HP vs. TQ
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Elite HDF Member
Joined: Sep 2007
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From: Nuevo México, Los Estados Unidos de América
HP vs. TQ
Sorry for the silly question, but here it goes:
Let's say you have your bike dynod such that it has a higher peak tq than hp. Say pretty close to peak tq between 2.5k and 4.5k. Then it drops back down to the cross over at 5.2k or whatever it's at. Then the HP curve increases again to peak at 5.5. Should I just be riding the TQ curve? shifting around 4k?
What if my peak hp and peak tq were basically the same? Which one do I want to ride?
With my canned stage I I was riding the high RPMs much more than I am now. My hp would increase to rev limit, and I felt it pulling more up high. Now that's changed.
Really I'm just trying to get a sense of what to do with/how to read Dyno numbers. At what point do you decide to ride the hp vs. tq numbers? If the tq is higher does that mean always shift before the crossover? Only in the lower gears? Once into 3rd or 4th ride the hp curve? How does tq versus hp at a given rpm translate into acceleration/seat of your pants feeling?
Thanks
Let's say you have your bike dynod such that it has a higher peak tq than hp. Say pretty close to peak tq between 2.5k and 4.5k. Then it drops back down to the cross over at 5.2k or whatever it's at. Then the HP curve increases again to peak at 5.5. Should I just be riding the TQ curve? shifting around 4k?
What if my peak hp and peak tq were basically the same? Which one do I want to ride?
With my canned stage I I was riding the high RPMs much more than I am now. My hp would increase to rev limit, and I felt it pulling more up high. Now that's changed.
Really I'm just trying to get a sense of what to do with/how to read Dyno numbers. At what point do you decide to ride the hp vs. tq numbers? If the tq is higher does that mean always shift before the crossover? Only in the lower gears? Once into 3rd or 4th ride the hp curve? How does tq versus hp at a given rpm translate into acceleration/seat of your pants feeling?
Thanks
Banned
Joined: Jul 2005
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From:
RE: Where to Shift HP vs. TQ
ORIGINAL: Herr Monk
Sorry for the silly question, but here it goes:
Let's say you have your bike dynod such that it has a higher peak tq than hp. Say pretty close to peak tq between 2.5k and 4.5k. Then it drops back down to the cross over at 5.2k or whatever it's at. Then the HP curve increases again to peak at 5.5. Should I just be riding the TQ curve? shfiting around 4k?
What if my peak hp and peak tq were basically the same? Which one do I want to ride?
With my canned stage I I was riding the high RPMs much more than I am now. My hp would increase to rev limit, and I felt it pulling more up high. Now that's changed.
Really I'm just trying to get a sense of what to do with/how to read Dyno numbers. At what point do you decide to ride the hp vs. tq numbers? If the tq is higher does that mean always shift before the crossover? Only in the lower gears? Once into 3rd or 4th ride the hp curve?
Thanks
Sorry for the silly question, but here it goes:
Let's say you have your bike dynod such that it has a higher peak tq than hp. Say pretty close to peak tq between 2.5k and 4.5k. Then it drops back down to the cross over at 5.2k or whatever it's at. Then the HP curve increases again to peak at 5.5. Should I just be riding the TQ curve? shfiting around 4k?
What if my peak hp and peak tq were basically the same? Which one do I want to ride?
With my canned stage I I was riding the high RPMs much more than I am now. My hp would increase to rev limit, and I felt it pulling more up high. Now that's changed.
Really I'm just trying to get a sense of what to do with/how to read Dyno numbers. At what point do you decide to ride the hp vs. tq numbers? If the tq is higher does that mean always shift before the crossover? Only in the lower gears? Once into 3rd or 4th ride the hp curve?
Thanks
if you consistently ride on the tq/hp peak some day you will miss a shift and that can get expensive sometimes.
Road Warrior
Joined: Feb 2007
Posts: 1,372
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From: pinchatooly
RE: HP vs. TQ
On the street ,,,,,tq. will always feel better...The tq.@ the rear wheel is what you translate to that stump pulling feel..H.P.works when you are matched with that sport bike and plain and simple want to be able to run 125 m.p.h and then kick it in ***..It's a lot of $$$$$$$$$ to get the both to be there all the time.. Bottom line ,,,, lots of $$$$$$$$$$ will get the real answer!
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Elite HDF Member
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From: Nuevo México, Los Estados Unidos de América
RE: Where to Shift HP vs. TQ
...sure...
but if you're shifting when you feel "it's done" then you've already lost seconds in feeling it.
There ought to be a fairly straight forward answer to this queston. Alghough I guess it's a little weird because race bikes produce far more hp than torque, generally with a steady increase until redline, or close, so there is not that much to think about. But since us big V-Twin riders tend to tune for low-end torque, seems there's a little more to think about. Sure, I could ride 'till I feel like shifting, but if I could shift sooner to more power, that would make sense. But I also still imagine at some speed those hp numbers become more valueble. While pulling out of a light I feel allot of power between 2.5 and 3.5k range, at 60mph I need to be in the 4k+range (even though I know I producing less tq in that range) to "feel" it powering forward.
So where's our straight-forward answer?
but if you're shifting when you feel "it's done" then you've already lost seconds in feeling it.
There ought to be a fairly straight forward answer to this queston. Alghough I guess it's a little weird because race bikes produce far more hp than torque, generally with a steady increase until redline, or close, so there is not that much to think about. But since us big V-Twin riders tend to tune for low-end torque, seems there's a little more to think about. Sure, I could ride 'till I feel like shifting, but if I could shift sooner to more power, that would make sense. But I also still imagine at some speed those hp numbers become more valueble. While pulling out of a light I feel allot of power between 2.5 and 3.5k range, at 60mph I need to be in the 4k+range (even though I know I producing less tq in that range) to "feel" it powering forward.
So where's our straight-forward answer?
Road Captain
Joined: Jan 2006
Posts: 566
Likes: 3
From:
RE: Where to Shift HP vs. TQ
You want to maximize your horsepower in order to get the most performance out of your bike. It's almost always best to shift at high rpm close to your peak HP. If you shift at your peak TQ you will lose lots of acceleration.
Below is an article that you probably will find interesting. Look especially at the shift point charts where it's clear that shifting at peak TQ makes you lose lots of driving force.
http://www.sportrider.com/tech/146_0402_art/index.html
Below is an article that you probably will find interesting. Look especially at the shift point charts where it's clear that shifting at peak TQ makes you lose lots of driving force.
http://www.sportrider.com/tech/146_0402_art/index.html
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Elite HDF Member
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From: Nuevo México, Los Estados Unidos de América
RE: Where to Shift HP vs. TQ
I'll figure out my numbers according to that article. But it sounds like if you are getting that lurch we all love when you shift, you should have shifted sooner.
Road Warrior
Joined: Feb 2007
Posts: 1,372
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From: pinchatooly
RE: Where to Shift HP vs. TQ
Dude >>>>>>>>>>>>&g t;>>>>>>>>> H.P. IS NOT SOMETHING YOU NEED TO ,,,, NEED,,,Untill you need to go warp speeeeeeeed!!!! Allround street you need tq. H.P is good for more ,,when you need to go warp speed..Not when you need to be conserened with when to shift..When you satrt to build H.P. then your talkin [sm=nxsmile.gif]And a whole bunch of $$$ BLING. T.Q. FOR THE STREET!!!!
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Thread Starter
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Elite HDF Member
Joined: Sep 2007
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From: Nuevo México, Los Estados Unidos de América
RE: Where to Shift HP vs. TQ
I can't find all the info I need for to calc my drive power at rear wheel... but in my driving experiance I have found that in the lower gears I get more punch shifting early, and later on rev it higher... maybe it's in my head...
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From: South of Dallas Area, Texas
RE: HP vs. TQ
Use the butt dyno.
The bike will tell you when and where to shift.
You should be able to feel it. Dont dwell on the numbers.
Sounds weird but it really works.
I hit the rev limiter on my Fatboy once by accident and once more just to see for sure it was the limiter.
Havent hit it since, and I dont have a tach on it.
MikeM
The bike will tell you when and where to shift.
You should be able to feel it. Dont dwell on the numbers.
Sounds weird but it really works.
I hit the rev limiter on my Fatboy once by accident and once more just to see for sure it was the limiter.
Havent hit it since, and I dont have a tach on it.
MikeM
