| Author | Message | ||
     1_mike |
Those of you with a good tuneup (good fuel and timing maps), how do you stay out of the redline, hard shutdown area...? Especially getting on the freeway, the engine climbs to the redline as fast as I can pay attention and shift....on a good day. Otherwise.... I'm still messing with the fuel, right around 2500rpm, but above 3000 is about perfect, cruse and light or heavy acceleration is really nice. I'm just having trouble staying out of the redline cylinder-drop area. And sometimes kinda hard. Was going around a left hand corner near home the other day and hit the throttle hard...I was already just a few off the redline to begin with. Hitting even the soft rpm shutdown isn't fun in a corner. Buell's head and camshaft choice seem to want another 1000/1500 rpm capability than the 6500ish redline the engine has. Any of you raise the redline on a stock engine ? How long will the lower end deal with it...? Mike | ||
| Firemanjim |
Mike,piston speed on the 1200 is getting up there so pushing a stock motor not a great idea. | ||
| Gunut75 |
Jim is right. At red line the piston speed is really getting up there. Get that fueling right in the 2500 area, and start 500 rpm lower. Of course this all depends on what mods, etc, etc. If you have a Jardine, or D&D, or similar mid/upper range pipe, it will be more difficult to get really good tuning in the 2500 rpm area due to lack of back pressure. But, oh-boy do they scream in the upper range. Or......get a shift light, and shift when you need to. My $0.02 YMMV  | ||
| 1_mike |
Hmmm.. I really don't think the actual piston speed is that big a deal at about 72 ft/sec. Many "older" American car engines are capable of more than that and newer race ("American") engines run piston speeds of in the 90+ ft/sec. Hell..even my old Pro Gas Anglia (English Ford) was running a little over 85ft/sec. with a stock block Chevy. But can the crankcase, rods and rod bearings contain the heavy 1200 piston, rod and crank at that rpm. Oh well, thought I'd ask. It just seems to "almost"...rpm as fast as an I-4. At least when on the throttle hard and the "seat of the pants" shift point....! Gotta learn that "Harley" shift point.., it just seems counter intuitive to shift when the engine is still pulling hard..! Ahh...just thought...an air shifter connected to the tach., adjusted to automatically shift at 6700rpm. Mike | ||
| Fast1075 |
I would humbly submit that Firemanjim speaks with the voice of experience and wisdom...the road to wisdom is paved with broken parts, grasshopper. The XB9 motor on the other hand,is much more RPM friendly owing to the shorter stroke and longer rods. But it is not a rev monster either... But I understand where you are coming from..it is a pain for it to hit the limiter while it is still pulling hard...have the same problem with mine.. Try to mod it so it turns 7500 or 8000 and it will have a short life on the street indeed...but the ending will be spectacular. | ||
| Sifo |
Just learn to love the short shift. The XB12 responds quite well being short shifted. It doesn't really give much more pushing to the redline though. I don't think piston speed is the only factor at play. A 45 degree twin isn't exactly the best platform to try to balance. Spinning a heavy out of balance flywheel at high RPM isn't really something I want to sit my fun parts so close to. I also don't think the roller bearings deal well with this kind of abuse. They have advantages, but don't like to be hammered on. | ||
| Sloppy |
Learn to shift earlier!!! Those of us who transferred from inline 4's took awhile to understand that 2k rpm on the Buell is like 6k rpm on an inline 4. 72 ft/sec piston speeds are VERY high for a street engine. Those are verging on race engine speeds and those need to be rebuild every season. (Note, we're not talking about drag engines as they only have to last a weekend, or about 10 miles - you can push those piston speeds higher). I like to keep mine below 60 myself. I don't think the few extra HP at redline is worth it for a street bike. | ||
| Rageonthedl |
you need this....  | ||
| Gunut75 |
Those of us who transferred from inline 4's took awhile to understand that 2k rpm on the Buell is like 6k rpm on an inline 4. I was going to mention that too. Ya have a very fun stable according to your profile. Changin' up between a couple different motors there eh?  | ||
| 1324 |
If you're having trouble keeping away from redline now, don't do the XB9 primary swap! It is seriously challenging in first gear on the street. I've been thinking about a shift light. Even better would be a shift alarm like my car has. Anyone have any recommendations? Rage, what brand light is that? | ||
| Rageonthedl |
Its a Dyna Shift Minder and Shift Light. The thing that controls the light is that litte box above the speedo. you could hook any light, horn, alarm or all three to it. At one point i was going to have a switch that I could turn the air box into the shift light (it was a kick ash air box with open filter mod) It already had a red LED inside of it. | ||
| Slaughter |
Rev limit IS the shift alarm! It's a totally different machine than a quick-revving I-4. Just takes some adapting to the different shift points. Coming up on rev limit happens so fast that it's just not worth worrying about some alarm more than a shift light. IF you wanted to raise the rev limit, you really need to lighten the pistons and beef up the bottom end - or just be willing to have more frequent rebuilds. Buell Yoda: "Different beasts they are the Buells." | ||
| 1324 |
Slaughter, I agree with your comments in premise, but I've been told by several Buell/HD engine builders that hitting the rev limiter will shorten the life of the bottom end. Do you have evidence to the contrary? Because if this is really no big deal, I won't sweat it. Rage, thanks, I'll check that out. I never really saw the point of the shift light until I bought a vehicle that came from the factory with one. The light is really nice, but the alarm is really something special. No need to take notice of a flash, just listen for the beep. I can see value in this on the bike even more since I'm rarely looking down. | ||
| Rageonthedl |
I will say that I rode my bike HARD from day one. The Heads I had on the bike were put on around 10,000miles. and in 35,000 the only problem i had was the the shif drum was going bad. It would not stay in second gear unless you held up on the shifter arm. I even had an XB9 ECM tuned for my 12 motor. This was back in 2005 so we didnt really have ECM Spy or Erik Buell Racing ecms, Just race ecm, Power Comanders (junk), FI piggy back sysyems, and Direct Link. But I would run it up past the stock redline for a 12. You just cant abuse it. Have to give it some respect or the motor will blow. | ||
| Slaughter |
Hitting the rev limit really DOES shorten the life and beat the &$^*$ out of the bottom end. IF you're riding and accelerating hard, a "warning" of some sort just isn't going to work because of the speed at which you come up to the limit. Best thing is getting the proper feel for the bike. The limit comes so fast that you really must rely on the right wrist to keep out of harms way. I don't know of ANY device that can keep you from hitting rev limit other than the right hand and the brain. Shift light set a few hundred RPM below the limit will help. You are absolutely correct - the rev limit IS damaging over the long term. (Message edited by slaughter on December 10, 2010) | ||
| 1324 |
To your comment about the shift light a few hundred before the rev limiter - that is exactly what I mean with the alarm as well. Personally, while ripping through first requires brain/hand training (agreed), I'd also like to have one for when you're riding around in top of the gear (whichever) and fluctuation between 5k and redline. There have been times when I've hit the rev limiter in second or third while not even going WOT. As you are aware, these engines love to be over 5k. While there is ample torque down low, there are times to live close to redline. Plus, it sounds/feels so good! | ||
| No_rice |
all you really need is to figure out your bike. if your starting into a corner near redline, thats a problem in the first place and its not the bikes... up shift. if your carrying decent speed it wont be a problem. actually running a higher gear through a corner then REALLY need will more help you figure out how to carry even more speed into a corner and through it, because then you cant rely on pure power upon exit, you have to rely more upon your riding ability and how smooth your corners are. and you really shouldnt need a shift light/alarm(maybe if your all out drag racing or something) i almost never look at the tachs on my bikes. but still end up shifting with in at most a couple hundred of red line(not that i NEVER hit, but its rare and often times only if im at the track). all you have to do is listen, feel, and learn. | ||
| 1324 |
Let's agree to disagree - upshifting isn't always the solution when you're looking to drive out of corners. That ~4k flat spot is really what ruins things in my mind. I've owned numerous other bikes, been to various tracks, and put about 20k between my two XB's. After all of that, it is MY personal opinion that a shift light/alarm would be useful. Not for you? No worries, different strokes for different folks. However, judging by the cars/bikes on the market with this option installed at the factory, I don't believe it is without merit. Again, just my $0.02. I don't want to derail the OP's thread any more, so I'll leave it with that. | ||
| M1combat |
Stay off the limiter as much as you can. Or go to an '08 crank and rods with forged pistons like I did... You'll get there either way if you can't keep the revs down  . | ||
| Sifo |
I think it's safe to say that longevity of the engine and high revs are an inverse relationship. The rest is just details. Flat spot around 4k rpm? What setup is doing that? I would find that very annoying on my XB12. That's right in the middle of the fun on my bike. | ||
| Sloppy |
Don't forget folks that the bearings are roller, not plain. Meaning they are far heavier and mounted in different metals with different expansion rates. You need to be careful in trying to relate bottom end forces between the XB and other engines. Plain bearings have far less mass and hence can handle higher speeds. There are other negatives to the roller bearing design as well but that's not the discussion here. The XB bottom end is very similar to a two stroke and they are very limited to rotation speeds due to bottom end forces as well. Before you consider higher piston speeds, first compare the speeds to where your horsepower curve is. Then ask, is the % extra horsepower worth the decrease in life? If your income is based upon your finishing position, then it is well worth it. If not, then you'll need to make your own call. | ||
| Ourdee |
Maybe it is just the earlier builds, but, I don't find any difficulty shifting consistently a hundred revs under the limiter on my 08. The 4 to 4500 area is where mine likes to stand up. | ||
| Pragmatic |
While I do not know how much shorter engine life is when constantly redlining the Buell, I do know that of my two regular bikes (the other a 1997 Bandit 1200) I need to be much more concerned about which gear I'm in in the Buell. I find that unless my stock 2008 XB1200SS is above 3500 (or better yet 4000) it will not accelerate with authority. The Bandit can be left in any gear at any time as long as I'm over 2500 rpm it will pull well (if I'm not going anywhere fast I've let it pull from 1500 rpm). Of the two bikes I usually short shift the Suzuki and rev out the Buell. Since the redline is much lower on the Buell I end up shifting both at 6500 - 7000, right at redline on the Buell and 2000 rpm below it on the Bandit. Riding through towns (45 mph) I naturally find that the Bandit is in top gear and the Buell is in third. In either case I can accelerate well once the town ends. |
