A Torque Curve for Every Purpose | GTAMotorcycle.com

A Torque Curve for Every Purpose

That's a great article. It takes a lot of time and effort to tune part-throttle driveability, and that's not even accounting for what's needed for emission control.
 
this was the best torque curve ever on an inline 1000, just sayin. pump gas
kit vs stock 2.0.jpg
 
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Graphics would have helped.

I keep it simple, just go by displacement and engine configuration will give you a good idea
 
bigpoppa said:
Graphics would have helped.

I keep it simple, just go by displacement and engine configuration will give you a good idea
Click to expand...
Sort of but many companies have the same engine size and configuration with vastly different tuning in various bikes (for instance Aprilia, Ducati, etc with their big sport bike motors in adv bikes at 1/2 to 2/3 of the hp).
 
Dyno sheet for a TZ350
dyno_tz350_john_storrie.jpg



The other end of the scale
ss-fe-ie-dyno-feb-2020-jpg.996093

A Ducati 900SS (Yeah this is an EFI bike, couldn't find a carb one, they're ABOUT the same)

Notice the difference?
Those two bike will lap Mosport at about the same lap time... IF you know how to ride them.
The Ducati is insanely easy to ride, while the TZ is trying to kill you most of the time
 
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I suppose theoretically as tq and hp are the same at 5252 rpm it could be accurate and coincidentally there was a dip in hp at that point 🤷‍♂️


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SVeezy said:
I suppose theoretically as tq and hp are the same at 5252 rpm it could be accurate and coincidentally there was a dip in hp at that point 🤷‍♂️


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Click to expand...
Nope. HP has to be higher than torque after 5252 (and has to be lower than torque below 5252). The torque curve continues to fall, the hp curve is rising. The plotting software (or data set) has an error in it. The lines should make an X not two V's.

H = T x rpm/5252

There's also no scale for torque although it appears to be the same scale as HP in this case.
 
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GreyGhost said:
Nope. HP has to be higher than torque after 5252 (and has to be lower than torque below 5252). The torque curve continues to fall, the hp curve is rising. The plotting software (or data set) has an error in it. The lines should make an X not two V's.

H = T x rpm/5252

There's also no scale for torque although it appears to be the same scale as HP in this case.
Click to expand...
That would depend on the ignition timing and when the rev limiter kicks in.
As this is a low HP, reasonably high torque motor its entirely possible its programmed this way.
 
TK4 said:
That would depend on the ignition timing and when the rev limiter kicks in.
As this is a low HP, reasonably high torque motor its entirely possible its programmed this way.
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No it doesnt. It depends on math.
 
Using the "USUAL" formula to calculate horse power, the torque line and the horsepower line on a graph will ALWAYS cross or meet at 5252 RPM
www.motorauthority.com

Why do horsepower and torque cross at 5,252 rpm?

We've talked in the past about the relationship between horsepower and torque. They work together, and horsepower needs torque to make you and your car happy. There's one magic number though that doesn't get much ink spilled its way, virtual or otherwise. The number is 5,252, and it's the point...
www.motorauthority.com www.motorauthority.com

...it's because torque is scientific measure of circular force, while "horse power" is a number made up to sell steam engines to stupid farmers (and they were getting ripped off. a GOOD draught horse can approach 40 horse power)

I think the issue here is that on the graph of the Meteor 350, the lines switch colour at 5252 rpm.
 
GreyGhost said:
Nope. HP has to be higher than torque after 5252 (and has to be lower than torque below 5252). The torque curve continues to fall, the hp curve is rising. The plotting software (or data set) has an error in it. The lines should make an X not two V's.

H = T x rpm/5252

There's also no scale for torque although it appears to be the same scale as HP in this case.
Click to expand...

Point taken and valid, I suspect the hp curve is incorrectly transposed with the tq curve below 5252


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GreyGhost said:
Um. . . Notice anything wrong with this plot?
Click to expand...
It says max power at 6,070, but the power line has fallen on the graph at that point, so they changed the colours when they crossed.
 
eiyNSgx.jpg

There I fixed it
 
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