Does my car not make the advertised HP?
06-28-2005, 06:41 PM
#26
Administrator
here are the timeslips from Mazda's testing that they did whn restating to the current advertised numders- all 94.xx or better.
http://rotarynews.com/node/view/208
just in case you think its not "car guys" using the formula quote from a response to the discussion about th etesting
http://rotarynews.com/node/view/208
just in case you think its not "car guys" using the formula quote from a response to the discussion about th etesting
In the old days, before the technology to produce affordable electronic horsepower guesstimators existed, we determined horsepower with a pencil, a piece of paper, the weight of the car and the quarter mile trap speed. The trap speed formula was used because it allowed less room for driver error. Now, some may say �this doesn�t take wind resistance, barometric pressure, or temperature into the equation�. That�s true, but neither does a GTech.
A neutral party, Road and Track, says the Rx-8 they tested was doing 96 MPH when it finished the quarter. Someone here previously said an Rx-8 weighed 3344 pounds. If I follow the formula we used in the seventies, ((.00426 times 96 MPH) to the third power) times a weight of 3344, I see 228 horses. If that same Rx-8 produced 165 horsepower, it would have a trap speed of 86 MPH. Interestingly enough, that�s the same trap speed as a Miata. Nothing against the Miata, but does anyone reading this really think the Rx-8 has to work hard to keep up with one?
A neutral party, Road and Track, says the Rx-8 they tested was doing 96 MPH when it finished the quarter. Someone here previously said an Rx-8 weighed 3344 pounds. If I follow the formula we used in the seventies, ((.00426 times 96 MPH) to the third power) times a weight of 3344, I see 228 horses. If that same Rx-8 produced 165 horsepower, it would have a trap speed of 86 MPH. Interestingly enough, that�s the same trap speed as a Miata. Nothing against the Miata, but does anyone reading this really think the Rx-8 has to work hard to keep up with one?
06-28-2005, 07:31 PM
#30
Administrator
thank you guy- i love you too
lets back track and start at the top. dmp claims that his car cant be making the advertised hp because it trapped at 90 mph in the 1/4 mile. so dmp you appear to believe there is a relation between hp and trap speed. do you have a formula that expresses that relationship?
lets back track and start at the top. dmp claims that his car cant be making the advertised hp because it trapped at 90 mph in the 1/4 mile. so dmp you appear to believe there is a relation between hp and trap speed. do you have a formula that expresses that relationship?
06-28-2005, 08:32 PM
#32
RX8 and a Truk....
Thread Starter
Originally Posted by zoom44
so maybe its your trap speed that is the problem
That's what I thought we were talking about? lol
The trap speed is EXACTLY the problem, as trap speed is an indicator of 'power'... 
I went to the track not being able to care less about my e/t.
:D
06-28-2005, 08:34 PM
#33
Humpin legs and takin nam
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I think he means YOUR trap speed. Meaning, maybe you didn't get the most optimal run.
What conditons did you run? Did you get wheel hop? What did you launch at? What is your racing experience?
Not putting you down or doubting your abilities. However, you put alot of stock in your trap speed but do not mention how it was attained.
What conditons did you run? Did you get wheel hop? What did you launch at? What is your racing experience?
Not putting you down or doubting your abilities. However, you put alot of stock in your trap speed but do not mention how it was attained.
Originally Posted by dmp
That's what I thought we were talking about? lol The trap speed is EXACTLY the problem, as trap speed is an indicator of 'power'...
I went to the track not being able to care less about my e/t.
:D
The trap speed is EXACTLY the problem, as trap speed is an indicator of 'power'... I went to the track not being able to care less about my e/t.
:D
06-28-2005, 08:40 PM
#34
Administrator
exactly its your trap speed in question as in "how did you only get 90 mph". also please answer my question-
Originally Posted by zoom44
thank you guy- i love you too
lets back track and start at the top. dmp claims that his car cant be making the advertised hp because it trapped at 90 mph in the 1/4 mile. so dmp you appear to believe there is a relation between hp and trap speed. do you have a formula that expresses that relationship?
lets back track and start at the top. dmp claims that his car cant be making the advertised hp because it trapped at 90 mph in the 1/4 mile. so dmp you appear to believe there is a relation between hp and trap speed. do you have a formula that expresses that relationship?
06-28-2005, 08:53 PM
#35
RX8 and a Truk....
Thread Starter
Originally Posted by guy321
I think he means YOUR trap speed. Meaning, maybe you didn't get the most optimal run.
What conditons did you run? Did you get wheel hop? What did you launch at? What is your racing experience?
Not putting you down or doubting your abilities. However, you put alot of stock in your trap speed but do not mention how it was attained.
What conditons did you run? Did you get wheel hop? What did you launch at? What is your racing experience?
Not putting you down or doubting your abilities. However, you put alot of stock in your trap speed but do not mention how it was attained.
No wheel hop, decent tire spin - Trap speed doesn't take near the skill as e/t's...Trap speeds and vehicle weight show relative power of a car...for instance...
a WRX with 227hp can run, say, 14.2 stock, but only about 90mph. Why? the launch . If the driver messes up the launch, there's a good chance he'll run, say, 14.9, but his trap speeds will still remain close to the good-launch runs.
06-28-2005, 08:54 PM
#36
Humpin legs and takin nam
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Gotcha, the final mph is determined from the time you actually launch, not the time the light turns green.
Last edited by guy321; 06-28-2005 at 09:01 PM.
06-28-2005, 08:56 PM
#37
RX8 and a Truk....
Thread Starter
Originally Posted by zoom44
exactly its your trap speed in question as in "how did you only get 90 mph". also please answer my question-
It's pretty clear how my car only got 90mph, then a 91mph run....My car is making about 185whp, as your online calculators are pointing out
If I use the trap speeds you mention a couple posts up in your calculators, it's 210whp+. Maybe those online calcs aren't as off as I believed?
Should I find a FAQ about what drag racing e/t slips mean, and how to read them? Do you want an online calculator- would that satisfy you?
Attached is my car's weight slip from tonight - same levels of gas in the tank, etc.
06-28-2005, 08:56 PM
#38
RX8 and a Truk....
Thread Starter
Originally Posted by guy321
Gotcha, the final mph is determined from the time you actually launch, not the time the light turns green.
No....MPH is determined by the time it takes your car to pass between a known distance near the finishline - the speed 'traps'.
Oh - as for my experience, I've got about 50 or so runs down the 1/4 mile in various cars; but only 3 in an rx8. :D
06-28-2005, 08:58 PM
#39
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i ******* agreed with you ;P
I said that e/t is the time from the light turns green, if you mess up the launch it hurts you..
but trap speed is the speed/time from the time you actually launch your car till you finish. Please read better
However there could still be other reasons.. Are you sure your car is running optimally? Have you checked all your plugs? In checking mine at 24k, I noticed that one of my boots were not seated correctly and was corroded, along with the plug.. that particular plug had not been firing and was gummed up (trailing plug).
I said that e/t is the time from the light turns green, if you mess up the launch it hurts you..
but trap speed is the speed/time from the time you actually launch your car till you finish. Please read better
However there could still be other reasons.. Are you sure your car is running optimally? Have you checked all your plugs? In checking mine at 24k, I noticed that one of my boots were not seated correctly and was corroded, along with the plug.. that particular plug had not been firing and was gummed up (trailing plug).
Originally Posted by dmp
No....MPH is determined by the time it takes your car to pass between a known distance near the finishline - the speed 'traps'.
Last edited by guy321; 06-28-2005 at 09:01 PM.
06-28-2005, 09:02 PM
#40
RX8 and a Truk....
Thread Starter
Originally Posted by guy321
i ******* agreed with you ;P
I said that e/t is the time from the light turns green, if you mess up the launch it hurts you..
but trap speed is the speed/time from the time you actually launch your car till you finish. Please read better
I said that e/t is the time from the light turns green, if you mess up the launch it hurts you..
but trap speed is the speed/time from the time you actually launch your car till you finish. Please read better
And trap speed doesn't count the time you launch...it only counts from the time you enter the traps at the end of the track....see the difference?
Please write better!
06-28-2005, 09:04 PM
#41
RX8 and a Truk....
Thread Starter
Originally Posted by guy321
However there could still be other reasons.. Are you sure your car is running optimally? Have you checked all your plugs? In checking mine at 24k, I noticed that one of my boots were not seated correctly and was corroded, along with the plug.. that particular plug had not been firing and was gummed up (trailing plug).
You're right on my point...something is amiss with my car's power...IF the engine really is making 238hp, my car has something seriously wrong with it, because by Zoom's own links, the car should be trapping MUCH faster.
:D
06-28-2005, 09:07 PM
#42
Humpin legs and takin nam
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Personally, I think the engine makes around 220 something the way the PCM is set up
I just like to be antagonistic
I just like to be antagonistic
Originally Posted by dmp
You're right on my point...something is amiss with my car's power...IF the engine really is making 238hp, my car has something seriously wrong with it, because by Zoom's own links, the car should be trapping MUCH faster.
:D
:D
06-28-2005, 09:10 PM
#43
RX8 and a Truk....
Thread Starter
Originally Posted by guy321
Personally, I think the engine makes around 220 something the way the PCM is set up
I just like to be antagonistic
I just like to be antagonistic
lol...
:cheers:
06-28-2005, 09:15 PM
#44
Administrator
maybe you didnt have your foot in it between the traps?
so you believe "Trap speeds and vehicle weight show relative power of a car...for instance..."
so how do they do that?
so you believe "Trap speeds and vehicle weight show relative power of a car...for instance..."
so how do they do that?
06-28-2005, 09:18 PM
#45
Administrator
Originally Posted by guy321
Personally, I think the engine makes around 220 something
ok thats what you think but we are trying to prove one way or the other here.
besides your thought goes along with my proofs. 228 is within 5% of the advertised hp and it is also "220 something"
06-28-2005, 09:19 PM
#46
Administrator
Originally Posted by dmp
..IF the engine really is making 238hp, my car has something seriously wrong with it,
06-28-2005, 09:24 PM
#47
Humpin legs and takin nam
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Yes, so I can argue both sides and be correct
I did offer good advice about checking out your cars before/after runs though. I think there are many people who's cars are not running optimally and do not know it..
I personally have had bad coils, which were going bad a while before they were noticeable (and dangerous). Also, my plugs were changed once when I flooded and I noticed my bad plug boot AFTER this, so I'm thinking the dealership replaced them loose and/or didn't care to replace them. (i never messed with the plug side when I was changing out the coils) I'm going to change them soon.
I did offer good advice about checking out your cars before/after runs though. I think there are many people who's cars are not running optimally and do not know it..
I personally have had bad coils, which were going bad a while before they were noticeable (and dangerous). Also, my plugs were changed once when I flooded and I noticed my bad plug boot AFTER this, so I'm thinking the dealership replaced them loose and/or didn't care to replace them. (i never messed with the plug side when I was changing out the coils) I'm going to change them soon.
Originally Posted by zoom44
ok thats what you think but we are trying to prove one way or the other here.
besides your thought goes along with my proofs. 228 is within 5% of the advertised hp and it is also "220 something"
besides your thought goes along with my proofs. 228 is within 5% of the advertised hp and it is also "220 something"
06-28-2005, 09:25 PM
#48
RX8 and a Truk....
Thread Starter
Originally Posted by zoom44
maybe you didnt have your foot in it between the traps?
so you believe "Trap speeds and vehicle weight show relative power of a car...for instance..."
so how do they do that?
The bigger question is 'You do NOT believe that??'
06-28-2005, 09:33 PM
#50
RX8 and a Truk....
Thread Starter
Originally Posted by guy321
I found your problem... You weigh 260 lbs!!!
3300 lbs - 3040
I weigh 100 lbs less, so does that mean my car (could) have better trap speeds?
3300 lbs - 3040
I weigh 100 lbs less, so does that mean my car (could) have better trap speeds?
I was speculating my car's weight, with me in it...Combined weight is 3255.