task and I'm not sure if anyone has done a six speed one - space is pretty tight!

I have the vw six speed conversion it's not cheap but what I needed. The extra gear didn't improve fuel enconamy much

 

[Dr HMS Derv Destroyer]

Don't forget tom, your running stupid power which will kill a jc5

those 02M boxes take allot , seen a few crazy PD's running 500+NM without failure. Boxes need overfilling abit to help lube third gear as it only gets splashed

 

[Edges]

When people say it's costs a lot... How much are we talking? It's something I want to look into (more for cable shift really though)

 

[Jaff.]

At least 1k

box - 500-1000
flywheel - 400 ish
adaptor plate - 200 ish
cables - 50 ish
hydro clutch conversion bits 1-200 ish
mounts - 1-200 ish
custom shafts - 300ish

off the top of my head

 

[Jay Payne]

I know of one very good reason to want a 6th gear!... While on the way to work on dual carriage ways or motor ways sitting at 60 or 70 the car seems far to high up the revs and would be lovely to have a 'motorway gear'

Then just change 5th. Easily done. our race car had a shorter one fitted for racing so for the road just go longer.

 

[Timmsy]

So if you say changing 5th is easily done what sort of ratio would be best? Also which longer 5th would work?

 

[Chip-mk1]

Standard jc5 boxes are strong enough if treated properly.

people run them on boosted clios without problems ( generally a refresh is done for peace of mind )

my last one did 10k miles of boost and was 100k miles old before that.

Conversely on my n/a mk1 with a 8krpm Clio Williams engine I got through 8 boxes in 18months including a couple of 172 ones.
Porkie has killed a couple too.

I think it's revs and aggressive changes that kills them more than boost does tbh.

 

[Tutuur]

Timmsy: diesel 5th will probably work

As said, a 02m box conversion isn't cheap but it's worth it if you're running big power!

 

[Chip-mk1]

I cant tell you if it is compatible as its not a swap I have ever done, but a jc5-138 has a fifth gear ratio of 42/31 which is a reasonable amount (7 ish %) taller than the 172/182 ratio of 39/31.

If you use that and a Ph1 box (15/58 which is 5% taller diff than a phase 2 15/61) then you can build a pretty tall 5th gear.

It will really blunt the performance in 5th though of course, but then you can just change down a gear I guess if you want performance.

I did consider it as a cruising gear in my turbo, but the problem I have is that I have enough power that 4th gear isnt tall enough for me on tracks with big straights as my 4th gear runs out at about 130mph with the ph1 diff, which is nowhere near enough, especially as Ideally I like to change before the redline as mine hits peak power quite a bit before peak rpm, but if I then put the taller 5th gear it would drop the revs too far on change really as 5th ends up geared 1.395 * higher than 4th, where as standard its 1.295 (which is already a bigger jump than 3rd to 4th is as thats only 1.284).


I considered using it on my mk1 as well, which runs a ph2 diff, as I figured it would get me slightly better economy on a run to and from the track, and as that car is N/A (ie slow!) it doesnt need more than the 125mph that I have in 4th anyway, but then I figured if I ever take it to the ring or spa I might need to use 5th on the really long straights and would then really curse myself for ruining it just in an attempt to gain an mpg or two in a car who's main function is track not commuting.

 

[Timmsy]

Thanks for the above Chip. I guess it really comes down to how the car is being used then, tbh i'd probably get really bored of a long 5th, just a shame you cant have the best of both worlds and have all the normal 5 gears then a 6th for the long final gear that never really gets used unless on a commute to work/motorway work

 

[Chip-mk1]

Thanks for the above Chip. I guess it really comes down to how the car is being used then, tbh i'd probably get really bored of a long 5th, just a shame you cant have the best of both worlds and have all the normal 5 gears then a 6th for the long final gear that never really gets used unless on a commute to work/motorway work

Yeah I would like to have a ph2 diff and slightly lower geared fifth and then have a sixth gear about 15% taller just for cruising.

 

[Tav]

My point was that if you want a longer 5th that'd be easier but...

How does the 6th comapre to the 5th? Is it longer or is it the same and the extra gear is just packed in, so intermediate ratios are shorter. Lupo GTi is like this.

Also the amount you'd spend doing it will be nowhere near what you'd save on fuel I'd think...and if you were doing big mileage that'd need that....buy a diesel!

 

[Tutuur]

If you think the 6 sp will be taller from the get go you're completely wrong!