Stock Greddy - Dyno Questions
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Stock Greddy - Dyno Questions
To give a quick background. '90 miata with greddy kit. Pretty much stock kit, upgraded the plugs and wires and i have a fm heatshield on it. After breaking it in thoroughly (1300 miles at about 3.5-4 psi) i upped the boost to about 5.5 psi - 6 psi. My oil gauge isn't going crazy even at wot, so i'm assuming i'm not knocking. It pulls pretty good.
Today i put it on a chassis dyno at school, and we were trouble shooting the dyno for a while and finally made a few runs. The way we have it set up it is measuring wheel speed and not engine speed so i don't have a plot right now. (will be making more runs tomorrow and will have a plot, after i convert to engine speed with the gear ratio).
My question is, I showed a max torque of 158.8 ft-lbs of torque, and a max hp of 94. (i think the conversion that is programmed in to calculate hp is way off). Does that torque reading seem pretty accurate? Should it be higher/lower? I am kinda weary to how accurate the school's dyno really is.
Also I know to calculate HP it's hp = 2*pi*N*T So when measuring wheel horsepower is the N = to WHEEL SPEED? or is N = to ENGINE SPEED?
Any help is appreciated!
-Sean
Today i put it on a chassis dyno at school, and we were trouble shooting the dyno for a while and finally made a few runs. The way we have it set up it is measuring wheel speed and not engine speed so i don't have a plot right now. (will be making more runs tomorrow and will have a plot, after i convert to engine speed with the gear ratio).
My question is, I showed a max torque of 158.8 ft-lbs of torque, and a max hp of 94. (i think the conversion that is programmed in to calculate hp is way off). Does that torque reading seem pretty accurate? Should it be higher/lower? I am kinda weary to how accurate the school's dyno really is.
Also I know to calculate HP it's hp = 2*pi*N*T So when measuring wheel horsepower is the N = to WHEEL SPEED? or is N = to ENGINE SPEED?
Any help is appreciated!
-Sean
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Cool, thanks for the replies. I need to check into the software, because i know it was just overhauled last year. They are using labview (from national instruments) to gather the data from a pressure transducer they put on the the back wheel. (We ran it in 5th 4th and 3rd gear....with 3rd gear having the best results) We are putting it back on the dyno today at 10 mst.
I was gonna pay to go put it on a nice dyno at a tuning shop, but although my schools dyno is a lil ghetto, its also $0.00/hr.
It just seemed odd the combination of a high torque value with such a low hp value.
Am I safe to assume i am having no knock by listening and oil gauge alone? I know i should put in a knock sensor/wideband 02, but i won't be able to do that for a few weeks.
I was gonna pay to go put it on a nice dyno at a tuning shop, but although my schools dyno is a lil ghetto, its also $0.00/hr.
It just seemed odd the combination of a high torque value with such a low hp value.
Am I safe to assume i am having no knock by listening and oil gauge alone? I know i should put in a knock sensor/wideband 02, but i won't be able to do that for a few weeks.
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