Lucas_Gchips

On tansmission ratio change from 5 speed to 6 speed
1st gear 12% longer
2nd gear 18% longer
3rd 13% longer
4th 5% longer
5th 8.5% longer
6th compared to 5 speed in 5th 23% longer

I hope my math is right, this is also taking into account diff ratio change 3.889:1 to 4.111

Yippers®

--------5 speed ------------6 speed

1st 3.778x3.889=14.693---- 3.50x4.111=14.389
2nd 2.176x3.889=8.462---- 1.889x4.111=7.766
3rd 1.429x3.889=5.557---- 1.231x4.111=5.061
4th 1.029x3.889=4.002----- .967x4.111=3.975
5th .838x3.889=3.259------ .806x4.111=3.313
6th ---------------------- .684x4.111=2.812

Based on NA gears ratios.
So I get 1st being ~2% longer, 2nd being ~9% longer, 3rd being ~10 percent longer, 4th being .7% longer, 5th being ~1.7% shorter and 6th being ~16% longer than the 5th in the 5 speed.
My math bad?

Lucas_Gchips

The Diff ratio should be divided.

As Lower Gear Ratio will mage gear Longer, But a Higher Diff Ratio will make it Shorter, so both have to be taken into account.

ie if both 1st gears where same say 3.5:1 and diff gears 3.89 and 4.11, the 4.11 will make gear shorter.

so i used eg for 1st in 5 speed 3.78/3.889 = real end ratio 0.97
in 6 speed 3.5/4.111 = real end ratio 0.85
ie about 10%+ difference.

Also i know know in 3rd i can easily hit 105+MPH

with my 5 speed, could never get close to that.

Yippers®

Here is a clip from the Bentley's. It is for the 5 speed but if you substitute the 6 speed gears I think you'll get what I posted above.

Ratio i, calculating
Transmission ratio

Transmission ratio =
No. of teeth driven gear: No. of teeth drive gear

Ratios Formula
iG = gear ratio ZG2 :ZG1
iA = axle ratio ZA2 :ZA1

iov= overall ratio iG x iA


Example:
5th gear Final drive
Drive gear ZG1 = 37 ZA1 = 9
Driven gear ZG2 = 31 ZA2 = 35

Calculations:
iG = 31 : 37 = 0.838
iA = 35 : 9 = 3.889
iov = (31 : 37) x (35 : 9) = 0.838 x 3.889 = 3.2598

So, substituting the 6 speed's 5th gear, it would be
iG= 29 : 36 = 0.806
iA= 37 : 9 = 4.111
therefore iov=(29:36).806x(37:9)4.111=3.3135

Yippers®

5 speed V/1000 rpm in 3rd (5.557 from the table above)
Figure tires as (my OEM Sport)24.9"dx3.1415=78.223" circ/36.37"/meter=1.987 meters
V = 1000 : 5.557 x 1.987 x 0.06 = 21.45km/h x .621 mile/km= 13.32 mph/1000rpm x 7(000)rpm = 93.24 mph @7000rpm

6 speed values for 3rd (5.061 from the table above) would be
V= 1000 : 5.061 x1.987 x.06= 23.56km/h x .621 m/km= 14.63 mph/1000rpm x 7(000) rpm= 102.41 mph @ 7000rpm

Toaster29

I know you were around during the invention of modern math, but geez!! :P =)

Yippers®

Just more friggin ammo for all you pups ... lol
Damn I'm old.
All that gearing/speed stuff comes mostly from trying to select primary and secondary sprockets for motorcycle racing. .. trying to figure out what gearing would give what speed at what rpm, in what gear. I also dicked around a lot with the available ratios when looking into a NeuS4 6 speed vs the RS2.

Toaster29

you've still got plenty of time

Yippers®

either croak, have your stick go dead or become one of those doods you see doing the highspeeed shuffle across the street in 20 to 25 years? Still think being in your mid 50's ain't all tha told?