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Model specific boards => Golf mk3 => Topic started by: vwwvgolf on 03 February 2015, 18:17

Title: gearbox speed/revs/gear for 16v
Post by: vwwvgolf on 03 February 2015, 18:17

hi,
just fitted lightened flywheel and recon'd box with the 3.9 F.D. pretty sure its CDA code
any one got what the speeds should be at certain rev in the gears. just want to check that they did actually change the F.D when it was remade
thanks

Title: Re: gearbox speed/revs/gear for 16v
Post by: VW BUSH on 03 February 2015, 21:01

1st 3.300    2nd 1.944   3rd 1.308   4th 1.029    5th 0.837
Old FD 3.684
New FD 3.9 (which 3.9 FD is it? there are a few with slightly different ratios)

So calculate road speed as engine speed in RPM through the gear+FD ratio and circumference of wheel into m/s then convert to mph.
hope that helps.
I have a spreadsheet I can mail out if anyone needs it of all VW box ratios and trans info.
Or if someone can suggest a way of posting it on here....

Title: Re: gearbox speed/revs/gear for 16v
Post by: vwwvgolf on 04 February 2015, 12:39

it should have the 3.94 FD fitted.

so if i wanted to find the speed of old box in 5th, i would do: 0.837+3.684+ 1353(i think is the diameter of wheel) then what?   was never anygood at maths!

Title: Re: gearbox speed/revs/gear for 16v
Post by: VW BUSH on 04 February 2015, 23:34

Quote from: vwwvgolf on 04 February 2015, 12:39

it should have the 3.94 FD fitted.

so if i wanted to find the speed of old box in 5th, i would do: 0.837+3.684+ 1353(i think is the diameter of wheel) then what?   was never anygood at maths!

http://en.wikipedia.org/wiki/Gear_ratio
Bottom of the page, easier than me trying to explain :wink:

Title: Re: gearbox speed/revs/gear for 16v
Post by: vwwvgolf on 05 February 2015, 19:48

cheers man ill try get my head round this later

Title: Re: gearbox speed/revs/gear for 16v
Post by: vwwvgolf on 06 February 2015, 12:21

http://www.boosttown.com/gearbox_differential/speed_calculator.php


used this to help. much easier! thanks for the ratios tho!

Title: Re: gearbox speed/revs/gear for 16v
Post by: VW BUSH on 06 February 2015, 20:26

No probs.
I've got an engineering calculator I use for this sort of thing.
It's amazing how quickly you forget 7 years at college and become a retard :grin:

Title: Re: gearbox speed/revs/gear for 16v
Post by: VW BUSH on 06 February 2015, 20:26

No probs.
I've got an engineering calculator I use for this sort of thing.
It's amazing how quickly you forget 7 years at college and become a retard :grin:

Title: Re: gearbox speed/revs/gear for 16v
Post by: VW BUSH on 06 February 2015, 20:28

^^^
See

Title: Re: gearbox speed/revs/gear for 16v
Post by: vwwvgolf on 07 February 2015, 08:48

ive forgotten nearly everything from school lol i blame beer!