5th gear ratio mod

[R0B]

Hi all, have been reading up on changing the 5th gear ratio to help with fuel economy on the highway.
Back story is I will be buying a polo Tdi 1.9 to drive from Sydney to Goulburn for work, wanted to get 5th gear sitting as low as possible in the rev range as I’ll be sitting at about 120kph.
As I don’t physically have a car yet I’m a little unsure what the gearbox code itself is, and if a 5th gear ratio change is available/possible

Any advice would be great.

[kaanage]

I looked into this a while back and the only option I found was to fit a 6 speed gearbox. I couldn't even find a taller final drive option

Great choice for that commute, BTW

[Ozsko]

I looked into this a while back and the only option I found was to fit a 6 speed gearbox. I couldn't even find a taller final drive option

Great choice for that commute, BTW

I would be a bit concerned about the pull from Picton Road up to Mittagong with a higher ratio and it would be a hard way to find out the installed ratio was too high.

[R0B]

I looked into this a while back and the only option I found was to fit a 6 speed gearbox. I couldn't even find a taller final drive option

Great choice for that commute, BTW

Was that due to the type of gearbox the polo has? What is the gearbox code for them?

I’ve found a couple different places overseas that supply kits to change the ratio but without knowing the trans code I can’t confirm of these are the correct ones

Did you end up fitting a 6 speed ?

[R0B]

I would be a bit concerned about the pull from Picton Road up to Mittagong with a higher ratio and it would be a hard way to find out the installed ratio was too high.

So far from what I’ve read, a .592 ratio 5th gear will see about 1900rpm at 120kph which is right about where I want it and we’ll within the torque curve. Obviously anything under 90th kms will be interesting but the hours which I drive there is generally little to no traffic

[kaanage]

I just went by comments on the UK forums about the options (or rather lack thereof) for internal ratios for the PoD.

I never ended up modding the drivetrain. The ring gear size issue stopped me getting the LSD and the 6 speed box is about 20kg heavier than the 5 speed so I didn't think there was enough benefit.

Worrying about one climb on the route is silly - you can always shift down.

Sent from my moto g31(w) using Tapatalk

[HaydEn]

I just went by comments on the UK forums about the options (or rather lack thereof) for internal ratios for the PoD.

I never ended up modding the drivetrain. The ring gear size issue stopped me getting the LSD and the 6 speed box is about 20kg heavier than the 5 speed so I didn't think there was enough benefit.

Worrying about one climb on the route is silly - you can always shift down.

Sent from my moto g31(w) using Tapatalk

What 6 speed?

There’s ~3kg difference between a 02A/J and a 02S/R


Sent from my iPhone using Tapatalk

[kaanage]

I was thinking of the 02M as I don't think the 02S is strong enough for a tdi.

Then again this guy put one into his souped up GTI so it may work
UK Polo GTI 320BHP

Sent from my moto g31(w) using Tapatalk

[HaydEn]

I was thinking of the 02M as I don't think the 02S is strong enough for a tdi.

Then again this guy put one into his souped up GTI so it may work
UK Polo GTI 320BHP

Sent from my moto g31(w) using Tapatalk

02S comes in our GTD’s/MK5 diesels


Sent from my iPhone using Tapatalk

[R0B]

I just went by comments on the UK forums about the options (or rather lack thereof) for internal ratios for the PoD.

I never ended up modding the drivetrain. The ring gear size issue stopped me getting the LSD and the 6 speed box is about 20kg heavier than the 5 speed so I didn't think there was enough benefit.

Worrying about one climb on the route is silly - you can always shift down.

Sent from my moto g31(w) using Tapatalk

Was that the lack of options due to what box the polo's have? Can i ask what the gearbox code is for a polo TDi or do they differ?

So far darkside development seem to have all 5th gear pars available (Gearbox compatibility depending) and would be alot cheaper and easier than swapping to a 6 speed which is also an option if there is no 5th gear compatible.
Darkside Developments - 5 Speed 02J, 02A ,02B, 02C & 02Z - .592, .622, .658, .681, .700, .717 & .744 5th Gear Sets

[R0B]

Do you have a link for a 6 speed box conversion? i keep reading the different boxes need different clutches etc, being new im not across a;; the 1.9 variants and there differences

[R0B]

......

[JTop]

I'll answer simply and quickly
Yes. Boxes of the same generation, O2r(Seat Cupra R+others), O2s(Polo +others), O2m(older Audi S3-TT couple others) and will match up to the block no issue. The box codes all vary. (I'm forgetful so I may have mixed these up)
BUT. Their mounting method to the Polo chassis will have to be varied to accommodate. Ie. box is cut up to suit the gearbox mounting bracket. Then you too have to focus on the driveshaft hub cup sizes, as they will vary from box to box and to the car you are putting it into. SO do your research before you dive into a box.

And as you do go with a different box. They will have their own input spline of varying counts.
So you do need to update the clutch disk and optimally; full kit to suit this change.

Hope this gives you some idea. Enjoy