Lightest tire to free up some horsepower for Dyno #s

Lowering the mass of the wheel, tire, rotor and or chain sprocket will only effect the rate of acceleration and skew the number on the dyno. Actual HP at the crankshaft has in no way increased or decreased.

 

(To quote Panther Bob)

Yuppers...

 

Guess That's a bet =) I will show Dyno graphs of his bike before and after when everything is finished.
When have you dynoed a bike at the crankshaft? We are talking about rear wheel HP Not at the crank. So I guess the charts will be the same then as before with the heavy stuff vs the light stuff????????? I think not guys but we will see =)

I reread what you have said But I will say this The hp at the crank is fixed unless more motor mods are given. But by doing such things it will free up real world HP at the tire and not only on the dyno.
Say his bikes makes 200 hp at the crank and the chain and so on takes 10% off of that to the rear wheel so he has 180 hp now with lighter parts at 200 hp at the crank it takes 5% that's 190 HP at the rear wheel do you guys get that?

 

Again that's just a skewing of the number....Horsepower at the crank has not changed....you're just reducing parasitic drag.

Apparently your reading comprehension skills need a little work. Yes the graph will change....however the motor is not making more horsepower...

If I shave 10 lbs of weight from the drum the tire is spinning I can make the graph look fantastic however the fact remains that the bike made the exact same amount of horsepower as before the weight was reduced.

 

I worked in a powertrain laboratory for a dozen years as a test engineer. Many times to the non-technical types I had to explain the concept of how an inertia dyno can be "gamed" from test to test by switching tires or to some extent testing in a different gear. Lots of people didn't "get it" and never will.

Critical testing always used the engine dyno lots more dough for testing unfortunately.

 

I understand that and so does he.But the fact is it will gain him rear wheel HP! I understand the fact of the crank HP will be the same. The point is simple he wants to make 200 rear wheel hp and let him get it any way he would Like. If you guys really want to be help put him in the direction of the hardest lightest rear wheel tire.

Answer this one most people get this wrong every time without a load are you even making HP?

 

I would tend to say no...your just pumping air...but then that's all a turbine engine is doing....my brain wants to say no.

 

...only because it's measured on an inertia dyno (completing your sentence).

No load, no torque, no power.... except noise & heat!

 

5min and a piece of graph paper and you can make a dyno sheet that says anything you want on it. Save you valuable dyno time and wear and tear on your motor.

 

Then you aren't paying him for his motor-building skills, you're paying him for his dyno operating skills.

You already seem to know that it will put more horsepower to the ground by lightening rotating hardware. So what's the point? (Other than having a chart that shows a bigger number.)

 

It's a Harley??

 

In other words, you want a big number to brag about. cool

Dynos are for charting improvements. Not making arbitrary numbers. Come back on a cooler day and you will make another couple HP. I don't really care about the numbers, I care about how they change when I make adjustments.

If you put on a lighter tire, you're not "freeing up" anything. You are just making a number that means diddly squat. As soon as you put back on the tire you will be using, the number disappears. If you want to go that way, spend some money on a magnesium wheel, drill it to the point of self destruction so that it will last one run, run a small bald tire ( pirelli is lighter than dunlop), use a 420 chain, drill your sprockets to swiss cheese, take the rear rotor off, weld the sprocket carrier to the wheel with tack welds and throw out the cushes, and you will "free up" ten more HP.

 

Why not just pump the tire up to 50psi?
Or better yet... use a shagged rear tire from a 1000cc race bike.
There should be enough rubber off the sides to make the tire as light as possible.

But its still a "farce". Id be more impressed if he showed me a timeslip with a 10.00 et and 160mph trap.

 

Who needs a tire.. Just Dyno it on the Rim like a Real Man!

 

Ok, that makes sense.

You do realize that after your done spending all that time tuning for your NEW setup, it will be worthless on the street or track.

 

Why use the rim? Just use the sprocket carrier and sprocket on the rear axle. Just make a custom spacer to keep it aligned.

 

Correct :up:

Anyways Let him do what he wants to do. He came on here asking a honest question. Anyways have fun guys iIm over the dumb Azz'z comments

 

And that is where I come inn. Say some fat fuck sucks the chrome off my peck her and oh my goo is all over she was the best! Not like that skinny won't swallow missionary matters what the fuck tire size!

You think that roller knows what weight is rolling on top of that tire? You catch that? Roll her over and over, I can't find any hole is flab beer gas dead.

What do you mean? This thread is peppered with valid info. You see those BMW's preset to that same HP number? Say it gets there faster with less weight. Have you change a thing yet but a tire? Did the HP change or did it reach that number a touch faster is a lighter bike down the track is faster, no? Same HP, same day. One change at 1320, no change on the roller is same day HP reached how much quicker? There is you 90% worth of I have no clue like the rest I guess is some guess. Shove the other 10% UP year azz you don't get it right.

Absolute your ass is grass is only one answer you do the math.

 

im going to do this.

 

LMAO.... Screw the sprocket just let the chain flap on that thing!!