| Author | Message | ||
     T_man |
Just purely out of curiosity - does anyone know if anyone makes a Turbo for the 1125R/CR? | ||
| Ratgin |
hehe Just purely out of curiosity- how would you keep the front on the ground when it spools up? | ||
| Chadhargis |
I guess I'm just a really poor rider, but so far I've not been able to use the power it makes stock. | ||
| Xl1200r |
Not as a kit, no - but I'm sure it wouldn't be too terribly difficult to fit a small one now that there are options to crack the ECM (or use the Race ECM). You'd likely need larger injectors, but after that it's all tuning. Part of what makes forced induction hard on Buells is how the plumbing would need to make it's way around the outside of the frame (unless a really trick custom piece of plumbing could be made) and get to the throttle body on the top of the engine. | ||
| T_man |
I don't have much experience with turbo's so if I was ever in the market for one, I'd want a simple bolt on job. Saying that I also have no idea what a bolt on turbo might cost - any ideas? As for wheelies - yessssss please! 3rd gear power wheelies would be a welcome effect! Isn't that half the fun anyways? Having your bike claw for the sky under throttle? It is for me! Sure it would make it a handful at the drag strip - a lesson in throttle control on the circuit - but can you imagine the fun? But I digress... its only a hypothetical query... for now  | ||
| Jelomadnes |
If I'm not mistaken, I believe I saw a picture on this site that showed a Buell with the turbo from a Mini Cooper. It was built by some french guy. I know it was an XB frame, I can't remember if it was an 1125 or 12, though. | ||
| Miko_k |
I've seen the Lazareth Lightning with a mini cooper M45 Eaton Supercharger | ||
| Xl1200r |
Minis are supercharged, not turbocharged. All he had to do was mount a blower on top and run an output shaft from the crankcase with a belt up to the blower. Not any more or less complicated, but not the same thing. | ||
| Miko_k |
The Mini Cooper switched to a turbocharger for 2009  | ||
| Dirty_john |
I remember seeing a supercharged XB12R in the magazines, it would probably be easier to suprecharge than turbocharge, have read recent articles on supercharged vee twins here in Europe | ||
| Carbonbigfoot |
I have read that the large pulses of exhaust, and the similar issues at the intake, make turbocharging large twins a challenge. Not the ideal platform for that. Supercharging, on the other hand, makes a little more sense. To me. But I know nothing from a practical standpoint. Just conjecture. FWIW. R | ||
| Dirty_john |
carbonbigfoot - correct, supercharging should give a smoother pick up as well, there is no room on the 1125R as far as I am concerned for a plenum chamber to smooth out the vee twin power pulses, a supercharger makes much more sense and the low rpm boost should be more controlable and come on stream smoother and quicker - but hey - that's only my opinion | ||
| Firemanjim |
That is not the case--just need a big enough plenum to ease the pulses. Turboing is a matter of matching turbo size to engine size/HP wanted.Plumbing is nothing special. But matching fueling to boost is the challenge. Need a boost referenced fuel pressure regulator and a means to add more fuel--- | ||
| Boogiman1981 |
the stock air box is pretty big i thought? maybe not big enough? wonder how much pressure the seals in it would take before they popped off | ||
| Rfischer |
I ran a turbo for years on my big-twin FXR. Worked like a charm. There are some major caveats tho' - - CR deeds to be lowered; ideally to 9:1 or so. Otherwise boost has to be severely limited to avoid engine-killing detonation. - For engine life, an intercooler should be run to lower charge-air temps. Pressurizing air elevates its temperature [remember high-school physics?]. Detonation-city. - the ECU will need a piggy-back boost referenced device to correct A/F mix under boost as well as pull timing out. Again, to prevent detonation. - "Blow-through" designs did not work very well on carburetor applications, but are fine with EFI. - The turbo itself should be a variable-vane design so it can spool up quickly at lower engine speeds [low exhaust-gas velocity]. Non-variable types are prone to 'turbo-lag' which on a motorcycle can be tricky; a big hit in power as the motor spins past 5-6K can be difficult to control. It's been done on air-cooled Buells by many. The 1125R presents special design and packaging issues, but I'm sure someone will have a go at it. Someone with considerable engineering and fabrication skills. And, for what it's worth, a turbo is a much more efficient way to boost a street motor than a supercharger [blower]. There are no mechanical drive losses and far fewer parts to break or require service. They are also much lighter. Also easier to include an intercooler in the set-up; that is almost impossible with a blower [on a bike]. The one advantage a blower has is instant boost because it is mechanically driven by the motor. New variable-vane turbo designs have taken away a good deal of that advantage. (Message edited by rfischer on September 24, 2009) | ||
| Torquaholic |
Rfischer wrote: "The one advantage a blower has is instant boost because it is mechanically driven by the motor." My knowledge relates to turbos vs supers in cars, I'm pretty sure it translates directly to bikes too. IMHP, the debate between "instant boost" on a supercharger and delayed boost in a turbo (a.k.a. Turbo lag) is misguided. I'm all for turbos, I don't think a supercharger has any advantage outside of relative tuning ease because their boost comes on at a linear rate, relative to rpm. Yes, a supercharger is always moving air while the engine is on, but the impellers are only running at a set ratio relative to RPM. If the blower is set up to run 6# of boost, that's usually 6# at high rpms, near red line. At cruising speeds and low rpms, most of what the supercharger does is eat power from parasitic drag on the serpentine belt. Not enough rpm to move enough air to really benefit from a supercharger at low rpms. The result is horrible gas mileage. That is, unless the blower is geared to run very high boost levels, stuff any street motor would have a hell of a time with. Turbos do not run off of rpm, they run off of engine load and exhaust gas volume/velocity. Cruising at low rpms, turbos spin loosely in the exhaust flow, creating very little backpressure and do not create parasitic drag on the motor. A turbo motor will get basically the exact same gas mileage while cruising as a naturally aspirated version of the same motor. Under heavy load, EG: going WOT at 2,500rpms in 6th gear will cause the turbo to spool up right there, full boost. The mechanical advantage of a lower transmission gear, like first gear, reduces the load on the motor and delays the boost from building as quickly in a turbo. Either way, there is no parasitic loss with a turbo, only a slight increaase in exhaust backpressure. Once the turbo spools, usually it hits max boost much sooner than a supercharger would on the same motor. Ever seen a torque curve comparison between a turbo and super charger on the same motor? Big torque difference down low, once the turbo kicks in... Supercharger doesnt stand a chance. Superchargers need low gear ratios to help the motor get to the high rpms it needs to make the desired boost levels. Turbos dont need as much gear because turbos function effectively with more load than supers. Not saying turbos are perfect. Tuning them isnt exactly easy, and usually theres more weight invloved with extra hot and cold side piping used on a turbo kit, but that really doesnt mean much on a bike... Just my rant for the day. Sorry if i wrote too much. | ||
| Redscuell |
I've lots of experience with turbocharging car engines, starting in the 70s. And that experience is that it's not worth the pitfalls, when done on a petrol engine, especially one with a manual trans; including factory installs. The head gasket, expecially, 'goes' in a heartbeat even with a knock sensor. The ideal combo is a diesel automatic, in my experience; because the diesel has nothing to fear from detonation, and the automatic doesn't allow the pressure to drain away during shifts. And I'm thinking that the octanes available at the pump in USA are quite low any more? Here 98 ron and even higher is readily available. | ||
| Rfischer |
It's all about controlling charge-air temperature. And cylinder pressures. I ran 16 lbs. of boost on my mod'ed 'Subie STi with no detonation. BIG intercooler. Could have gotten to 18 lbs.+ with a re-program of the ECU, but elected not to push the envelope as it was a street car. Lot's of guys go 20 lbs.+ after 0-ringing the heads to prevent blowing head-gaskets out. My FXR was limited to about 10 lbs. with no special mods to the motor, but with an intercooler. However, that was enough to produce 100 hp/100 ft. lbs. out of stock displacement. "Adequate" for a daily-rider. And, the variable vane or twin-scroll turbos spool up much faster from lower exhaust-gas flows so the lag and fall-off between shifts is not the issue it once was. Lastly, my 'Benz E55 runs a blower. The boost starts just about right off idle, and continues to blow hard >6000 rpm. I am not fully familiar with the design and engineering used by AMG in this application, but the comments by Torquaholic certainly do not apply. The car, a 4000 lb. sedan with a mere 5.5L of engine displacement, will blow the tires off in first gear and pull like a thermonuclear Peterbuilt past 150 mph. It flat leaves the newer 6.3 AMG's, which have higher peak hp numbers, in 50 mph roll-ons. | ||
| Xl1200r |
Yes, a supercharger is always moving air while the engine is on, but the impellers are only running at a set ratio relative to RPM. If the blower is set up to run 6# of boost, that's usually 6# at high rpms, near red line. At cruising speeds and low rpms, most of what the supercharger does is eat power from parasitic drag on the serpentine belt. Not enough rpm to move enough air to really benefit from a supercharger at low rpms. The result is horrible gas mileage. That is, unless the blower is geared to run very high boost levels, stuff any street motor would have a hell of a time with. This is a lot of misguided info. A blower is set up to run a given amount of boot based on the engine it's on, and max boost is achieved at low RPMs - whatever it makes extra as the revs climb is dumped. Case in point, I have a supercharged Chevy Cobalt. Max boost from the factory is about 12.5 psi, which it gets to at about 2800-3000 rpm, and it stays at 12.5 psi until I shift or get to redline. Also, a supercharger, when not under load, can run in a much bigger vacuum than a turbo can. Yes, it takes power to drive the blower, but when there's no load, the vacuum created has the opposite effect, allowing a much smaller (by density) fuel charge into the engine, resulting in HIGHER fuel mileage. | ||
| Rfischer |
 Although, the fuel mileage on the E55 sucks. And it has a magnetic clutch on the blower to eliminate parasitic loss from the blower when not under boost. However, it doesn't take much throttle to engage the blower, so the fuel savings is pretty minor. | ||
| Xl1200r |
I'm not familiar with the E55 blower, but that magnetic clutch almost seems like it's the problem. If they had configured it to run in vacuum, I bet there's be a jump in mileage. Cruising on the highway, I'm around -10 in/hg on my Colablt. I have no idea what that would convert to in engine displacement, but the physics of it dictate that with the vacuum, the engine is taking in fuel and air at a rate of an engine that is smaller than 2.0 liters. Both are good, turbos are getting much better, both still have a place. | ||
| Torquaholic |
In response to Rfischer and Xl1200r's comments about my info being misguided, I have to add there's a difference in turbos' vs. Centrifugal superchargers vs. Positive Displacement (roots or twin screw type) superchargers. Most factory installs are running the later type of supercharger, and they are better at building boost at lower RPMs than the centrifugal type, the type I was referring to. In cars, most of the aftermarket bolt-on superchargers that I experienced seemed to be the centrifugal type, (EG: Vortech brand blowers). Positive displacement blowers, (EG: Kenne Bell and Stillen) although they still have parasitic drag associated, do build boost sooner than the centrifugal type. Since the two comments by Rfischer and Xl200r are referring to factory installed, roots type blowers, I can see how they both thought my info was incorrect. Here's a reference, one of many available online, that outlines the difference between the three forced induction types. Regarding Centrifugal type superchargers: "Because the engine belt drives it, the Vortech's pulley will always spin proportionally to the engine RPM. The problem with this is, even 9,000RPM is not enough spin to generate any usable boost. Vortech gets around this problem by utilizing internal step-up gearing that increases the speed of the compressor blades to nearly ten times the speed of the engine. Capable of just under 60,000rpm, the Vortech's compressor generates significant boost at high engine RPM's, and can generate even more boost by changing to a smaller pulley, which will run the Vortech at a faster speed. At low engine RPM's, the stepper gears can only do so much, spinning the Vortech at less than optimal speeds and generating minimal boost." Regarding Roots type superchargers: "Because the Stillen blower doesn't use any step-up gearing and doesn't need to spin very quickly, the twin internal rotors always turn at the same RPM as the engine. This means that the Stillen unit will always shovel the same amount of air relative to the engine, even low in the rev range. This kind of instant, low RPM response means that the positive displacement supercharger lives up to its literal name, making the powerband feel like it came from a larger displacement engine." I'm sorry for any information I wrote that may have come across as misguided. I obviously forgot to clarify that I was speaking about Centrifugal type blowers. I think this shows that we are all correct to a degree. Different experiences lead to different perspectives. | ||
| Blower1 |
Turbocharger makes more top end power than Roots type supercharger. Roots type supercharger makes more low end torque. I have a Mini Cooper S Supercharger in my old GS 1150. It have a more torque than my 1125R. Pic of GS:  | ||
| Xl1200r |
Regarding Roots type superchargers: "Because the Stillen blower doesn't use any step-up gearing and doesn't need to spin very quickly, the twin internal rotors always turn at the same RPM as the engine. False again. I can't think of any roots-type blowers that don't spin faster than the engine. Just because there's no step-up gearing doesn't negate the difference in pulley diameters between the blower and the crank. I don't know much about centrifugal superchargers, but I would have to guess that low boost at low RPMs is mainly a factor of how large they are. | ||
| Rfischer |
I ran the Vortech on a purpose-built Ford 351W 414" stroker a number of years ago. It was lazy on the bottom-end until I geared it up and went with a cog-belt drive. Then it spun up faster and no slippage. And I didn't have to run a crazy-loose converter. Could pull the front wheels when on slicks. A 1/2 ton pick-up no less. And, yes the E55 uses a roots-type blower with some fancy-schmancy helical rotors. Still has a noticeable whine tho'. As for the electro-magnetic clutch, I don't think it has much to do with poor fuel economy; nor frankly does it do much to help economy, whatever may have been the engineers' intentions. BTW, Volvo uses a similar blower clutch on certain of their marine diesel motors that have both a blower and a turbo. Off idle to about 1500 rpm. then it decouples the blower once the turbo has reached a threshold boost level. Great power out of the hole and better economy at 1800 - 2000 cruise rpm. (Message edited by rfischer on October 01, 2009) | ||
| Junkyrddog780 |
That GS is sinister looking. |
