Ph1 172 Gearbox v 172 Cup Gearbox - Differences etc?

[StevieSAW]

Hi all,

as per title. I have a Ph1 172 and there is a suspect drone when revving - it sounds like a worn diff, but the car has sat for years unused and may need a good oil service.

i have a 172 cup gearbox with the car that I could swap over if faulty.

is there major differences between the boxes?

iv read about Ph1 box having a longer final drive. Is there anything else?

any help appreciated.

cheers

 

[scotiamr2t]

I had this saved on a spreadsheet, sure its right...........if not one the tech gurus on here will correct it

Jc5+Jr5 gear ratios:
Differential ratio: 15/61 - 4,06
1 : 11/41 - 3,72
2 : 21/43 - 2,04
3 : 28/39 - 1,39
4 : 31/34 - 1,09
5 : 37/33 - 0,89

Jc5 129 Clio Cup gear ratios:
Differential ratio: 15/61 - 4,06
1 : 11/34 - 3,09
2 : 22/41 - 1,86
3 : 28/37 - 1,32
4 : 34/35 - 1,02
5 : 39/31 - 0,79

ive left my ph1 with the standard box as for knockhill I cant see the cup box making a huge difference

 

[StevieSAW]

Hi Scotty boy, how's tricks.

excellent info mate, nice one.

hhmmm - it's hard to say mate. You could probably accelerate out of a few corners better in 3rd with the cup box rather than the Ph1..... Maybe only just but could be significant.

 

[scotiamr2t]

Not too bad mate, good little base for a fun little track car you got from your uncle. in dire need of a few washes though, possibly the dustiest car I've ever seen!!

if chasing lap times it may be worth it seen as you have a box sitting anyway. I just couldn't be arsed changing my box over before this years track season.

 

[StevieSAW]

Good stuff mate. Your right its abso mining lol. In need of a very lengthy detail inside and out lol. You gt a thread for yours and I'll get a look? Still at the gym/playin footy?

Just had. Read of this thread reg gearbox - seems to show big imporvements. Maybe worth it later in time if the box does fail, and also set about getting a decent diff and d the clutch while a it. We're aiming to take the car across Europe to the ring, so best be as preventative as possible.

 

[scotiamr2t]

I started a thread when i first bought my car an since its changed alot but the thread hasnt been updated from then, epic fail! Sure am fella, joined that new gym to see what its like an its actually decent.

I have a cup gearbox threre just not changed it yet, possibly over winter. regarding diff expect to pay more than you did for the actual car (£1000+)! Ring trip is on the agenda for me next year

 

[Budgie]

Difference is negligible between them tbh.

Either will work nicely.