| Author | Message | ||
     Panshovevo |
My new to me 1125CR seems to have most, if not all of the common performance mods done, such as aftermarket exhaust, Race Tuner ECM, de-noided, K&N filter, supposedly dyno tweaked for the filter and exhaust. Although it already has more power than I can safely and legally use, I'm always looking for ways to improve whatever I have, and love to tinker. An acquaintance tells me that a Rotax rep told the racing team at the dealership he worked at that the motor was designed to make 180 hp in stock trim, but Harley made them limit it to 150 or less. He claims their team made 190 at the rear wheel with a few relatively minor tweaks, but couldn't give any details. Has anyone gone deeper into the setup to find more power? If so, where did you find it? Does anyone know what the valve to piston clearance is in stock configuration? Cam specs? Head gasket thickness? | ||
| Albert666 |
I think they be talking out of their arse the wsbk 1190's were barely making that | ||
| Snacktoast |
the wsbk 1190's were barely making that The WSBK bikes, at the time of the shutdown, were somewhere north of 200 rwhp. Now, that being said, if anyone is telling you they are making 190 rwhp on 1125cc they're not telling the truth unless they've turboed it. No way, no how. To get anywhere near that neighborhood, you're looking at increased bore size, cams, head work and larger valves, compression, etc. And if they were anywhere near that number (which I doubt), they would have done major mods to get there. | ||
| 99buellx1 |
And would be riding a highly stressed bike that would make a terrible daily driver. | ||
| Panshovevo |
Unless they had a really "happy" dyno, which considering it was a dealership, is a real possibility in my book. I know Jim Leinweber can regrind a cam within the limits of what is there to work with, but does anyone know if any off the shelf internal parts are being made or have been made for the engine? | ||
| D_adams |
True RWHP, you _might_ squeeze 155 out of an 1125 displacement motor, but you'd have a very hard time doing so and it would be a rolling grenade just waiting to go boom. Even an 1125 upgraded to an 1190 displacement will barely make 160 hp at the wheel, although that's with the stock 1125 cams, full exhaust, ecm and boosted compression via a thinner head/base gasket. I've got an 1190RX that's making a rough 173-174 hp at the wheel now and it's better than the 1125 motor by a fair margin. Squeezing another 15 hp out of it will be VERY hard to do, even with a decent budget to work with. | ||
| Dennis_c |
The Daytona sport bike back in 09 made 150+ at the rear wheel from what I understand and the motor was 100% stock they could not do anything to it. different ECM and exhaust that's it. | ||
| Snacktoast |
The Daytona sport bike back in 09 made 150+ at the rear wheel from what I understand and the motor was 100% stock they could not do anything to it The internal parts of the engine could not be changed (read: replaced with other components), however the compression on those engines was higher ~15.0:1 and they ran the spec Sunoco 260 fuel. Stock heads (ports, valve sizes and springs), cams, pistons, etc. This setup is typically 150-155 rwhp with the EBR race exhaust. | ||
| Dennis_c |
From what I remember Buell done very good in 09 did not have motor problems in the Daytona Sport bike class. Also in 09 there Supper bikes made if I remember right 175 HP or more. I am not perfect but I ma crowding the guy that is HA HA | ||
| Stevel |
I think there is far too much emphasis on horsepower with this engine. There are several issues with the motor, but they tend to be in the area of usable power as opposed to total power. Low to medium engine speed performance is poor and can be enhanced. Total power can also be improved a bit as well, but all of these mods will be expensive because aftermarket parts are simply not available and each part will have to be custom made. The aftermarket has not done this because the demand is low and is uneconomical from a business point of view. EBR's demise has certainly not helped this situation. Personally, I find it an entertaining challenge, but getting the right parts made is like pulling eye teeth. I have designed the parts I want, but find myself at the very end of these firm's priority list. Eventually, I hope to have these parts before the end of the year, but I'm at the mercy of others. I hope to achieve a total power of just under 200 HP, but more importantly is to improve drivability and controllable power from 2500 RPM. Expecting reliable engine speed and durability above 11,000 is wishful thinking and unnecessary in my view. The current design, with the existing port sizes, throttle body size and cam timing approaches that of a Formula 1 engine and in doing so, totally trashed low speed performance producing a very narrow efficient power band. I believe reducing cam duration and overlap will reduce pumping losses and enhance drivability in the desired engine speed range. To compensate for this loss of duration will be a greater valve lift and faster cam ramps, hopefully enhancing low and mid range torque without sacrificing top end power. | ||
| V74 |
I was hoping Stevel was going to chime in with his thoughts. He really knows his stuff,he has done some real in depth research and I enjoy reading his technical posts.search out his other posts and learn . | ||
| Panshovevo |
Stevel, I hear and understand what you're saying. Until we have reliable variable cam or valve timing, and possibly variable port geometry, all engines will be a compromise, and will perform best in the rpm range their cam(s) is/are designed for. (I've been dreaming of reliable computer controlled solenoid operated valves since 1987...) I was rather shocked to find the size of the throttle bodies on the engine, having never noticed that detail in the specs I read on the bike before buying one. By comparison, an aftermarket air-cooled engine I picked up recently for a future project originally used a single carburetor a bit smaller than the size of one of the dual TBs used on the Helicon, and makes way more torque at a much lower rpm, but uses more than double the displacement to do it. (There was also a dual throat TB option that shared a common manifold between the cylinders) I understand that some of the air-cooled Buell models incorporated active exhaust systems, but don't yet know any details...except they are troublesome. I would love to hear more details on your project, and your progress. Can you tell me what the existing valve timing is, what your target timing is, and where you plan to go with the static compression ratio? Thanks for posting this, and thanks in advance for any details you can share. PM or email me if you prefer. (Message edited by Panshovevo on June 03, 2015) (Message edited by Panshovevo on June 03, 2015) | ||
| D_adams |
You will not get anywhere close to that with an 1125 without spending either large amounts of time or money to get there. Can it be done? Probably not. Even with a best case scenario, I doubt you'd ever break 180 hp at the wheel or even come close to it. Cams might net you 5-7 hp, the 1190 displacement will get you up to 155-160 hp, so realistically, you _might_ bump up against 165-170 hp at the wheel, and then only with a larger diameter exhaust (primaries, etc) and a bumped up static compression ratio. Start throwing more money at it via a supercharger or turbo, sure. Nitrous would be another way to get there. Naturally aspirated, not happening. My best effort to date has been 174 hp to the ground out of an 1190 SX. Is there more in it? Possibly. Can I get parts for it now? Not if it's a catastrophic failure, so I doubt I'll push it much more. | ||
| Snacktoast |
Stevel, It sounds like you are in search of a unicorn. A superbike style engine with easy street manners from 2500 rpm?  Personally, I think you're barking up the wrong tree with the wrong powertrain. I can appreciate your interest in the idea, but I don't believe it's realistically possible. Decreasing cam timing and overlap to get your 2500 rpm streetability will shift your torque curve dramatically lower and shrink your peak horsepower number significantly without using a turbo to bring top end back.... I think I'm wasting my typing here. | ||
| Figorvonbuellingham |
Just buy a S1000RR. | ||
| Stevel |
Well folks I've spent a lot of money already on this project and this is not my first rodeo. I am making these changes based on more than 50 years of hot rodding experience. Additionally, I have built a stroker crank using a stroke of 74mm. I will not increase the bore size with the existing cylinder, as it is already very unstable. I will close up the top of the cylinder to improve the stability. I have sufficient evidence of bore shift under stress. Increasing the stroke to 74mm will deliver a final 1199cc displacement. I have gone with custom designed pistons from Pistal in Italy in the standard size of 103mm. However, I could not retain the factory piston dish displacement of 16cc. Otherwise, the static compression would be way too high. Nor could I retain the existing 12.4 to 1 compression with the cam changes. The existing cam timing is Intake 15-60 and Exhaust 60-15. I will reduce this to 20-50 and 50-20 respectively. The new cam timing cannot handle compression above 11.5 on pump fuel without experiencing detonation. Consequently, my pistons will have a dish volume around 22cc and that factory center dome will be gone as it contributes to spark shrouding and poor flame propagation. The poor flame travel is primarily caused by insufficient mixture turbulence caused by the short stroke and lazy ports, but the increased stroke will improve turbulence and my port changes will create greater air velocity and also enhance turbulence. Unfortunately, there is insufficient space with the standard dimensions of the cylinder heads for cams, finger followers and springs to handle valve lift beyond 10mm. EBR trimmed the spring seat and the top of the valve guides to squeeze out 11mm lift with their racing cams. My target is 14mm of valve lift, but to do that I have to mill the spring seats about 2mm, decrease the cam base circle and increase the valve stem length. Obviously the valve springs are insufficient and must be changed. I will use Beehive springs wound with ovate wire for additional spring clearance. Unfortunately these springs have a larger OD and will not fit without boring the spring pockets to a larger diameter, but there is room to do this. I have reasonable confidence these changes will wake the motor up with a decent chance to hit my intended numbers. Please keep in mind that this engine has received NO real development since ROTAX designed it. It is a challenge. Every one of my parts had to be custom made, including cam masters. This effort represents serious money and many, many hours already. | ||
| Fresnobuell |
Sez the guy who in the same post states he's after 200HP? Confused. Honestly, the vast majority of HP seekers would do well to master the 140 ponies of the stock engine (with ECM and pipe.) | ||
| Panshovevo |
Sounds to me like Stevel knows what he's doing, and is on the right track. Steve, I guess you already have your pistons covered, but if you need any in the future, Shaker Products has provided custom CP pistons for a number of applications I'm aware of. There is a cool pic on an 1125R (or similar) wheelying out of a turn on the page linked below. Just for clarification, are you shooting for 200 hp at the crank or rear wheel? I talk to the owner of Spyke/STD (Bill McCahill) from time to time. I'll check with him to see what, if anything, he has done with Buells. He's had his fingers in a lot of pies over the years, and is a hell of a nice guy. http://terrymfstewart.com/pistons/ Edited to add that it won't surprise me a bit to find that Bill has had something to do with development of some part of the Buells. He knows and works with a lot of people in the industry. (Message edited by Panshovevo on June 03, 2015) (Message edited by Panshovevo on June 03, 2015) | ||
| Stevel |
Fresnobuell, It is kind of like a philosophy thing. Yes, I'm certain total power will improve, but more important is controlling the power from a rider's point of view. With today's most powerful bikes, electronics control the throttle and for me, I have a problem putting my life in the hands of a transistor. I want the throttle plates on the end of cables I control. Consider that a Formula 1 car is under full throttle 90% of the time, yet a Moto GP or Superbike is under full throttle 10% of the time, torque control is premium on a bike. Also consider that the value the twin has over a 4 cylinder bike is torque control, it is my personal belief that the best mods enhance the natural abilities of the base design. Using mods that emulate a 4 cylinder bike is usually self defeating on a twin. | ||
| Stevel |
Panshovevo, Thank you for the piston tip, but I went to CP 18 mos. ago. EBR used CP pistons on their first versions of their 1190. They did offer me pistons in AL2618, but were milled from billet, not forged. I prefer forgings as they offer additional strength at no extra cost in weight. The problem became finding someone that has slipper type bridge piston forgings in the correct diameter. I can now state that these could not be found anywhere in the US and most manufacturers in Europe. Several firms in Europe offered forgings that would work, but most wanted a minimum order not less than 100 and often 1000 was their minimum. I ran into Giorgio Casolari of Pistal at the Cologne Moto Sport Expo last November and he offered me a very nice double bridge slipper design forging in AL2618 with a 48mm long wrist pin, much shorter than the stock 60mm length. Pistal's minimum is 4 pistons. (Anybody need some pistons?) Engine design is all about compromise, as you stated. This engine is no exception. I don't think we will ever see variable ports and cam timing on a bike. These things will take space, add weight, complexity and cost. However, an Air Flow bench is not the total answer either, big is not always better. The bench can tell you all about pressures and volumes, but two heads may appear the same in flow on the bench and in the rear world one may drastically out perform the other. Air column velocity is also very important. port volume reductions was one of the most significant changes made in Formula 1 in the '80's. I say this because the intake ports in the Helicon have no venturis. The cross sectional area measured at the flange is smaller than the CSA beneath it. It should be the other way around. This is especially bad because the throttle bodies are so large velocity is already low. | ||
| Stevel |
Snacktoast, Cam design is so much more than duration and overlap. 20-50/50-20 is certainly not short. 15-60/60-15 is way too long for the intended engine speed range. Why tune your valve timing for 15K RPM when the engine can never achieve it? It makes no sense. What does make sense is centering as much valve lift as mechanically possible over the point of maximum piston velocity without suffering reversion and drastic pumping losses. | ||
| Stevel |
D-adams, I can understand your negativity, but I don't agree with it. Of course I could be wrong and you correct, but even with failure, I will know more than I do today. This is called evolutionary development. Yes, it is expensive, but this motor deserves the development chance. It has had none. I think the basic design is excellent and it has serious potential. Of course EBR did no favors for this motor's reputation with its dismal performance in WSB. I often complain bitterly that no one has made the development effort and in that way, I feel like the Lone Ranger. On the other hand, it is also kind of cool to be the only guy doing this. It is certainly challenging and expensive. The project is quite a bit more than the few paragraphs I've written here. There are also those mods required to enhance reliability. There are other points of concern like top end oiling. | ||
| Mrlogix |
}(Anybody need some pistons?) Ok, I'll bite. How much? | ||
| Stevel |
Ok, I'll bite. How much? About 400 Euro each plus pins, rings, skirt coating and VAT. | ||
| D_adams |
The thing about this quest for more power is, you're starting off with a motor that made all of 146 hp at the crank and only on average maybe 125 hp at the wheel. You haven't stated if your goal is 200 hp at the crank or at the wheel, but honestly, even squeezing 54+ hp more out of this (1125) motor is pretty much unrealistic, short of the mods I mentioned earlier. Turbo, supercharger or nitrous. I'm not trying to be negative here (I suppose it sounded that way a little bit) but I just simply don't believe it's mechanically possible to obtain those numbers with this motor if it's naturally aspirated. Years ago, I asked about the theoretical limits of the headers. 150 hp was it based on flow modeling. Stepping up to the larger race headers at that time, it was more around 175 hp, and that was with a factory built motor (ie; 1125RR model with a much larger airbox that was never available to the general masses) intended for flat out racing and getting as much out of it as possible. That 175 hp at the wheel would equate to over 200 crank hp. The 1190RX/SX engine has an even LARGER rear header than the previous models. I've not gotten a good look at the wsbk headers, but from the small pics I recall seeing, the front was considerably larger as well. I know at least one of those bikes was pushing over 200 hp at the wheel, but even that wasn't enough to keep up with even the mid-pack runners. With more than 100 ft/lbs of torque available by 5k rpm, you'd think they would have run away from the field. The 1190 had numerous changes to get it to the power level it's at. I know the wsbk bike made the power numbers you seem to be after, but at what cost? They had many employees, plenty of damn smart engineers and a decent enough budget to get to that point, do you? I'm guessing this year's wsbk bikes were worth somewhere north of $100k each, but that's still only 1/5 what it would run you for one of the top team's bikes out there on the circuit. I can only imagine the amount of man-hours that went into the development of the motors alone. | ||
| S21125r |
"Anybody need pistons" Might be a good option for those looking to do turbo project on a standard stroke Helicon. Stevel - If I understand correctly, you will be shrink porting to increase port velocity - have you done any calculations on theoretical port velocity with a stock heads and do you have a new target velocity in mind that your shooting for? I know the old 1200 Sportster motors had lazy ports (<200FPS IIRC) and many 883 to 1200 conversions had better power because of the smaller ports. I vaguely recall a guy featured in one of the cycle rags several years ago who was even making 1200 ports smaller than 883 ports and getting impressive HP/Tq numbers out of them. | ||
| Mrlogix |
I am kind of on the same adventure as Stevel. I have fallen in love with my 1125R. I already know that it will never be at WSBK standards, but then neither am I or my riding skills. I have been in several types of motorsports over the past 35 years (dirtbikes, drag racing, autocross, flat track, cars, trucks, bikes, etc.). My pursuit for more power goes hand in hand with longevity and reliability. I choose a Buell to begin with because it is different than the rest. If it was all about power potential I would own and develop a V4 like Honda. As an engineer and an enthusiast I like taking the odd way out and push the boundries. Don't know if I agree with everything everyone here has expressed, but that's cool. If we all thought the same and liked the same stuff we would all be on Suzuki's and driving Camaro's. OOPs, let the but hurt begin.  | ||
| Stevel |
S21125r, Yes, I will be shrink porting and no, I don't have any numbers in mind. I am limited to the existing castings. I did ask EBR if they were going to better head castings and never got an answer. The castings really need serious help. They are deficient in many areas. Some of the faults in the heads and cylinders can be helped with welding, but the welding would best be done before final machining. In that light, I asked EBR for bare castings and never got a response to that request either, by providing those EBR had everything to gain and nothing to lose, but it is water over the dam now. So, I am very much limited to the current castings. I will use epoxy and a flow bench and I will get what I get. Once I know what that is, I'll try to repeat those changes with welding if possible. | ||
| Stevel |
D_adams, Have you considered that the power increase observed by these really smart guys with the larger pipe diameters might not have been because of the increased flow of the larger header pipe, but was a result of the lower gas speed in the pipe and lower reflected vacuum during cam overlap? Of course this would indicate that these really smart guys might have been chasing their tails and that couldn't be, could it. Their WSB success might indicate otherwise. Perhaps their poor cam profiles might have been the cause all along and not header diameter. You state that it isn't possible to reach my numbers, yet Honda had exceeded 150 HP/liter in the late 60s.There are ample examples of naturally aspirated motors approaching 200 HP/liter today, Why not the Helicon? | ||
| Albert666 |
the wsbk headers had 70mm secondaries |
