Massive Torque

[tinbender0]

Just as I suspected JC, so if a harley had a busa size sprocket. Obviously they would produce less torque as specified ?Is this a correct assumption?

 

[Johnnycheese]

no you have it wrong
I will have to did you some Harley I tuned and you will see what I mean.

 

[tinbender0]

 

[Spike]

For anyone who cares. Horsepower is a calculation. Here is the formula.

Horsepower = ( Torque * RPM ) /5252

 

[Mr Brown]

(Spike @ Oct. 19 2006,18:51) For anyone who cares.  Horsepower is a calculation.  Here is the formula.

                        Horsepower      =            ( Torque * RPM ) /5252

Thank you, I had forgotten the exact numbers.

 

[Johnnycheese]

as you see the torque doesn't go up and then down like a busa
this is a VTX1800 the dual mapping is the differance between one map for both cyl. and a seperate map for each cyl.
just another nice feature on the pc3usb

 

[tinbender0]

ok, so the torque readings on the dyno chart would be the same no matter what gearing/sprockets you have for that bike?

 

[Johnnycheese]

(tinbender0 @ Oct. 19 2006,21:14) ok, so the torque readings on the dyno chart would be the same no matter what gearing/sprockets you have for that bike?

no they would be within + or - 5
but the curve would be the same.
look at the graph you are missing the point.
at 2K this bike has 90# of torque and it doesn't go under that. look at a Busa and see what it is.

 

[xzvs]

My buddy has a harley and said -- ya , I bet you dont have 74 ftlbs of torque stock
I said -- nope sure dont
Big grin from Harley guy
..... I have closer to 100
Grin gone

 

[Mr Brown]

(Johnnycheese @ Oct. 19 2006,21:54)

(tinbender0 @ Oct. 19 2006,21:14) ok, so the torque readings on the dyno chart would be the same no matter what gearing/sprockets you have for that bike?

no they would be within + or - 5
but the curve would be the same.
look at the graph you are missing the point.
at 2K this bike has 90# of torque and it doesn't go under that. look at a Busa and see what it is.

Why doesn't the tq curve fall off like it does on a Busa? Would it fall if the rpm's kept climbing?

 

[TheAtomicAss]

(Mr Brown @ Oct. 19 2006,16:58) But the torque applied (Wheel) is still an application of the torque available (Crank) right? If you put a sprocket four miles in diameter on the back of a bike, it will still only have as much force pushing the sprocket as it does with a tiny one, right?

The sprockets are that large out of necessity. Belts don't like taking the sharp corners that chains typically do around the front sprocket. And if you make the front sprocket larger to alleviate the turning angle for the belt, you have to adjust the rear sprocket to keep the gear ratio in the same general area.

But all thing being equal, as you adjust one sprocket, it adjusts the multiplication of the torque applied to the wheel. 100ft/lbs is impressive at the crank, but not the wheel. My Ninja 250 makes 12ft/lbs peak, but puts down almost 250ft/lbs peak at the wheel, in first gear, due entirely to gearing.

 

[frisbee]

I got 137!!

But then again .... I got NOS!!

 

[TheAtomicAss]

(Johnnycheese @ Oct. 19 2006,18:08) and you have to look at curve. any Vtwin is a long flat line (hardly no curve)
so the torque is low and constant

Why is that, anyway? I can't understand why a V makes a torque line, but inlines make a curve. My Ninja 250 makes a curve, despite being a twin. (inline)

And what do singles typically make? I've never seen a dyno for one.

 

[tinbender0]

(Johnnycheese @ Oct. 19 2006,19:54)

(tinbender0 @ Oct. 19 2006,21:14) ok, so the torque readings on the dyno chart would be the same no matter what gearing/sprockets you have for that bike?

no they would be within + or - 5
but the curve would be the same.
look at the graph you are missing the point.
at 2K this bike has 90# of torque and it doesn't go under that. look at a Busa and see what it is.

can't tell rpm's on my dyno chart but i see what you mean ....curve starts about 60 goes to about 95 mid way and gradually starts to come down till i guess redline,, back to where it started

 

[Russ Schaeffer]

OK guys, maybe I can help. Lets hope. Torque is a momentary force that is applied to rotate something about an axis.  Think of a socket and ratchet with a 12 inch handle, put that on the end of the crankshaft.  If you hung a 100 lb weight on the end of this 12 inch ratchet you would have 100 ft lbs of torque. The younger guys call it 100 lb/feet.  
The Dyno-Jet dyno is an inertial type, it measures how long it takes to accelerate a known weight and makes the torque calculation from that.  Horsepower is a calculation using torque and rpm, always crossing at 5252 rpm  (550 ft/lbs per second).
Gearing does not matter in the calculation of torque on an engine dyno.

Thanx,
Russ

 

[tinbender0]

But as we know a larger rear sprocket accelerates faster than a smaller one,,,10-4 and a smaller on enables you to go faster top end,,,BUT you're saying the final answer is that no matter what gearing there is!! THE DYNO knows the difference by mathmatical equations from the tire speed and rpm....and that if we dynoed the same bike over and over with all combinations of gearing the end result will be the same torque reading....

dang,,,, I hope this is the right assumption now