| Author | Message | ||
     Od_cleaver |
I think that the seat dam serves a couple of purposes. The outer features provide some support for the seat. The inner web keeps metal items we might carry in the area behind the battery away from the battery terminals. The best solution would be one that directed the hot air away from the rider and bike in the shortest path possible with the smallest restrictions to air flow as possible. Perhaps Buell has part of the solution with the air deflector kit. I will order one today so that I can play in this experiment with you guys. This leaves the air restriction problem. On the right side we have the rear brake reservoir. On the left side we have the bundle of wires. At idle with the fan running, most of the hot air that I feel is pushed past this brake reservoir. I don't remember feeling much air flow thru the wire bundle side. Both left and right frame openings look to be the same size. Has anyone tried to open up the wire bundle and reform it to open up this area for more air flow? I keep wondering if Buell had an EC to the wire bundle late in the development cycle and forgot about air flow. A simpler solution might be to open up the right side more by moving the brake reservoir to the pocket behind the battery. However, from the pictures that I have seen, this probably would make the right side air deflector the new restriction point. | ||
| Thelumox |
i just did 100 miles with the bungee covers off and tool kit removed. there is less heat on my right thigh for sure. my fan only comes on when i shut the engine off, and i could feel hot air coming out of the bungee holes, as well as down through the shock cavity (and out the right/left side). i'll be watching this thread to see what others come up with. | ||
| Electraglider_1997 |
Thelumox, I'm glad you are seeing good results. Here's my first report. I just did 77 miles of mostly highway speed miles, 60 to 70 mph. I'll preface this by saying it is only 80 degrees outside because we had a nice storm go through late last night. My fan did not come on until about 35 miles and it ran until I pulled over at 60 miles. At the 60 mile mark my swingarm oil tank thermometer was at 179 degrees (perfect). The bottom right side gas tank was warm but not hot and I could hold my hand against it without any burning sensation at all. The top of the ECM and battery were warm but again they were not any hotter than probably 100 degrees F. The fan cycled off after a minute or two and I road another 17 miles. The fan did not come on again until I got the ULY into my garage and shut the engine off. Since the last 6 miles were city miles the oil was at 190 degrees F at the swingarm oil tank when I looked at it in my garage at engine shutdown. The gas tank was warmer but I could still hold my palm against it without injury. During the entire ride my right leg felt fine and never felt like it was ready to spontaneously combust like it normally has. Much of the ride I felt no heat on my leg at all. I feel "flowing the air" back through the under-seat really makes a difference in comfort and certainly the price is right. It makes sense because the left side is clogged full of wire harness so air can't easily go out that way so it flows to the paths of least resistance which is to the right and down the shock area. By opening a new path through the under-seat area the heat that normally dead ends in the ECM/Battery area is able to escape and I believe they are now cooler because of this. The real test will be when it's over 90 degrees out. | ||
| Electraglider_1997 |
Thelumox, What was the temperature out while you were doing your 100 miler? And how fast were you riding? (Message edited by electraglider_1997 on July 27, 2007) | ||
| Thelumox |
this morning it was 80F, chilly for central florida. two hours later it was around 88F. all speeds, and the last 10 miles or so was in town. normally i wear textile padded riding pants that insulate me from the right side heat. today i rode in jeans, which usually results in a "cooked" leg. i can still feel the hot air, but i think it is much better. i have a RSS from american sportbike. BTW, what is this heat deflector? i haven't seen anything except the shields that Odie at specialOPS sells. | ||
| Electraglider_1997 |
Thlumox, Click here http://www.buell.com/en_us/gear/accessories/Produc t.asp?Menu_ID=2&ProductLineID=2&CategoryID=5&Produ ctID=4139 | ||
| Thelumox |
thanks. | ||
| Jameslaugesen |
Looks pretty convincing. I've almost finished wiring the thermometers up, then I will do some experiments, hopefuly with numbers for you's. It would be cool if Packdog could do a few experiments with those temperatures loggers too. I like the idea of opening up the sides more; tidy wiring, etc. | ||
| Hughlysses |
I got my deflectors in yesterday and installed them tonight. I removed my Special Ops side heat shields but reinstalled the top one. It doesn't look like it'll do anything to impede the airflow and should (a) help insulate the seat from the heat and (b) help keep hot air from "leaking" out around the front edges of the seat. I'll do a test ride tomorrow to see how this combination works. I'm interested in seeing if the rear brake reservoir can be moved a little on the right and the wire bundle moved a little on the left without too much difficulty to make it easier for the hot air to exit through the deflectors. Evidently Buell intended for most of the exhausted hot air to take this path, so it makes sense to me to try to go this way. Looks like Electraglider is making progress with his approach. On a related issue, there's an interesting discussion going on on the Yahoo XB12X Group about fan noise. One theory that's been advanced is that slowing down the fan slightly (10-25%) using an in-line resistor would significantly reduce the fan noise. Another guy (with a background in acoustics) thinks the problem is related more to mechanical vibration caused by the fan rather than the airflow, and that a resilient mounting for the fan might correct this. Wouldn't it be great if we could figure out how to significantly reduce the fan operation AND make it significantly quieter when it does run? I'll be following both threads with great interest. | ||
| Bertotti |
I wish a Buell person would pipe up in this thread. I would love to know how they intended the air to flow. I am still going to try and route all I can down and out. Preferably through the shock opening and if need be through the rear of the seat pan. | ||
| Hughlysses |
I was looking through the earlier thread on the deflectors: http://www.badweatherbikers.com/buell/messages/142 838/293989.html?1185211509 From Unibear's photos, it's obvious the XB12X has less area for the airflow to exit behind the fan than the XB12R, and I'd guess the XB12S. This explains one thing- there seem to have been far more complaints about fan noise from Uly owners since the bike was introduced. Undoubtedly the Uly fan has to work harder and longer to keep the rear cylinder cool compared to other XB's. This would also seem to explain the fairly common incidence of failed fans on early Ulys, even though they evidently used the same fan as earlier XB's which hadn't seemed to have had any fan problems. Looking at the photos, I see a couple of things that could be done to make more room for air flow. One thing would be to move the brake reservoir out from under the seat, to a location similar to the tube framed bikes (probably somewhere on the inner top side of the right passenger peg support). I think this can be done fairly easily. Another easy mod might be to cut back at the front of the underseat pan when it "hugs" the rear shock. This would provide more area for airflow between the shock and the underseat pan. I like Unibear's approach of "walling off" the fan exhaust air from the bottom of the seat, the battery and the ECM with foil (or something similar). This could still be done in conjunction with the air deflectors. Moving the brake reservoir and making a little more room for airflow around the shock might make this a good solution. If I make any progress with this approach, I'll post the results. | ||
| L_je |
Everything aft of the frame puck and inboard from the centerline of your knee sits inside of a poorly defined airflow regime. Furthermore, anything aft of the pegs sits inside of an aerodynamic eddy. The XB fan works because it imposes a low pressure boundary condition just aft of the rear cylinder. A couple of inches of water of fan pressure is just what is needed to help pull air in across the cylinders and get it to exit into the eddy region of the rear wheel-well. Removing the fan may work in race applications, but I think it would cause a lot of harm on the street. Slowing the fan down will certainly quiet it down, but at the expense of fan pressure/flow. In a nutshell, the louder the fan, the more air it is moving (for a given diameter). There could be some acoustic interplay caused by the seat pan of the Uly that makes the fan noise more objectionable. Some questions: 1) If you can feel the engine heat on your legs, are you wearing enough protective gear? 2) How can you even hear the fan, unless you are loafing below 30 mph? and finally 3) Have any of you ridden past NASA JPL, Northrop Grumman, Boeing, or Lockheed facilities and had the engineers laugh at you? | ||
| Hughlysses |
Some questions: 1) If you can feel the engine heat on your legs, are you wearing enough protective gear? 2) How can you even hear the fan, unless you are loafing below 30 mph? 1) When it's ~95 deg. F outside, and you're stuck in rush hour traffic, unless you're wearing an air conditioned fireproof suit, you're gonna feel it. 2) Fan noise isn't that big of a problem for me; I always wear earplugs. I was recently doing some 30-40 MPH loafing on dirt roads in the Francis Marion National Forest and the fan got a little obnoxious in those conditions. | ||
| Bertotti |
I am always loafing through town. Between 25 and 35. The fan sometimes runs more then other times. Heat has some interplay there but so does, in my case, wind direction if I'm in a head wind of course less fan. Dead air means more fan. I am working on the same approach as Hughlysses. I think that is how it should work. I had an radical idea of removing the bottom of the under seat storage area and directing it out the back more. I would of course run a vent of some sort towards the rear to prevent splash up. I just can't bring myself to cut chunks out of my almost two month old baby yet. When the tire does bottom out where under there does it hit? | ||
| Od_cleaver |
Hughlysses, If I ride relaxed with my right knee just about touching the frame, I can feel the heat thru an Aerostich Roadcrafter suit. If I move my knee into the wind just a little bit, the heat disappears. I think rider size and position are why some complain and others don't. I know when that lousy fan turns on up to about 60 or 65 mph. Animals even find the fan noise curious. The dumbest critter on earth, a cow, will look up when the Buell passes. While traveling in Canada earlier this summer, I can across a grizzly bear crossing the highway. When I got near him he stopped, turned his head to look at me and then dove into the brush (who needs a bear bell when you have a Ulysses). | ||
| Iugradmark |
I appreciate the honest discussion started in this thread. It seems like too often when the heat / fan issues are brought up that certain riders seem to shout down the problem. The recent motorcycle magazine reviews seem to agree that there is a problem and I am guessing that some of the 2008 changes are trying to address the problem. I wear ear plugs and a riding suit and the heat and noise are a problem. My fan runs even when temps are in the mid 70's and running down the highway. I think the comments about dead air space or trapped air are correct. I hope this thread leads to a reasonable solution that will work for those of us that believe this is a serious issue and are trying to live with our pre-2008 bikes. | ||
| L_je |
The faster you go, the more likely it is that the fan will engage. -the waste heat from the engine increases fairly linearly with speed -the airflow and heat transfer (especially wrt the rear cylinder) does not increase linearly with speed (at least not enough to offset the waste heat) At 80+ mph, the fan will engage, regardless of ambient temperature [1]. At speed less than 25 mph, the fan will engage, regardless of ambient temperature [1]. I have a trellis frame, air-cooled Ducati. My left leg bakes on that bike. No fan. No airflow obstructions. The trellis frame allows for just enough airflow (and even radiation losses) that a fan is not needed, but the heat is still there, and just as much of it. __________________________________ [1] temps <<32F not considered | ||
| Iugradmark |
Jason, I had a Ducati ST2 air cooled faired bike and heat was never an issue. I really believe that some better air flow can help this bike. The best solution is for the factory to figure this out but since they have not I am hopeful we have some smart folks here that can do it. | ||
| Hughlysses |
Alright, I tried out my idea today. I moved the rear brake reservoir out from under the seat using a piece of scrap ~3/4" x 1/8" steel strap I had.  It doesn't look too bad and the reservoir is more accessible. I got the idea from my 2000 S3. I had to shorten the hose and protective cover a couple of inches. As you can see below, this opened up the air path from the fan significantly.  Here's a shot of the original Special Ops heat blanket. It covers everything from the airbox back to the rear of the battery. While it does a decent job of keeping the heat away from the seat, it seems to me like it helps hold the heat in on the battery and ECM.  I came up with the idea of cutting down the blanket and using it to keep the heat away from the ECM and battery as well as the seat. This helps force the hot air out of the two side vents via the heat deflectors and out around the rear shock above the rear hugger.  I may eventually use tape to seal the blanket to the under-seat pan at the rear to make sure no hot air is leaking under it. I didn't have very good test conditions today; it was only about 80 degrees F this afternoon. I took the bike for a ~10 mile ride at 35-40 MPH around town. It seemed like the bike went significantly longer before the fan kicked on, but that's purely a subjective observation. The deflectors seemed to do OK keeping the heat away from my legs and the cutdown blanket seemed to keep the seat even cooler than before. I'll keep you posted if this seems to be a worthwhile modification. (Message edited by hughlysses on July 28, 2007) (Message edited by hughlysses on July 28, 2007) | ||
| Hughlysses |
Oh yea, I also took some adhesive backed aluminum HVAC tape and closed off the large opening in the right hand deflector for the rear brake reservoir. I figure that'll keep a significant amount of hot air off my right leg.  | ||
| Bertotti |
Hughlysses that is close to what I want to try but I also want to block off the side vents. I think all the air should go out the shock opening. Is the rear reservoir clear of the swing arm when compressed? | ||
| Midnightrider |
I just bought a oven thermometer with a remote readout. I'm placing the probe in the underseat compartment behind the battery. I plan to make some runs - stock set up, then with the bungee caps removed, then maybe with some extra holes and pvc pipes (ala electraglider) and see what happens. I'll let you know | ||
| Hughlysses |
Is the rear reservoir clear of the swing arm when compressed? Yea, I think it'll clear fine. It has a slight "S" bend in it which moves the reservoir out away from the swingarm slightly. | ||
| Midnightrider |
Well, I tried. Truth is it's too damn dark to do this well. A VERY limited test. Ambient air temp for both runs was 85F. I had to putter around town to get gas, then onto the beltway. By time I hit the beltway the underseat area was up to 98F. Over the next 5 minutes of highway riding (70-75 mph) it slowly crept up to 115F. Where it stayed for the next 15 minutes. As I pulled off the beltway and into Home Depot I noticed the fan was on. Even though I ran without earplugs, I didn't hear it until then (Drummer, though). When I shut it off the fan when on high. The temp only rose to 119 then dropped to 115 before the fan shut off (1-2 minutes) Did my shopping, 15 minutes, came back out. Underseat temp was 103. Popped the seat, popped the bungee covers off, replaced the seat. Temp had dropped to 98. Back on the beltway and home. Temp gradually rose to .....115F. Never higher. Pulled into the drive, the temp went up to 119F as the fan kicked in. Then down. So all this very limited testing showed was - the temp under the seat was the same for stock as with the bungee covers uncovered. What is didn't prove - It didn't measure the "right thigh" temp. It didn't measure the volume of air that passed by the probe (is it possible more hot air - but not hotter air, went out the bungee holes). It didn't measure what might happen with holes in the seat dam (maybe tomorrow) And it didn't measure what might happen when I add some holes to the seat pan If there are any other variations please let me know. I also bought a thermometer to drill into the oil filler cap (credit to electraglider) but I'm a little reluctant to try that until the replacement cap I ordered today is in hand (just in case I really screw it up - I don't want to be grounded for a $5 oil cap) | ||
| Electraglider_1997 |
Midnightrider, I am very interested in your empirical evidence. The holes I put in the seat dam as shown in the photos doesn't weaken it as a seat brace. But in my opinion they are necessary in actually allowing air to easily flow to any open holes in the rear seat compartment. | ||
| Midnightrider |
Hi Glider Makes sense to me. I plan to do more testing tomorrow. Tonight, I had to strap the remote digital readout for the underseat thermometer to leg with velcro. It's not illuminated so I was trying to get an occasional peak when I would go under a streetlight or when a passing car would light me up. I would often have to take one hand of the controls to tilt the readout so I could see it. Not a great way to navigate the DC beltway. I guess if nothing else there may be evidence that the suspected increased air flow from the uncovered bungee holes has NOT increased the temp in there, which was one of my concerns. I'm also looking at the way I mounted the probe. I just took a couple pieces of painters tape and taped it to the floor of the seat pan. I'm thinking a more accurate way would be if I could actually get the probe off the floor and measure the air temp, not the floor temp. Most of the 1/2" pvc I bought tonight is threaded - so I can install it, then do some comparison runs with it opened and compare it to runs with the holes plugged. I plan to put some holes in the seat dam and put to 1/2" holes in the seat pan. With the Drummer I can't always tell when the fan kicks on at highway speeds - but I absolutely believe it'll run less with any of the modifications. I'll PM you with my cell - please give me a call if you want to get in touch with me tomorrow | ||
| Midnightrider |
Here's how I ended up  Street elbow through a 3/4 " hole. There is a metal retaining nut and a green hose washer ( Hey - home depot is closed at 1 am). The end facing the battery has internal threads - so I can screw a cap in tomorrow for a "before and after" test. The end going down trhough the seat is also threaded | ||
| Midnightrider |
Here's under the seat. When I paint this black they will disappear - and be completely hidden by the side bags anyway  I know the pics are crappy - but if I use my cell phone I don't have to resize them | ||
| Midnightrider |
Finally - the holes in the seat dam. Also 3/4" holes with a thread fitting screwed into it. I'm no engineer but I seem to recall some sort of concept that the material in the hole (the pvc) will carry the load better than just an empty hole  | ||
| Electraglider_1997 |
Midnight, Looks good. Three thoughts though. 1)That elbow above the rear fender may make contact if the swingarm fully rotates up If I'm looking at that photo correctly. 2) Those fittings in the seat dam probably aren't necessary and they have effectively reduced those holes from 3/4" to 1/2". 3) If water does make its way up into those 2 street elbows in your seat compartment they will drain into the compartment because you've got them facing downhill. Chances are though, with those fittings above the rear fender this will not be a problem. Let us know how this setup works. Thanks. (Message edited by electraglider_1997 on July 29, 2007) |
