PH1 / 172 Cup gearbox

[Gman]

Hi all, I've done a search but can't find a answer, I'm thinking of building a new gearbox up for my 172cup with a diff and was wondering exactly what the differences are between my box and a ph1 box, mainly is there any difference between how the diff is mounted??
The reason i ask this is I'm sure i can remember someone telling me PH1 boxes had issues in this area and as my car spends a lot of time on track i don't want any reliability issues.

Gman

 

[Gman]

Anyone?

 

[Russ_16v]

Earlier ones (Mk1 Clio's) has issues with the diff circlip breaking, but iv personally never had any issues with Ph1 boxes doing that, (My black Ph1 was regularly tracked with over 190bhp and 140,000 miles)

The ratios are different mind, the Ph1 box is longer legged - one modification I wanted to do was fit a Cup box to get the better ratios

 

[Gman]

I didn't think the ratios were different enough to make any real difference??

Looks like i'll be best just rebuilding my box, would have been nice to build one up just so i could swap it out and in on the same day.

 

[Russ_16v]

Well speed wise, my old 172 would show just over 120mph in 4th up Avon Rise at Combe, where as my friends Cup would show 110 at the same revs, so im sure the difference would be noticeable (if not huge)

 

[Jay Payne]

Yes it is noticeable for sure. Ph1 box has a much taller final drive.

Using Russ' track Comparision oulton park down the hill towards the 2nd chicane. Ph1 just touches limiter in 3rd but ph2 final drive means you change into 4th at top of hill

 

[Russ_16v]

Out of interest, which one do you prefere Jay?

I love mk1 ratios, 3100rpm is 60mph lol

 

[Jay Payne]

Phase 2, better acceleration. Thats what weve always run in the race car. The was/is an even shorter stock final drive ratio out there somewhere but very rare. Martin t Agency ordered in about 20 crown wheel and pinions for us trying to find it but always came through as 61/15 (4.07) phase 2/williams

 

[domke]

the best choice for a track/race gearbox is ph2 final drive 15/61 (4.06) and Laguna II 1.8 16v Jr5 gears, top speed will be about 130-135 mph on 7200 rpm, but it have a bit too slow 1st gear.

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

 

[RS_Nicks]

Re: PH1 / 172 Cup gearbox differences

This is interesting, I have the same issue - and am considering options to sort my box out.

Mine has sloppy linkage and crunches at speed going down the box particularly. It's only got 48k on it, but it's been track ready for most of its life.

My query is, when did the gearboxes changeover? I have a 52 plate non cup 172 that I know has a speedo sensor (I changed it as it failed) and a 52 plate 172 cup but i can't get to it at the moment as its at a race shop. Will the cup one have a speedo sensor or cable?

Im keen to source a replacement and have it repaired ready to drop in.

I would really appreciate a table of gearbox model codes against clio models / years if that's possible?

Cheers.

 

[the.wolf]

will all laguna's 2.0 JC5 and JR5 gearboxes fit clio sport 172 MY00 P&P?