Joe Perez
#43
There are 2 definitions of wheel torque.
Wheel Torque = torque measured at the crank, minus drivetrain losses
or
Wheel Torque = torque measured/calculated at the wheels
Tom is referring to the first, you are referring to the second. Stop acting like you've caught him out on some fundamental misunderstanding of dynamometers when all you've done is insult him repeatedly over a slight semantics issue. I hate the guy as much as anyone here, but make him look stupid over REAL things, not trumped-up ****.
Wheel Torque = torque measured at the crank, minus drivetrain losses
or
Wheel Torque = torque measured/calculated at the wheels
Tom is referring to the first, you are referring to the second. Stop acting like you've caught him out on some fundamental misunderstanding of dynamometers when all you've done is insult him repeatedly over a slight semantics issue. I hate the guy as much as anyone here, but make him look stupid over REAL things, not trumped-up ****.
Dude, in first place he was the one who started arguing by making the comments and didn't let go - it was in a thread I told someone else what torque a Dynojet shows.
Second, he could've said what you said above and while not technically correct (something called wheel torque which is not wheel torque) instead of doing his random chatter.
Instead he started posting random dyno stuff back which didn't prove or explain anything on the subject and really showed how much he knew ...
I can bet the only dyno experience he has is looking at someone else doing pulls on a Dynojet and he has never touched any other brand dyno machine ever ...
Did you see that reply of his with the quote from a Mustang employee explaining a chassis dyno can't measure crank torque ... Hellooo, who in the first place said chassis dyno can measure crank torque I had the word estimated everywhere... ?!
Third, initially I didn't plan on posting this but now here it is - I pointed to the Dynojet guys our discussion and asked them which of the two of us was right - me or Tom. Here is the answer which came from Dynojet Inc. - this is a direct copy & paste of the answer I got (even the caps is theirs):
"YOU are absolutely correct.
However, with our Inertia based with Eddy-Current equipped model 224xLC (Load Control) dyno, which we have been selling for 4 years now, you can view both ‘Cell Torque’ at the drum, or ‘Steady State’ Torque at the engine. These load control dyno runs will be labeled with a .dlf file extension, whereas most of our Dynojet Inertia dyno runs will read .drf. Dyno Run Files are for the standard, basic, Inertia dyno runs, and Dyno Load Files indicate that the eddy-current load control was utilized during that particular dyno run.
However, the largest majority of our installed chassis dynos, are Inertia only.
Keith Royle
Director of Dynamometer Sales
Dynojet Research Inc.
800-992-3525 "
So, here you have it straight from Dynojet - the inertial Dynojets out there show estimated crankshaft torque, not torque at the wheels and you won't see "wheel torque" written on all those inertial Dynojet printouts either.
Looks like for some newer eddy-current loading ones of theirs, the program can also can show the cell torque reading, similar to the loading ones of the competition, but that's not the torque numbers/graphs we discussed in the original threads.
That Dynojet director said it above - their machines estimates "torque at the engine" and confirmed my posts were the correct ones...
So, next time that quack-quack-yo-chicken-yo guy better read/learn more engineering stuff instead of arguing using random dyno related paragraphs he found with google ...
Last edited by j_man; 01-04-2008 at 04:32 PM.
#45
The point is that actual wheel torque is actually extremely high, due to the fact that you're multiplying the RPM of the engine by the gear ratio and the rear end ratio to get the actual wheel torque. That's not what anyone refers to when they say wheel torque, though; when I say wheel torque, I mean what the engine is producing at the crank minus the drivetrain losses. My engine probably makes 230ft.lbs, assuming 15% driveline losses, which means 201tq, but the actual torque at the rear wheels is significantly higher than that, since I have to multiply it by 4.1 and then account for the tire diameter as well.
Ok, I wasn't thinking. I totally buy that. I guess you're *measuring* driveline losses, and normalizing for gear ratios. But, you're right, wheel torque is kinda a dumb, ambiguous term to use. It really is horsepower / rpm or something silly. Normalized wheel torque is I guess what I would call it.
Easy. Tell the guy you'll leave the car there. Maybe he'll even give you $50.
Your own damn fault. You need to be cool without a reason. Do it for a reason, you're shafted, the reason could suddenly become important.
#51
Daym, you all have nice avatars now Am I the last without one? ...
Last edited by j_man; 01-05-2008 at 01:06 AM.
#56
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Thread Starter
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Background:
It's Greek for "come and take them".
Did you see 300?
"Spartans, lay down your weapons."
"Persians, come and take them!"
That move kind of recreates the battle at Thermopylae between the Persian slave army and the Greeks, where a few hundred Greeks held off countless thousands of Persians for several days. The pic in my avatar is an inscription that is found near where this battle took place.
Modern Day:
Term has been used by victims from city of New Orleans who had its agents confiscate firearms post Katrina under the guise of public safety. However, now that the city has come back, rebuilt, etc, the city is unwilling to return lawfully owned firemarms to legal citizens. The citizens are basically saying "you can have my guns over my dead body."
It's Greek for "come and take them".
Did you see 300?
"Spartans, lay down your weapons."
"Persians, come and take them!"
That move kind of recreates the battle at Thermopylae between the Persian slave army and the Greeks, where a few hundred Greeks held off countless thousands of Persians for several days. The pic in my avatar is an inscription that is found near where this battle took place.
Modern Day:
Term has been used by victims from city of New Orleans who had its agents confiscate firearms post Katrina under the guise of public safety. However, now that the city has come back, rebuilt, etc, the city is unwilling to return lawfully owned firemarms to legal citizens. The citizens are basically saying "you can have my guns over my dead body."
#59
Hope I'm not late to the party. Anyway. Quote and response:
In the scene where King Arthur comes upon the peasants and calls the one an "old woman", you can read that the other who was digging up God knows what, had this line, "Dennis, have you seen the cat's front legs?" In reference to the cat that is beaten around throughout the movie. lol
I highly recommend any Python fan read the Holy Grail script. They have all kind of little lines in there which are inaudible in the movie which are just absurdly funny...
Scene 6
[clop clop clop]
SIR BEDEVERE: And that, my liege, is how we know the earth to be banana-shaped.
ARTHUR: This new learning amazes me, Sir Bedevere. Explain again how sheep's bladders may be employed to prevent earthquakes.
BEDEVERE: Oh, certainly, sir.
SIR LAUNCELOT: Look, my liege!
[trumpets]
ARTHUR: Camelot!
SIR GALAHAD: Camelot!
LAUNCELOT: Camelot!
Scene 6
[clop clop clop]
SIR BEDEVERE: And that, my liege, is how we know the earth to be banana-shaped.
ARTHUR: This new learning amazes me, Sir Bedevere. Explain again how sheep's bladders may be employed to prevent earthquakes.
BEDEVERE: Oh, certainly, sir.
SIR LAUNCELOT: Look, my liege!
[trumpets]
ARTHUR: Camelot!
SIR GALAHAD: Camelot!
LAUNCELOT: Camelot!
#60
Senior Member
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Posts: 1,482
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What is your name?:Joe Perez
What is your quest?:I seek service at the Howard Johnson's
What is the airspeed velocity of an unladen miata?:...What do you mean,a domestic or jdm miata?
...um...I don't know that AHHHHHHHH!!!
What is your quest?:I seek service at the Howard Johnson's
What is the airspeed velocity of an unladen miata?:...What do you mean,a domestic or jdm miata?
...um...I don't know that AHHHHHHHH!!!