Nissan 370Z Forum - View Single Post

cossie1600 · 09-19-2011, 11:24 AM

i am trying to calculate my engine speed based on my gps datalogs. when i put in all the data like wheel size, road speed, gear ratio and diff ratio, the rpm is always off by 500 rpm. anyone know what it could be? is our gauge that far off in terms of revs or is the gear ratios incorrect or is it my gps

here is what i used

2nd gear limiter is 69.4mph
final drive is 3.446
2nd gear ratio is 2.324
tire size is 26.8 as i have 285 35 19

what do u guys think

09-19-2011, 11:24 AM	#1 (permalink)
cossie1600 A True Z Fanatic Join Date: Jun 2009 Location: californee way Posts: 5,380 Drives: 370, Leaf Rep Power: 29	engine speed / gears / road speed i am trying to calculate my engine speed based on my gps datalogs. when i put in all the data like wheel size, road speed, gear ratio and diff ratio, the rpm is always off by 500 rpm. anyone know what it could be? is our gauge that far off in terms of revs or is the gear ratios incorrect or is it my gps here is what i used 2nd gear limiter is 69.4mph final drive is 3.446 2nd gear ratio is 2.324 tire size is 26.8 as i have 285 35 19 what do u guys think