[SOLVED] Incorrect Gear Readings

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Mike S2k
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[SOLVED] Incorrect Gear Readings

Post by Mike S2k » Sun Dec 11, 2011 3:49 pm

Hi,

I've recently bought the Pro version of the app and so far i'm very impressed. I use it with a Chinese copy of the KiwiWifi OBD and it works very well.
One thing I cannot get to work correctly is the gear reading. I have set gear ratios, tyre size, power and max revs but the gear aways seem to low.

I went for a test drive and and it said I was in 3rd gear when I was actually in 4th and never seemed to go up.

The car is a Honda S2000 and the figures are

1st: 3.133
2nd: 2.045
3rd: 1.481
4th: 1.161
5th: 0.970
6th: 0.810

Final drive: 4.100

237 bhp (177 kW; 240 PS) @ 8,300 rpm

153 lb·ft (207 N·m) @ 7,500 rpm

redline 8900

Tyres
f: 205/55VR16
r: 225/50VR16

Thanks
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Harry
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Re: Incorrect Gear Readings

Post by Harry » Sun Dec 11, 2011 4:35 pm

Hi,

Looking into this there seems to be a secondary gear reduction. I have no idea how the Honda drive is constructed, but you may try multiplying this to the drive ratio.

- Harry
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Mike S2k
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Re: Incorrect Gear Readings

Post by Mike S2k » Sun Dec 11, 2011 7:39 pm

Hi Harry thanks for the quick reply. Do you have any idea how I would go about multiplying this into the gear ratio? Thanks
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Harry
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Re: Incorrect Gear Readings

Post by Harry » Sun Dec 11, 2011 7:47 pm

I'd leave the gear ratios as they are but enter 4.95 (= 4.10 x 1.208) instead of 4.10 for the drive ratio.

The logic LapTimer calculated gears from rpm and speed:

Code: Select all

rpm / gear ratio / drive ratio * wheel circumference = speed
LapTimer selects the gear that equals this equation (using the right units for speed, and distance, etc).

- Harry
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Mike S2k
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Re: Incorrect Gear Readings

Post by Mike S2k » Sun Dec 11, 2011 10:43 pm

Much better. Thanks Harry
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