| Author | Message | ||
     Johnnylunchbox |
Very informative and a good read. http://vettenet.org/torquehp.html | ||
| Reepicheep  |
He is closer then most, but still (IMHO) gets it wrong. Torque, by itself, is a COMPLETELY useless measurement. It measures nothing (I could be making 500 ft lbs of torque, but only at .0001 RPM, and go NOWHERE). Torque times peak RPM (which is exactly what peak horsepower is, which is what is normally quoted) is a BARELY useful measurement. It measures exactly what your bike actually does at exactly the moment you can no longer do it anymore (you have to shift). What people really want is the Horsepower versus RPM curve for the full range of the engine. Deciding if a given curve is "good" or not depends on your application. If you are racing, you don't care that much about low RPM power, you just row the gearbox to stay at peak power (which will always be far higher then low end power, regardless of how "torquey" your engine is). If you are tooling around on the street, you don't really care about peak RPM so much, you never run the bike there, you want decent power down low so you can tool around town with decent throttle response without sounding like you are on a dremel tool, or constantly rowing the gearbox. If you want a sport oriented streetbike, you want good high rpm horsepower, but without butchering the bottom end power to the degree the bike is a pain in the ••• to ride and always needs to be shifted before you can make it do anything useful. His math was good though. (Message edited by reepicheep on February 17, 2005) | ||
| Jlnance  |
A good article. | ||
| Evaddave  |
Reep, I'm picking nits here, but what you said:
is not always the case. It's quite possible for the peak horsepower to be reached before peak RPM. (I did a search for "dyno chart" and found examples of both peak HP @ peak RPM, and peak HP before peak RPM.) In the end, it's only numbers, anyway. Ride what makes you smile.  | ||
| Reepicheep |
Good point! s/exactly/generally/ (hope you speak Unix  ) Also, I should amend the "(you have to shift)" with "(you either have to shift or are about to go down in power)". | ||
| Jlnance |
echo "doesn't everyone?" | sed -e 's/^d/D/' -e 's/ e/ E/' | ||
| Reepicheep |
/usr/bin/yes (no kidding, it is there, I have used it, in a very dark moment in midst of some pretty important data, fsck, and a rapidly failing HP-UX scsi drive...) YES(1) FSF YES(1) NAME yes - output a string repeatedly until killed SYNOPSIS yes [STRING]... yes OPTION DESCRIPTION Repeatedly output a line with all specified STRING(s), or ‘y’. --help display this help and exit --version output version information and exit | ||
| Rick_a  |
That's not always true. Maybe for small displacement two strokes. Most race engine builders are looking for broad, rideable power characteristics...from club racers to Moto GP. In Drag racing it may be more the case, but even there a bike requiring high RPM launches can create problems with wheelspin. | ||
| Evaddave |
yeah, I speak Unix, but it's late on a Friday, and I can't think of anything sufficiently geeky to write back. I knew about /usr/bin/yes, but have been sufficiently fortunate to--so far--never need it. | ||
| Bigdaddy  |
Which MAN pages did Ken Thompson write? Let's talk UNIX. $ PATH=pretending! /usr/ucb/which sense no sense in pretending who | grep -i blonde | date; cd ~; unzip; touch;strip;finger;mount; gasp; yes; uptime; umount; sleep | ||
| Reepicheep |
You can tune a file system, but you can't tuna fish. | ||
| Jlnance |
Greg - I'm gonna remember that one BTW, I put a deposit on an M2 on Thursday | ||
| Bigdaddy |
Jim, That was a targeted response -- I knew you'd get it. It goes back a few years, scary how many, and the guy that did the original is a UNIX almost-legend named Boo Boo. Congrats on the M2 and I can guarantee lots of smiles in your future. I got plenty of spare 'stuff' too. BTW, I'm back to normal, well, until I do another 40 hours before Monday AM and then I'll be all hosed up again. Later. G2 | ||
| Jlnance |
I never heard of Boo Boo, but it turns out that Google has. Just don't post when you get hosed up :-) Hey, it's just me in the house now. You have a standing invitation to come over, grill steaks, and discuss the finer points of motorcyles, kernel design, and encryption algorithms whenever you get a chance. | ||
| Bigdaddy |
I've never Googled Boo Boo, but that's not surprising. He's one of them guys that if you ever get stuck on a project with him you constantly feel like you're the village idiot -- fricking genius. Ping me off line with your Google results of Boo Boo -- I'll tell you if you got the right one :-) You've, not surprisingly, hit upon three of my favorite subjects: ribeye steaks, motorcycles, and encryption. I can't get motivated about kernel design these days. I look forward to the steak grilling and if you really want to be placed in the zombie zone (some folks are never the same) we can discuss enc-algos. G2 (Message edited by bigdaddy on February 19, 2005) |
