Ricardo 4.6 final drive

I've an option to get a Ricardo 4.6 final drive for my 02a set up. I'm not really sold on the idea of such a low final drive, I've talked it over with a few guys and tried out a number of combinations, nonetheless I'll probably acquire it anyway and decide later.
I've spent an solid half hour trawling the internet but can't find anything too specific on this final drive or the use of them apart from the obvious need for them or Ricardo wouldn't have bothered making it. I've never seen these for sale and am worried I'll only to be stuck with it if I don't use it, would there be much interest and anybody have an idea what it would be worth please?

 

I have a 4.25 final drive from a 02J which is the same. If you are interested, let me know.

 

It's worth 150/250 - condition dependent & whatever someone is prepared to pay.

I've seen them before - it's a tarmac-ish rally final drive really, cutting the top speed down markedly, unless a 6-speed Gemini/Ricardo kit is fitted. Even then, top speed is pegged. You're best trying rally classifieds, eg rallycarsforsale.net.

You could also try some maths on spacing the gears, eg a diesel 5th - click - which then will leave other gaps to fill.

 

The trouble with a final drive that low is you effectively make first gear redundant. First gear ratio of 3.778 is ridiculously low and the 3.300 is really not much better. You would be able to take off in second gear. Huge wheels would help but then that just raises the gear ratios through the other gears too.

A low final drive does close up all the other ratios though, but that can cause problems too, as you may be forced to up change earlier due to running out of revs sooner. It becomes circuit specific when you start going that low in the final drive department.

Most of these serious competition final drives were based around using pukka gear kits with first gear ratios starting around 3:1, this is a usable ratio and helps close the gaps up to the rest of the gears.
If only VW made a first gear for any of their boxes with a ratio of around 3:1.[:^(]

 

2.5 and 2.7 are the ones I've seen (020 / 02A) - ballpark recollection rally homologation ratios IIRC.

 

a 4.2 is enough for an 02a with std cogs - like has been said, 1st becomes unusable

 

Putting aside the idea of using the 4.6 final drive as it would leave me only 4 speed box instead of 5 (1st being unuseable) I'm looking to having some regular trips to Knockhill for track nights and the corners would simply be taken in the next gear up instead of really matching a longer/shorter gear to any particular corner, back to my first idea on the drawing board.

Current ratios - AGC code;

1st 3.778
2nd 2.105
3rd 1.345
4th 0.971
5th 0.795
Final drive 3.994

Using 1st and 2nd from CHN to lengthen 1st and 2nd and tighten the gaps up to third are;

1st 3.3
2nd 1.994
3rd 1.345
4th 0.971
5th 0.795
Final drive 3.944

Should I also use the 4th and 5th from the CHN to close the gaps further? Rev drop from 3rd to 4th and and 4th to 5th would be 1711 and 1403rpm respectively.

1st 3.3
2nd 1.994
3rd 1.345
4th 1.034
5th 0.838
Final drive 3.944

 

You are blessed with a brain Strimmer.
Now put the later box you suggest, with the closest ratios together along with that LSD you got and get the car rolling.

PS. How the fook do you cut Kingspan!

 

Talks on re-build have commenced

Use a decent saw, the Kingspans not hard to cut but a good sharp saw will help get straight edges and a tight fit between the rafters/joists, cut it a couple mm bigger for a snug fit.

I'll need to vist you this week, see how the build's coming on

 

Old thread rejuvenation. I'm in the market for a low FD for an 02a (6 speed quaiffe) for my tarmac rallycar, if anybody has one lying around....

 

Gearbox bearing failure means I need a low FD CWP for a Quaffe 6 speed synchro gearset
NOW. (its in bits ready to start rebuild)
Anybody?

 

I have a 4.25 for an 02a, nothing lower as I don't use the later boxes, just aquired it somewhere - had a plan! Not sure if that will do?

 

Thanks, picked up a whole 'czm' 02j last night. With a 4.2 FD in it.
T plate N/A 20V Golf, allegedly.
It had only done 80K (yeah, right, of course, that's why it took 1/4 gallon jizer to clean the crud off???)
Hoping to get time to strip it tonight
Cheers
Jon

 

02J CZM will have a 4.23 FDR with the same gears pacings as an ABF CDA or VR6 CCM unit.

 

I had a czm gearset in my 02a casing before going to the sqs dogbox. Infact IMO its the best set of 02A ratios for a valver - equivalent to that old 020 favourite the 2Y with a 3.9FD

 

Going to be the quaife 6 speed syncro gearset and the 4.2fd. The 4.2 will help getting the lardy **** thing off the line..

 

Is it a better ratio set than the czm? Id check before strippingit......

Edit

CZM: 3.3, 1.94, 1.31, 1.03, 0.84
Quaife: 2.72, 1.92, 1.5, 1.2, 0.95, 0.8
SQS: 3.0, 2.28, 1.76, 1.47, 1.23, 1.04

 

Its got to be stripped anyway. The box was a 1/3 the entry fee of a rally and Ive just had one dnf due to gearbox... The quaife ratios have a taller 1st, hence the need for a lower FD. Rest are closer (not cloe enough really, but its bought and paid for) The huge difference is in the size of the teeth. The quaife are like something out of a massey ferguson. Rumour has it my quaife gear diff will not work in the 02j casing. Need to do more research.
Box 1/4 stripped so far..

 

I used to have an 02a quaife diff in an 02a case, with 02j gears/cwp - no issues