Author |
Message |
Skylerxb12r
| Posted on Tuesday, August 19, 2008 - 08:54 pm: |
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Has anyone built anything for the 1125r? I have been brainstorming something XBRR'ish with scoops toward the top of the windshield. Considering how well the bikes run without the inner airbox lid it is apparent that the factory inlet scoop is a bit undersized for operation below 80mph. A couple of, say 2 1/2", diameter tubes routing fresh air through the top of the airbox would seem to at least provide more slow speed air and maybe even more high speed "boost." Thoughts? |
Buellborn
| Posted on Tuesday, August 19, 2008 - 10:59 pm: |
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WooHoo! More scoops? |
Tijuanajack
| Posted on Wednesday, August 20, 2008 - 12:23 am: |
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I've thought about it but haven't been able to find that kit. If any one does please let us all know. |
Geforce
| Posted on Wednesday, August 20, 2008 - 06:56 pm: |
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Turbocharger is what we need, this is the only vehicle I own without one on it....so far... lol But I like her just the way she is. |
Trojan
| Posted on Thursday, August 21, 2008 - 05:10 am: |
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Considering how well the bikes run without the inner airbox lid it is apparent that the factory inlet scoop is a bit undersized for operation below 80mph. Ram air does nothing below around 100mph, so making something for below that speed is a waste of time I'm afraid. At best it could channel some cooler air to the airbox but there would be no ram air effect. The stock 'ram air' scoop is large enough that airflow is not restricted at 'normal' speeds, so ram air would only be of benefit at extreme race speeds anyway. A lot of what you see as 'ram air' on modern production bikes is just fashion and has no real benefit interms of increased airflow. |
Oddball
| Posted on Thursday, August 21, 2008 - 07:17 am: |
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Wasn't there a claim, statement or some such on here recently saying that benefits of the ram air on the 1125 began at 80? Granted, it still exceeds posted limits but is more easily reached and benefited from if so. My last ride that was just faster than the average of the traffic pack. I'd also like to think if the XBRR's ram air design was a benefit to the 1125 it would have been used. If an 1125RR ever hits the tracks i guess we'll know. (Message edited by Oddball on August 21, 2008) |
Xl1200r
| Posted on Thursday, August 21, 2008 - 09:02 am: |
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Wasn't there a claim, statement or some such on here recently saying that benefits of the ram air on the 1125 began at 80? Granted, it still exceeds posted limits but is more easily reached and benefited from if so. My last ride that was just faster than the average of the traffic pack. Matt says 100mph, Buell says 80mph, and both fall into the range that I've heard since I can remember. Slower than that, and you just can't build up enough pressure to make a difference. True, 80mph is easily obtainable on freeways and some more open back roads, but the ram-air effect is only going to really matter when you're at WOT - meaning, you need to be at 80mph and willing to blow right past it. |
Slaughter
| Posted on Thursday, August 21, 2008 - 09:20 am: |
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It is really NOT ram air - as others have stated. I've seen some of them more accurately referred to as cool air intakes. Cooling induction air is good - but doesn't buy you much in exchange for obnoxious ducting. |
Black_snowman
| Posted on Thursday, August 21, 2008 - 12:54 pm: |
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It's always bothered me a little that it pulls air in after it comes out of the radiators (at least if you're going slow enough). Moving the intake up to the airbox probably wasn't an option for noise reasons, and they still had to put in the silly solenoid to make the .gov happy. |
Skylerxb12r
| Posted on Thursday, August 21, 2008 - 04:41 pm: |
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Took a few measurements this afternoon and came up with the following: Cross sectional area of fresh air (ram air) passage at the scoop/lower air box junction is roughly 5.1 in^2 and the combined throttle body cross sectional area is a little over 9 in^2. It seems that the snorkel could definitely be a restriction. Twin ram air passages with a section area of 2.5 in would at least equal the section area of the throttlebodies. If the reports of fairly substantial hp gains by running without the upper airbox (I have read claims of 8hp) are true then it seems that a larger fresh air opening would be beneficial. It is unfortunate that the frame restricts the size of the tube coming in through the bottom. Seems like the only way for a larger inlet is going to be through the top. |
Madduck
| Posted on Thursday, August 21, 2008 - 05:21 pm: |
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If you want to improve "breathing" at street speeds, think of a large "still" airbox volume for the two cylinders to draw from when they need to. Ramming air in is quite unproductive. Think chevy induction cowling pullin air in from the lower edge of windshield. Twins are pretty big cylinders lto fill so all you need is roughly 4 times the volume of a cylinder. Pressurizing or ramming is damn hard to do for large displacement twins. A lot of racers prefer to design exhaust systems that "pull thru" for a given range of rpms. Sucking is quite often more effective than ramming. |
Black_snowman
| Posted on Thursday, August 21, 2008 - 05:46 pm: |
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"Sucking is quite often more effective than ramming." - Madduck I bet this gets quoted a LOT on the board from here on out. |
Xl1200r
| Posted on Thursday, August 21, 2008 - 05:55 pm: |
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Cross sectional area of fresh air (ram air) passage at the scoop/lower air box junction is roughly 5.1 in^2 and the combined throttle body cross sectional area is a little over 9 in^2. It seems that the snorkel could definitely be a restriction. You're assuming that the throttle bodies are trying to pull in air 100% of the time. Valves open and close. Each throttle body only opens one at a time, and only for 25% of the time (appx for a 4-stroke engine). That means that HALF of the time, ONE of the TBs is open. The other half, both are closed. 9 sq in x 25% = 2.25 sq in. The opening *shoudln't* be the resriction. Madduck - interesting bringing up the cowl-induction stuff... I wonder if it would be benneficial to draw air in from the rear of the bike where temperatures are cooler on the 1125? Or perhaps extending the existing ram-air scoop forward so that the air it pulls in is ahead of the output from the radiator fans? |
Skylerxb12r
| Posted on Thursday, August 21, 2008 - 06:14 pm: |
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I am more concerned with providing sufficient cold air for slow(er) speed use than trying to increase the ram air effect. I realize that the induction pull through the throttle body is by no means steady or at full demand all of the time. At 10,000 rpm at full throttle the the intake events are happening about 840 times/sec so we can treat it as a steady draw. I have a crude experiment set up where i have a vacuum guage tapped in to the airbox so i can determine if the engine is able to create a negative pressure in the box at high engine speeds. I'll be back shortly with some results. |
Xl1200r
| Posted on Thursday, August 21, 2008 - 06:54 pm: |
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At 10,000 rpm at full throttle the the intake events are happening about 840 times/sec so we can treat it as a steady draw. But unless you're also magiclaly changing the cam timing, the TB's are still only pulling about 25% of the time, no matter how fast the cycles are. Regardless of how fast you spin the motor, the ratio of the intake valves being open to them being closed remains the same. I'm interested to see how your experiment works out. You should be able to do it with the bike sitting still in neutral. |
01xjbuell
| Posted on Thursday, August 21, 2008 - 08:12 pm: |
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I just removed the ring around the fuel fill and used the cut out version of my XB's fuel fill surround. Not very scientific at all, but seems to have better throttle response. Ah, and forgot to mention, with the inner cover off, this thing is LOUD @ WOT. Intake is MUCH louder than exhaust (Message edited by 01xjbuell on August 21, 2008) |
Black_snowman
| Posted on Friday, August 29, 2008 - 04:51 pm: |
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I love that intake sound I took my inner airbox cover off and changed nothing else. Don't have a dyno so can't answer to power but it smoothed out the motor a bit. I get barely any loping even at idle, it can idle in 1st with only the occasional little jerk. It's also much smoother on clutchless shifts. At 1st I thought I was just getting lucky or the weather but I've been running it for a few days now and it's definately better. |
Kttemplar
| Posted on Friday, August 29, 2008 - 05:53 pm: |
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Skylerxb12r, sportrider.com did some testing on various ram air systems in the past, I don't know if you have seen the data. Here is the link, since you are going down the same path. It is not of the 1125R, but the testing and theory might answer some questions for you or give you some ideas. I thought the stuff was interesting. http://www.sportrider.com/tech/146_9508_ram/index. html Mike |
Cutty72
| Posted on Monday, September 01, 2008 - 09:23 pm: |
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I did a dyno run with and without the inner air box, within a couple days of each other. There was less than a half hp difference. Don't care, sounds better and that's all that matters. |
Mustangturbo
| Posted on Friday, September 05, 2008 - 05:14 pm: |
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I think that water sprayers inside of the pods would help to ditch some heat in a hurry. It wouldn't be hard to find a place to put a half gallon of water. I bet it would kill 10 degrees in a hurry while its on its way down the road. |
Mikellyjo
| Posted on Friday, September 05, 2008 - 05:18 pm: |
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Imagine what the sanctioning bodies would say when Buell presents a model with water sprayers. Heck it's hard enough to get a belly pan to hold the fluids inside the engine let alone the over spray. Great idea though for the street...like a shot of gatorade on a hot day for the beast. |
Easyrider
| Posted on Sunday, September 07, 2008 - 02:59 am: |
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Cutty72, I did the same, only added fuel to the WOT range and won 6 RWHP and 5 NM of torque?... without air filter and a closed airbox.. I can't believe somebody would like to drive like this all the sand and dirt comes in the engine.. But the air is a ristrictor. I mapped the bike with K&N and won 8 HP and 7 NM of torque only it runs after i mapped it much smoother over the whole range.. I wil post results later in other topic. The topic is called So where do we learn. (Message edited by easyrider on September 07, 2008) |
Oddball
| Posted on Sunday, September 07, 2008 - 07:06 am: |
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Maybe some co2 spray for a quick radiator cool. http://www.nipponpower.com/product.phtml?p=1034 |