Gen. I ram air

[satariel666]

Ram plays only with good aerodynamics setup - not with vehicles which have aerodynamics like a shool bus and Imean v-max.
This not obvioulsy that simple to just grab some pvc pipe and put on your bike to make it work like ram air, same with converted scoops - thats not gonna work.

 

[Saml01]

I can't agree,
I had a 1995 CBR600 (F3) and a friend had a 1994 CBR600 (F2)
The only thing that was different then the F2 in the engine was the ram air.

F3 was quicker.

I remember keeping accelerating when the speedo was slammed at max (280kph).
Note, We both Had full yoshimora set, stage 1 Dynojet, hot cams, and I had my engine ported.

So you think your ported engine had nothing to do with it?

 

[Fire-medic]

I think KJ is doing a good thing by pondering the issue, I don't agree w/all his input.

Cars can achieve low coefficients of friction, lower than a motorcycle, because of some fundamental differences. One is ground clearance. Bikes need it to corner, cars, not-so-much.

Another is air beneath the vehicle which contributes to drag. Cars again are better at this than bikes because they can use ground-effects bodywork to greatly lessen the drag of air allowed under the car. Again, bikes cannot really achieve this to the extent of cars. Cars can use bellypans to smooth the flow of air which does intrude underneath. Sports-racing cars such as Jim Hall?s notorious Chaparrals used a variety of methods to seal air from intruding under the car, including body panels which were an interference fit to the ground, and even small engines which evacuated air from beneath the car to create a ?low-pressure zone? underneath (the 2J ?sucker-cars?, see ?em on youtube). This was hugely successful, and was soon outlawed in competition, but not before others tried it.

The faired design underneath at the front and rear of nearly any car today is there to promote the efficient flow of air under it entering and exiting. The less disturbance of the air next to the body surface, the less drag, this is called 'optimal laminar flow' and has been used since the time of WW I in both cars and planes on, of course, both the topside and the underside. Here is an article about basic aero principles from the civilian branch of the USAF: http://www.cap-ny153.org/forcesdrag.htm

Third, the coefficient of drag for bikes is far-greater than cars. Bikes are around the .40 mark where production cars are able to get below .30. Marketing and oddly-enough, racing has a hand in this. Remember the BMW K1? It was one of the most completely-faired bikes of modern times, and it was not a big seller. That may be due to the cost compared to what other bikes which offered more speed for less $. Still, it was a legitimate 150 mph motorcycle, BMW's first for consumers, and its aero shape was a big contributor to its top speed performance. Look at its front wheel, covered nearly entirely except for its contact patch and to provide cornering clearance, the design is what pilots refer to as 'wheel spats.' And of course, the rest of the bike's faired design showed many hours in the wind tunnel to reduce drag by reducing frontal area, and by allowing the disturbed air to maintain its 'laminar flow' across the body contours, and then to re-join airflow from the opposite side of the body at the rear of the bike. Remember the Porsche 917's that did 250 mph at LeMans, with the long, tapering tail? It was there to allow the air to converge smoothly as it left the main vertical body cross-section. A German engineer arrived at a 'fix' for having such a taper, his name was Kamm, and what he did was to abruptly chop-off in a vertical plane the end of the body after its widest point. While not as-efficient as the long, tapering tail, it did allow a more-compact design.

I mentioned racing as contributing to drag. In the 1950's, the FIM outlawed the use of fairings where the front wheel was enclosed by the same fairing as the body, the so-called 'dustbin' fairings. These proved to be very unstable at higher speeds in the presence of a crosswind especially at places like Spa in Belgium. They also mandated the body fairing had to allow the front wheel contour to show itself and to not be covered by the fairing body. We now accept this as a fundamental part of motorcycle design, and it has become 'normal.' The main body fairing curvature to the arc of the front wheel is what we expect to see, and it provides space for the radiators which have grown larger and more-numerous with the increases in engine output.

KJ's example of the different-sized holes in cardboard as examples of motorcycles 'grabbing too-much air' is correct in the size of the hole affects the ease with which the blunt object passes through the air, but ignores the differences in the size of the engines, their pumping of air through them, and the rpm's at-which they operate. Since most motorcycle engines operate at rpm speeds of twice or three times the rpm-speed of cars, they pump more air for a given displacement. Thus, they need correspondingly-greater amounts of air available to them than the lower-flowing by virtue of lower-rpm car engines.

The air scoops of the 1960's and 1970's muscle cars were crude devices which owed their existence as much to the marketing department as to the powertrain department. Sometimes the presence was entirely marketing, as in the 1970's Pontiac Firebird Trans Am's with their famous 'shaker hood scoops,' which was solid and had no opening for air to enter! But, in the fast-food restaurants, high-schools, college campuses, and workplace parking lots, the Trans-Am was king in style if not in maximum performance.
The Plymouth Duster and Dodge Demon with their functional scoops, were ahead of the Trans-Am in functionality, but the area of the opening was small, and its benefit came principally from being able to show your buddies how you could control its opening, and proudly display the neat 'open-toothed mouth' graphic on ea. side of the scoop, visible when open. The factory AF/X dragsters (Ford Thunderbolts) frequently deleted one or more of the round quad headlamps and replaced it with a round tube which ducted air to the carb. It wasn't until the end of the 1960's when automakers decided to tap the supply of air at the base of the windshield, and the 1971 GM F-body cars with their concealed windshield wipers, provided a location from-which to draw air to a ducted air cleaner. The 'cowl-induction' scoop which moved the air inlet much-closer to the windshield was another example, and was controlled in-opening by a vacuum circuit to the carb.

We have all seen the Japanese car commercial where the forced-induction engine empties a huge sealed chamber filled with colored air to demonstrate the pumping appetite of its design.

Anything which can improve the supply of air to the engine is going to benefit the engine's breathing, within limits. The pressurization of the airbox is minimally increased, but it is increased in a properly-designed system. For someone who is working in his small space who is not an engineer, he has achieved something of value. Whether it is of value to you depends on marketing forces, your "willingness-to-pay." Some people will buy it because it is rare, its cost prohibits many from getting it, and simply, because it works.

Trolling around at speeds of 50 mph and below, accelerating from a stop to redline in first gear, you are not likely to see much benefit as you would as in making a quarter-mile pass, but as you go faster, its value and performance become more tangible. Increase airflow to the engine, have the engine tuned to take advantage of it and your power increases. Who cares if it's on the order of 3-4%? That's more than the same bike without it.

In the pharmaceutical industry, companies spend hundreds of millions of dollars to bring new medications to market. If the new Rx does the same thing in terms of effectiveness for a given disease or illness as existing drugs already approved and on the market, it will be approved. If its costs to manufacture are less than existing drugs, so-much the better! If its side-effects are less than other approved and sold drugs, it goes to market because it allows more people access to treatment with fewer complications.

In the case of this ram-air system, probably the 'acid-test' would be to equip and tune the bike to run without it and then to do the same thing with it, after modifications to the bike to maximize the system's use are done. Quarter-mile and top-speed runs to establish a direct comparison are what is necessary to once-and-for-all settle the question of "does this system increase a motorcycle's performance?"

And, at bike nights across the country, the display of your bike equipped with a system no one else has, is reason-enough for someone to buy it.

 

[rebar]

And, at bike nights across the country, the display of your bike equipped with a system no one else has, is reason-enough for someone to buy it.

Well put. Thats me :eusa_dance:

Sadly I dont think I can get over the fact pushing unfiltered air into my engine. That and I want the Gen2 scopes for my bike.

Ricks scoops have filters.

http://homepage.mac.com/rg500delta/TL1000/Airbox%20design%20v2%20pressure.html

 

[Fire-medic]

'Rebar's' point:
Yep, "I have one, you don't!"
and
You can get Gen II style scoops for your Gen I bike, and a filter (the stock filter) is part of the design.

 

[rebar]

'Rebar's' point:
Yep, "I have one, you don't!"
and
You can get Gen II style scoops for your Gen I bike, and a filter (the stock filter) is part of the design.

The scoops I have were designed for Vgas keihin flat slide carbs.

I'm not the only one who has them. Spyder13 has them. A guy named Donovan and others.

These are the scoops I have, but the pics don't show the filter insert on the very front.
http://www.ramair4vmax.com/photo_gallery/photo_gallery3.htm

I like them so far. They look sick, but I still need to seal the scoops to the carbs with the thin rubber gasket supplied in the kit. They actually run richer than my open Vgas stacks at the moment probably due to the lack of a gasket at the carb and air filter. Not much spare time lately.

I honestly could care less if they don't produce more hp. I don't drag race and don't need to loose my license. But I bet I could talk most people into believing they do. cept you guys:biglaugh:

 

[KJShover]

Now here is a good read.

http://www.sportrider.com/tech/146_9508_ram/index.html

 

[mattness]

my bro and his wife both bought 2 brand new gsxr 600s in 05. he rode his home on the interstate and they trailered hers home, they did an actual break in on hers by the book and my brother would occasionally ride her bike, and it was ALWAYS faster than his. both same year, same day, same weight, same oil, everything.

so if someone is faster than you its just the way it happens bro

 

[Fire-medic]

And done in 1995 when Yamaha was going from the FZR/YZF to the R1, with the 'Max soldiering-along...

The car and truck guys pull all-sorts of engine data off their CAN-bus electrical engine management systems. The same should be able to be done w/the Gen II f.i. I assume. It's a lot more involved than simply running a wire from a sensor when you tap into those systems, though. Either you have to be an electronics tech or a mechanic who has been schooled on the data transfer systems to get into them. I haven't even mentioned an electrical engineer with a concentration in that particular field...

The Sport Rider article was a good read, kinda quaint how they refer to the Honda F3 & the Kawi 9 as their current frames of reference. That made me wonder while I was reading it 'why don't they use something contemporary?' Then I saw the published date at the end of the article.

 

[rebar]

my bro and his wife both bought 2 brand new gsxr 600s in 05. he rode his home on the interstate and they trailered hers home, they did an actual break in on hers by the book and my brother would occasionally ride her bike, and it was ALWAYS faster than his. both same year, same day, same weight, same oil, everything.

if someone is faster than you its just the way it happens bro

I cant agree with you on that one Matt. Looks like the break in had something to do with performance.
Back when I used to screw around with RC models I would hear about the fanatic racers dynoing multiple engines or motors and picking the best one. They aren't all equal.

The Sport Rider article was a good read That made me wonder while I was reading it 'why don't they use something contemporary?' Then I saw the published date at the end of the article.

That's enough data for me. Now who's going to develop a efi system to replace my keihin 39mm flat slides?

 

[Fire-medic]

Production tolerances. Isn't that what makes one faster than another? Luck-of-the-draw on random parts being assembled? Car racing has stories of the favored race teams being allowed access to parts storage at the assembly lines, measuring all the parts, looking for the 'correct' dimensions from which to assemble their 'regular production' engines. The British had a way of selecting the 'better parts' for their assemblies and then charging the customer for the hand-selection in those models. Unless you just outright flog unmercifully a new engine, I think it has more to do with production tolerances than break-in.

 

[gamorg02]

I cant agree with you on that one Matt. Looks like the break in had something to do with performance.
Back when I used to screw around with RC models I would hear about the fanatic racers dynoing multiple engines or motors and picking the best one. They aren't all equal.



That's enough data for me. Now who's going to develop a efi system to replace my keihin 39mm flat slides?

theres EFI options for you. you want them WITH ram air? i bet you could get someone to fabricate connectors to the 'real scoops' and go from there. get the 'learning' mode one for like $7k or whatever and ur golden.

 

[rebar]

theres EFI options for you. you want them WITH ram air? i bet you could get someone to fabricate connectors to the 'real scoops' and go from there. get the 'learning' mode one for like $7k or whatever and ur golden.

7K? ouch:biglaugh:


Let me screw around with the flat slides for a while. I'm a bit worried about the condition of these carbs. Im the third owner. First screw I removed was stripped. Tried to remove the float bowl drain and its torqued in there hard.:bang head:
I hope that's not a indication of the over all condition of these.
http://www.amazon.com/Loctite-Thread-Stripped-Thread-Repair/dp/B000WSEUII

 

[bobzdar]

Did you guys read the design info? .3psi boost vs. vacuum with the stock setup. Probably worth 5-6hp at 100mph. Not a ton, but also not just for show. Positive pressure in the airbox from 35mph up, so should also provide an economy benefit. The guy actually did his homework, using a pitot tube to measure airflow to determine how to shape the scoops to get the most airflow, manometer to measure pressure in the airbox etc. Not cost effective, but a nice setup.

 

[satariel666]

Did you guys read the design info? .3psi boost vs. vacuum with the stock setup. Probably worth 5-6hp at 100mph. Not a ton, but also not just for show. Positive pressure in the airbox from 35mph up, so should also provide an economy benefit. The guy actually did his homework, using a pitot tube to measure airflow to determine how to shape the scoops to get the most airflow, manometer to measure pressure in the airbox etc. Not cost effective, but a nice setup.

No, its not...

 

[bobzdar]

I think KJ is doing a good thing by pondering the issue, I don't agree w/all his input.

Cars can achieve low coefficients of friction, lower than a motorcycle, because of some fundamental differences. One is ground clearance. Bikes need it to corner, cars, not-so-much.

Another is air beneath the vehicle which contributes to drag. Cars again are better at this than bikes because they can use ground-effects bodywork to greatly lessen the drag of air allowed under the car. Again, bikes cannot really achieve this to the extent of cars. Cars can use bellypans to smooth the flow of air which does intrude underneath. Sports-racing cars such as Jim Hall?s notorious Chaparrals used a variety of methods to seal air from intruding under the car, including body panels which were an interference fit to the ground, and even small engines which evacuated air from beneath the car to create a ?low-pressure zone? underneath (the 2J ?sucker-cars?, see ?em on youtube). This was hugely successful, and was soon outlawed in competition, but not before others tried it.

The faired design underneath at the front and rear of nearly any car today is there to promote the efficient flow of air under it entering and exiting. The less disturbance of the air next to the body surface, the less drag, this is called 'optimal laminar flow' and has been used since the time of WW I in both cars and planes on, of course, both the topside and the underside. Here is an article about basic aero principles from the civilian branch of the USAF: http://www.cap-ny153.org/forcesdrag.htm

Third, the coefficient of drag for bikes is far-greater than cars. Bikes are around the .40 mark where production cars are able to get below .30. Marketing and oddly-enough, racing has a hand in this. Remember the BMW K1? It was one of the most completely-faired bikes of modern times, and it was not a big seller. That may be due to the cost compared to what other bikes which offered more speed for less $. Still, it was a legitimate 150 mph motorcycle, BMW's first for consumers, and its aero shape was a big contributor to its top speed performance. Look at its front wheel, covered nearly entirely except for its contact patch and to provide cornering clearance, the design is what pilots refer to as 'wheel spats.' And of course, the rest of the bike's faired design showed many hours in the wind tunnel to reduce drag by reducing frontal area, and by allowing the disturbed air to maintain its 'laminar flow' across the body contours, and then to re-join airflow from the opposite side of the body at the rear of the bike. Remember the Porsche 917's that did 250 mph at LeMans, with the long, tapering tail? It was there to allow the air to converge smoothly as it left the main vertical body cross-section. A German engineer arrived at a 'fix' for having such a taper, his name was Kamm, and what he did was to abruptly chop-off in a vertical plane the end of the body after its widest point. While not as-efficient as the long, tapering tail, it did allow a more-compact design.

I mentioned racing as contributing to drag. In the 1950's, the FIM outlawed the use of fairings where the front wheel was enclosed by the same fairing as the body, the so-called 'dustbin' fairings. These proved to be very unstable at higher speeds in the presence of a crosswind especially at places like Spa in Belgium. They also mandated the body fairing had to allow the front wheel contour to show itself and to not be covered by the fairing body. We now accept this as a fundamental part of motorcycle design, and it has become 'normal.' The main body fairing curvature to the arc of the front wheel is what we expect to see, and it provides space for the radiators which have grown larger and more-numerous with the increases in engine output.

KJ's example of the different-sized holes in cardboard as examples of motorcycles 'grabbing too-much air' is correct in the size of the hole affects the ease with which the blunt object passes through the air, but ignores the differences in the size of the engines, their pumping of air through them, and the rpm's at-which they operate. Since most motorcycle engines operate at rpm speeds of twice or three times the rpm-speed of cars, they pump more air for a given displacement. Thus, they need correspondingly-greater amounts of air available to them than the lower-flowing by virtue of lower-rpm car engines.

The air scoops of the 1960's and 1970's muscle cars were crude devices which owed their existence as much to the marketing department as to the powertrain department. Sometimes the presence was entirely marketing, as in the 1970's Pontiac Firebird Trans Am's with their famous 'shaker hood scoops,' which was solid and had no opening for air to enter! But, in the fast-food restaurants, high-schools, college campuses, and workplace parking lots, the Trans-Am was king in style if not in maximum performance.
The Plymouth Duster and Dodge Demon with their functional scoops, were ahead of the Trans-Am in functionality, but the area of the opening was small, and its benefit came principally from being able to show your buddies how you could control its opening, and proudly display the neat 'open-toothed mouth' graphic on ea. side of the scoop, visible when open. The factory AF/X dragsters (Ford Thunderbolts) frequently deleted one or more of the round quad headlamps and replaced it with a round tube which ducted air to the carb. It wasn't until the end of the 1960's when automakers decided to tap the supply of air at the base of the windshield, and the 1971 GM F-body cars with their concealed windshield wipers, provided a location from-which to draw air to a ducted air cleaner. The 'cowl-induction' scoop which moved the air inlet much-closer to the windshield was another example, and was controlled in-opening by a vacuum circuit to the carb.

We have all seen the Japanese car commercial where the forced-induction engine empties a huge sealed chamber filled with colored air to demonstrate the pumping appetite of its design.

Anything which can improve the supply of air to the engine is going to benefit the engine's breathing, within limits. The pressurization of the airbox is minimally increased, but it is increased in a properly-designed system. For someone who is working in his small space who is not an engineer, he has achieved something of value. Whether it is of value to you depends on marketing forces, your "willingness-to-pay." Some people will buy it because it is rare, its cost prohibits many from getting it, and simply, because it works.

Trolling around at speeds of 50 mph and below, accelerating from a stop to redline in first gear, you are not likely to see much benefit as you would as in making a quarter-mile pass, but as you go faster, its value and performance become more tangible. Increase airflow to the engine, have the engine tuned to take advantage of it and your power increases. Who cares if it's on the order of 3-4%? That's more than the same bike without it.

In the pharmaceutical industry, companies spend hundreds of millions of dollars to bring new medications to market. If the new Rx does the same thing in terms of effectiveness for a given disease or illness as existing drugs already approved and on the market, it will be approved. If its costs to manufacture are less than existing drugs, so-much the better! If its side-effects are less than other approved and sold drugs, it goes to market because it allows more people access to treatment with fewer complications.

In the case of this ram-air system, probably the 'acid-test' would be to equip and tune the bike to run without it and then to do the same thing with it, after modifications to the bike to maximize the system's use are done. Quarter-mile and top-speed runs to establish a direct comparison are what is necessary to once-and-for-all settle the question of "does this system increase a motorcycle's performance?"


And, at bike nights across the country, the display of your bike equipped with a system no one else has, is reason-enough for someone to buy it.

Just fyi, the scoop was fully functional on trans ams until '74 (it had a solenoid operated flap), at which point it would no longer pass drive by noise standards and they had to close it. It operated under the same principle as cowl induction, pulling high pressure air from the windsheild base. The later trans am scoops are easily opened and made functional...

 

[one2dmax]

How about some math. The stock engine with a good pipe and jet kit will make say 125rwhp. It's going to be somewhere around 85% VE (Efficiency). Standard Atmoshpheric pressure is approx 14lbs so if you could force the equivalent amount of boost into the engine you could double the engines effective size. So, 14lbs of boost would be 250rwhp. The engine does gain some effeciency but most power adders require power to make power so their effeciency isn't that much. A roots style blower is maybe 30-40% effecient and the best turbos are maybe 80-90%.

BUT, you also lose power on them due to heat generated by the compression process (boyles law). So, the effeciency suffers again. You can offset this by intercooling but then that creates some restriction and loss of effective boost (though you make more power with less boost since it's colder air).

In a perfect gain to make this easy:
125 HP
divided by 14 (to get the gain per lb of boost)
equals 8.9 HP

Divide that number by 30% (.3psi) and you get 2.67 HP. So, keep in mind this is without any correction factors at all. So, the real world number is likely 1.5-2hp. Not worth farting into a can to sniff.

Sean

 

[KJShover]

So, the real world number is likely 1.5-2hp. Not worth farting into a can to sniff.

:rofl_200::rofl_200:

http://www.youtube.com/watch?v=OM9jhGiIAFM

 

[MaxMidnight]

Quote: "Not worth farting into a can to sniff."

I guess that would depend on what you had eaten or drunk the night before?......

Shall I shut the door behind me as I leave?

 

[satariel666]

How about some math. The stock engine with a good pipe and jet kit will make say 125rwhp. It's going to be somewhere around 85% VE (Efficiency). Standard Atmoshpheric pressure is approx 14lbs so if you could force the equivalent amount of boost into the engine you could double the engines effective size. So, 14lbs of boost would be 250rwhp. The engine does gain some effeciency but most power adders require power to make power so their effeciency isn't that much. A roots style blower is maybe 30-40% effecient and the best turbos are maybe 80-90%.

BUT, you also lose power on them due to heat generated by the compression process (boyles law). So, the effeciency suffers again. You can offset this by intercooling but then that creates some restriction and loss of effective boost (though you make more power with less boost since it's colder air).

In a perfect gain to make this easy:
125 HP
divided by 14 (to get the gain per lb of boost)
equals 8.9 HP

Divide that number by 30% (.3psi) and you get 2.67 HP. So, keep in mind this is without any correction factors at all. So, the real world number is likely 1.5-2hp. Not worth farting into a can to sniff.

Sean

You forgot to add that 2hp will boost only at 150 mph :rofl_200:


Serioulsy, if you cant afford Rotrex supercharger then invest some money into big bore and lower end reinforcments - thats the real gain.
Just IMO...