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Old 01-26-2017, 11:17 AM   #1272
Scooby Newbie
Member#: 426075
Join Date: Jul 2015
Location: Snohomish, WA
2015 WRX


Originally Posted by mishapopa View Post
yep... sounds like something i said but it either wasn't caught or people haven't rode a bicycle before. except with a turbo charged engine it's like being on steroids trying to ride the bike in the hardest gear up a 60 incline.

feet = pistons... legs = rods... go ride a bicycle and think about it apply thinking to engine. don't do steroids though.
As it happens, I bicycle commute 30 miles per day. My route includes a couple of significant grades.

My personal dyno curve does not look like a car's dyno curve at all. I produce most of my torque at a low RPM, and it drops off steeply at RPMs rise. But because of the way that the math works, I probably produce my peak horsepower at 75rpm or so. The thing is, that I *can't* physically make as much torque as the RPMs climb. If I could, my legs would take much more abuse mashing the pedals at high RPM than they do at low RPM.

Riding in too high a gear on the bike, I have low RPMs and need to make more torque to get the equivalent horsepower that I would get if I gear down and make more RPMs. The good news is that if change gearing to require less torque, I can pretty easily raise the RPMs enough to get the horsepower I need.

As I said in my very first post on the subject, an engine does need to make more torque at a low RPM than it does to make the same power at a high RPM. There is no dispute there. The difference between an engine and the bike analogy is that an engine *can* make lots of torque at high RPM. There is no way to demonstrate that with your legs on a bicycle.
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wadeh is offline   Reply With Quote