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BRUN
03-03-2008, 09:01
is this the box for a valver ?

as its the only one to give me a part number on dialogys, dont recall it having an S in the middle so im just checking

Justin..
03-03-2008, 20:17
isnt that the exchange number? ie - its been rebuilt.

BRUN
03-03-2008, 22:11
:oops: yup it is lol, i realised that a few mins after posting this up

Justin..
03-03-2008, 22:14
:)

BRUN
04-03-2008, 12:06
can anyone confirm its a JB3-24 ???

none of the others it says are the one for my car

Yanoo_
04-03-2008, 15:28
can anyone confirm its a JB3-24 ???

none of the others it says are the one for my car

My Dialogys doesn't want to run properly but my repair manual says JB3-048 for Valver.
Torque ratios: I: 3.09, II: 1.842, III: 1.32, IV: 0.967, V: 0.795, differential: 4.214

Yanoo_
04-03-2008, 16:48
Brun, I made a calculation for you with my Renault gearbox program (under construction... perhaps I'll finish it in a week or two). The 5th gear and the final ratio is too long in the JB3-024 for a Valver IMO.
(The top speeds are theoretical, Max rpm: 7200, Max Torque @ 4250 rpm, Max P @ 6500 rpm, wheelsize: 195/50 R 15, dynamic wheel radius: 0.95* nominal radius)

http://kepfeltoltes.hu/080304/for_brun_www.kepfeltoltes.hu_.jpg

BRUN
04-03-2008, 17:16
thanks a lot mate

BRUN
04-03-2008, 17:18
so only 5th is different

what would that actually mean in real driving terms, would my revs be lower than before ?......because i wouldnt mind saving some cash on petrol lol

Yanoo_
04-03-2008, 18:45
"i wouldnt mind saving some cash on petrol" :D
Yes, the longer 5th gear would reduce the rpm compared to a shorter 5th (at a given a speed).
A question: 3.5625 final ratio is not short (the 3rd longest JB3 final ratio) are you sure is only the 5th different? (Williams has 4.06 and a Phase 1 Valver has 4.214 (JB3-048) )

white16valver
04-03-2008, 21:04
I would have thought that a longer final drive ratio would have affected all the gears? But I might be wrong.

I'd definitely be interested in finding a more relaxed 5th gear though - cruising at, ahem, 3 figures is a noisy and thirsty affair! lol

Yanoo_
04-03-2008, 23:52
I would have thought that a longer final drive ratio would have affected all the gears? But I might be wrong.

I'd definitely be interested in finding a more relaxed 5th gear though - cruising at, ahem, 3 figures is a noisy and thirsty affair! lol

Final drive ratio has effect onto all the gears.

BRUN
05-03-2008, 10:31
my dialogys just wont give me an JB3-048 !

got the part number for it from an old system but its an old number which doesnt work anymore

BRUN
05-03-2008, 10:40
so if 5th affects all the gears, does that mean my car would be slower??

Yanoo_
05-03-2008, 12:43
so if 5th affects all the gears, does that mean my car would be slower??

"5th affects all the gears" No! 5th gear doesn't affect all the gears, that's an "independent" gear. If you change it it'll affects only in 5th gear.

The final drive ratio affects all the gears. The final drive ratio is the ratio of the driven shaft. In your case (Renault - FWD car) it is the ratio between the output shaft of the gearbox and the crown wheel (or cog/plate wheel which is the correct name in English?) of the differential. So if it's longer (for example 3.5625 instead of 4.06) the acceleration will be reduced in all gears but the (theoretical) top speed will be higher (in all gears). (That's an other question the the pulling power will be decreased by the longer FDR therefore (probably) the real top speed in 5th gear will be lower). At a given speed (for example 60 mph), the rpm will be lower in all gears (compared to a shorter final drive ratio).

A shorter final drive ratio has an opponent effect.

If you use a longer 5th gear it'll have same effect as above but only in 5th gear.

I hope you don't think I want to reason or something :)

BRUN
06-03-2008, 15:04
im such a numpty !!!

its dawned on me today what the JB3-S-24 actually is

its a refurb of either an 091 or 053 box, it isnt a JB3-024 as i first thought, and both of those boxes are used on valvers so ive nothing to worry about !

white16valver
06-03-2008, 18:44
lol

Oh well, prompted a bit of useful discussion! :lol: :D