Dyno!

[Baddie]

Hello legends,
I’ve just finished watching a YouTube video on a 2010, 2011 kawa against a 2010 BMW stock.

After watch you will see that the bmw wins with 167.3hp. (Maybe because the 2011 Kawa rev limiter kicks in at 13,500 rpm??????)

http://www.youtube.com/watch?v=vL9eV7NMd_s

What I’d like to know is where do they get 200+hp in the advertising for the 2011 Zx10r?

http://www.youtube.com/watch?v=u8XyejmN ... re=related

And also a mate is telling me his 08 R1 has 170.8 hp with a race air filter and Pc3 is this possible with these two items attached ?.

[Wattie]

200Hp with ram air.

every dyno is different.

At FX my stock 06 gumby had 159hp, when the cbr's all had 155 with mods.

[Six Addict]

also crank and flywheel, and calibration of the dyno...

[Baddie]

Ok..this might seem a silly question but "Ram Air" .Can someone explain?

[Wattie]

oh dear....


when your bike is doing 200kmh+ the air is rammed into the airbox faster than the engine can suck it in, acting like a turbo so to speak.

a dyno cant replicate that.

[Blurr]

Do you know anything at all about the bike you bought. Try read at least one spec review.

As Wattie said

[dutchy]

a dyno cant replicate that.

Now I can't help but wonder if anyone has ever attempted a dyno run in a wind tunnel. The mind boggles!!
I wonder how the figures would differ for all the big bikes.

[Wattie]

i would imagine Kawsaki would have, hence being able to quote the figures with ram air.

[Baddie]

Do you know anything at all about the bike you bought. Try read at least one spec review.

As Wattie said

I’d like a dollar for every Web page and forum on Zx10r I’ve read over the past few weeks.

Nothing about Ram Air here..
http://www.bikez.com/motorcycles/kawasa ... r_2010.php

This one mentions RAM Air..but doesnt explain what it is and how it works.

http://www.topspeed.com/motorcycles/mot ... 80090.html

I have to say I’m not right into the Technical specification of my bike and I’m guess you don’t need to be a rocket scientist to know all about the Zx10.

I was just wondering where did Kawasaki get there information from. (ie 200+ HP)

If I’m not correct the question was more about Ram Air and not my bike specification.

This is the type if information I was looking for ?".(Which wattie Explained very well "when your bike is doing 200kmh+ the air is rammed into the airbox faster than the engine can suck it in, acting like a turbo so to speak.") cheers thanks for that

Maybe I should have asked a more direct question, like "How does RAM AIR effect a motorcycle?".

Here is the Technical meaning for RAM Air;
A ram-air intake is any intake design which uses the dynamic air pressure created by vehicle motion to increase the static air pressure inside of the intake manifold on an engine, thus allowing a greater massflow through the engine and hence increasing engine power.
The ram air intake works by reducing the intake air velocity by increasing the cross sectional area of the intake ducting. When gas velocity goes down the dynamic pressure is reduced while the static pressure is increased. The increased static pressure in the plenum chamber has a positive effect on engine power, both because of the pressure itself and the increased air density this higher pressure gives.
Ram-air systems are used on high performance vehicles, most often on motorcycles and race cars. Ram-air has been a feature on some cars since the late sixties, but fell out of favor in the seventies, and has only recently made a comeback. Modern parachutes use a ram-air system to pressurize a series of cells to provide the aerofoil shape.
At low speeds (subsonic speeds) increases in static pressure are however limited to a few percent. Given that the air velocity is reduced to zero without losses the pressure increase can be calculated according. The lack of losses also means without heating the air. Thus a ram-air intake also is a cold air intake. In some cars the intake is placed behind the radiator, where not only the air is hot, but the pressure is below ambient pressure. The ram-air intake effect may be small, but so are other mild tuning techniques to increase cylinder filling like using larger, fresh air filters, high flow mass flow sensors, velocity stacks, tuned air box and large tubes from the filter to the engine.

Cheers.

[olcoop]

I think manufacturers quote hp figures at the flywheel. I would think that they mount the motor directly to the dyno without the gear box and drivechain etc. They also probably pressurise the airbox to simulate the RAM Air effect. Of course a bike dyno check is done at the back wheel so all drive train losses are evident.

[Kawawog]

I think manufacturers quote hp figures at the flywheel. I would think that they mount the motor directly to the dyno without the gear box and drivechain etc. They also probably pressurise the airbox to simulate the RAM Air effect. Of course a bike dyno check is done at the back wheel so all drive train losses are evident.

Ive always asumed this aswell with manufacturers figures, unless rwhp was stated..

[s man]

All HP figures are quoted at the crank. The figures you are seeing are rear wheel HP,the power that is being put down on the road. IMO that is all you need worry about.
On [rule of thumb] the bike will loose around 25+
hp in driveline/altenator/tyre pressure, losses. Remember [rule of thumb] As has been memtioned "dyno's aint dyno's" they are a tuning tool only. If you start with
"x" hp & after your mods you end up with "x" hp. It will tell you, you have a net gain or loss of "x"hp. Dont get bogged down in my bike only has "x" on the dyno, & it should have "x". It means nothing.. Hope that helps?