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Audi TT 2000-2006 TT 02Y (FMN, FZL) gear ratios seem wrong in Table c. on page 34a-4


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Last Post: Dec 30, 2015 11:23 PM Last Post By: wmorrison65
Bartsimpsonhead

Posts: 1
Registered: 04/23/13
TT 02Y (FMN, FZL) gear ratios seem wrong in Table c. on page 34a-4
Posted: Sep 27, 2015 5:37 PM
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Hi Guys,

I was using the gear ratios for the 02Y (FMN, FZL) transmission's 1st to 6th gears from Table c. 02Y manual transmission spec (AWD) on page 34a-4 to put into an app on my iPad (to do some rear-time logging), and the app said the ratios for 4th and 5th gear appear to be wrong.

Apparently the ratio for 5th gear (41:37 = *1.108*) should be smaller than the ratio for 4th gear (45:41 = *1.098*).

Given that 3rd gear is (47:32 = *1.469*) and 6th gear is (38:41 = *0.927*) it does seem likely 5th gear should be smaller than 4th gear.

Could you please clarify if this is an error, and what the correct ratios might be.

Thanks,

Martin

Edited by: Bartsimpsonhead on Sep 27, 2015 5:38 PM
wmorrison65

Posts: 1
Registered: 12/30/15
Re: TT 02Y (FMN, FZL) gear ratios seem wrong in Table c. on page 34a-4
Posted: Dec 30, 2015 11:23 PM   in response to: Bartsimpsonhead in response to: Bartsimpsonhead
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You're forgetting there are two final drives ratios, one for gears 1-4 and one for 5-6. Your app probably doesn't support that.

These transmissions use two output shafts so the transmission can be more compact. Each output shaft has a different final drive ratio.

One might expect the 5th gear ratio number to be lower than 4th, but it's not. But the effective ratio IS when you multiply each gear by the corresponding final drive ratio.

The Bentley manual should list the two final drive ratios on the same page as the 1-6 gear ratios.

If you want to do some rough calculations with an app that only supports one final drive ratio, what you could do is:

  • Multiply 5th and 6th gear ratios by the final drive ratio for 5-6
  • Divide each result by the final drive ratio for 1-4
  • Use the results in your app for 5th and 6th gear, using the 1-4 final drive ratio for ALL GEARS

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