Final Dyno Results for the Project Bike

[Big Mike]

Well as many of you may know I have been working on a supercharged Valk for a while now. I will be posting some pics soon, the tins are out being painted, the dragon scales are coming off. The dyno read out said that we were at 130.7hp dropping off at 6800 rpms. That is with me on the bike. Tuner says that should someone about 160lbs be riding  and a couple small adjustments, such as more air pressure in the rear tire, we could squeeze 140. Top speed on the dyno was 128mph in 4th gear. We did not do a 5th gear run. All I know is that it runs like a raped ape, whatever that is. I am pleased how it has turned out. I will not be doing another. the only mechanical issue I am still having is getting the digital display to work properly. The RPMs drop off to zero when I hit 4000. Can not figure it out. The bike runs just the display reads zero. I am not too worried about the bike because the rev limiter will shut it down, just good info to know when running hard so I can shift before the limiter kicks on.

[Sodbuster]

kinda gives ya goosebumbs .... good job !!

[designer]

I got to know, what does a 140hp valk cost?

[Big Mike]

It may be for sale after INZANE. I do know the asking price but I do have many thousands invested. About 8k just in chrome

[designer]

How much just in the supercharger?

[old2soon]

Ah what the heck-i'm on social insecurity=go ahead and build me two or three. Sounded good fer a fraction of a second or so. RIDE SAFE.

[Ferris Leets]

What difference would the rider's weight make to the Hp?  Sounds like BS to me.

[Big Mike]

A heavier person just like lower air pressure is going to cause more friction between the tire and the road, or in this case the dyno drum. More air pressure in the tire and a littler person will create less friction. Less friction and less wieght will spin the drum faster and more quickly, thus creating more HP.

About the cost for the charger, I lost count between 4-5k, and mine was used.

[old2soon]

What difference would the rider's weight make to the Hp?  Sounds like BS to me.

    H/p should remain as a constant. You take a lighter driver/rider in a given acceleration the lighter driver on equal machines should do better. This is by no means 100% accurate. Have seen it in a friends turbo charged pinto. The wife was about 105 pounds and the husband was around 280 pounds. She had lower E T all the time. In the same car. 175 pounds might not sound like much-but it takes a little more oomph to get it rollin. I'm done-flame on-i'll be sure to be holding some bratwurst-save money on the charcoal doncha know. RIDE SAFE.

[Ferris Leets]

A heavier person just like lower air pressure is going to cause more friction between the tire and the road, or in this case the dyno drum. More air pressure in the tire and a littler person will create less friction. Less friction and less wieght will spin the drum faster and more quickly, thus creating more HP.

About the cost for the charger, I lost count between 4-5k, and mine was used.

The horse power isn't changing just the readings.  Sounds likie a calibration issue to me.

[Big Mike]

Then why is it that the auto companies dyno and use the numbers when the engine is tested on a stand with nothing dragging the motor down? As soon as you hook up a/c, PS, a car body, and a person, the motor is not able to produce the same HP as it can when sitting in a stand. The same is true here. If not, then why dont they use the numbers they get from the completed product? It is because the numbers are lower and people want the hight HP number, even if it is somewhat fabricated.

[Ricky-D]

If the rating is taken at the crankshaft, it is usually reported as Shaft Horsepower.

Any accessory that is operated by the motor takes horsepower and depending upon where the rating is taken can result in lower figures.

This doesn't mean the motor is making less horsepower but simply the reporting method cannot adjust for all of the variables and can only report the final conclusion.

Motorcycles report horsepower as Rear Wheel Horsepower and is affected by all the operating systems on the bike as well as rider weight and tire pressure. Keeping the headlights off will increase the final figure.

***

[Momz]

Dynos do not measure HP.
Dynos measure torque; HP is a calculation based on torque/RPM.
Barometric pressure, ambient temp, and Dyno calibration and Dyno warm up are other factors in the final measurement.
If the Dyno does not have an exhaust  air/fuel mixture ratio monitor versus RPM, the results will not be accurate.

I've had quite a few years working with Dynos for engine performance, emissions, and "coast down" friction.

Good Luck Mike and I'm sorry to hear of the passing of your friend and Dyno Operator.

[Ferris Leets]

Simple physics.  Rear wheel horsepower on a dyno is a calculated number.  Has to be calibrated for tire size. pressure and a whole lot of things i know nothing about.  When I had mine done I did not notice the operator checking.  My stock  IS came out at 101 HP.  The chart has really sharp break offs because I told him to take it to the limiter.  Peak HP was about 5K.  I don't remember but I think the peak torque (99 ft lb)was about 5500.  I'll have to dig out the charts and put them on here.
   

[98valk]

A heavier person just like lower air pressure is going to cause more friction between the tire and the road, or in this case the dyno drum. More air pressure in the tire and a littler person will create less friction. Less friction and less wieght will spin the drum faster and more quickly, thus creating more HP.

About the cost for the charger, I lost count between 4-5k, and mine was used.

I've read over the yrs that low tire pressure and low weight on the rear tire in realtionship to how much power is being made will cause more tire slippage on the drum and lower the numbers.
a correctly inflated tire will give the best traction and a low inflation tire provides poor traction, same as riding on the street. low weight and the tire/bike start to ride up on the roller and the tire starts to skip/lose traction. This is what I 've read over the yrs from experienced dyno operators.

[Jeff K]

Weight of rider on a dyno has no affect on the numbers. But I think that HP number is low. It should be 140-145 with the newer kits. I always saw close to 140 on the older kits on bikes with stock pipes.

[98valk]

Weight of rider on a dyno has no affect on the numbers. But I think that HP number is low. It should be 140-145 with the newer kits. I always saw close to 140 on the older kits on bikes with stock pipes.

higher HP bikes like the busas' it does. there are numerous runs out there where more HP was made with an addtional person sitting on the bike. I tend to remember that even some higher HP cars and trucks are having the body straped down to increase traction. this is all over the websites.

[Jeff K]

Weight of rider on a dyno has no affect on the numbers. But I think that HP number is low. It should be 140-145 with the newer kits. I always saw close to 140 on the older kits on bikes with stock pipes.

higher HP bikes like the busas' it does. there are numerous runs out there where more HP was made with an addtional person sitting on the bike. I tend to remember that even some higher HP cars and trucks are having the body straped down to increase traction. this is all over the websites.

Now you are talking weight vs traction. Strap the Valk down right and there shouldn't be any traction issues. I've made a lot more than 130 hp on a dyno with a 160# rider.

[TJ]

Weight of rider on a dyno has no affect on the numbers. But I think that HP number is low. It should be 140-145 with the newer kits. I always saw close to 140 on the older kits on bikes with stock pipes.

higher HP bikes like the busas' it does. there are numerous runs out there where more HP was made with an addtional person sitting on the bike. I tend to remember that even some higher HP cars and trucks are having the body straped down to increase traction. this is all over the websites.

Now you are talking weight vs traction. Strap the Valk down right and there shouldn't be any traction issues. I've made a lot more than 130 hp on a dyno with a 160# rider.

When did you get so skinny???  lol

[Jeff K]

Weight of rider on a dyno has no affect on the numbers. But I think that HP number is low. It should be 140-145 with the newer kits. I always saw close to 140 on the older kits on bikes with stock pipes.

higher HP bikes like the busas' it does. there are numerous runs out there where more HP was made with an addtional person sitting on the bike. I tend to remember that even some higher HP cars and trucks are having the body straped down to increase traction. this is all over the websites.

Now you are talking weight vs traction. Strap the Valk down right and there shouldn't be any traction issues. I've made a lot more than 130 hp on a dyno with a 160# rider.

When did you get so skinny???  lol

Kevin was on the bike, not me.

[Hoser]

Here is a dyno run on a good running stock tourer, the curve should be similar, higher or lower totals according to state of tune and/or degree of modifications.  Hoser

[Jeff K]

TJ's Dyno sheet

[F7daved]

I also think another thing some of you are missing is the dyno operator, and the dyno quality like brand name. Ive had quite a few snowmobiles, dirt bikes, street bikes and go karts dynoed, and let me tell you the difference is in the $'s that dyno cost, and  the operator's time behind it. My friend spent huge money on his Harley motor and  had it dynoed at the dealer where they had a dyno jet. My buddy wasn't happy with the #'s so we went to dyno jim in NY where he has a nascar super flow and what a difference. So even mikes numbers might be low for some, ill bet on a real dyno like the super flow the #'s would be different. Just my 2cents

[Imohtep]

One with Magnacharger 1gen, with Cobra 6x6.
About 85% of power out, because it goes too lean (working on that...>there's going to be two
Mikuni HSR 45 carburators in future).

ATTENTION! hp's and Nm's from backwheel...