Power Flat Spots

[Greg Field]

You may be right. I may try what you suggest if I take it back to the dyno. I just scored a set of Ti pipes, so I may have to do some remapping.

[Ryland3210]

Greg

 

For me it is still hard to believe that the measured Power/torque difference is caused by the filter element. It seems more to be related to the differences in the air box design. I beleive the difference caused by the filters themselves will be unmeasurable.

Swap the filters in the airboxes and measure aigain to be sure.

 

I too would like to see the results of the test motoguzznix requested.

I also wonder whether simply cutting the top off the airbox and using the paper filter would get the same or better results than the bellmouthing and three teardrop shaped holes do.

[Skeeve]

I too would like to see the results of the test motoguzznix requested.

I also wonder whether simply cutting the top off the airbox and using the paper filter would get the same or better results than the bellmouthing and three teardrop shaped holes do.

 

And so we come full circle!

 

The airbox breathes more freely w/ the "non-top" top you describe, but many who've gone that route have mentioned the intake noise becomes a substantial consideration in terms of their decreased riding enjoyment. I always wear earplugs when I ride, but even so, the less noise the better. If you can approximate the "non-top" air box top performance by going w/ the 3 holes [1], then why not save yourself the drain on physical resources (rider endurance) that the added intake noise would cause?

 

I have yet to get a heat gun for flaring the intake bells, & have been spending some time shopping the spirits section of the supermarket for the correct form [bottle] to use: right now, Baileys is in the lead, but the Malibu coconut rum bottle is a contender too! I've cut the 3 holes already, tho' I went a slightly different route, using a 1&1/4" hole saw for the back corners of the lid, & 1&1/2" for the center hole: these are similar to the 1" size specified by Phil A. for all 3 holes, but are the closest "fit" I had among my cheeep hole saw kit to approximate a ratio of "phi" between the hole areas. Ratchethack may think me some sort of superstitious cargo-cult worshiping aborigine for it, but that dang transcendental "phi" just keeps coming home to roost, so I figured "why not?" Besides, it's not likely to be enough of a difference to hurt anything, & bigger is better, right? [Can you tell I'm a Yank? ]

 

While the lid was off, I got a good look inside the airbox, & I think the next problem is the square-edged "shelf" [sorry I didn't take pix!] at the back of the airbox proper underneath the filter: there's only a narrow space on either side of it leading down to the throttle-body intake horns, and it would appear to be the single greatest impediment to easy-breathing for the V11 motor aside from the airbox lid [which we're already in the process of remedying.] Air does not like turning sharp corners, and it's clear there's space beneath the airbox to allow for some "softening" of that hard edge; it's also pretty clear that it was just easier for production to make the vacuum mold for forming the airbox w/ that nice sharp corner there. It won't require a lot of work to improve it, just enough to change

 

|_ to \_

 

 

I'd let you know how it turns out, but since I've never dyno'd the bike, I'll just have to take it on faith that it'll be an improvement. Hard to see how it wouldn't be... but yes, I'll take it slow & careful when the time comes, because who wants a form-fit, no-removal possible, custom airbox-on-spine frame?

 

 

 

[1] "What's w/ the 3 shells?" Quick - name the movie!

[Phil A]

Skeeve,

You will find that you will need two bottles. One with a longer thinner neck and one with a shorter steeper neck.

Start with the flatter one and get the outside part of the bell done first. Then use the more tapered one to "throat" the bell. Yes I know this sounds arse about, but you will see why as you do it. "all is not always as it seems"

 

Another tip is to heat the plastic in the exact place you want things to happen. You wont get much if any heat transfer through the plastic.

 

Heat the plastic until it goes "Shiney" that is its critical temperature. Dont try and do too much re- heating on top of each other. Simply heat it up.... do some molding then quench it with water. Then repeat the process.

If you keep adding too much heat on top of each process, you will get the whole thing out of shape.

 

Yes, the hole sizes are just a comprimise on noise and filter life.

 

If you want maximum power, throw away the airbox and the pods and put bell mouths on the injecter bodies.

 

 

Phil.

[Guest ratchethack]

Ratchethack may think me some sort of superstitious cargo-cult worshiping aborigine. . .

. . . that dang transcendental "phi" just keeps coming home to roost, so I figured "why not?"

Well who cares wot I think, and why would it make any difference wot anyone else thinks, f'er that matter??

 

But now that you've rattled my cage, Skeeve, o' course I'm obliged to throw in.

 

I've been dropping in on this thread occasionally (though I admit with far less than half interest), just 'cause I'm curious.

 

Um, how many o' you Gents will be joining Bill Ross with Team Subtle Crowbar and the Mandello Meteor on the salt flats at Bonneville for a shot at top speed honors in your class with your own Guzzi?

 

How many will be racing in BOTT?

 

How many ride on the street at sustained and extended WOT at max torque and power RPMs?

 

Um, (Part II) the reason I ask is that unless you're planning on something very close to any o' the above, I reckon wot you've been slicing and dicing ad infinitum here (bell-mouthing snorkels, the perennial plumber's nightmare and tail-chasing folly of "ram-air" , transcendental "phi" airbox holes and the like) are considerations that add up to naught but a pocketfull o' shadows and moonbeams?!?!

 

CONSIDER:

 

UNLESS you're riding BOTH at WOT AND at torque and power peaks on some kind of SUSTAINED time intervals on a regular basis (a scenario the likes o' which I frankly have serious doubts that too many o' you Gents are likely to find y'erselves in, possibly ever ) , and in the case that for some unfathomable reason, you really do simply HAVE TO HAVE the kind of infinitessimally tiny power increases you seem to be obsessing over ad nauseum here that are only possible to realize at extremes that I (for one) achieve within a chip-shot of never , there's a much easier way to achieve far greater results:

 

Open up the throttle some more. 99.9999999999998% of the time, you've still got some left, and that'll generally do the trick every time. . .

 

As f'er Y'ers Truly, I reckon I'll try a bit more high-speed compression and a bit less low-speed compression damping on the shock for my next Fall mountain ride tomorrow. I actually detect a real difference with this kinda change on the road on a regular basis.

 

BAA, TJM, & YMMV

[Skeeve]

Well who cares wot I think, and why would it make any difference wot anyone else thinks, f'er that matter??

 

But now that you've rattled my cage, Skeeve, o' course I'm obliged to throw in.

 

That's what I was hoping for!

Um, how many o' you Gents will be joining Bill Ross with Team Subtle Crowbar and the Mandello Meteor on the salt flats at Bonneville for a shot at top speed honors in your class with your own Guzzi? How many will be racing in BOTT? How many ride on the street at sustained and extended WOT at max torque and power RPMs?

 

Not I, he realistically said...

 

Um, (Part II) the reason I ask is that unless you're planning on something very close to any o' the above, I reckon wot you've been slicing and dicing ad infinitum here (bell-mouthing snorkels, the perennial plumber's nightmare and tail-chasing folly of "ram-air" , transcendental "phi" airbox holes and the like) are considerations that add up to naught but a pocketfull o' shadows and moonbeams?!?!

 

CONSIDER:

 

UNLESS you're riding BOTH at WOT AND at torque and power peaks on some kind of SUSTAINED time intervals on a regular basis (a scenario the likes o' which I frankly have serious doubts that none too many o' you Gents are likely to find y'erselves in, possibly ever ) , and in the case that for some unfathomable reason, you really do simply HAVE TO HAVE the kind of infinitessimally tiny power increases you seem to be obsessing over ad nauseum here that are only possible to realize at extremes that I (for one) achieve within a chip-shot of never , there's a much easier way to achieve far greater results:

 

Open up the throttle some more. 99.9999999999998% of the time, you've still got some left, and that'll generally do the trick every time. . .

 

Well, Ratch, it's hard to argue w/ your logic, yet I'd like to point out that this is Americ^H^H^H^H^H^H^H, uh, "Freedonia" & we can fiddle & tinker w/ our machines to our hearts content! So there's one reason for all this slicing & dicing & Julienne frying of airbox lids. More & better reason(s) is the power issue: Phil A. as presented some pretty compelling data that there's free horsepower to be had, simply from a few non-horrendously difficult nor un-neighborly adjustments made to the stock parts, requiring no significant expenditure of fund$.

 

That's efficient & economical, which are two of my favorite "e" words! "Easy" is another one, & this mod kinda falls under that heading too, all the more reason for my willingness to futz about with it.

 

And all that free horsepower isn't just at the top end; some of it is right there in the cruise band, where you'll have the throttle turned to -just there- for the next 3 hours buzzing up the 5 fwy to get to "good road country." Which means you'll burn less fuel [1] getting hither & yon. [2] And once you get to the good road places, which always seem to be a couple thousand feet higher than where I live, the bike will have an easier time of breathing at altitude. Having just come back from a vacation in Utah, I can tell you: going from sea level to a mile up really let's you know how much you air you use!

 

Thanks for the contribution to the thread, I feel much more grounded now.

 

Ride on!

 

[1] Yes, it might be so very little less that it's near impossible to measure. But Guzzis last a long time, & I'm not planning on getting rid of mine any time soon. So it all adds up. I'm willing to wait...

 

[2] And burning less fuel while hithering & yonning is the most practical way to decrease air pollution (shh! don't tell the Greenies, but nobody's going to stop running their errands, etc. to save the planet!)

[dlaing]

snip

And all that free horsepower isn't just at the top end; some of it is right there in the cruise band, where you'll have the throttle turned to -just there- for the next 3 hours buzzing up the 5 fwy to get to "good road country." Which means you'll burn less fuel [1] getting hither & yon. [2] And once you get to the good road places, which always seem to be a couple thousand feet higher than where I live, the bike will have an easier time of breathing at altitude. Having just come back from a vacation in Utah, I can tell you: going from sea level to a mile up really let's you know how much you air you use!

 

Thanks for the contribution to the thread, I feel much more grounded now.

 

Ride on!

 

[1] Yes, it might be so very little less that it's near impossible to measure. But Guzzis last a long time, & I'm not planning on getting rid of mine any time soon. So it all adds up. I'm willing to wait...

 

[2] And burning less fuel while hithering & yonning is the most practical way to decrease air pollution (shh! don't tell the Greenies, but nobody's going to stop running their errands, etc. to save the planet!)

1] All that power adds up. Better muffler 3HP, better crossover 2HP, better airbox 4HP, porting 2HP, high compression pistons 1HP, hotter cam 2HP, remap 1HP, total gain 15HP...Now when Ratchet is fighting the trade winds on the way back from Lost Wages, Nevada, he'll top out at 120MPH while Skeeve blows by him at 130MPH, and the stock Hayabusa blows by at 160MPH...and my BigBore V11+ slipstreaming the Hayabusa

2] It will only save you fuel if you don't properly enrichen the mixture, or if it was too rich to begin with. I guess only the greenies know that people are already better optimizing their errands, etc., in an effort to save the planet.

Heck I spend nearly as much time here as I do out riding. Nearly 6000 posts, averaging 10 minutes per post, that 60,000 minutes or 1000 hours. On V11 over 40,000 miles averaging 40MPH, thats 1000 hours. Pretty sad for my soul, but good for the environment to enjoy motorcycles on the Virtual Highway that Al Gore took the initiative in Congress to help create.

[Greg Field]

Adding to what Skeeve said, it's free power while allowing those who are so inclined to keep in place a paper filter. Plus, it's kinda fun . . . and helpful on the occasions where we are at WOT trying to pass that 14th-in-a-row semi in the only passing lane for the next 23 miles.

[Guest ratchethack]

I guess only the greenies know that people are already better optimizing their errands, etc., in an effort to save the planet.

Not a good guess, Dave.

 

Of course you've presented yet another Modern-day Classic here.

 

This is wot I call typical blind, raving, falsely self-righteous, backward and upside-down Green Weenie Feel-goodism in the act of actually creating MORE pollution, rather than LESS:

 

Only a Green Weenie would attempt to make himself FEEEEEEELL GOOD ("At least I'm doing something!" ) by justifying airbox modifications that can only make infinitessimally tiny differences to mileage (to the point of unmeasurably tiny) at throttle openings that achieve worst case mileage , on a motorcycle that gets simply awful mileage to begin with -- as motorcycles go. (Many 5-seat sedans achieve similar mileage to that of a V-11.)

 

Now, if you were actually sincere about "saving the planet" by getting better mileage, Dave, you'd take Badnog's suggestion and ride a motorcycle that gets double the mileage of your Guzzi (or better), and uses far less oil than you evidently use in the process.

 

But we all know that for Green Weenies, it's more important to FEEEEEEELL GOOD about "saving Moms Gaia" than it is to actually do something that has measurable results --even if you FOOL YOURSELF with backward reasoning and upside-down facts. Sorta like the example of your Green Weenie "peerless leader" Algore, who consumes 20X the average homeowner's energy, and justifies it by paying carbon offset credit "indulgences" to his own corporation, eh, Dave?

 

FWIW -- Last I checked, I got 50 mpg on the Yammerhammer XT600 single. So consider THIS, Dave -- every time I ride it, I'm "saving Moms Gaia" (by your standards) in significant, MEASURABLE WAYS that you aren't -- and I'm certainly no falsely self-righteous Green Weenie .

 

Now this fact doesn't particularly do anything for MY self-esteem, which doesn't depend on silly notions of "saving the planet" created by imaginary, propaganda-driven, fabricated for consumption of The Gullible, Chicken Little scenarios, as dictated by Green Weenie designer propagandists in the first place. . .

 

But sumpin' tells me this fact doesn't do YOUR self esteem much good a-tall . . .

 

Gotta go ride now.

[dlaing]

Not a good guess, Dave. <_>

 

Of course you've presented yet another Modern-day Classic here.

 

This is wot I call typical blind, raving, falsely self-righteous, backward and upside-down Green Weenie Feel-goodism in the act of actually creating MORE pollution, rather than LESS:

 

Yah, sure optimizing your errand creates more pollution and not less????

[dlaing]

 

Now, if you were actually sincere about "saving the planet" by getting better mileage, Dave, you'd take Badnog's suggestion and ride a motorcycle that gets double the mileage of your Guzzi (or better), and uses far less oil than you evidently use in the process.

Yah, that would be the logical thing to do, but when you are stuck on a bike it is hard to give in to something that makes more sense on paper.

Sure some bikes get better gas mileage, and some make more HP, but there is nothing out there like a Guzzi for the riding pleasure.

Is there a bike out there with at least the same power over the entire rev range, that gets a real 50MPG (US) with a lead wristed 230lb rider?

I considered trading in for a 750Breva, but my experience with the small blocks makes me skeptical that one would last 50,000 miles without major part replacements and engine overhauls, especially considering that the bike would spend so much time at WOT. The suspension and lack of power leave little to be desired.

Before I got my bike, I considered the Suzuki SV650. It probably would have been a good choice and I would probably have twice as much money in my bank account right now.

But now I am hooked on the V11 and it is difficult to look elsewhere.

But if someone gives me $7000 for my bike, I'll buy either a BMW 800 or a Suzuki SV650, or maybe a Ninja twin, just to be green.

Think Ratchet, for $7000 you could upgrade your suspension, get some spare parts, and best of all, I'll kiss this forum good buy, so that you will be able to propagandize with no interference from me.

What an offer!!!!

Please say yes.

Maybe some of the others that share your blind seething hatred for me will kick in a few bucks to get rid of me?

[Skeeve]

2] It will only save you fuel if you don't properly enrichen the mixture, or if it was too rich to begin with.

 

Nope. Parasitic drag doesn't work that way. Let's turn the problem around to illustrate it better:

 

[the following is NOT factual! Any attempt by readers to use these numbers to later justify their power claims will be immediately laughed off the forum! Consider yourself warned! ]

 

Intake drag from stock airbox = 1 inch of vacuum.

Intake drag from mod'd. airbox = 0 inch of vacuum.

Forced induction of 1/2psi fed into stock airbox.

 

How much power would you pay for that 1/2psi of forced induction? 'Cause that's roughly the power freed up by the difference in vacuum between the stock vs. modified airbox [assuming 29.92" of mercury = 1 atm.]

 

Now, before we get carried away, let's remember that these numbers are completely made up, waaay beyond hypothetical! They're only to illustrate a point, O.K? That point being that even w/o adjusting fuel mixture for best power, reducing intake restriction is going to result in "increased" power by virtue of decreasing lost power.

 

 

O.K., logic lecture is over. In all deference to Ratch', I don't expect there to be a noticeable difference between the stock & modified airbox on the rider's part, at least not until you're driving back across the Mojave from Vegas into a 30kt headwind at 85mph. Then all of a sudden, that extra skosh of responsiveness will be immediately discernible...

[dlaing]

Nope. Parasitic drag doesn't work that way. Let's turn the problem around to illustrate it better:

 

[the following is NOT factual! Any attempt by readers to use these numbers to later justify their power claims will be immediately laughed off the forum! Consider yourself warned! ]

 

Intake drag from stock airbox = 1 inch of vacuum.

Intake drag from mod'd. airbox = 0 inch of vacuum.

Forced induction of 1/2psi fed into stock airbox.

 

How much power would you pay for that 1/2psi of forced induction? 'Cause that's roughly the power freed up by the difference in vacuum between the stock vs. modified airbox [assuming 29.92" of mercury = 1 atm.]

 

Now, before we get carried away, let's remember that these numbers are completely made up, waaay beyond hypothetical! They're only to illustrate a point, O.K? That point being that even w/o adjusting fuel mixture for best power, reducing intake restriction is going to result in "increased" power by virtue of decreasing lost power.

 

 

I agree, but without re-mapping the fuel you will be pushing it in the direction of running too hot.

Yah, it is a ditch pump and can probably take it, but fueling should ideally be optimized for power, keeping a good engine temperature, while optimized for fuel efficiency. A bit of challenge with minimal thermostat controls, still somehow it works.

If the fueling is already above stoich, increasing the forced induction will hurt power, possibly efficiency and possibly burn valves.

The biggest benefit will be where it is too rich, and more importantly to the thread topic, the biggest gain will likely be at 4000RPM, at the dreaded flat spot.

Notice in Greg's chart, the biggest gain in HP is not at 4000RPM but the greatest percentage gain in HP is at about 4000 - 4250RPM, helping to fill that hole.

Of course on Greg's bike he has the Mistral cross over that does not suffer from the dreaded flat spot, so it is not the best example for filling the hole. Still it shows that there is more than one way to fill a hole, if only partially.

Combine an open airbox lid and a Mistral crossover and the 4000RPM hole is gone....although it may have moved down to 3500RPMs???

Add Skeeves hump flattening, and who knows?????

[Guest ratchethack]

Yah, sure optimizing your errand creates more pollution and not less????

Um, correct me if I'm wrong, Dave, but isn't the whole Algore Green Weenie message (or at least the facade, which is, after all, the most important part ) to completely ditch the "errands" that use so much energy and pollute so much, in favor of more efficient "errands" that use SIGNIFICANTLY less energy and pollute SIGNIFICANTLY less?!

Yah, ...but ...it is hard to give in to something that makes more sense on paper.

Hmmm. It "makes more sense on paper" for a Green Weenie to get SIGNIFICANTLY worse mileage than using a vehicle with a dramatically lower carbon footprint?!

 

That, and it's evidently too "hard". Right. There's the conviction level of the typical Green Weenie , right there.

Sure some bikes get better gas mileage, and some make more HP, but there is nothing out there like a Guzzi for the riding pleasure.

Aha! The truth comes out!

 

So "pleasure" trumps "saving the planet" in terms of gas mileage achieved, eh, Dave?

 

Now that doesn't quite sound like the "carbon neutrality" that Chief Green Weenie Algore has been preaching to the rest of us (including you, Dave), does it???

 

It rather sounds lots more like wot you and Algore are both actually DOING though -- doesn't it, Dave?

 

"In total, Gore paid nearly $30,000 in combined electricity and natural gas bills for his Nashville estate in 2006... Gore devoured nearly 221,000 kWh—more than 20 times the national average."

 

SOURCE: ­The Tennessee Center for Policy Research is an independent, nonprofit and nonpartisan research organization committed to achieving a freer, more prosperous Tennessee through free market policy solutions. See "Al Gore’s Personal Energy Use Is His Own Inconvenient Truth” here:

 

http://www.tennesseepolicy.org/main/articl...?article_id=367

 

Again, we all know that for Green Weenies, it's more important to FEEEEEEELL GOOD about "saving Moms Gaia" than it is to actually do something that has measurable results --even when you FOOL YOURSELF with backward reasoning and upside-down facts -- eh, Dave?

 

Thanks for laying out your er, true Green Weenie hypocrisy so clearly.

[Skeeve]

I agree, but without re-mapping the fuel you will be pushing it in the direction of running too hot.

 

Well, w/o changing the exhaust system at all, it all should just fall under "reducing power losses."

Yah, it is a ditch pump and can probably take it, but fueling should ideally be optimized for power, keeping a good engine temperature, while optimized for fuel efficiency.

Optimizing fueling for power would increase power, meaning you could run reduced throttle [& hence, fuel burnt] for the same road speed. Combined f/x here: the immeasurable but real decrease of power used for sucking air thru the constricted stock airbox, plus the increase in power from properly adjusting the f/a ratio.

 

If the fueling is already above stoich, increasing the forced induction will hurt power, possibly efficiency and possibly burn valves.

SMACK!

 

You're missing the point here! Look, the forced induction example was just to demonstrate that there *is* power consumed in the intake system of any combustion engine: it's just where the power comes from that differs! Turbos take it from the otherwise lost expansion of hot exhaust gases, superchargers take it off the crank, NA engines take it off the top of the piston by creation of vacuum, jet engines do it just by variations of the turbo or supercharger methods above, or in the case of ramjets, by the approach from which their name is derived...

 

Leave PCIII/TuneBoy/TechnoResearch arguments out of this! Sheesh, the same idea apply if we were using a carbed Spot 1100 for this example, in fact, it would be more correct, since the max "boost" of the ram-air on the Spot/Sporti/RS models probably closely approximates that entirely hypothetical 1 psi of boost (and that at their 150mph nominally "geared" top speed!) And, since Bernoulli never sleeps, carbs are far more "automagic" in their adjustment to the reduction in intake drag we're talking about here. Mix in exhaust or valve timing changes at the same time? All that ceteris paribus sh!t goes out the window, & yes, you've got to rejet!

 

Combine an open airbox lid and a Mistral crossover and the 4000RPM hole is gone....although it may have moved down to 3500RPMs??? Add Skeeves hump flattening, and who knows?????

 

Well, quite frankly, I honestly don't think the "hump flattening"[1] would have any f/x on the 4k-5k flat spot: it's pretty clear that almost all of that is due to a combination of intake&exhaust harmonics, and the rather sharp edges in the airbox construction would almost only be a concern when the engine is sucking in GREAT GULPING GARGLES of air, ie: that same portion of the powerband that Ratch' scoffs at, up in the last 1k rpm before redline. I just figure that since I've gone so far as to pull off the airbox lid & fiddle w/ it, I might as well do what little I can with the rest of the airbox in situ while I'm at it. It's all just personal entertainment, really...

 

Ride on!

 

 

[1] My proposal is quite the opposite, in reality: the hump is almost perfectly flat & square-edged to begin with! What I intend to do is more on the order of "edge-rounding" than any other description...