| Author | Message | ||
     Gofastalot99 |
Has anyone ever cut/smoothed/enlarged the intake duct behind the fork tubes? I'm not talking about replacing the duct, just taking the stock one and somehow making it better. I'm thinking about messing with it this winter but just wondered if anyone else ever did this. | ||
| Terrys1980 |
The minimal amount of gain, if any, isn't worth the time and effort. | ||
| Brother_in_buells |
Have you seen this? http://www.badweatherbikers.com/buell/messages/290 431/740787.html?1400936377 | ||
| Bob_thompson |
Never did anything to the duct to continue to use its limited air flow in at speed. Not much until 130 and above. So to get a little more air into the injectors I did the simple modification below. Be aware though of additional intake noise in the higher rpm's and some at idle also. That along with my own exhaust system, K&N air filter and a Buell race ECM programmed to my exact system has brought my 1125R alive in all rpm ranges. Bob  | ||
| Gofastalot99 |
I've seen the bug catcher - a little more extreme than I'm looking for. I applaud the creativity, but...just not for me. I'm not removing the inner box or planning scoops or anything like that. Just wondering if anything can be gained by modifying the duct. I've looked and looked and can't find anyone who did it yet. Oh well. I'll probably get one on Ebay and play around with it. | ||
| 1125rcya |
It's all the little minimal stuff, makes your bIke a little more personalized. Maybe you should look into intake stacks too. Even if you gain a hundred thousandth of a second it's worth your time and a step in the right direction. Hundred thousandth thoughts, win race's! | ||
| Nobuell |
There is really no way to straighten the duct and get it to fit back in. Just not enough room. Therefore flow increase due to minimizing directional change cannot be accomplished. The only thing that can then change is the intake area or intake profile. Since the intake area would be difficult if not impossible to increase, that leaves the actual intake profile. ASHRAE has various loss coefficients (Co) for various intake configurations. The stock intake duct is similar to ASHRAE fitting number 1-1. It has the highest loss coefficient of any intake configurations because the duct wall is thin compared to the size of the opening. Additionally, it has no flange and is essentially open around the outside of the duct. Envision an HVAC duct sticking through a wall with the open end a few inches from the wall face. The Co for the stock configuration will be around 0.72 assuming the duct wall is 0.125 thick and the duct opening is around 3. The 0.72 is then multiplied times the Velocity Pressure (Vp) of the air entering the duct opening. 60 MPH is 5,280 ft/min. The Vp is 1.76 wg, therefore the loss for the stock entry is 0.72 x 1.76 = 1.267 wg. That is approximately 0.0469 psi. By adding a ½ flange all around the intake the Co will drop down to approximately 0.50. Therefore the loss will be reduced to 0.88 wg or 0.032 psi. The most efficient opening would be a smooth converging bellmouth. The Co will be approximately 0.09. Therefore the loss will be reduced to 0.15 wg or 0.0059 psi. The best loss reduction from the stock configuration would be 0.0469 psi 0.0059 psi = 0.0410 psi. That is a theoretical 0.0410 psi pressure increase within the intake at 60 MPH. All of the above values are based on clean approaches to the inlet. The stock 1125 is nowhere near clean and I doubt that the efficient bellmouth could be applied due to space limitations. The best chance would be the addition of the flange resulting in a 0.0261 psi increase. I dont know how much HP that would be equal to if any. Perhaps somebody out there can address the HP increase but think it is quite low considering the boost pressure of a turbo system. Does any body know the value of the vacuum pulled by the motor when operating? It seems to me the best that can be accomplished at highway speed would be to pressurize the intake plenum enough to be near zero but that is a guess. At track speeds, the whole scenario is changed. The Vp at 120 MPH is 6.95" wg. The loss reduction will be approximately 0.1621 psi | ||
| Aj2010 |
I thought about increasing the size of the inlet duct by removing the upper/forward section and sealing the lower/back half of the duct to the frame. Thus using the frame/fuel tank to replace the forward portion of the duct. I stopped thinking about this mod shortly after hearing the fuel in my frame boiling. It seemed to me that a larger duct that has one side made out of aluminum that is hot enough to boil gasoline would likely lose as much by heating as it gained by increased volume. Or worse. After that I got to work on adding pipe wrap and heat shielding everywhere including the underside of the air box. | ||
| Stevel |
Yes, airflow for the airbox is a problem, but it is not the biggest problem. That is inlet air temperature. You can monitor this by selecting it from the instrument menu.. In traffic, the airbox temperature can easily exceed 20 C degrees above ambient. This heating is caused by poor airflow, waste heat from the radiators and rising engine heat. These causes not only heat the airbox, but also heats the frame and the fuel inside. This heat issue is the 1125's biggest design fault and significantly impairs both horsepower and smooth running. One of the greatest attributes an inline V Twin has is being narrow. This attribute has been completely trashed with the existing design. Not only is this design dysfunctional, but it is truly ugly. So, for all you "Favorite Mod guys" in last week's thread, forget the fuzzy mirrors and cool stickers, show some innovation and do a meaningful mod......fix this problem. | ||
| Terrys1980 |
The heat radiated from the ground as more effect on IAT than any part of the bike and it can not be avoided. The temperature of the asphalt or concrete can easily be 20-30°F above ambient. The IAT sensor is not in the airbox. Most people that have relocated the IAT sensor to get a more accurate temp reading and it stayed consistently higher. (Message edited by terrys1980 on October 26, 2014) | ||
| Bob_thompson |
Stevel & Terrys1980, most of what you guys have said, I believe, is spot on but I will add; on my '08 1125R, performance exhaust K&N & Buell race ECM, yes the inlet air temperature is very important especially when doing some aggressive riding and wanting the greatest h.p. and performance. What I have seen in my rides out from my metro house to the canyons here is that when at fair speed, above 50 mph or so the inlet air temps. are just fine and when ambient temps. are not real high they stay fine until I get back to the metro area and my speeds back down to just 20-30 mph. Then inlet temps. usually go pretty high due to lack of air flow I'm sure but never usually above about 210 degrees or so. Stopping for a long light will make it rise somewhat also. MY low speed performance and idle remains good. Now I attribute my own experience mostly to the tuned system I have especially the race ECM which richens the mixture throughout the rpm range. It changed greatly after I installed that, tuned by Michael Richter at Buell to my exact system, in 2009 along with some exhaust wrap from the heads to the muffler. It was the best performance mod I ever made. I also believe my mod for the air box by the fuel filler cap, as seen in my post above, has helped somewhat too as it now pulls in some cooler air from there whether at speed or not. Bob | ||
| Mrsuperbuckets |
Hey Stevel, do you own a 1125r or are you just slander bashing for no reason? If you owned one you would see that every part of the design serves a purpose, yes heat management sucks, but the amount of room the had to work with was tiny. The wheelbase is short, and yet the managed to get the riding position to be comfortable. That is something no sportbike has ever done before. Yes the bike has issues but what bike doesn't? The ktm breaks down every 10 miles, ducati's are overpriced and run just as hot as the buell if not hotter, Harley's shit themselves whenever you rev them and, inline 4's have as much soul as queen Elizabeth. The 1125 has problems yes, but if you can work your riding style around the bike, then you see that it is a amazing machine. Like bob said, if you ride at a normal speed it isn't a issue. | ||
| Mackja |
install an race ECM, makes all the difference in the world. | ||
| Terrys1980 |
Here are some pictures from the 1190RX parts manual. Maybe someone will be inclined to do a retrofit. The system definitely allows more air in. The air temp sensor is located just after the air filter and is part #29.  | ||
| Stevel |
Superbuckets, I currently own two 1125s and 3 extra engines. I develop motors as a hobby and have been for more than 50 yrs. The 1125 is one of my current engines I am developing. Yes, I'm bashing the 1125 design. The bike has excellent possibilities and potential, but does suffer serious flaws, which I am addressing. As I have stated many times in earlier threads, the 1125, unlike other bikes, has not received the redesign cycles many of the other bikes and engines have. Therefore, most of the initial flaws still exist. Unlike most of the other brands, there is not sufficient units in existence to warrant the aftermarket to offer solutions to these faults economically. So to a very large extent, I feel like the lone ranger in creating these solutions. However, it is also the same situation, that created the challenge that got my interest. After all, anybody can bolt on parts someone else designed and made. It is a whole other story to develop and make the parts yourself. So, if at times, you can read personal frustration in my comments, I hope you can understand. Designing and manufacturing your own hard parts is very time consuming and expensive. Especially when you know there is no financial respite in the future. I am not a business and have no intention of selling anything. I have stated my discovered flaws in this forum in hope that others, with my same interest, will do the same offsetting some of the required development cost as well as great ideas to pursue. If you can find some time, just check to see how many piston, camshaft, con rods, crankshaft and cylinder head parts offerings are out there for purchase for the 1125. You will soon figure out there is nothing, but fuzzy mirrors, stickers and bull shit parts, none of which address the flaws many times mentioned here by myself and others. | ||
| Mrsuperbuckets |
mr.stevel, after reading that comment I Understand completely were you are coming from, I know first hand the potential this bike has, I am currently in the middle of a rebuild after a hard crash. The block itself is very strong, and the chassis is impeccably balanced and, It is quite apparent with some major love it could be a true super bike contender, as is apparent wth the 1190rx. But for every good there is a downside, such as the location of the intakes and the radiator heat issues. Being you seem to know quite a bit about these engines, could you email me and, possibly help me with some things during my rebuild. I am very familiar with the xb platform, but I have very little knowledge about the Loki platform. As a long time buell fan, and in the past I even fitted a fatboy motor in the xb12r chassis "that was a massive pain in my a**"and basically, I had to rebuild the entire motor with very pricey parts "thank god for full ride scholarships" and that really is what taught me about how amazing buells were. But I dont know a damn thing about the loki platform and It seems like they had to cut many corners to get the bike at a competitive price. | ||
| Dannybuell |
Stevel - do you have a camera? I am VERY curious about YOUR engineering efforts. Please share! :-) | ||
| Figorvonbuellingham |
Stick the 1125 in a tubular trellis frame. Heat issues solved. | ||
| Stevel |
Danny, I have no photos at the moment. I will supply them when my changes are complete. so far, I have the following pieces. 1). Full Showa race suspension. 2). EBR chain mod with swingarm 3). Modified EBR race exhaust 4). 6" PVM Mag real wheel Alu PVM front 5). 72mm stroker crank nitrided and balanced 6). Custom Carrillo connecting rods I need to make pistons, cams, valve springs, spring retainers and other miscellaneous cylinder head parts. I also need to weld up the cylinder head ports, re-machine the valve spring pockets for the new larger diameter beehive springs and re-machine the ports. The current intake port cross sectional area increases as it approaches the valve seats, which is backwards. It should decrease increasing port velocity (venture effect). Hopefully, This will increase mixture turbulence and speed flame propagation and combustion efficiency. I will circular mill a precision slot around the top of cylinder bore in the existing open deck cylinder for a pressed in spacer. The spacer will be slotted for water flow to the cylinder head. This mod will effectively convert the open deck cylinder to a closed deck design. This will greatly stiffen the cylinder and stabilize the bore, which I believe is moving around under chassis stress. Remember the engine is a stressed chassis component. Ideally, I need a new cylinder casting, but it appears that EBR has not made this change and I cannot afford to do this myself. Perhaps some of you have noticed the poor low speed drivability with the lack of power below 3500 RPM. This is partly due to the cam timing. Both the stock cams and the race cams I have measured are 15-60 intake and 50-15 exhaust. This valve timing might be effective for a 15,000+ RPM motor, but is not correct for a motor running 10,500- 11,500 RPM. It sacrifices bottom end torque for top end power that the engine can never reach. I wish to use valve timing like 20-50 50-20. Nobody makes these cams, so I am now making cam masters that will allow a cam grinder to grind them up for me. Hopefully, I will have my first set in January. This timing change will have a profound effect on the piston design. I will not be able to run the stock 12.4 static compression ratio without pushing the engine into detonation. With the stock cam timing and a static CR of 12.4, the effective CR is only 8.6 to 1. that is why your stock Buell 1125 doesn't rattle and you can burn pump fuel without a problem. Closing the intake valve earlier starts compression earlier, so the static CR will have to be reduced with a new piston. However, opening the exhaust valve 10 degrees later will drastically reduce valve train loading and that's also very good. Currently, the cam is forced to open the exhaust valves under significant cylinder pressure. This adds unnecessary stress and wastes power in the usable engine speed range. Piston design will also have to change with the new cam timing. Unfortunately, like the cam story, no one makes the piston I need. There are several companies that will make custom pistons, but most have a minimum quantity of at least 100. Some will do two, but they make these from AL2618 billet. First I want to use AL4013 high eutectic silicon alloy, as it has a smaller expansion coefficient (tighter piston to cylinder clearance) than 2618. Although 2618 is stronger and commonly used for racing pistons, it does not work well for street use. Lastly, a forging is much stronger for a given weight than a billet and is a necessity in my view. As you can imagine, there are several other parts I must make, most I can make myself, but others like pistons, cams and valve springs, I must source and that is the source of my frustrations. I also suspect I will have to deal with other, unknown problems at the moment. One of which is oiling. I think I need more flow, but I don't know yet. I guess you cam imagine just how expensive this is to do and is probably more money than most of you would want to spend. I am doing this as fast as my budget will allow. If any of you want to acquire similar parts, let me know. As my project progresses, I will share what lessons I learn with the forum. | ||
| Dannybuell |
OMG Steve, You are on a mission! I am enjoying your writing, As a non-engineer I look forward to the critical analysis that follows this discussion. | ||
| Archy81 |
Hi all, About the problem with the airbox and air temperature. Ive done the following to modify. I clogged up the ram air inlet from the lower have of the inner airbox, mouted the TM high velocity intake stacks, made about 6 (18mm) holes just above the k&n airfilter in the top cover of the inner airbox and mouted a top airintake airbox cover. That and the barker exhaust with the ebr ecm for the barker makes the ride very good. Just lost some top ens speed. Meaning its like a flash at 210 km/h and speed is still increasing but not as fast as it used to be. (Message edited by archy81 on December 06, 2014) | ||
| Stevel |
Since some of you are considering velocity stacks, the stock intake runner length is 23 CM. This length tunes the third harmonic standing wave for maximum closed intake valve back pressure for an engine speed of 9700 RPM. Adding runner length lowers the standing wave tune engine speed. Optimum length for 7,000 RPM = 33 CM, 8,000 RPM = 28.6 CM, 9,000 RPM = 25.1, 10,500 RPM = 21 CM. Changing this length affects the volumetric efficiency curve. There are many factors that effect this curve, Like port volume, port shape, shape of valve guide, port diameter, cam timing and cam ramp acceleration rate and others. If you don't know what your doing, you should leave it alone. | ||
| Cf_z |
http://www.badweatherbikers.com/buell/messages/290 431/751159.jpg ^^This mod makes little to no sense. You already have a relatively large gap (as far as airflow goes..) around the entire airbox outer cover perimeter. Naturally aspirated engines are just vacuums, and there is PLENTY of space to suck more than enough air in thru this perimeter.. Cutting a scoop into your cover, right behind a low pressure zone is certainly not beneficial over simply removing the inner airbox cover.. other than potentially even more intake noise.
Thats simply untrue.. at least as far as being the cause of the higher IAT numbers. The radiators are pushing coolant temp air directly at the IAT... this should be common sense.
This is very, very true. As mostly a lurker on here, I look forward to seeing your progress and what you are able to achieve. Also on a side note to the IAT sensor location, its actually relatively easy to remove it from its location with its grommet, cut a hole in the factory air filter housing and re install it there.. cant get much more accurate intake air temps than that. | ||
| Bigblock |
Move the IAT to another location. Try behind the windscreen somewhere. I did that for dragracing, and the IAT reads lower AT when idling or in traffic(staging lanes- at the tree) and keeps the motor tuned slightly richer for cooler IA at that low no speed, and as soon as you open the throttle and the cooler air starts flowing the engine behaves properly, no lag for the system (IAT, etc. down the line) to compenstate for air now moving in to the tract. | ||
| Noobuel |
That style of air box cover was available from the factory, it's not a modified piece. See here: http://goo.gl/uTxsBn | ||
| Froggy |
His airbox cover is a modified piece, and the XBs use an entirely different inner airbox design with their covers. In fact, the XBs don't even suck in much air from up front with the stock setup. I tested it with a burning incense candle, it had most of the air intake coming from the left frame area, which is where the largest holes of the inner airbox are on the late XBs.  | ||
| Nuts4mc |
WOW froggy, swiss cheese! (Happy Holidays btw - check the oil and gas level in the snow blower - we're sending you a bad storm)...back to the problem...in the '80s several manufacturers (air cooled inline 4s) were running oil coolers about the same place as that air intake on the 1125...I can't remember if it was Honda or Kawasaki ...but one of them had built a "spoiler" into the top of front fender to send air up that way...I've been eye balling garage door gaskets (the kind made from rubber/vinyl...that go on the bottom of the door to seal the door against the ground) with a "big lip"...kinda like this one: http://www.homedepot.com/p/ProSeal-20-ft-Nail-On-G arage-Door-Bottom-Seal-57020/202324680 ( you may have to flip the picture 180 degrees to understand my application)trim and attach the small "leg" to the top (across, perpendicular to the radius of the fender) of the front fender back far enough to let the large "leg" direct the flow of air up into the inlet...what do you guys think? (Message edited by nuts4mc on December 12, 2014) | ||
| Hybridmomentspass |
"Have you seen this? http://www.badweatherbikers.com/buell/messages/290 431/740787.html?1400936377" I wish I hadnt | ||
| Nobuell |
Hybrid - I cannot get the link to work | ||
| Terrys1980 |
Yes we have all seen this blasphemy. http://www.badweatherbikers.com/buell/messages/290 431/740787.html?1400936377 |
