nihilanthic: i was not commenting directly about you. just making a statement about this thread in general. i didnt even read your previous post.

 

Well that explains a lot

I wish I had the ability to make a friggin FLASH video to explain this, becuase its ridiculous someone can take calc and 'not get it'

 

differentials? where!

I think no one will ever stop argueing about this until Steve Hawking himself posts what he has to say on the matter. But then again....

 

MATHEMATICAL FACT IS MATHEMATICAL FACT!

Its not anyones fault but thier own if they cant comprehend it.

 

People end up just like the ones they hate. I'm thinking of a word that rhymes with slimjab.

 

Exasperation eventually sets in, dude. Besides, if I was slimblabbing it up I would be personally insulting them. Im not!

 

I'd note that the road speed goes from ~40 to ~100 MPH during that pull. The folks who believe power is the determining factor know that your example represents slow driving. Much better to downshift and start your pull at higher RPM, because there's more power available.

 

Yeah, mathematical fact is mathematical fact, but mathematics does not govern the reality of vehicle acceleration. What I'm getting at is that it's great to base a theory on fundamentally sound principles, but the reality is that theory is often incorrect, for whatever reason.

So at this point, I think it's been argued well enough. Let's just take our arguments to the track and see what happens.

I'm considering building the bottom-end of my DSM with 10:1 CR and increasing the bore. Then again, I haven't even touched the head yet, so maybe it'd be a better idea to port and then verify any actual gains (I've never dynoed before so I tune my car and judge my mods based on 1/4-mile performance) before moving to the block. My personal goal is to run an 11.5 or faster on a small 16g turbo.

Speaking of reality though, I just bought a house and I don't really have the money right now to be screwing around with a car that will soon no longer be used as my daily driver, so I guess like many things these ideas will have to remain on paper (or whatever the internet equivalent of "on paper" would be).

 

You still dont get it.

For a given amount of power for half the rpm range vs only the very end of it, the former will go faster, because it will out accelerate the latter car in the first part of every gear past 1st gear.

If you take the former car and make it not lose torque, it will change the overall power the engine makes (by INCREASING IT) and thus making the arguement fall apart because nobody here can not throw a wrench into the arguement to twist it to suit their needs.

YES A MORE POWERFUL ENGINE IS GOING TO GO FASTER, DUH.

Two engines of equal power, one of which makes it sooner and for the entire 'powerband' vs one that only makes it at the very end of its rev range, the former will go faster.

END OF THREAD.

 

Power + gearing = force at road speed

torque + gearing = force

I think what everyone is trying to say is that power and torque are intimately related, but gearing is what puts the power down.

 

No, I just don't care anymore. I'm tired of reading your nonsensical posts about doing magical things to engines that are all theoretical anyway, and in fact, the only part of your post that I actually read is quoted above.

 

rarson, if a car out accelerates another car at the beginning of the gear, and then the rate of accelreation slows down to as fast as the other car accelerated the whole time at the end of the gear, and both cars had the same PEAK power, the former one merely had it for a longer time, which one is the faster car?

DUHR.

 

I guess that would be one hell of a clutch

 

putting a twin disc clutch and flywheel into a Dodge Ram Cummings Diesel. Now THAT is one hell of a clutch.

 

Nihilanthic, if a tree falls in the woods and nobody is around to listen to your pointless babbling, does anyone care?

DUHR.

 

You're missing the point. Extremely short gearing would allow the F1 engine to move the vehicle EXTREMELY slow. The gearing would convert the high rpm power into pavement torque.

 

I prefer the automatic in my 3500. Much easier to haul with that way


No, I'm not missing the point. Everyone else apparently missed mine. You'd need 25.10:1 gears in the diff to get the motor to spin high enough to move the vehicle. Any clutch that would pull that much weight while the motor is turning 18,000 rpm would be, like I said, one hell of a clutch. And it will STILL not move it faster than the CAT engine that was meant to be in it.

 

I explained it completely, its not pointless except when it falls on deaf ears....

Oh, ****

 

I drove my V8 RX7 today. It seriously made my weekend, just driving it for a few minutes.

I was stopped at some railroade tracks and this dude in a protege pulled up from the other direction, and he looked seriously confused. He drove by very slowly, looking at my car. I just rolled on through and opened it up, bwahahahaha....... it was great. V8 7's kick ***.

 

Right, well I agree that it'd be pointless to engineer such an engine into such a vehicle, as like you pointed out, it wouldn't work well even if you got it to work at all.

 

Yeah, I think I'd like one myself. If I had the money to build one, I would. Too many other car and non-car related things going on right now for me to do it.

Only things I dislike about V8's are the sound and the dropping of torque towards the higher rpms, but fortunately both of those things can be addressed with a little more money.

 

Okay, so perhaps you could explain to me then why a theoretical argument that only you care about regarding two theoretical cars with two theoretical power bands in a completely made up scenario with absolutely no basis in reality is "not pointless."

See, I would actually argue the opposite.

 

You get used to the v8 sound. It's a safe bet that in the eyes of the general public, a V8 7 is far more unique and desireable than a rotary 7. The general public thinks the rotary is a 4 cylinder with a more annoying exhaust note.

 

What is this thread about, rarson?

Honestly. What do you think its about?

Its about people who say things like "power vs torque" and don't really understand what the hell they are talking about.

My EXAMPLE (because I did not feel like getting on google and searching for a few hours to find two engines with the same redline to illustrate a point anyone with a brain could get with sufficient reading comprehension) was why people who say "torque" (but its really a case of having higher power at lower rpms...) makes a car faster are half right, but well, not really right, and why power matters, and what a powerband IS.

That, and people really just fall apart when they don't understand gearing, or how that relates to the engines output curve, blah blah ******* blah.

Now you get all uppity about my attempt at explaining it because its a scenario?

You think If I did all the math and jimblabbed it up with gearing, tire diameters, gear spacing by shifts, computed the acceleration curves in each gear that anyone would read it, or would their eyes glaze over?

****, anyone who has the attention span to read all that **** would know what Im talking about ANYWAY, and people with short ones who go "tl;dr" or gripe about it not being set in reality (like you) still dont.

Its virtually impossible to find a real apples to oranges comparison, becuase THERE ARE NO TWO CARS WITH EXACTLY THE SAME GEARING, REDLINES, BLA BLA BLA, EXCEPT "PEAKY" VS NOT WITH THE EXACT SAME PEAK POWER, DUMBASS.

But since you want real things and pretty pictures becuase thinking in the abstract is beyond your ability, fine, Ill post up some damn graphs to you and every other visual learner.



As you can see, this car has a HUGE powerband. 4.5K to 6.6K more or less. As long as you pick a gear within that rpm, you will be accelerating as fast as the motor is capable of doing, because its within the POWERBAND. Note the implications of that:

• There is "torque dropoff" or a negative slope
• Inverse Jerk
• Shorter gearing WILL NOT make it accelerate faster once it is within the powerband - the torque is lower at higher rpms (IOW POWER BAND IS FLAT) and thus in a engine such as this TALLER gearing is advantageous
• This will be faster than a motor with a peaky powerband (think S2000 or RX8 powerband) of equal intensity (same max power but for not as long of a time) in a car with the weight, regardless of gearing, unless you have a CVT.

Now, the only comparable graph at all I can see, is a more 'peaky' powerband of 400 peak power (vs 420, and Im waiting for the bitching about the difference now )



Now, which engine will accelerate harder? The top or the bottom one?

Also, for the bottom one to accelerate as hard as the top one (granted it was 400 hp flat with no curve up to 420...) you would have to keep it between 6500 and 7000 rpms... the previous one is around 400 at 4500 rpms!

Now, if people STILL WONT GET IT, ill go draw them transposed over eachother Jesus christ.

 

People's eyes glaze over no matter what you post because you inevitably use 1,000 words where 10 would have sufficed and you have no real-world experience to back any of it up.

BTW, how's that 2.3T FC project coming?