I dynoed my previous car (a '97 Mustang Cobra) in 4th gear because it was a 1:1 ratio. Since the Maxima 5 speed has no 1:1 gear, what gear do most people dyno in? Do you use any correction factors to adjust your numbers because of this?

Thanks,
Dan
'01 Black SE 5-spd
'99 White SE Auto (wifemobile)

 

I don't know if it really matters. Mostly everyone does 4th gear, but the people that do 3rd and 4th gear usually end up with the same numbers anyway. But I was say a greater percentage use 4th gear rather than 3rd gear.

 

Dyno in the highest gear that allows the car to pull off of idle at full throttle without stalling. This gives you the broadest "test" range to measure torque and horsepower at the entire operating RPM range. Doing it in the highest gear possible minimizes the possibility of the tires spinning on the dyno and giving you false readings (unless you're pushing a 1000hp supercharged corvette which lights the tires in 4th gear). It's also easier on driveline components.
At least that's what the guy who dyno'ed my bike said when I asked him the same question. He did it in 4th and it pulled a VERY anemic 85hp at the wheel. Time to upgrade. 100 flywheel hp isn't enough for a bike anymore. Err maybe I should adjust the valves or something. Oh well.

 

Then why are the dyno charts that I've seen for the Maximas so low? I was thinking maybe the tranny ratios were throwing the numbers off. The torque numbers I've seen look fine, but the horsepower numbers concern me.

No offense to anyone who has dynoed and posted their results or anything like that intended. I'm just concerned that maybe Nissan's 222HP claim is somewhat inflated. I've seen charts showing 160 FWHP for an automatic, 170 for a stick. I'd expect these exact numbers for a car with 200 HP. Allowing 15% driveline loss for the stick, I'd expect 188, giving 20% to the auto I'd expect about 177 from a 222 horsepower engine. So what gives?

Thanks,
Dan

 

For 3rd gear I've seen 200 HP from a Maxima with a cone intake for a 2000. and 185 in 4th gear. That is inline with 10-15% drivetrain loss.

My auto put down 166 in 3rd gear.

 

I dynoed my Max in 3rd and 4th, the result were more different than you may think.

4th gear put down 186hp and 195tq "corrected"
3rd gear did 200.5hp! and 196tq "corrected"

 

do it in 4th. 3rd gear is shorter-geared, so the numbers will be artificially higher.