speed in 3rd gear
11-17-2006, 10:36 PM
#1
speed in 3rd gear
Just noticed that my 8 seems to top out at a higher speed than any of the others Iv'e seen in 3rd gear
most seem to be 148 km/hr - 92 mph
Mine is 165 km/hr- 103 mph
Mine is an 03 model imported from Japan - anyone know why this would be ?
most seem to be 148 km/hr - 92 mph
Mine is 165 km/hr- 103 mph
Mine is an 03 model imported from Japan - anyone know why this would be ?
Last edited by Brettus; 11-17-2006 at 10:41 PM.
11-17-2006, 10:57 PM
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Doesn't your wheel speed = engine speed (rpm) dividided by 100 in 3rd gear? At least it is in the '06s. So...103mph = 10300 rpms...doesn't exactly work. Either you have different gearing or your speedometer is off.
11-17-2006, 10:59 PM
#6
Originally Posted by Vash137
Doesn't your wheel speed = engine speed (rpm) dividided by 100 in 3rd gear? At least it is in the '06s. So...103mph = 10300 rpms...doesn't exactly work. Either you have different gearing or your speedometer is off.
11-18-2006, 07:44 AM
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Originally Posted by Vash137
Doesn't your wheel speed = engine speed (rpm) dividided by 100 in 3rd gear? At least it is in the '06s. So...103mph = 10300 rpms...doesn't exactly work. Either you have different gearing or your speedometer is off.
You are limited to 180 km/hr? That's only 110 mph! Man, are you being cheated. I rarely drive anywhere close to 110, but I enjoy knowing I can if I need to.
11-18-2006, 12:33 PM
#9
Originally Posted by RotrDoc
That would be "Vehicle Speed (mph) = Engine speed (tachometer rpm) divided by 100"??
You are limited to 180 km/hr? That's only 110 mph! Man, are you being cheated. I rarely drive anywhere close to 110, but I enjoy knowing I can if I need to.
You are limited to 180 km/hr? That's only 110 mph! Man, are you being cheated. I rarely drive anywhere close to 110, but I enjoy knowing I can if I need to.
Anyway - tyre size is 235/40/18 which is a tad smaller than stock but not enough to make that much difference .
Only thing I can think of is that Mazda changed 3rd gear very early on in production. I'll check a couple of other imports here when I can.
I always wondered why people talked about changing into 4th at 85mph & thought that maybe they weren't taking it right to the redline
11-18-2006, 12:53 PM
#10
Originally Posted by Brettus
Anyway - tyre size is 235/40/18 which is a tad smaller than stock but not enough to make that much difference .
11-18-2006, 01:09 PM
#11
Originally Posted by MazdaManiac
Uh, duh. You are kidding, right? That is nearly a +4% speedo error! (Which is significant - especially in light of the non-linear error built into the speedo from the factory.)
Mine reads 165km/hr - everyone else seems to be around 145 km/hr
when I change from 2nd to third my revs drop from 9000 to 6500 - other shots of RPM guauges i've seen drop to 7000rpm .
11-18-2006, 01:14 PM
#12
Originally Posted by abbid
^ how do you come up with that logic?
The speed sensor counts the pulses the wheels generate.
if you have smaller wheels, youll generate more pulses because you complete a revolution faster.. hence your speedo is faster..
The speed sensor counts the pulses the wheels generate.
if you have smaller wheels, youll generate more pulses because you complete a revolution faster.. hence your speedo is faster..
11-18-2006, 01:17 PM
#13
Originally Posted by Brettus
No - your speedo will read the same for any given wheel speed - it is just that you will actually be going faster or slower depending on wheel size.
Same thing.
Are you drinking?
11-18-2006, 01:54 PM
#15
if your wheel sizes are not the same as factory sizes your speedometer will be giving you an incorrect output. Thats why when people buy winters tires that are 17 inch they increase the side sidewall size to keep with the overall same circumference. If you had 1 inch wheels your speedometer may read 300mph but you would really be going that fast your speedometer would be wrong. This is why you think your going faster but your really not. The shifts from 1-2 maybe pretty close to stock but as you get faster the amount that this fault affects your readout gets bigger. Just basic physics.