The Effect of Dynoing in Different Gears

DarkZide · 02-24-2011, 01:21 PM

I could be totally wrong here, but i think the 1:1 rule was started for a few reasons.

First, cars have all sorts of gear ratios, but what we are after is engine output. It's not feasible to put an engine on an engine dyno so we go after the reading that is closest to that, and that would be a 1:1 ratio output from the engine to the gearbox. Final drive is mostly irrelevant, as it won't necessarily affect peak power, but where you make peak power.

Second, disregarding overdrive, the 1:1 gear is usually towards the top of the gearseat without being in overdrive, so it takes a lot longer to go through that gear, which equals a longer amount of time for the dyno to take readings. Imagine trying to count a stack of money thats being put down bill by bill every second, then imagine trying to count a stack of money that someone just throws down all at once.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
5th and 6th Gears Grind	nicole	Engine & Drivetrain	4	12-28-2010 08:41 AM
3.89% is in effect	dalparadise	Nissan 370Z Pricing / Ordering Discussions	3	01-10-2010 06:59 PM
Oil cooler and effect on volume	tbonesteak	Engine & Drivetrain	15	01-02-2010 03:41 PM
Tire Patched- any effect on performance?	davidyan	Wheels & Tires	32	12-06-2009 09:18 AM
5zigen Dynoing their white Nissan 370Z in Japan 12.10.08	AK370Z	Nissan 370Z Photos / Spyshots / Video / Media Gallery	29	12-17-2008 03:19 PM

02-24-2011, 01:21 PM	#21 (permalink)
DarkZide Enthusiast Member Join Date: May 2010 Location: TN Posts: 291 Drives: 2010 370z BC M6 Rep Power: 17	I could be totally wrong here, but i think the 1:1 rule was started for a few reasons. First, cars have all sorts of gear ratios, but what we are after is engine output. It's not feasible to put an engine on an engine dyno so we go after the reading that is closest to that, and that would be a 1:1 ratio output from the engine to the gearbox. Final drive is mostly irrelevant, as it won't necessarily affect peak power, but where you make peak power. Second, disregarding overdrive, the 1:1 gear is usually towards the top of the gearseat without being in overdrive, so it takes a lot longer to go through that gear, which equals a longer amount of time for the dyno to take readings. Imagine trying to count a stack of money thats being put down bill by bill every second, then imagine trying to count a stack of money that someone just throws down all at once.