| Author | Message | ||
     Lenb |
I never said that torque and power were the same thing. I just used the example of a 600 and 1200 where coincidentally, the 600s torque was half of the 1200 and the rpm was double. I don't think the R1 with 95ftlbs and the Cummins with 400ftlbs is a fair comparison. But let's have a look at that example anyway: Let's say the Cummins is geared (for argument's sake) to pull a 18,000lb camper up a 7° incline at 70mph at its (say) 3000rpm 400ftlbs torque peak in a given gear; That means that the R1 would be able to do the same job if geared to do 55mph @ the 10,000rpm 95ftlbs torque peak. So yes, the R1 could do it, it would just pull the load up the hill slower with the engine revving at the 10,000rpm. For that matter you could probably get the same load up that hill using a re-geared 12V cordless drill - if you were prepared to move as slowly as the hour hand on your watch! By the way, the R1 engine would not blow up either - it could do it all day - as 10,000 is still 2000rpm below redline. (As an aside: I don't know about Yamaha but Honda have a "24 hour redline test" that all new engines need to pass before being approved for mass production.) (Message edited by lenb on June 07, 2006) | ||
| M2nc |
Okay - You are going in the right direction just need to take your line of thought out some more. I don't know if gearing will help the little motor pull that weight or not, but if you continue to increase the mass to 100,000lbs. Do you think the R1 motor can still pull the load? Okay maybe in inches per hour. Add more weight, let say 200,000lbs. Do you still think it will pull the load? Eventually you will reach a point that the R1 motor will not move the mass. Now you can increase the gearing in the Cummins engine and the motor will still be able to pull the load when the R1, no matter what the gearing will not. Torque is a finite measurement so an engine with more torque can always do more work. Gearing will skew the amount of work an engine can do due to the pulley effect or lever effect the gearing has. Though at this point you are past my off the top of my head knowledge and I do not want to calculate the force advantage gearing adds, I will have use general terms. Gearing will add force to the work the engine is doing. If the two engines are geared the same, the one with more peak torque at a constant rpm will do more work. Now increase the ratios of the gears to the advantage of the engine with less torque, it is not a one to one ratio. With the tighter gearing you also have added friction and more rotational energy that act like a counter force to the lever force of the gears. Factoring in the added counter forces the added force of twice the gear ratio will not double the work the engine does. How much more will it add? That will take more time than I have to calculate. | ||
| Lenb |
if you continue to increase the mass to 100,000lbs. Do you think the R1 motor can still pull the load? increasing the load from 18,000lb to 100,000lbs will reduce the speed of the R1 from 55mph to 9.9mph (assuming the R1 engine can be geared to run at its 10,000rpm torque peak). The Cummins engine will be slowed to 12.6mph @ 3000rpm. Add more weight, let say 200,000lbs. Do you still think it will pull the load? Yes, at 4.9mph (again assuming the R1 engine can be geared to run at its 10,000rpm torque peak at that speed). The Cummins engine will be slowed to 6.3mph @ 3000rpm. If the two engines are geared the same, the one with more peak torque at a constant rpm will do more work True. Eventually you will reach a point that the R1 motor will not move the mass. No, theoretically there is no limit. Depends if you have the patience to move with the speed of a minute or hour hand or even slower. With the tighter gearing you also have added friction and more rotational energy that act like a counter force to the lever force of the gears. Factoring in the added counter forces the added force of twice the gear ratio will not double the work the engine does. How much more will it add? That will take more time than I have to calculate. and I'd want to be paid if I had to do those sorts of calculations  | ||
| 71sportster |
This is giving me a headache. Please notify me when the 1200's are able to beat the 600's. | ||
| Lenb |
Please notify me when the 1200's are able to beat the 600's. It'll be when a production XB12 engine can be made to make peak power at about 8500rpm. Of course 600s will probably rev to 20,000rpm then. (Message edited by lenb on June 08, 2006) | ||
| Josh_ |
It's not the bike. | ||
| Spatten1 |
"but if you continue to increase the mass to 100,000lbs. Do you think the R1 motor can still pull the load?" With equal horsepower, yes the R1 will do the same work as the Cummins. That is what horsepower is, a measure of work performed. Gearing must be adjusted, but it is simple math. It would be impractical to use the R1 engine, as it would wear out much faster if used for long distance trucking purposes. M2, you seem to be stuck thinking that 100 pounds of steel weighs more than 100 pounds of feathers. | ||
| Spatten1 |
"It's not the bike." It is the bike when I am deciding which one to use for track days. Same rider, different bikes, 40 extra HP tends to help. | ||
| 71sportster |
It would be very difficult to make an air cooled engine rev to 8500 RPM's. The tolerances necessary to keep the thing running are just not tight enough and the temperature variation too great. Until Buell starts building that water cooled bike, we'll all just have to be content with 40 HP less. | ||
| Wademan |
Thanks lenb. I started to try but just gave up at the first negative comment (a page back). Very good and accurate responses. Does an engineer justice. Wademan Recent MTU ME Grad | ||
| Spike |
So are we in agreement that the techno-marvel 600s make great race bikes and track toys, but the lack of decent power below ~7k rpm makes them downright irritating to ride on the street? | ||
| Chadhargis |
If you're racing or trying to turn fast lap times at said track day, the extra HP will help you, but if you're working on skill, corner entry speed, and smoothness, power matters very little. My last track day I got passed by a guy on a vintage Triumph putting out 55hp at the rear wheel on skinny tube tires. My bike was putting out 25 more horses, and he was still spanking me. He was an amazing, smooth rider. Never challenge a really good rider who's on an Aprilla RS250 either.  (Message edited by chadhargis on June 08, 2006) | ||
| Lions |
Spike sez:"So are we in agreement that the techno-marvel 600s make great race bikes and track toys, but the lack of decent power below ~7k rpm makes them downright irritating to ride on the street?" ummm...absofreakinlutely not! They are a blast on the street!  | ||
| Bigj |
Mr. 71, BMW's R1200S revs to 8500 rpm. | ||
| Spatten1 |
"Until Buell starts building that water cooled bike, we'll all just have to be content with 40 HP less" Agreed, and it is still a really fun street bike. I love the buell engine on the street. Unfortunately I am a one bike guy and I'm not happy with it at the track. I have to decide which is more important to me, street or track. If the 600's are too anemic on the bottom, you can get a 750 or 1000. The cool part about the 1000's is that at low RPM they behave about like the Buell, easy to control. When you rev it up it is a different bike. You are in control or the bike's manners, depending on what revs you use. I will agree that there is less of a soulfull feeling with the I4s. No doubt the Buell engine feels great, regardless of power. | ||
| Spike |
Agreed, totally. Only difference is that I don't spend that much time at the track, so I make the trade for the more entertaining street bike. Even if I did start putting in more track time I'd likely keep running the Buell for a while since the handling is at least on par with the competition and the power delivery makes it easier to learn how to properly ride the bike. If I were to make the switch to an I4 it would most definitely be a liter bike, which seems to be common choice among those that like(d) Buells. The one thing I find common on every street bike is that more low end translates to more fun. Revving an engine hard to get to the power can be fun for a while, but it eventually gets tiring. | ||
| 71sportster |
Mr. 71, BMW's R1200S revs to 8500 rpm. Need I explain the difference between a Harley and a BMW? | ||
| Lenb |
Thanks lenb. Very good and accurate responses. Does an engineer justice. Wademan Glad my efforts were appreciated! (and that all that study is good for something!) If I were to make the switch to an I4 it would most definitely be a liter bike No doubt an I4 1000 will do anything a Buell can do. However, for my skill level and the kind of riding I do, I find them unsatisfying and frustrating as it's not possible to use a large part of the available engine performance. Personally I like to be able to feel like I am riding a sportbike hard to really enjoy it. On the Buell it's possible to hit the rev limiter quite a bit with spirited riding - even on the street. Try that on something like a ZX10R! As far as I4 600s are concerned, Sure, they have a more usable "real world" performance but I hate that they are gutless unless you rev them like you're trying to hurt them. (Message edited by lenb on June 09, 2006) | ||
| M2nc |
and I'd want to be paid if I had to do those sorts of calculations  AMEN! Last point, I promise. (cross fingers and all) Theory and Reality do not always match. Though on paper, the increase in power caused by the increase in gearing is exponential, in reality as the gear ratios increase to keep the R1 motor at those higher RPM the force needed to turn the gears will over come the power the engine makes. So in reality, the engine will stop. No doubt an I4 1000 will do anything a Buell can do. However, for my skill level and the kind of riding I do, I find them unsatisfying and frustrating as it's not possible to use a large part of the available engine performance. Ditto! As far as I4 600s are concerned, Sure, they have a more usable "real world" performance but I hate that they are gutless unless you rev them like you're trying to hurt them. You made this point originally about the affect of the flatter torque curve and you were right on! Let's ride. | ||
| Lenb |
Theory and Reality do not always match. Agreed! as the gear ratios increase to keep the R1 motor at those higher RPM the force needed to turn the gears will over come the power the engine makes. So in reality, the engine will stop. Hmm... I may be wrong but I think the torque required to turn a gearbox remains more or less constant regardless of the speed at which you try to turn it. Of course, the power losses in the transmission will increase with revs as power is proportional to engine speed. But enough of that (too much like work!) I've got a ride-day on Sunday and the weather forecast is predicting fine weather! The only disappointing thing is that I've got to fit my stock muffler as my "new" race muffler doesn't fit  (the subject of another thread). | ||
| 71sportster |
Years ago I had an '87 Yamaha FZ600. That was a pretty potent bike. Todays modern 600's make that bike seem like a dog. Anyone who thinks 600's are "gutless", either hasn't ever ridden one, or doesn't know how to ride. | ||
| Benm2 |
The CB900F, the KZ1000J, the GPz550, the GS1000, and many other AIR COOLED bikes rev to 8500 rpm. Also, Ducati has an entire range of air cooled two-valve twins that rev over 8500 rpm. There have been scores of them. In fact, the original FZ600's were air cooled. | ||
| Lenb |
Anyone who thinks 600's are "gutless", either hasn't ever ridden one, or doesn't know how to ride. Harsh words and anyway, I said: "gutless unless you rev them like you're trying to hurt them." | ||
| Josh_ |
Pretty funny, but running around the track this week I found my 1300cc to be pretty gutless under 6000RPM (keeping in mind it has 60ft/lbs as low as 2000RPM). The 600s in the right gear would walk away from me out of turns if I was one gear down. | ||
| 71sportster |
The CB900F, the KZ1000J, the GPz550, the GS1000, and many other AIR COOLED bikes rev to 8500 rpm. Also, Ducati has an entire range of air cooled two-valve twins that rev over 8500 rpm. There have been scores of them. In fact, the original FZ600's were air cooled. Again, we're talking Japaneese technology Vs. Harley technology! | ||
| 71sportster |
Two more things: long stroke twins, with Rocker arms & pushrods Vs. I-4's with short strokes and Overhead cams. | ||
| M1combat |
I had an '82 CB750F-SS that I ran at 11,500 for about three minutes straight one time... The redline was at 9500. Air cooled. One of the best sounding bikes I've ever heard with a 4to1 Kerker w/ no baffle and four K&N's... SWEET music . | ||
| 71sportster |
Last years Bike Week, at the Cabbage Patch, they took an 80’s vintage, air-cooled, Suzuki 750, drained all the oil out of it, and duct taped the throttle wide open. They suspended it 100 feet in the air, from a crane and the thing just continued to run for about 20 minutes! After awhile, the grease & filth on the outside of the engine caught fire & they had to lower it to put the fire out. The thing eventually stopped running, but it was from a short circuit, after the fire burned away all the insulation on the main wire harness under the tank. I’m convinced, if you plugged in a new harness, you probably could have ridden the thing home. Try that with a Harley. The Harley guys were severely disappointed. | ||
| M1combat |
Pretty much the same thing at Four Corners a couple years ago . Some guys were out by the bon-fire revving the CRAP out of some IL4... It never went so they got mad and threw it in the fire... I walked over to my 750 and started it up and gave a few revs for the fallen IL4... Then I sat near our camp fire with a few pistols just in case anyone decided mine should be next . | ||
| Blake |
Anyone check out the 600cc shootout in July Cycle World? They hated the R6 for street duty. And the bike didn't come anywhere near the gloriously predicted 120 RWHP. Though the 109 RWHP it did make was impressive, all the way up at 14,420 rpm. Based on the dyno results, the Honda CBR600RR looks like the best 600cc (excludes 636cc Kawi and 675cc Triumph) repliracer for street duty. At 8,000 rpm and again at 10,000 rpm for instance the Honda is posting over 10 RWHP more than the R6. The R6 is making 45 RWHP at 8,000 rpm. Bike for the street? No thank you! Also interesting but already widely reported is the fallacy of the R6's MotoGP-like 17,500 rpm rev limit. The tack reports a 17,750 rpm rev limit, but in truth the engine is actually spinning at 15,950 rpm. A quote from the article: "If you're a racerr chasing after Yamaha contingency money at the track, then the new R6 is the cat's meow. But (dodgy) delivery under 10K leaves the average street rider chasing his tail with this one, or as Hoyer put it, "Livable as a streetbike, yes, but not that much fun." That pretty much sums up my take on all the 600 class repliracers. If I were looking to purchase a repli-racer IL4, it would need to be a liter bike. Why are Buells so much fun? I think one answer is that their engine performance is the antithesis to that of the R6. I could deal with something in the middle though. A twin that revved to 10K and made 120 rwhp would work fine for me. I don't think I'll ever part with my big bellering 1.25L Cyclone though. |
