| Author | Message | ||
     Mako |
did hd make buell put small headers and milder cams in so harley riders would like it more? It sounds like the ports are huge compared to the exhaust, shouldn't it be the other way around? I think it would be a great motor tuned for high rpm hp. and a little less torque? | ||
| Dannybuell |
do you have the race module? torque really falls off with the EBR race module with it's Idle Air Control feature which gives it a freewheeling dieseling kind of torque. shifts between gears don't require nearly the precision the stock ECM demands. | ||
| Redbat |
Dannybuell, "torque really falls off with the EBR race module"? What the heck are you talking about? Believe me, there is no loss of power. HP & torque increase with the EBR module. | ||
| Stirz007 |
Hp/Torque curves for three scenarios: Bone stock: 118Hp/67 ft-lb with race ECM and can: 126/71.5 with DSB build: 144/80 Keep in mind these were done at 4500 ft elevation and with stock mapping (which runs rich at altitude), so you'd expect 10-15% better numbers at sea level. I ran it at NOLA last October and had a hard time keeping the front end down a few times | ||
| Cherry_bomb |
i was very surprised by mine doing 138hp with a slightly tuned ebr-ecm and the stock can (catalyst converter) and the twin-stacks and the modified air intake. at 1800ft. so, i decided to go with this can, since on most racetracks in europe, they very picky with the noise regulations. (Message edited by cherry_bomb on December 05, 2012) | ||
| Carbonbigfoot |
Maybe. I read somewhere that the specs that they gave Rotax were "It needs to fit in this box (meaning a particular size), make torque like a 1200 sportster, and not stop at 5800 rpm. Redline @11.5." WRT the redline, I think it's pretty much done because of piston speed. I think it's pretty bad assed that there's ONLY another 25 or 30 HP in the stock motor! R | ||
| Jdugger |
Getting an extra 30 HP out of this motor will require a bit of motor work. That's roughly what a DSB-Spec build will get you, and to do that you need to deck the heads, degree the cams (non stock) and of course fuel, ecm and exhaust. With new rod bolts you can safely spin to 11,125. That said, they seem to be pretty reliable, even in that state of tune. Certainly in stock trim this is a very durable motor. | ||
| Mako |
still seems like most of the dyno sheets have a very flat power curve, could it put out even more with a "peaky" cam profile, a little more dirt bike like? I guess the drag racers will find out or already know? | ||
| Rogue_biker |
V-twins are inherently torque rich due to their relatively longer stroke compared to their 4-cylinder (or even triple) counterparts. Given the same displacement, a V-twin will always have a longer stroke than an inline multi-cylinder. That is the advantage and disadvantage of the Twin--long stroke means torque but it limits the revs due to limit on piston speed. That's why Ducati V-twin in the Panigale has to use nearly 1200 cc's to develop the power of a comparable 1000 cc inline four. So truth be told if you want BOTH torque and HP go with a large displacement four. There is no substitute for twice the number of cylinders. | ||
| Boogiman1981 |
J when i was emailing EBR last year I asked specifically about cams spec'd for DSB and was told that the DSB engines use factory stock cams with careful attention paid to assembly i.e. degreeing the cams | ||
| Stirz007 |
Boog - in my case, this is true. They actually replaced one cam so they could get the degree right. Up here, I really couldn't feel that much of a difference - - then I went to low altitude: Like JD sez "that thing pulls like a train". | ||
| Jdugger |
Boog -- you may be correct. I don't know how they did it (they mentioned adjustable cams), but I do have a picture of my motor with a big degree wheel on it... | ||
| Dannybuell |
What I define as usable torque is drop throttle oversteer. If my s1 is coming into a turn and I want more turn in with no other input, I throttle back for oversteer. If that isn't enough I start trail braking, leaning more and turning the bars. Drop throttle oversteer gives me excellent road feel as the bikes torque goes into the front tire. The CR w/EBR race module does not give S1 quality drop throttle oversteer. | ||
| Redbat |
Dannybuell, you are referring to engine braking, not torque. They are not the same thing. | ||
| Dannybuell |
sorry, didn't mean to change the subject. | ||
| D_adams |
http://www.youtube.com/watch?v=BVuESJdhOfI&t=55s Had to google that one. Seems like thats more of a "loss of control" problem, not torque related at all. I guess if it happens too radically on a bike, you'd end up high-siding it and go flying for a bit. | ||
| Figorvonbuellingham |
What is DSB build? | ||
| Bextreme04 |
Daytona SportBike... I believe it is the engine build specification they used in the bikes racing in the DSB racing series | ||
| Stirz007 |
DSB in a nutshell: increase compression, reset cam timing, new pistons and rods, higher redline. Muy bueno. | ||
| Mako |
I am just looking for a way to get good hp at 7500ft. higher revs seem like the best way for dirt bikes up here. Is twin mc the only one working on cam design for retail? | ||
| D_adams |
http://danielcrowerracing.com/i-5912878-buell-1125 -rr-4-cam-set.html Those have been available for some time now. | ||
| Dannybuell |
a good suspension setup keeps your F/R balance. The EBR ECM controls the engine braking. At reduced or no throttle it makes you wonder where the engine's torque went. The S1 decelerates as intensely as it accelerates, it will throw you forward almost as hard as it will throw you back. Call me crazy, I see this as a reflection of torque, either way. The CR with the EBR ECM decelerates like a diesel, there is no forward intensity. Forward deceleration pushing through a well setup suspension gives great forward grip and all that extra grip makes the bike want to turn in at a faster rate. The engine's torque/braking is bled off with the Idle Air Control and the slipper clutch at higher RPM's. I have wondered a few times at higher RPM's when the decel rate fell off, was it the slipper clutch or the ECM? | ||
| Boogiman1981 |
Dean yes those have been. Would like a set but don't have the funding. That being said: "Brice, That’s a per cam price. By rule a stock cam is required (at least for an 1125) in Daytona Sportbike. DSB spec 1125 engines are high compression, blueprinted, with stock cam timing set dead nuts nominal. No trick parts, just some TLC during assembly. We can build them all day long, and they make 148-152 RWHP. Depends on the heads, and other normal tolerances we can’t control, or alter by rule. The above assumes our full exhaust kit, and programmable ECM kit. Thanks, Michael" | ||
| Battyone |
The 1125's rev limit is governed by the valve shims.I've got a screwed head to prove it.Better/lighter valve train and attention to detail may improve this. Even standard rod bolts are ok above 11k... The circuit bikes that have had bolts let go probably do them under engine braking from high rpms.I've hit 12,500 Joe managed 13,400 still no broken rods or bolts. And 67.5mm is not a long stroke!!! busa is 63mm!!! the cubes are in the bore size.The 1125 rides like no other twin I've ever ridden,more like an inline 4 with out the smooth bottom end? Read the cam timing thread.Rear exhaust is 4degrees advanced.maybe that's the cam change done for full dsb? It doesn't need/want more cam,if you increase the rev limiter it just keeps going.If the fuel map had cells above 10,700 it could probably be tuned to extend power. from my drag racing experience this last 12months I'd say the easiest way to get more power than stock is fueling and timing changes.the result of some timing changes suggest that a twin plug head would make a big difference.More power is going to cost big bucks. Dris built a motor with Hi comp pistons,new cams,bigger lighter valves and lighter rods,along with some port cleaning...and made zero extra hp over his stg1(153hp)...that suggests the bottle neck is elsewhere. The 1190 uses longer rods as well as the bigger bore and shower head injectors. it is not going to be cheap or easy to get more power out of the motor. And for road use,work to get the bottom end more twin like would be much more useful. | ||
| Jdugger |
Danny, You are confused. You are not getting "drop throttle oversteer", you are simply transferring weight to the front wheel which compresses the forks, making the bike turn in tighter. I truly doubt you are "backing it in" for every corner, which is what drop throttle implies. And, you are confusing torque for engine braking. While there's a correlation depending on engine design, they are not related. High compression, heavy flywheels, and lots of other factors will all contribute to the effective force of engine braking, and thus weight transfer to the front wheel when you let off the throttle. | ||
| Redbat |
In the early days of EBR one could order a race ECM with or without engine braking. I chose with, but I don't think they offer a choice anymore. Dannybuell, you are going to have to stop using the word "torque" to describe how a bike decelerates. | ||
| Dannybuell |
Thank You all for helping me improve my focus on this subject. | ||
| Jdugger |
If you get the programmable ECM, the IAC has a programmable map. | ||
| Hughlysses |
I am just looking for a way to get good hp at 7500ft. Sounds like a good reason to add a turbo to me.  That's why the things were invented in the first place; so piston-engined aircraft could make good power at high altitude. | ||
| Andros |
How about if you only want a torque increase and dont need a high revving beast? What do one do then? |
