Guys i dyno'ed my 03 today and it ran 280.2 on a DD @ the crank.

I dynoed a few months back on the same dyno @ 287.9bhp @ the crank.

The 287 bhp run was in 4th gear and the lower 280 run in 3rd.

Do you guys know if the zed dynos with higher numbers in 4th ? Because i have got HFC and a zorst on nw and it dynoed lower than before ?

Thanks guys.

 

how is this a crank measurement if you are measuring while the car is in 3rd/4th gear. Sounds to me like you are measuring hp at the wheel.

 

The dyno is set up in shoot out mode ? with no correction. It's just the wheel HP X a set drive train loss.

 

Temp and humidity can have a lot to do with it. Quality of gas.

But yes, a dyno will put out slighly different numbers in different gears. Find out which gear is 1:1 for the Z and dyno in that.

 

5th gear is the closest to 1:1 for 6MT and 4th gear for auto.

 

So am I correct that he should dyno in 5th?

 

+1
Different gas and weather conditions play a factor in the numbers.
Especially if your in a state that runs the ethanol in the gas during the winter to improve emissions.
You may have got your gas last time, just before they started running it with ethanol, and now you got some that has it in it, which decreases performance.

 

the dyno operator keeps telling me his dyno dynamics will not work at the road wheel speeds in 4th let alone 5th!! Is he having me on ?

 

I've had variances of +/-10 wHP bewteen 3 back-to-back dynos...then add weather and gas differences b/c it's a different day.

 

many dynos are different. the correct gear to run is the one that the dyno operator tells you to.

it does not necessarily have to be 1:1, and 1:1 does not necessarily give better or worse numbers than >1:1 .

Your best bet is to use the SAME GEAR every time, but it doesn't matter much if it is 4th, 5th. Most dynos are not set up exactly the same.

There has been much arguing about this but from my experiences and talking to dyno owners, this is the truth