HP question.... street vs cruiser

[FootNote]

A buddy of mine is going to pick up a 2008 Ninja zx10.

The question I have is, Does this bike have as much power as he thinks it does? He is talking 160-180hp (forgot exactly) when I am going to be spending a decent amount of money to get over 120 HP on my vmax.

Now I know street bikes and crusers are tuned diffrently but is there THAT big of a diffrence?


Also as a secondary question, what is the diffrence between engine HP and RWHP?

Thanks.

Ignorently yours,
Michael

 

[RaWarrior]

Re: HP question.... street vs cruser

Engine HP is measured at the crank, before transmission and driveline. Yamaha's claim of 145hp in the Vmax is "at the crank". Stock rear-wheel HP(rwhp) is around 115....those 30hp vanish mainly through the two 90* turns in a shaft drive system, with some losses through the transmission. That's why shaft drives are kind of fading away....everything uses belt or chain now, they're far more efficient drive systems

Sportbikes lose much less power through drive. Example...a S1000rr is around 200 at the crank, and dyno's at 192-193 at the tire.

So even if he has 160hp(crank), he's going to put virtually all of that to the tire. Where your vmax (unless you do a chain drive conversion), will always lose a good 20% to it's shaft drive.

So no, there isn't that much difference in "tune" between a sportbike and say the Vmax motor. Both are high compression, DOHC, and for a 25 year old engine making 145hp, that's pretty good. But add the drivelines in, and it's where the Max loses out.

However straight cruiser motors are made for torque. Most still use pushrods, don't have tons of compression, and due to their size can only spin to 6 or 7k RPM. So a 1900cc cruiser v-twin might only wheeze out 100hp at the crank while a 600cc sportbike will put out 110...that's a difference of tune.

So your buddy with the ZX10 it going to serve your ass to you. Not only does he make more power, he puts a higher percentage of it to the ground. Plus, he'll have a substantial weight advantage also.

 

[Jack Butler]

Re: HP question.... street vs cruser

Here's your ZX-10R specs...

http://www.mcnews.com/mcn/technical/200801perfindex.pdf

With a little work his numbers should be close.

 

[FootNote]

Re: HP question.... street vs cruser

Engine HP is measured at the crank, before transmission and driveline. Yamaha's claim of 145hp in the Vmax is "at the crank". Stock rear-wheel HP(rwhp) is around 115....those 30hp vanish mainly through the two 90* turns in a shaft drive system, with some losses through the transmission. That's why shaft drives are kind of fading away....everything uses belt or chain now, they're far more efficient drive systems

Sportbikes lose much less power through drive. Example...a S1000rr is around 200 at the crank, and dyno's at 192-193 at the tire.

So even if he has 160hp(crank), he's going to put virtually all of that to the tire. Where your vmax (unless you do a chain drive conversion), will always lose a good 20% to it's shaft drive.

So no, there isn't that much difference in "tune" between a sportbike and say the Vmax motor. Both are high compression, DOHC, and for a 25 year old engine making 145hp, that's pretty good. But add the drivelines in, and it's where the Max loses out.

However straight cruiser motors are made for torque. Most still use pushrods, don't have tons of compression, and due to their size can only spin to 6 or 7k RPM. So a 1900cc cruiser v-twin might only wheeze out 100hp at the crank while a 600cc sportbike will put out 110...that's a difference of tune.

So your buddy with the ZX10 it going to serve your ass to you. Not only does he make more power, he puts a higher percentage of it to the ground. Plus, he'll have a substantial weight advantage also.

Thanks for explaining it... and explaining it in a way I can understand lol

Trust me I know he would hand me my ass, no doubt about that. I was just kind of shocked those sports bikes are that much more powerfull than vmaxes.

 

[FootNote]

Re: HP question.... street vs cruser

Here's your ZX-10R specs...

http://www.mcnews.com/mcn/technical/200801perfindex.pdf

With a little work his numbers should be close.

Yeah I was just surprized because there was such a big gap between the two.

 

[MaxMidnight]

Re: HP question.... street vs cruser

Your best chance is to nail it off the line as you should be able to launch harder.
The ZX10 will try to pull a wheelie so he won't be able to put all of the available power down.

Gun it in first and second then roll off and look smug when you stop! h yeah:

 

[acammer]

Re: HP question.... street vs cruser

Your best chance is to nail it off the line as you should be able to launch harder.
The ZX10 will try to pull a wheelie so he won't be able to put all of the available power down.

Gun it in first and second then roll off and look smug when you stop! h yeah:

Agreed... he'll hand it to you, from 60mph roll. From a stop is where the Max shines, street racing demon if there ever was. If you lose to a liter bike or 600 from a stop up thru the first 2 gears, you have nobody to blame but yourself.

 

[SpecOps13]

I can run a buddies R1 and scare him with low gear acceleration through 2nd gear. Then he wipes my butt the rest of the way up and has a top speed that I can only dream about... Kill him in the lower gears then drop off like you're finished. Tell him you figured he didn't have a chance so you shut down.. You'll drive him nuts for a few seconds anyway...:rofl_200:

 

[acammer]

I can run a buddies R1 and scare him with low gear acceleration through 2nd gear. Then he wipes my butt the rest of the way up and has a top speed that I can only dream about... Kill him in the lower gears then drop off like you're finished. Tell him you figured he didn't have a chance so you shut down.. You'll drive him nuts for a few seconds anyway...:rofl_200:

There are several local gentleman sportbikers in my little city that are afraid of Mr. Max and won't race him anymore, due to exactly what SpecOps describes. The Max really has a natural talent to leave the line hard and stronger than almost anything, certainly anything that isn't launched perfectly. A good quick 1-2 shift will keep this pull going strong, when guys see the launch, then the shift light and the wheelie on my 1-2 shift (I'm usually more than a few lengths ahead) they think they are just going to keep getting yanked and they give up. There is a stretched 'Busa I see all the time that refuses to run me anymore, I embarrassed him in front of his buddies once, and that was enough. Once these guys figure out they can crush me in the upper gears, they are all gonna want 60mph roll ons.