wingsfan

I'm sorry. I don't speak engineer, so you'll have to translate for me. What assumption are you claiming was inaccurate?

I left all that in Corvallis. I work on translation initiation these days.

88IntegraLS

Differential equations (what I was studying at the time) is not the same subject as differential calculus. Differential calculus is much easier, and a requirement for all business and horticulture majors. Differential equations lay the foundation for finite element analysis, heat transfer predictions, rocket trajectory simulation, and other engineering problems. Differential calculus simply relates position to velocity to acceleration, etc.

But by explaining this, does it make me guilty of what you accused me of in the past (dousing every post with engineer-speak)?

wingsfan

I do love it when engineering/physics/math types get uppity about the alleged superiority of their education and training.

Amazingly enough, even I had to suffer through DiffyQ many moons ago.

My point earlier was that you kept making repeated references to calculus that served no purpose other than to tout your ability to perform the calculations (a few examples below).
http://www.theforumlounge.com/showth...ulus#post75334
http://www.theforumlounge.com/showth...ulus#post75551
http://www.theforumlounge.com/showth...ulus#post56088

Which prompted my response
http://www.theforumlounge.com/showpo...&postcount=122

and

http://www.theforumlounge.com/showpo...&postcount=153

So, if the "invalid assumption" was my uninformed familiarity with what classes you were actually enrolled in then you're entirely correct. However, that's an excessively trivial detail that wasn't at all relative to the criticism.

I think you know the answer to that without having to ask.

88IntegraLS

I guess I'll agree to disagree with your viewpoint, as I have in the past. Not worth wasting effort arguing over your perception of me becoming uppity here or anywhere else. Have a nice day.

wingsfan

As I pointed out, I took the class. Yet you seemed to think you needed to point out the difference. Why do you suppose that is?

How could that not be construed as uppity?

rarson

I don't need to score well on an IQ test to feel better about myself.

rarson

So now you're telling me how I feel? I feel pissed off? Well, honestly I didn't think I was pissed off. It really doesn't **** me off when you post because normally I don't even have to read most of it, because it's all just crap anyway. I guess I need to check in with you from now on to find out what my particular feelings are on a particular thing, since I obviously don't know what I'm thinking.

Supposedly??? SUPPOSEDLY??? Like it's that hard to believe that someone could take a high-school calculus course, or a college calc course? You know they even offer multiple calc courses in college! Yup! I actually took two of them the one year I spent in college (that's one class per semester, for those who are weak in math).

Look, don't act like I don't understand some sort of key idea dealing with modding cars. The fact of the matter is that you're arguing some asinine technical theoretical detail while I, like the rest of us, prefer to stay in the real world.

rarson

Not to mention... you know what? I'm not trying to tout my own intelligence here, but calculus was really one of the easiest math classes I have ever taken. Now granted, I had a GREAT teacher (and I was lucky enough to have the same high-school calc teacher in college, as she left my school and moved to my college). But calc was on the order of algebra in terms of ease of comprehension. If you ask me, trig is much harder to learn.

So stop acting like calculus is some big, mythical, hard-to-comprehend math that only sages understand. The only reason calc is near the end of the math ladder is that it uses so many other math areas for it's basis (like algebra and trig). Once you get there, it's pretty damn much cake.

Nihilanthic

Yhbt.

trinydex

i don't wanna read through all the trash but here's what i had to write about it.

torque can be loosely associated as a product of exhaust gas velocity. horsepower can be loosely associated as a product of mass flow. an example to clarify is that big horsepower cars flow a lot of air and what we view as torquey cars generally make thier torque low when the volume flow has high velocity. now i say loosely associated because gearing has to do with both factors and also because of what i'll explain next.

high horsepower engines with enough compensative gearing make high amounts of torque, however we do not view these cars as torquey but peaky. take for example an f1 2.4 liter v8. it'd be hard to convince me that this motor doesn't make a ton of torque at 16k rpms... but that's the problem isn't it... 16k rpms makes your car sound like... well an f1 car. so snap back to the real world for a second.

a typically torquey motor is the lsX motor where X can be 1, 2, 6, 7 etc... basically the vette/fbody motor. this motor generally displaces more than 6 liters so it flows a ton of air. but generally it flows at lower cylinder pressures than a turbo car like the evo. now with that basic qualification out of the way it doesn't matter.... now i say this because if you flow 1 pound through a 2 inch^2 hole... the hole loosely dictates the speed of the gas. that said the lsx's optimum flow is TYPICALLY at the midrange which gives you that low end torque feel.

now why did i say optimum flow? well because the cross section of the pipes going in and pipes going out of the cylinder dictate the flow speed and hence the torque (loosely again). so when you achieve optimum flow you achieve some level of peak torque (this can be modified). so if you made all the ports REAL big in the lsx would it then become peaky? absolutely. this is what's known as shifting the powerband or torqueband around.

see in the end this is a limitation of engineering, you're asking to maximize two fundamentally opposing quantities. here's the punch line. small flow area increases velocity but limits maximum flow potential, large flow area decreases flow velocity but increases maximum flow potential. NOW this is relative... what i MEANT to say was small flow area increases LOW END gas velocity but limits HIGH END maximum flow (tha last two adjectives were redundant) and large flow area decreass LOW END flow velocity but increases HIGH END FLOW VELOCITY which produces a HIGH END TORQUE!!! a bigger hole is idealized to a bigger flow.

if you had a 2" hole and it produced 100 foot/second flow speed at 4000rpm then a 3" might do the same at 6000rpm.

this is why in drag racing it's always better to shift the rpm higher, because you're never going to lose torque unless you can't gear yourself into the powerband.

if you cut yourself short by getting low end torque, you're LOSING HIGH END TORQUE!!!

now to answer your question of what gets you to keep the torque from dropping off. well the answer to any limitation of engineering problem is likely variable geometry of some sort. you can have a variable geometry turbocharger, this allows you to flow fast at the low end and fast at the high end... this creates a nice torque band that is relatively flat the whole way through, never dropping off while your hp increases the whole time. the other way is variable valve timing, you can change the flow characteristics/speed of the engine by changing the valve timing (mivec).

ball bearings and various sizings of turbos would only change what they call "static" quantities. in order to get the best of both worlds you need dynamic quantities.

in the end horsepower is how fast torque is happening in a really really laymens way of thinking. obviously if torque is happening fast you get to where you want to go fast. how do you get torque to happen fast? stay in a lower gear for longer. why can't that always happen? big piston can't move fast enough i.e. 9000 rpms.

jimlab

Just FYI, when a thread hasn't had a new posts in 8 months, no one has any questions left...

trinydex

oh that was a quote from something i wrote a long time ago in another forum, wouldn't be referring to anyone here.

jimlab

Apparently, you missed my point...

ariha

god this is amusing.

trinydex

if you don't wanna read what i had to write, no sweat. if you want to stop bumping the thread... you'll have achieved the goal of your point.