Horsepower numbers
02-27-2018, 08:11 PM
#1
Instructor
Thread Starter
Horsepower numbers
I wondering if HP numbers on a auto car like the A6 with a 1.15 transmission ratio would be different than one with a 1:1 ratio. Or Like our A8 transmission left in 5th gear on dyno would it make a different number than if put in 6th gear. Would a 1.15 ratio be 15% higher HP than a 1:1 ratio ?
Last edited by ZR1-ab; 02-27-2018 at 08:12 PM.
02-28-2018, 06:01 AM
#2
Instructor
The power the engine makes is what it is, the trans transfers that power to the wheels. The gear ratios will impact the butt dyno.
02-28-2018, 11:58 AM
#4
Le Mans Master
Nah, it doesn't matter what gear you're in. You want to make sure your engine speed is high enough that the converter is well coupled and that's all that matters, really. But let's say you're in a 1.25:1 ratio, it does not change anything. The computer measures the change in speed of the drum and does that math and that's it.
How can that be? Well, a higher gear starts accelerating the drum from a higher initial speed and over a wider MPG range than if you were in a lower gear, so it all works out the same.
Of course if you did it 1st it'd be over too quickly for the computer to make much sense out of the drum acceleration, and if you did it in 8th you'd way overspeed the drum.
I'd figure 5th works nicely, but each operator may have their own preference.
Nothing wrong with leaving it in 4th either.
How can that be? Well, a higher gear starts accelerating the drum from a higher initial speed and over a wider MPG range than if you were in a lower gear, so it all works out the same.
Of course if you did it 1st it'd be over too quickly for the computer to make much sense out of the drum acceleration, and if you did it in 8th you'd way overspeed the drum.
I'd figure 5th works nicely, but each operator may have their own preference.
Nothing wrong with leaving it in 4th either.
Last edited by davepl; 02-28-2018 at 11:59 AM.
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fmcokc (03-04-2018)
02-28-2018, 01:15 PM
#5
Team Owner
Nah, it doesn't matter what gear you're in. You want to make sure your engine speed is high enough that the converter is well coupled and that's all that matters, really. But let's say you're in a 1.25:1 ratio, it does not change anything. The computer measures the change in speed of the drum and does that math and that's it.
How can that be? Well, a higher gear starts accelerating the drum from a higher initial speed and over a wider MPG range than if you were in a lower gear, so it all works out the same.
Of course if you did it 1st it'd be over too quickly for the computer to make much sense out of the drum acceleration, and if you did it in 8th you'd way overspeed the drum.
I'd figure 5th works nicely, but each operator may have their own preference.
Nothing wrong with leaving it in 4th either.
How can that be? Well, a higher gear starts accelerating the drum from a higher initial speed and over a wider MPG range than if you were in a lower gear, so it all works out the same.
Of course if you did it 1st it'd be over too quickly for the computer to make much sense out of the drum acceleration, and if you did it in 8th you'd way overspeed the drum.
I'd figure 5th works nicely, but each operator may have their own preference.
Nothing wrong with leaving it in 4th either.
On the M7 you use 4th gear and with the A8 I believe with out looking to see which gear is closest to 1-1 which I think is 6th.
Using other gears will effect the results.
Last edited by 3 Z06ZR1; 02-28-2018 at 01:16 PM.
02-28-2018, 01:17 PM
#6
Le Mans Master
Bust out the ninth grade physics text and 'splain why it matters what gear you're in. It doesn't (beyond the computer measuring stuff I mentioned).
I say that dyno'ing in 4th or 5th or 6th is all about the same, except for friction differences. One of us is TOTALLY wrong.
Last edited by davepl; 02-28-2018 at 01:17 PM.
02-28-2018, 01:21 PM
#7
Team Owner
No it won't. Prove me wrong, big guy. I've got my claim staked above, I won't backtrack, now's your shot.
Bust out the ninth grade physics text and 'splain why it matters what gear you're in. It doesn't (beyond the computer measuring stuff I mentioned).
I say that dyno'ing in 4th or 5th or 6th is all about the same, except for friction differences. One of us is TOTALLY wrong.
Bust out the ninth grade physics text and 'splain why it matters what gear you're in. It doesn't (beyond the computer measuring stuff I mentioned).
I say that dyno'ing in 4th or 5th or 6th is all about the same, except for friction differences. One of us is TOTALLY wrong.
02-28-2018, 01:47 PM
#8
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1:1 is older info and really only matters on manual transmissions since 1:1 does not go through the countershaft and dynojets since they don't regulate load.
an auto and a mustang dyno (properly calibrated and set up) really doesn't matter. you don't use 1st gear due to either tire spin or not enough samples to get good readings, you want it to take longer than that to spin the drums but you also don't want to use a very high gear because you will load the motor a lot longer and risk potential damage.
you are arguing over "rules of thumb" not holy commandments.
an auto and a mustang dyno (properly calibrated and set up) really doesn't matter. you don't use 1st gear due to either tire spin or not enough samples to get good readings, you want it to take longer than that to spin the drums but you also don't want to use a very high gear because you will load the motor a lot longer and risk potential damage.
you are arguing over "rules of thumb" not holy commandments.
Last edited by Higgs Boson; 02-28-2018 at 01:47 PM. Reason: speleeng
02-28-2018, 02:06 PM
#9
Team Owner
Nothing older about it! 1-1 is used on the Manual and the Automatic as well for the best and most accurate results.
http://www.speedengineeringanddyno.com/dynotips.htm
http://www.speedengineeringanddyno.com/dynotips.htm
02-28-2018, 02:16 PM
#10
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Nothing older about it! 1-1 is used on the Manual and the Automatic as well for the best and most accurate results.
http://www.speedengineeringanddyno.com/dynotips.htm
http://www.speedengineeringanddyno.com/dynotips.htm
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The Yav (03-03-2018)
02-28-2018, 02:21 PM
#11
Le Mans Master
I love the determination to make 1:1 gearing in the transmission somehow mandatory while the rear end gearing is different car to car but somehow doesn't matter to the dyno.
Flail away, raggedy man.
BTW, the fact that someone calls themselves a tuner or can create a web page doesn't make them versed in the basic physics... Once you understand how an inertial dyno works, it'll make sense.
Flail away, raggedy man.
BTW, the fact that someone calls themselves a tuner or can create a web page doesn't make them versed in the basic physics... Once you understand how an inertial dyno works, it'll make sense.
Last edited by davepl; 02-28-2018 at 02:24 PM.
02-28-2018, 02:41 PM
#12
Team Owner
02-28-2018, 02:45 PM
#13
Team Owner
I love the determination to make 1:1 gearing in the transmission somehow mandatory while the rear end gearing is different car to car but somehow doesn't matter to the dyno.
Flail away, raggedy man.
BTW, the fact that someone calls themselves a tuner or can create a web page doesn't make them versed in the basic physics... Once you understand how an inertial dyno works, it'll make sense.
Flail away, raggedy man.
BTW, the fact that someone calls themselves a tuner or can create a web page doesn't make them versed in the basic physics... Once you understand how an inertial dyno works, it'll make sense.
I got your raggedy man DANGLING! Flail away! You posts are a fail to prove or a show a single fact .More bunk than anything!
02-28-2018, 03:00 PM
#14
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unless you want to get into a contest of who can post the most links to support our case, I will take it YOU are the one who has nothing left to offer.
use your own words and information/knowledge next time instead of being a simple repeater. you have a history of maintaining simple arguments with anyone who doesn't agree with you so no one really worries about your opinion, you realize this? of course you don't. ignorance is bliss after all, and you are the happiest guy alive.
02-28-2018, 03:16 PM
#15
Team Owner
I have provided actual information whereas you have only posted one clearly outdated link.
unless you want to get into a contest of who can post the most links to support our case, I will take it YOU are the one who has nothing left to offer.
use your own words and information/knowledge next time instead of being a simple repeater. you have a history of maintaining simple arguments with anyone who doesn't agree with you so no one really worries about your opinion, you realize this? of course you don't. ignorance is bliss after all, and you are the happiest guy alive.
unless you want to get into a contest of who can post the most links to support our case, I will take it YOU are the one who has nothing left to offer.
use your own words and information/knowledge next time instead of being a simple repeater. you have a history of maintaining simple arguments with anyone who doesn't agree with you so no one really worries about your opinion, you realize this? of course you don't. ignorance is bliss after all, and you are the happiest guy alive.
but WITH NO source or data but what your making up just like the other guy! So you resort to name calling!
Your ignorance is showing!
Here is another source PROVING MY POINT no shortage of them either! Your wrong! http://www.speedengineeringanddyno.com/dynotips.htm
Last edited by 3 Z06ZR1; 02-28-2018 at 03:21 PM.
02-28-2018, 03:26 PM
#16
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HAHA Funny you mention your "accurate information" but WITH NO source or data but what your making up just like the other guy!
So you resort to name calling!
Your ignorance is showing! Here is another source PROVING MY POINT no shortage of them either! Your wrong!
http://www.speedengineeringanddyno.com/dynotips.htm
but WITH NO source or data but what your making up just like the other guy! So you resort to name calling!
Your ignorance is showing!
Here is another source PROVING MY POINT no shortage of them either! Your wrong! http://www.speedengineeringanddyno.com/dynotips.htm
what name did i call you again?
by the way, when you quote "another source" it's probably good to make it a different one than the first time.
case in point indeed.
02-28-2018, 03:33 PM
#17
Race Director
02-28-2018, 03:40 PM
#18
Le Mans Master
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02-28-2018, 04:04 PM
#19
Team Owner
02-28-2018, 04:05 PM
#20
HAHA Funny you mention your "accurate information" but WITH NO source or data but what your making up just like the other guy!
So you resort to name calling!
Your ignorance is showing! Here is another source PROVING MY POINT no shortage of them either! Your wrong!
http://www.speedengineeringanddyno.com/dynotips.htm
but WITH NO source or data but what your making up just like the other guy! So you resort to name calling!
Your ignorance is showing!
Here is another source PROVING MY POINT no shortage of them either! Your wrong! http://www.speedengineeringanddyno.com/dynotips.htm