More controversial pipe info

[taxonomy]

Hi all,

I talked to a very knowledgeable person about pipes today.

When you see a dyno chart you are in fact seeing maximum possible torque delivered at RPM. In just about all cases throttle openings at less than full throttle will not deliver peak torque for any given rpm.

So, the best indication that you can use the extra hp or torque is that you ride with the throttle wide open. In the words of this person, "you can bake a cake as big as you like but if you only eat one piece it does not matter". To which I responded, "standing in a high ceiling room makes you no taller", and he said, "but it allows you room to grow."

It was postulated elsewhere that the "stronger signal" of a less restrictive after market pipe would increase throttle response.

In further discussion he said that the different gas velocity exiting the exhaust valve (depending on how much air was let in at partial throttle opening) would bounce around in the pipe differently and it would be a crap shoot to determine when the negative pressure wave arrived at the exhaust valve. In short the "stronger signal" wouldn't mean much. It could make things better or worse but odds were about even; but the stronger signal would likely make things "more better" or "more worse" at a given opening/rpm.

He said it takes about 3 hours of dyno work (by Erion Racing no less) to get maps of partial throttle openings more or less correct but that the power commander III would do a passable job of it. And that's just the fueling end of it.

Moreover in cases of relatively small changes in throttle position, like accelerating out of a corner, improvements in response wouldn't matter much. You would need a very large amplitude change in throttle position to make improved response (if any) matter to any measurable extent. In a word it would only matter if you "nail it"

So, in the end, pipes are best for straightaway acceleration where the throttle can be pinned, and a wide open throttle is the best indication you could use a pipe. It's also a good indication that you are using your pipe.

For most of us they are of no use.

A~

[butcher bergs]

Your threads give me a headache.

That is all.

[ChR1s]

It all depends. You running dino or synth? Also, what type of master link, rivet or clip? That can have a TREMENDOUS effect on riding enjoyment.

[Pigman]

Pipes do give u a benefit when tuned properly and in use with a PC or Bazza and air filter they have some great gains......and dyno charts don't lie.....and tend to run a lot smoother in the low end and just cruzing around.


also if you put the Yellow power band in you can hit terminal velocity quicker in the nebuelizer plutonium iridium quantum piceofshit........

[taxonomy]

Pipes do give u a benefit when tuned properly and in use with a PC or Bazza and air filter they have some great gains......and dyno charts don't lie.....

There are gains, but only at WOT.

and tend to run a lot smoother in the low end and just cruzing around.


also if you put the Yellow power band in you can hit terminal velocity quicker in the nebuelizer plutonium iridium quantum piceofshit........

Did the bike run rough before installing the pipe? No modern bike should. Are we talking about a 74 cubic inch Harley here? I think it's pretty speculative. After spending $$$$ on a pipe a rider is going to want to believe there was gain. I would really have to see data to believe there is benefit where people actually ride.

Also, I am not just talking about cruising around town here. Even in hard riding if you are not in the extra ft/lbs available at WOT, at any RPM you are not likely actually getting any benefit from an after market pipe unless you are at WOT. My guess is that most people never pin it.

By definition "rolling on the throttle" means less than WOT. That's what we do, right? It's all about corners?

[ChR1s]

So, what's your point?

Oh here >____< it is!

[Pigman]

This isn't even a good argument cause when you overlay a Stock Dyno run and one of the same bike and just some upgrades such as pipe PC and air filter the gains are pretty easy to see.....actually very easy WOT or NOT

thats why I have a PIPE because of GAINS of HP and it runs a lot stronger....

[taxonomy]

This isn't even a good argument cause when you overlay a Stock Dyno run and one of the same bike and just some upgrades such as pipe PC and air filter the gains are pretty easy to see.....actually very easy WOT or NOT

You have a part throttle dyno run chart?

[ChR1s]

That's an eddy dyno.

[taxonomy]

That's an eddy dyno.

Hysteresis, I believe.

[Pigman]

No need call YOSH R&D and tell them there Pipes JUNK and don't help...I am sure they will laugh...

[taxonomy]

Yana Shiki?

Wassupith that?

[ZX-12R]

There are gains, but only at WOT.

Also, I am not just talking about cruising around town here. Even in hard riding if you are not in the extra ft/lbs available at WOT, at any RPM you are not likely actually getting any benefit from an after market pipe unless you are at WOT. My guess is that most people never pin it.

That is completely not true. There are so many variables involved that you can't make a blanket claim like that. The gains will be most pronounced at high RPMs and WOT which is the combination that produces the largest volume of exhaust gasses but you can still have legitimate gains at partial throttle and lower RPMs. It's also possible to lose power at low RPMs especially in bikes with radical cam profiles.

[Pigman]

I have used them before......Knock off company but they have some stuff that others don't carry....and for the money its good stuff

got a set of Black anodized winshield bolts cheap.......plastic ones suck...
also a set of black leavers not bad quality at and for 25$ worth the money all day....long

[Pigman]

Tax smokes crack and reads SportRider way too much....

[Pigman]

check it http://www.yanashiki.com

[ChR1s]

Hysteresis, I believe.

Is there a pill for that?

[selltekk]

Let's face it. Most riders are not capable of riding beyond the capabilities of the bikes they own.

I will be the first to say that I am included in this group.

Another fact: Most sportbike riders get an aftermarket slipon, or full exhaust to further enhance the curb appeal and sound of their bike rather than for any real power gain, whether they realize it or not.

I will be the first to admit that I bought a pipe because:

1. It is lighter and smaller than the factory pipe.
2. At speed, my bike sounded to me like a Singer sewing machine rather than a motorcycle, and I wanted to be able to hear myself coming for ego purposes.
3. It is shiny. I like shiny things.
4. I got a good deal.
5. My bike runs rich stock, and the pipe seems to lean it out a bit.


the small power gains that you actually get from a pipe are really negligible in the real world. It's like putting rims on your car...or putting a flame paint job on your lawnmower...

[Kurlon]

I'd say your friend has spent too much time thinking and not enough time researching. : )

Nice theory, I've got dyno and seat of the pants data that says my Leo's helped my ST across the board, even at partial throttle.

Wing this past him... If a pipe change isn't affecting how the motor breathes at partial throttle, why does it need different fueling for partial throttle operation after a pipe swap? If you have to change jetting, you've altered something fairly significantly, just look at any Power Commander map from a bike with nothing more than a pipe change. All those non-zero numbers for low rpm, low throttle opening areas (aka the 'driving range') are changes in fueling from the stock 'zero map' included in the PC's firmware for operating a stock bike.

[Pigman]

The only Pipe is the one he is hitting.....go back to ENG school and think up some stupid theory on something else...

[taxonomy]

I'd say your friend has spent too much time thinking and not enough time researching. : )

I hate to say this now but the conversation I had was with Kevin Cameron. It was a work related thing but I wound up talking to him for about an hour. Not about just that but about other things too. He's a really nice guy, and smart too. I mean smart in a general sort of way.

I can't really say I am articulating things right and there may be holes in my idea, but I ran it by Mr. Cameron as best I could and I am pretty sure that he verified it.

He also went on to say that for a lot of people more power or different power slows them down. It was a long conversation, I am only somewhat capable of understanding it. When it comes to terms like "spray dispersial" he's piling up the dishes faster than I can dry. I dunno, I read Lyle Cummings and stuff like that for fun. It's not a real education but I like that kind of stuff.

The reason I called him was I am a library director and he'll be coming to do an author reading at my library in the late summer or early fall. It'll be from his newly published Top Dead Center I wrote him an actual paper letter and he called back yesterday. He just got back from the latest Indian Motorcycle Company rebirth, and we talked about that some too.


I'll leave it at this. I think that real world gains from pipes in classic out of the corner street sport riding are negligible. That's my opinion. I've thought about it some and talked to some very smart people about it. People I can say I really respect and that have engineering backgrounds. I've made my case. I hope to meet you all in person some day.

A~

[SSearchVT]

Short run dyno testing is done at wide open throttle. The main goal is usually just to establish a comparison between baseline and current set-up.

On a fuel injected engine WOT also takes the influences of the TPS and the O2 sensor out of the equation. The intake flow patterns are different because the butterflies or slides are out of the way - but the velocity is very close to that of a partial throttle situation because it is controlled by the engine (valves or reeds, and combustion chamber).

Depending on the test run - long run dyno testing can include the throttle position. This brings the intake flow patterns back into the mix, and how they relate to the TPS and the O2 sensor feedbacks (as well as a ton of others in the engine and on the recording instruments).

Long story short - if it isn't too late already... Short run dyno testing at WOT does give very useful information - and it should be used as a starting point on which direction to proceed.

[taxonomy]

Depending on the test run - long run dyno testing can include the throttle position. This brings the intake flow patterns back into the mix, and how they relate to the TPS and the O2 sensor feedbacks (as well as a ton of others in the engine and on the recording instruments).

Yup.

[Kurlon]

Cool, nice to hear in this day and age people still take up pen and paper, and this is coming from a geek. : )

I'll stand by the improvements in low speed operation on my ST3 after a pipe and PC3 to justify that there are real world, real use improvements to be had with a pipe. Add in the data from the dyno and fuel map, you'll have a hard time convincing me that my butt's decieving me.

[taxonomy]

Cool, nice to hear in this day and age people still take up pen and paper, and this is coming from a geek. : )

I'll stand by the improvements in low speed operation on my ST3 after a pipe and PC3 to justify that there are real world, real use improvements to be had with a pipe. Add in the data from the dyno and fuel map, you'll have a hard time convincing me that my butt's decieving me.

Yeah, it was great to talk to him. I figured the letter was the best choice.

I think you can get usable gains if you have "3D" fuel mapping capabilities and spend the time with it. This is the trick for me, you have to demand those gains. You may get better response. I think a lot of it could be realized on the fuel side without the pipe anyhow.

If your stock pipe was can deliver the rate of change that you demand when you roll on the throttle adding more capacity to deliver change won't matter. If you roll on slowly, like I do, all the crispness in the world wont matter.

I am a street rider, I don't ask much of my bike. At 70 peak HP, if that, the ceiling is pretty high. I can't imagine a ceiling of 150 HP. I can't imagine needing more HP, more crispness, more anything than is delivered on any stock sportbike over 600cc made after 2000.

That's me though. It may matter more with heavier bikes, 2 up, loaded or in other situations.

A