Does torque at RPM matter at less than WFO?

[taxonomy]

So, I am ridin' around with the aftermarket pipe that came on my used bike. Let's say, for arguement, it has a 5% gain in torque across the rev range.

Does addtional torque matter at less than WFO throttle? If I am at part throttle does the pipe matter at all? My bike may "make" 50ftlbs at 7000 RPM but it only does that with the throttle wide open. This is how dyno runs are done right, WFO?

It's not automatically making 50ftlbs just becuse the engine is spinning at 7000 RPMs. In fact, with a closed throttle it is consuming HP and torque via friction loss.

Now for the kicker. You should only seek addtional HP if you are twisting the throttle to the stop. This should be the "I could use the pipe" indicator. If you are twisitng the throttle to the stop you could use the HP. If you are not twisting to the stop you do not need a pipe. You are not useing the HP you have.

If you accept the above fact, the only reason besides looks sound and wieight, that you should put a pipe or a Power Commander on your bike is you ride with the throttle WFO. When you get WFO, get a pipe (or a diffrent bike)

There may be a flaw in the reasoning. I would be more than happy to have it pointed out. Just something I thought about when riding around with the loudish pipe that came with my used bike.

Adam

[Wishbone]

I think your nuts.

I have effectivly gained 15-20 rwh to my bike (I didn't dyno it before just the rwh numbers from online)and you sure as hell can feel it threw the entire throttle and and RPM range.

[taxonomy]

I think your nuts.

I have effectivly gained 15-20 rwh to my bike (I didn't dyno it before just the rwh numbers from online)and you sure as hell can feel it threw the entire throttle and and RPM range.

You can feel it across the whole throttle range (maybe) and you can feel it across the whole RPM range assuming the throttle is WFO. If you consider the variables in isolation it does not make sense, you must consider throttle opening and RPM.

Also, you may be able to feel it:

but that does not mean you are using it in a meaningful way.
but that does not make it good.

Unless you are using the available existing torque additional torque should not matter. The only way the "extra" torque will come into play is when you have used existing torque at RPM. That is, you have opened the throttle more. In ranges below over rev this would equate to WFO. Gains in torque from a pipe at less than WFO could be compensated for greater throttle opening. I am also not prepared to concede that part throttle openings would be better with a pipe without seeing it mapped at part throttle.

It's more important to consider torque than HP for this to make sense, I think.

Consider HP as the volume in a box and riding ability as objects put into the box. I don't need and can't use a bigger box until I have filled this box to the point I can no longer add additional objects. It matters not at all that I have made the house as big as a house if I cannot fill a shoe box.

I can see the box is bigger (or in this case "feel" the additional HP/torque) but I cannot use the extra volume in the box.

[butcher bergs]

WTF is this... the Scientist Forum?


Generally speaking, power mods increase power at all RPM's and all throttle inputs.

What I mean is there's a good chance you are making more power with less input from the throttle throughout the RPM range.

For example:

If you were making 100 hp at 50% throttle up to redline in stock trim, after you add some mods, you're probably now making, say, 110 hp at 50% throttle up to redline.

EDIT:

Another example:

On the dyno, let's say you were making 100 hp at 7K (WOT)

After some mods, the point at which you make that same 100 hp is now lower in the rev range....maybe now it's at 6K

[Evil_Weasel]

your theory is flawed. you left out steady throttle cruising...the exact sort of time an increase of torque would be useful especially if you wanted to roll on and pass a truck. with more torque across the rev range you would need less throttle imput to pass the truck in the same amount of tme (or faster). torque is the reason a ZX-12 never has to down shift out of sixth and a 600 does when trying to pass said truck in the same amount of time. WFO throttle has nothing to do with it. if that was the case everyone would run drag pipes.

unless the throttle is closed and the engine is in deceleration your bike will make 50 hp even if you hold the throttle steady at 7000 RPM.

more torque across the rev range is a good thing...ask any v-twin owner

[ChR1s]

Adam, shut up and ride already. And I mean that in the most liberal sense.

http://vettenet.org/torquehp.html

[seth399]

basically no mod is going to provide a linear increase across the RPM range. A header/exhaust might improve lowend/torque alot and some top end, or a ton of top end (might even lose some low end).

[butcher bergs]

basically no single mod is going to provide a linear increase across the RPM range.

Fixed.

Mods that compliment eachoth...........awww forget this shit!

Ride more worry less!

[seth399]

ahha agreed, I was assuming "single mod" in my reply...and to answer the orignal poster, no it does not only matter WFO

[Nix]

I'm gonna have to confiscate all of your "purple stuff" immediately...it's a matter of New England security.

[KB]

Dude guy, there is no replacement for displacement...........well maybe except BOOST!!!

KB

[butcher bergs]

Boost is addiciting.

[Bandit12k]

Boosted Bandit coming soon. Can't wait.


And my $.02 .... you don't always get more power in Off Throttle situations with any single mod.

For example, by putting a GSXR intake cam in my bandit engine, i gain hp and torque on top end, but loose torque and hp on the low and midrange. Better for revving, but looses the Grunt and Brute force of the 1200's trademark powerband.

Some exhausts do the same. Some low end power rely's on back pressure. On high end, you want a more free-flowing exhaust. This is another reason for the exhaust valves like on the GSXR's. They close up during low speed/rpm and open up top. They also help out for noise too.

[taxonomy]

I think this is my point, kind of, if you are not using the full potential of the bike adding toque will not have any impact. It's just more stuff you are not using.

When I had my CB1 I often rode the bike with the throttle against the stop. I could exit corners with the throttle pinned.

In that case, put me on a new bike and I would go faster.

I think in most cases people are using less than the available torque a stock bike would produce at any given moment. The additional "Mod" torque never comes into play.

I think if you were to graph the "used" hp in actual riding with an accelerometer that graph would fall under the line of the potential. I think the only time people may come close to using the full potential is straight line riding, as in the example of passing a truck.

Most people are not using the HP supplied with their bikes. Adding more does not matter. It's just more unused power.

You can't drink from a fire hose. Thats the scenario. If you're using that 150 rear wheel HP, more power to ya. I don't think in actual practice 90% of the riders can or do use more thank 50-60 hp. Maybe blasting down straights, but whatever.

A

[Paul_E_D]

Adam, Of course it's true that nobody NEEDS a pipe, nor really "uses" all the power. However, pipes and basic tuning have a way of revealing the character of the motor. This is often stifled by epa concerns. spend loads of money developing a killer motor, then cork it up to sell it to the public.

Brand new bikes are getting better and better off the showroom floor, but ultimately, epa and really sweet performance are at odds. I'm all for stealth, but I also like to feel the character of the motor I'm using. A pipe and some tuning are cheap and easy way to get a great feeling bike.

[GixerJockey]

your theory is flawed. you left out steady throttle cruising...the exact sort of time an increase of torque would be useful especially if you wanted to roll on and pass a truck. with more torque across the rev range you would need less throttle imput to pass the truck in the same amount of tme (or faster). torque is the reason a ZX-12 never has to down shift out of sixth and a 600 does when trying to pass said truck in the same amount of time. WFO throttle has nothing to do with it. if that was the case everyone would run drag pipes.

unless the throttle is closed and the engine is in deceleration your bike will make 50 hp even if you hold the throttle steady at 7000 RPM.

more torque across the rev range is a good thing...ask any v-twin owner

I had no idea you were so smart...

[taxonomy]

unless the throttle is closed and the engine is in deceleration your bike will make 50 hp even if you hold the throttle steady at 7000 RPM.

more torque across the rev range is a good thing...ask any v-twin owner

I own a twin. It is different from a four. That's certain.

So, really, with the butterflies partly closed and with less than the full CFM it's still making as much torque as it would when the butterflies are open all the way? It doesn't make sense to me really. If you're not flowing the full CFM flow you're effectively dropping BMEP and therefor torque. This would seem to make sense to me. Partly closed butterfly, flow less air, compress less air, reduce pressure on the piston crown, less torque.

At say, steady state 55 MPH I would think you would just open the throttle until the bike produced enough power to overcome drag. if you produced more, you'd accelerate.

[taxonomy]

Adam, Of course it's true that nobody NEEDS a pipe, nor really "uses" all the power. However, pipes and basic tuning have a way of revealing the character of the motor. This is often stifled by epa concerns. spend loads of money developing a killer motor, then cork it up to sell it to the public.

Brand new bikes are getting better and better off the showroom floor, but ultimately, epa and really sweet performance are at odds. I'm all for stealth, but I also like to feel the character of the motor I'm using. A pipe and some tuning are cheap and easy way to get a great feeling bike.

I am considering going back to the stock pipe on my SV and was wondering if it would effect the performance in any way that I could actually detect, beyond the noise.

I am now commuting 22 miles per day (round trip) on it. Most of my riding is this low speed droning on secondary roads. So, the Two Bothers can, while not neighbor annoying loud is just making me need better ear plugs and I am not crazy about the loud bike designation at work.

I'm trying to figure out if removing the pipe will actually have any "feel" difference. Will the motor spin up less quickly? I almost never use full throttle so I don't think I am ever bumping against the torque curve. I am always pretty damn far away from reline. After a sort of dearth of riding, just tooling around on the 400F, I am back to it but I think the high speed days are over. Like, maybe 150% of posted at most, maybe 1% of the time.

Will it make any difference? Does a pipe matter if you never use the top 25% of the torque curve?

If I could, I would have an engine that makes no noise at all. The pipe of the CB1 used to make me crazy after a long day. After an hour or so I think it hurt my performance as a rider.

[Kurlon]

Between pipes, air filter, and a PC3 + full map, my ST3 now operates MUCH smoother at partial throttle openings. Nope, I'm not going back, I will not hand back the gains I got a WFO 'because I'm not using them.' They came with huge gains in partial throttle operation, which is what I wanted.

[Honclfibr]

Probably not, unless the bike was actually tuned for the slipon there's a good chance you'll actually like the bike better with the stock pipes. Since your bike is carbureted the slipon is going to exascerbate the lean condition that exists from the factory at partial throttle.

On my old zx6r, installing a jet kit and fiddling with it actually helped a lot to smooth out the powerband. The slipon, eh, it was loud and obnoxious and made the bike pop on decel but didn't really do anything useful that I could find. First and last slipon I'll ever buy.

I am considering going back to the stock pipe on my SV and was wondering if it would effect the performance in any way that I could actually detect, beyond the noise.

I am now commuting 22 miles per day (round trip) on it. Most of my riding is this low speed droning on secondary roads. So, the Two Bothers can, while not neighbor annoying loud is just making me need better ear plugs and I am not crazy about the loud bike designation at work.

I'm trying to figure out if removing the pipe will actually have any "feel" difference. Will the motor spin up less quickly? I almost never use full throttle so I don't think I am ever bumping against the torque curve. I am always pretty damn far away from reline. After a sort of dearth of riding, just tooling around on the 400F, I am back to it but I think the high speed days are over. Like, maybe 150% of posted at most, maybe 1% of the time.

Will it make any difference? Does a pipe matter if you never use the top 25% of the torque curve?

If I could, I would have an engine that makes no noise at all. The pipe of the CB1 used to make me crazy after a long day. After an hour or so I think it hurt my performance as a rider.

[Paul_E_D]

Cork it back up! It's not going to change that much. I too was getting annoyed by the sound of my duc while commuting. I couldn't give up the feel though. You have different priorities, and likely won't miss it at all.

Don't try to convince these guys though

I am considering going back to the stock pipe on my SV and was wondering if it would effect the performance in any way that I could actually detect, beyond the noise.

I am now commuting 22 miles per day (round trip) on it. Most of my riding is this low speed droning on secondary roads. So, the Two Bothers can, while not neighbor annoying loud is just making me need better ear plugs and I am not crazy about the loud bike designation at work.

I'm trying to figure out if removing the pipe will actually have any "feel" difference. Will the motor spin up less quickly? I almost never use full throttle so I don't think I am ever bumping against the torque curve. I am always pretty damn far away from reline. After a sort of dearth of riding, just tooling around on the 400F, I am back to it but I think the high speed days are over. Like, maybe 150% of posted at most, maybe 1% of the time.

Will it make any difference? Does a pipe matter if you never use the top 25% of the torque curve?

If I could, I would have an engine that makes no noise at all. The pipe of the CB1 used to make me crazy after a long day. After an hour or so I think it hurt my performance as a rider.

[TLRMan]

Is this guy friggen for real???

BTW, you need torque to get Horsepower.

[akira700]

+1 to what Paul said.
Go back to stock.
You will notice it being quieter betcha you wont
notice any performance change.

You could also repack your pipe. I did that and it
made it much less obnoxious. The packing burns up
after a few years. So needs to be replaced periodically.

Check out Silent Sport - Area P :: No Limits

[akira700]

Oh, flame me if you must, but what the fuck is
WFO?
Is it the same as WOT?

[ChR1s]

...I think in most cases people are using less than the available torque a stock bike would produce at any given moment. The additional "Mod" torque never comes into play.

...

You are insane.

Torque is the ability to do work over time. More torque, less time required to accomplish the work. WFO has nothing to do with it. And CB1s are gay.