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View Full Version : The JB3 & JC5 ratio differences?



cliolord
06-03-2007, 21:19
I have wondered about this for awhile....It seems that my old valver engine with the JB3 gearbox had a totally different ratio in 4th gear to the JC5? 4th gear seems shorter in my JC5 box than the JB3 box did and seems to work alot better aswell. It will give around 107mph on the willy limiter on JC5 box 6,500rpm. I can't actually be sure if 3rd gear was also a shorter gear in the JB3 aswell? I can remember the revs dropped much more through a 3rd to 4th gearbox on my valver setup though. Has anyone notcied this? Sorry about the dragged out information lol

Riley
06-03-2007, 23:27
i was told that the 5th gear is longer in the jc5, but who ever it was who told me wasnt certain. My valver does about 110mph off limiter in 4th so sounds about the same to me

richy
06-03-2007, 23:50
my valver running jb3 box will do 112 in 4th at 7200rpm(ish)

MAXIBOY
07-03-2007, 00:50
well according to haynes

jc5 jb3

1st 3.7 3.1

2nd 2.1 1.8

3rd 1.3 1.3

4th 1.0 1.0

5th 0.8 0.8

041 3.3-1

045 3.4-1

046 3.9-1

048 4.2-1

005 3.6-1

010 3.6-1

015 4.2-1

the last are final drive ratios depending on box and code.

webermaniac
07-03-2007, 06:53
JC5 4-th gear is 1.029
JB3 4-th gear is 0.968
JC5 and JB3 3-rd gear is 1.321

northy
07-03-2007, 08:34
4th is around 105mph in my standard ecu'ed williams car.

sounds about right to me.

Martin
07-03-2007, 09:33
my old 19 box gave 120mph in 4th....willy box only 110ish

2 live
07-03-2007, 09:43
19s are geared diffrently again tho mate

nyk
07-03-2007, 13:27
I thought the 19 used the JB3 same as the valver ?? :?

MAXIBOY
07-03-2007, 13:28
same box different ratio,s

2 live
07-03-2007, 14:09
aye they a bit taller iirc

due to better aerodynamics or summat daft lol.

VIPERONE
07-03-2007, 14:10
there are around 10 different variants of the 3 and the 5 series

david932
07-03-2007, 21:37
well according to haynes

jc5 jb3

1st 3.7 3.1

2nd 2.1 1.8

3rd 1.3 1.3

4th 1.0 1.0

5th 0.8 0.8

041 3.3-1

045 3.4-1

046 3.9-1

048 4.2-1

005 3.6-1

010 3.6-1

015 4.2-1
the last are final drive ratios depending on box and code.

are these the williams final drives?

[-o< *prays they are not* [-o<

MAXIBOY
07-03-2007, 21:42
the last three are jc5,s. not sure which is fitted to the williams. there should be a tag on the box with a code.

david932
07-03-2007, 21:50
should the code reference 1 of the above numbers?

MAXIBOY
07-03-2007, 21:53
should do

jay s
07-03-2007, 22:12
ive got a jb3 053 in mine, its not on the above list tho :? anyway top speed in 5th seem to be 142mph @ 7.1k

Justin..
07-03-2007, 22:40
thats an R19 box. My one of those has a diff circlip issue and im gunna try and mod the diff. one day ... :lol:

jay s
07-03-2007, 23:00
ah did'nt know it was a 19 box :lol: the diffs ****ed in mine as well, wanna really get a willy box next..... 80mph @ 4k is not what i want.

dimkais
08-03-2007, 09:54
If you want i can sent you a pdf (i think) file that has ALL the gearboxes from JB1 to JC5 with ratios,final drives number identification etc... :) or i can post you what is says for JB3 and JC5 gearboxes...

Zollo
08-03-2007, 10:08
wanna really get a willy box next..... 80mph @ 4k is not what i want.

You should be looking elsewhere then... 4k is a pubic hair under 80mph in my Williams!

MAXIBOY
08-03-2007, 11:43
If you want i can sent you a pdf (i think) file that has ALL the gearboxes from JB1 to JC5 with ratios,final drives number identification etc... :) or i can post you what is says for JB3 and JC5 gearboxes...

can you send the pdf to northy and can northy sticky it please

cliolord
08-03-2007, 19:41
lol lots of replies. I was talking to someone in France awhile back who managed to get hold of a 6speed gearbox that fits to the williams/16v block and mounts in correctly AND houses the drive shafts :shock: You are looking at similar ratios, first is shorter and 6th is a little longer than 5th although he told me he cant get them any more :evil:

webermaniac
09-03-2007, 09:00
2 Dimkais: I want this PDF

northy
09-03-2007, 09:01
If you want i can sent you a pdf (i think) file that has ALL the gearboxes from JB1 to JC5 with ratios,final drives number identification etc... :) or i can post you what is says for JB3 and JC5 gearboxes...

can you send the pdf to northy and can northy sticky it please

Thank you Dimkais

northy
09-03-2007, 10:24
http://www.williamsclio.co.uk/forum/viewtopic.php?t=20270&highlight=