The discussion thread on 1/4 mile E.T. and Trap Speed, and their relationship to HP
#46
10-24-2006, 05:47 PM
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So VRAlex and all his crazy races from a roll prove that he (may) have the
highest horsepower 996TT based car out here. I do also understand that
it is very hard on our very expensive drive trains to launch quartermile runs!!
(especially if you are relatively new at it...) like me!
I think that all of the quartermile experiments have brought alot to the table
and is one of a couple VERY GOOD comparators! It is so important to have some accurate way of doing our own performance exams so that when we
spend more $$$$ we can see if it is worth it when we are done.
thanks guys for all the great info,
Marty
sorry to hyjack--We have learned more in the last 6 months than all the
other years combined.
highest horsepower 996TT based car out here. I do also understand that
it is very hard on our very expensive drive trains to launch quartermile runs!!
(especially if you are relatively new at it...) like me!
I think that all of the quartermile experiments have brought alot to the table
and is one of a couple VERY GOOD comparators! It is so important to have some accurate way of doing our own performance exams so that when we
spend more $$$$ we can see if it is worth it when we are done.
thanks guys for all the great info,
Marty
sorry to hyjack--We have learned more in the last 6 months than all the
other years combined.
#47
10-24-2006, 05:53 PM
Originally Posted by Jean
Scott, I agree with you (except that last sentence that I cannot read 
) , these calculators can never be 100% accurate just because of the variables involved (traction, weight distribution, exact weight, exact hp and probably this is the biggest uknown, etc..), however I was just interested in the fact that they are interrelated, the number (1450) used might be a point of debate but nevertheless there exists a link between them as shown.
If you go to the drag thread, you will see that many of the cars shown can get quite close to the theoretical number... Of course some others don't, but quite accurate I think.. I am sure your run will throw off any theory to the garbage
) , these calculators can never be 100% accurate just because of the variables involved (traction, weight distribution, exact weight, exact hp and probably this is the biggest uknown, etc..), however I was just interested in the fact that they are interrelated, the number (1450) used might be a point of debate but nevertheless there exists a link between them as shown.If you go to the drag thread, you will see that many of the cars shown can get quite close to the theoretical number... Of course some others don't, but quite accurate I think.. I am sure your run will throw off any theory to the garbage
#48
10-24-2006, 06:03 PM
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Trap speed is a very accurate predictor of horsepower. Short time has almost no bearing on trap speed. Short time has a large bearing on ET (given the same car).
#49
10-24-2006, 06:05 PM
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Originally Posted by Jean
.. What I am saying is that there is an instrinsic relaitonship between ET and trap speed ..
#50
10-24-2006, 06:13 PM
Mr Blonde
If you cannot see it from the formula above, I cannot do better I am afraid.
Maybe you would like me to start posting data graphs to prove it further?
To each his own guys, just try to be open to new arguments..
If you cannot see it from the formula above, I cannot do better I am afraid.
Maybe you would like me to start posting data graphs to prove it further?
To each his own guys, just try to be open to new arguments..
#51
10-24-2006, 06:17 PM
Originally Posted by MrBlonde
Trap speed is a very accurate predictor of horsepower. Short time has almost no bearing on trap speed. Short time has a large bearing on ET (given the same car).
I am not saying it will have a huge impact, as it is shown by the correlation formula, but if you can predict 600 vs 650FWHP as a result of a 2mph difference in trap speed, those 2mph can be coming from your 60ft hence ET times!If trap speed is a predictor of HP, certainly a rolling run under accurate measurements is more of a predictor since it follows the exact same principle while you eliminate the slightest potential variance due to grip etc... Pretty obvious.
Last edited by Jean; 10-24-2006 at 06:22 PM.
#52
10-24-2006, 06:22 PM
Originally Posted by Jean
So since you are mentioning it, how do you predict HP from trap speed? Are we going back in circles? There is a certain formula that is posted above, and that same formula also tells you the relationship between ET and trap speed.
If trap speed is a predictor of HP, certainly a rolling run under accurate measurements is more of a predictor since it follows the exact same principle while you eliminate the slightest potential variance due to grip etc... Pretty obvious.
If trap speed is a predictor of HP, certainly a rolling run under accurate measurements is more of a predictor since it follows the exact same principle while you eliminate the slightest potential variance due to grip etc... Pretty obvious.
whp = wt./[.17167et + .103 - .00017167(wt./(et/5.825)^3)]^3
But as I mentioned earlier...even websites that have both forumulas freely admit that the E.T to whp calculator is not nearly as accurate as the trap speed to whp one is. Which is why no one uses E.T to figure out whp. Only trap speed..since it's the only accurate method.
Last edited by Divexxtreme; 10-25-2006 at 02:23 AM.
#53
10-24-2006, 06:42 PM
Originally Posted by Divexxtreme
No, this formula gives you whp from E.T.:
whp = wt./[.17167et + .103 - .00017167(wt./(et/5.825)^3)]^3
But as I mentionod earlier...even websites that have both forumulas freely admit that the E.T to whp calculator is not nearly as accurate as the trap speed to whp one is. Which is why no one uses E.T to figure out whp. Only trap speed..since it's the only accurate method.
whp = wt./[.17167et + .103 - .00017167(wt./(et/5.825)^3)]^3
But as I mentionod earlier...even websites that have both forumulas freely admit that the E.T to whp calculator is not nearly as accurate as the trap speed to whp one is. Which is why no one uses E.T to figure out whp. Only trap speed..since it's the only accurate method.
http://www.stealth316.com/2-calc-hp-et-mph.htm
This has gone in the wrong direction I think, I am not debating the accuracy of the formulas nor am I saying that ET is a better indicator of HP if you re-read all my posts. I am saying there IS a "certain" correlation, which one is 100% correct, was not/t is not part of this debate.
After all this information posted if one wants to continue to believe that trap speed is 100% independent form the 60ft or ET, I can't help more I am afraid, the 60ft does impact the trap speed, to a certain degree, just as much as one can guesstimate 50FWHP for instance through a trap speed, making the HP guess through trap speed less than very accurate.
:cheers:
#54
10-25-2006, 12:03 AM
Originally Posted by Jean
Here is some reading Scott.
http://www.stealth316.com/2-calc-hp-et-mph.htm
This has gone in the wrong direction I think, I am not debating the accuracy of the formulas nor am I saying that ET is a better indicator of HP if you re-read all my posts. I am saying there IS a "certain" correlation, which one is 100% correct, was not/t is not part of this debate.
After all this information posted if one wants to continue to believe that trap speed is 100% independent form the 60ft or ET, I can't help more I am afraid, the 60ft does impact the trap speed, to a certain degree, just as much as one can guesstimate 50FWHP for instance through a trap speed, making the HP guess through trap speed less than very accurate.
:cheers:
http://www.stealth316.com/2-calc-hp-et-mph.htm
This has gone in the wrong direction I think, I am not debating the accuracy of the formulas nor am I saying that ET is a better indicator of HP if you re-read all my posts. I am saying there IS a "certain" correlation, which one is 100% correct, was not/t is not part of this debate.
After all this information posted if one wants to continue to believe that trap speed is 100% independent form the 60ft or ET, I can't help more I am afraid, the 60ft does impact the trap speed, to a certain degree, just as much as one can guesstimate 50FWHP for instance through a trap speed, making the HP guess through trap speed less than very accurate.
:cheers:
I'm afraid we're just going around in circles about this.
You have 3 veery experienced drag racers (myelf, Joe, and Kenny) all telling you that, in reality, 60' time and trap speeds are not related (within reason, obviously), but you keep arguing that they are.
I posted 3 runs that I made personally which prove what I'm saying is true. I also posted a formula (which is NOT the same as the one you are providing) that requires zero input of 60' time or E.T., but still gives you your HP from your trap speed and weight alone, yet you still refuse to believe what we are saying is true.
While there are formulas out there that di indeed try and take into account both E.T and trap speed to determine HP, they are never very accurate. Why? Because E.T. is the one variable that causes the results to be skewed, since in reality, it's NOT intrinsically related as you say.
I can testify to this fact since I've never found 'E.T.' or combination 'E.T./trap speed' calculators to be accurate. The only calculators I've found to be accurate are 'trap speed only' calclulators...like the one I provided, and the one on SMOKEmUP.com (who themselves admit, right on the website I proivided a link to, [b]that their E.T. based calculator is NOT accurate]/b], but their trap speed calculator is. I'll copy/paste the exact quote about their E.T. based calculator here:
Originally Posted by SMOKEmUP.com. They are talking about their E.T. based calculator
NOTE: SMOKEmUP.com believes this calculation is not accurate. We provide it only because if we didn't people would ask for it. Please use the HP estimation based on trap speed MPH, it is much more accurate.
Last edited by Divexxtreme; 10-25-2006 at 12:18 AM.
#55
10-25-2006, 12:13 AM
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Originally Posted by Divexxtreme
Jean-
I'm afraid we're just going around in circles about this.
You have 3 veery experienced drag racers (myelf, Joe, and Kenny) all telling you that, in reality, 60' time and trap speeds are not related (within reason, obviously), but you keep arguing that they are.
I posted 3 runs that I made personally which prove what I'm saying is true. I also posted a formula (which is NOT the same as the one you are providing) that requires zero input of 60' time or E.T., but still gives you your HP from your trap speed and weight alone, yet you still refuse to believe what we are saying is true.
While there are formulas out there that di indeed try and take into account both E.T and trap speed to determine HP, they are never very accurate. Why? Because E.T. is the one variable that causes the results to be skewed, since in reality, it's NOT intrinsically related as you say.
I can testify to this fact since I've never found 'E.T.' or combination 'E.T./trap speed' calculators to be accurate. The only calculators I've found to be accurate are 'trap speed only' calclulators...like the one I provided, and the one on SMOKEmUP.com (who themselves admit, right on the website I proivided a link to, [b]that their E.T. based calculator is NOT accurate]/b], but their trap speed calculator is. I'll copy/paste the exact quote about their E.T. based calculator here:
[quote =SMOKEmUP.com website]NOTE: SMOKEmUP.com believes this calculation is not accurate. We provide it only because if we didn't people would ask for it. Please use the HP estimation based on trap speed MPH, it is much more accurate.
Anyway; I've provided objective, empirical, and subjective evidence. I'm not sure what more I can do, if anything. It may simply be 'another agree to diasgree scenario.'
I'm afraid we're just going around in circles about this.
You have 3 veery experienced drag racers (myelf, Joe, and Kenny) all telling you that, in reality, 60' time and trap speeds are not related (within reason, obviously), but you keep arguing that they are.
I posted 3 runs that I made personally which prove what I'm saying is true. I also posted a formula (which is NOT the same as the one you are providing) that requires zero input of 60' time or E.T., but still gives you your HP from your trap speed and weight alone, yet you still refuse to believe what we are saying is true.
While there are formulas out there that di indeed try and take into account both E.T and trap speed to determine HP, they are never very accurate. Why? Because E.T. is the one variable that causes the results to be skewed, since in reality, it's NOT intrinsically related as you say.
I can testify to this fact since I've never found 'E.T.' or combination 'E.T./trap speed' calculators to be accurate. The only calculators I've found to be accurate are 'trap speed only' calclulators...like the one I provided, and the one on SMOKEmUP.com (who themselves admit, right on the website I proivided a link to, [b]that their E.T. based calculator is NOT accurate]/b], but their trap speed calculator is. I'll copy/paste the exact quote about their E.T. based calculator here:
[quote =SMOKEmUP.com website]NOTE: SMOKEmUP.com believes this calculation is not accurate. We provide it only because if we didn't people would ask for it. Please use the HP estimation based on trap speed MPH, it is much more accurate.
Anyway; I've provided objective, empirical, and subjective evidence. I'm not sure what more I can do, if anything. It may simply be 'another agree to diasgree scenario.'
#56
10-25-2006, 02:07 AM
Jean,
You might want to take a look at this:
https://www.6speedonline.com/forums/...200#post768200
I'm going to ask my buddy (Andrew) to come on here and explain his calcs. He's the brains behind them, so he can do a much better job explaining them than I can.
You might want to take a look at this:
https://www.6speedonline.com/forums/...200#post768200
I'm going to ask my buddy (Andrew) to come on here and explain his calcs. He's the brains behind them, so he can do a much better job explaining them than I can.
Last edited by Divexxtreme; 10-25-2006 at 02:10 AM.
#57
10-25-2006, 02:59 AM
Originally Posted by ari
I'm not doubting you beat a stage 1 X50 car. I'd love to see the vid anyhoo.
http://media.putfile.com/Stage-2-TT-...Stage-1-X50-TT
#58
10-25-2006, 03:29 AM
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Originally Posted by Jean
Mr Blonde
If you cannot see it from the formula above, I cannot do better I am afraid.
Maybe you would like me to start posting data graphs to prove it further?
To each his own guys, just try to be open to new arguments..
If you cannot see it from the formula above, I cannot do better I am afraid.
Maybe you would like me to start posting data graphs to prove it further?
To each his own guys, just try to be open to new arguments..
My best ever 60' time and my worst ever 60' time have near identical trap speeds (134 MPH). How does that work?
ET and trap speed aren't related either. A full chassis racecar will have a much lower trap speed for a given ET than an IRS street car. Our 996 TTs need a tinload more trap speed to get the same ET.
#59
10-25-2006, 03:46 AM
Mr Blonde, that is very deep thinking, "your formula is wrong" just because. I am not trying to convince you either, that will be up to you. It is not "my" formula, it is the formula found by a guy who is an authority in the subject and has been referenced by many automotive books, and whether he is right or wrong I don't really care.
Edit: Obviously comparing ET and trap speeds between totally different cars is not relevant to prove or disprove anything. We are talking about one same car here.
Edit: Obviously comparing ET and trap speeds between totally different cars is not relevant to prove or disprove anything. We are talking about one same car here.
Last edited by Jean; 10-25-2006 at 05:03 AM. Reason: Inappropriate language
#60
10-25-2006, 04:02 AM
Originally Posted by Divexxtreme