Ram Air Effect - Yamaha R6 Forum: YZF-R6 Forums
Reply
 
LinkBack Thread Tools Display Modes
post #1 of 35 (permalink) Old 06-21-2004, 01:01 PM Thread Starter
I eat my R6
 
Join Date: Jul 2003
Location: Bridgeport, CT
Posts: 4,159
Send a message via MSN to penfold
Ram Air Effect

All Info obtained from SportRider.com at these two url's.....

To view links or images in this forum your post count must be 5 or greater. You currently have 0 posts.
&
To view links or images in this forum your post count must be 5 or greater. You currently have 0 posts.

Only the Info pertinent to our bike is included here. As you can see, the Ram Air effect is no myth........atleast on the carbed bikes. I'm currently inquiring of SportRider to see if they plan on doing this with the FI version of our bikes and some of the others.
__________________________________________________ ___________

RAM AIR TEST (This story originally appeared in the October 1999 issue of Sport Rider.)
Finding out who's flowing and who's blowing
By Kent Kunitsugu
Photography: Fran Kuhn

The sales pitch has been long and heavy: "incredible volumetric efficiency"; "large volumes of high-pressure air...significant boost in high-rpm horsepower"; "force-fed, pressurized air results in...major increases in horsepower and torque." Ram air is one of the most highly touted advances made for sportbikes in recent years, yet its benefits are rarely objectively stated, or scientifically evaluated. First appearing on Kawasaki's ZX-11 model in 1992, ram-air induction has now become de rigueur; virtually all sportbikes these days come equipped with gaping air intakes on their fairings, along with the proclamations stated above.

Theory

The basic concept behind ram air is that a moving bike will stuff air into its forward-facing intake runners, resulting in a free supercharging effect. As speed increases more air is forced in, resulting in more power and, in turn, more speed. The faster you go, the faster you'll go. The first impression upon viewing the gaping maws of some ram-air-equipped bikes is that an enormous amount of pressure must be built up at high speeds, but this is not so. As air is jammed into the opening, the high-pressure area that is created builds outward, effectively stopping more air from entering. Picture a balloon being inflated with an air tank. If the balloon is sealed to the nozzle, it will expand easily. Hold it slightly away from the nozzle, however, and the balloon will only inflate so far.
The pressure build-up can be defined using the Pitot-static tube theory:

P = .5 x r x v2

Pressure (P) is force divided by an area. In the English system of measurement the units of pressure are (lb - force)/in2 which translates to psi. Density (r) is mass divided by volume. The units of density in the English system are (lb - mass)/in3. Velocity (v) is air speed, with units ft/sec. Plotting pressure vs. speed gives a graph that has theoretical pressure rising with the square of speed, and this is why ram air has much more effect at greater speeds. For a speed of 150 mph, the resulting maximum theoretical pressure would be about 27mb (approximately .4 psi). Millibar (mb) is a metric unit for pressure. We used millibar instead of psi to give more workable numbers.

Of course, this air has to find its way to the carb mouths, and there is some loss due to the inefficiency of intake runners and the airbox itself. Without going into a lot of theory, suffice it to say that efficiency depends on the relative areas of the fairing intake, airbox intake and the airbox itself; even with a good system the loss can be as much as 70 percent. There is also the niggling problem of the engine gulping air from the system. This will lower the efficiency further, especially at higher speeds.

The test: Part One

So how much horsepower is ram-air induction really worth? Astute SR readers will recall Jon Doran's ram air/dyno test (Ram air: What's it worth?") in the August '95 issue. While the article was well done, we decided to take the concept a step further. We took one of Pi Research's advanced, System 3 data-acquisition systems and hooked up one of its air-pressure sensors into the airbox of eight different modern sportbikes. We also mounted a wheel-speed sensor which allowed us to precisely measure and compare roadspeed with airbox pressure. Absconding with all the motorcycles to our top-secret, high-desert test site, we then proceeded to wring the piss out of each machine and gather data from each of the top-speed runs.

The results will-as Doran stated in his test four years ago-surprise you. All ram-air induction systems are obviously not created equal. In the following graphs, the upper line denotes wheel speed and the lower line represents airbox pressure.

YAMAHA YZF-R6: First up was Yamaha's 15,500 rpm YZF-R6. Note that the pressure drops below zero-that is, below ambient pressure-accelerating through second gear, and it finally builds once the bike gets past 85 mph. The spikes (present in all of the graphs) represent pressure buildup during shifts, since the throttle plates are closed momentarily. Pressure peaked at 17mb.

To view links or images in this forum your post count must be 5 or greater. You currently have 0 posts.


Note: In the next issue of Sport Rider, we will complete the second part of this test by pressurizing the airboxes on each of the bikes to the amount measured by the Pi System-while running on the dyno-to find out just how much power ram air is really worth. See Ram Air Test: Part Deux.

Ram Air Test: Part Deux (This story originally appeared in the December '99 issue of Sport Rider.)
Does it work? Pressurizing the airboxes of seven sportbikes on the dyno to see just how much horsepower ram air is worth.
By Kent Kunitsugu

It's crunchtime, ladies and gentlemen. After gathering hard information on the exact amount of airbox pressure present at speed in various ram-air-equipped sportbikes, via Pi Research's System 3 data-acquisition system, the time has come to strap these bikes to the dyno and see how much additional power is really available. This is where Sport Rider finally answers the question of whether all this ram-air horsepower hype is a measurable performance increase or nothing more than advertising smoke and mirrors.

We took the ram air data, seven current sportbikes and the Pi data-acquisition system to Two Brothers Racing in Santa Ana, California (
To view links or images in this forum your post count must be 5 or greater. You currently have 0 posts.
), where proprietor Craig Erion would run the bikes on his Factory EC997a Eddy Current dyno. The Eddy Current dyno was chosen because of its ability to hold a steady rpm; this made it a lot easier to set the correct airbox pressure, compared with the common Dynojet dynos that can only make a complete run through the rpm range. With the Pi System 3, measuring the airbox pressure at speed for the first segment of our ram air test was a simple task. And its sophisticated software permits the user to view the pressure data in real time using a laptop computer. This gave us the chance to set the pressure on the dyno to the same parameters derived from the previous top-speed test.

Our biggest obstacle to completing this experiment was figuring out a way to force enough air into each of the airboxes to simulate the pressure encountered at speed while running on a dynamometer. There is an incredible amount of wind energy at 150 mph. If you've ever popped up out of the bubble while braking for Turn One at Daytona, or even stuck your hand out of a car's window while traveling faster than 130 mph, you know what we mean. We required more than a fan setup that ran up huge cfm (cubic feet per minute) numbers. It would need to supply that volume at pressures above ambient, requiring a large, high-horsepower fan and the necessary ducting-not something readily obtained without spending huge amounts of money, nor easily built and mounted in the limited space and time we had available. Several fan options were tried but none could provide the amount of pressure we needed.
The setup we finally used may seem a bit unorthodox but it definitely gave us the necessary amount of wind energy and pressure. A pair of huge 185 cfm portable air compressors normally used with jackhammers were employed, and the requisite three-quarter-inch hoses directed the airflow. For the smaller bikes, we only needed to direct one compressor hose at a distance from the ram-air inlet to get the necessary pressure. The larger bikes, however, required us to use both hoses and, in some cases, seal up one side of the ram-air inlet while force-feeding the other.It should be noted that Eddy Current dynos typically give horsepower readings 15-20 percent lower than the more common Dynojet dyno readings. We started each run at 7000 rpm (both with and without ram-air assist), since we figured all of our top-speed data was gathered using full throttle and anything less than 7000 rpm in top gear would offer inconsequential ram-air pressure/data. Also, although many will argue that using air compressors brings up the issues of heat (compressing air raises its temperature) and moisture (compressing air also condenses the moisture in that portion of air), these graphs are basically relative in nature and the increase in air temperature and the amount of moisture condensation present were negligible.

Unfortunately, two bikes that were present during the top-speed data sessions had to be returned before we could begin the dyno sessions. Both the Kawasaki ZX-7R and ZX-9R are missing from these tests. However, we did manage to procure a Honda CBR600F4 and Kawasaki ZX-6R to take their places.

On each of the dyno graphs, the bold lines represent ram-air-assisted readings-solid for horsepower, dotted lines for torque. As we stated in "Ram Air Test: Part One" in our October issue, the results will definitely surprise you.

YAMAHA YZF-R6: Here is obvious proof that ram air works on smaller-displacement engines. Ram air helps the R6 hold its peak power higher and longer (12,000-14,000 rpm), and the torque curve is higher and flatter as well. This isn't just an incremental increase on top, either. We're talking about an average difference of five horsepower through the midrange and a far more usable power spread. The ram-air assisted reading would probably be higher at 13,000 rpm, but we were unable to generate the required airbox pressure on that particular run at that point. To give a relative reference, without ram air the Yamaha registered -11mb. Again, remember the lower peak-horsepower reading of 84.4 is due to the Eddy Current dyno.

To view links or images in this forum your post count must be 5 or greater. You currently have 0 posts.
penfold is offline  
Sponsored Links
Advertisement
 
post #2 of 35 (permalink) Old 06-21-2004, 11:19 PM
I eat my R6
 
Join Date: Jun 2004
Location: Oxnard, CA
Posts: 106
Re: Ram Air Effect

Quote:
Originally Posted by penfold
__________________________________________________ ___________
RAM AIR TEST (This story originally appeared in the October 1999 issue of Sport Rider.)
Finding out who's flowing and who's blowing
By Kent Kunitsugu


Picture a balloon being inflated with an air tank. If the balloon is sealed to the nozzle, it will expand easily. Hold it slightly away from the nozzle, however, and the balloon will only inflate so far.

A balloon doesn't have four carburetors, or throttle bodies, in the bottom of it inhaling all the air they possibly can.



Can I get an AMEN?

Miraclegrau's mechanic, among other things...


Big_Perm is offline  
post #3 of 35 (permalink) Old 06-21-2004, 11:23 PM
I eat my R6
 
Join Date: Nov 2003
Location: Tyler TX
Posts: 4,022
Send a message via MSN to loki1313 Send a message via Yahoo to loki1313
man, i think ive just overloaded my brain, but htanks for the great info pen
To view links or images in this forum your post count must be 5 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
loki1313 is offline  
 
post #4 of 35 (permalink) Old 06-22-2004, 12:13 AM
I eat my R6
 
Join Date: Aug 2003
Location: Green Bay, WI
Posts: 112
Whether or not the engine is fuel injected or carbureted has no effect on the ram air effect. The same air is going into the engine. The only difference is how the fuel is mixed with the air and the shape of the air limiter(slides or butterfly valves). The main thing you should ask Sport Rider is how much different the shape of the intake tract and airbox is. If it is very close, chances are the FI bikes will be making the same hp gain as the carbed bikes. I would bet if anything, Yamaha made the intake better, allowing more of a ram air effect to occur on the FI bikes. My two cents...
jar1075 is offline  
post #5 of 35 (permalink) Old 06-22-2004, 12:18 AM
I eat my R6
 
Join Date: Jun 2004
Location: Oxnard, CA
Posts: 106
Quote:
Originally Posted by jar1075
Whether or not the engine is fuel injected or carbureted has no effect on the ram air effect..
The question is: is the balloon fuel injected or carbureted??? Either way, I'll bet the balloon puts out about the same HP.

Miraclegrau's mechanic, among other things...


Big_Perm is offline  
post #6 of 35 (permalink) Old 06-22-2004, 12:22 AM
I eat my R6
 
Join Date: Sep 2003
Location: Oxnard, CA
Posts: 327
uh

THERE IS NO SPOON
To view links or images in this forum your post count must be 5 or greater. You currently have 0 posts.

call guiness..

Char
miraclegrau is offline  
post #7 of 35 (permalink) Old 06-22-2004, 07:14 AM Thread Starter
I eat my R6
 
Join Date: Jul 2003
Location: Bridgeport, CT
Posts: 4,159
Send a message via MSN to penfold
Quote:
Originally Posted by Big_Perm
The question is: is the balloon fuel injected or carbureted??? Either way, I'll bet the balloon puts out about the same HP.
add some Kanji stickers on it for even more gain.......

I bet the balloon is carbed tho. maybe we should find the merovingian as he might have the answers or atleast a hot piece of ass we can stare at. or possibly the key maker could unlock the mystery to this?

my question as to carbs vs FI was basically if one was more efficient at passing air than the other. I guess like jar said it would depend on the shape of the intact tract and other things such as the shape of and the diameter of the throttle bodies but given the existing carbs off of a '99 model and the TB's off an 03, all things being equal, which flows better as that would impact which one can gulp down more air.......
penfold is offline  
post #8 of 35 (permalink) Old 07-16-2004, 04:19 AM
I eat my R6
 
Join Date: Sep 2003
Location: UK
Posts: 330
The weird thing is that when a magazine in the UK tested the Ram Air effect on the ZX9R, which was supposed to have several chanbers and servos to adapt to changing speeds etc and so was the most advanced ram air in the world, they found no difference in performance and speed or acceleration either on the dyno or on the test track - they did runs with the ram air and runs with the intakes all covered up with duct tape and saw no difference what so ever...

I guess the debate continues...

Regards

Peter Sorrell
Wolf Racing

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Wolf is offline  
post #9 of 35 (permalink) Old 09-14-2005, 06:38 PM
My R6 eats me.
 
1st06r6's Avatar
 
Join Date: Sep 2005
Location: milpitas ca
Posts: 17
Bike: 06 R6

To view links or images in this forum your post count must be 5 or greater. You currently have 0 posts.
[QUOTE=jar1075]Whether or not the engine is fuel injected or carbureted has no effect on the ram air effect. The same air is going into the engine.


fuel injected or carburetors are you for real. A fuel injected motor will make more power over a carb any day. a carb has one setting it only know how much fuel to give depending on your jetting so if you have ram air your bike goes from fat to lean and .... fuel injection has all them sensors to tell the bike how much fuel it needs for all that air and that builds power. if that dose not help you under stand I'm sorry there are many other variables but that is the most important


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
1st06r6 is offline  
post #10 of 35 (permalink) Old 01-21-2006, 07:17 AM
I eat my R6
 
Tycho C's Avatar
 
Join Date: Jan 2006
Posts: 105
?

So how does an FI R6 know how much air is going into the engine? There is no pressure sensor, only temp and RMP sensors that tell it how much SHOULD be going in. I have a limited understanding of FI but I would think simply upping the pressure would lean it out without remaping (say if you added a turbo). Vacuum system?
Tycho C is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Yamaha R6 Forum: YZF-R6 Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
Do Bends Effect Power.. Wolf Exhaust and fuel delivery 29 07-05-2011 11:13 PM
Ram Air Effect penfold Exhaust and fuel delivery 4 02-03-2010 03:26 AM
Type of Gas in Colder Weather 91 or 89 cause and effect ???? Shawbitz General Discussions 15 11-27-2004 02:00 AM
Yamaha R6 Neon/Ground Effect Kit?? xxxxxxxxxxxxPolish General Discussions 5 01-27-2004 02:07 PM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome