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1/4 mile ET/HP calc

Posted By: 0x01b8

1/4 mile ET/HP calc - 03/30/10 07:19 PM

I'm the guy that wrote the 'RPM/Speed Visual calc' that's linked up in the Tech Archive section. I just finished working on a new calculator and thought you might get some use out of it -

1/4 Mile ET, HP, and MPH Visual Calculator

thanks for reading
-john
Posted By: RapidRobert

Re: 1/4 mile ET/HP calc - 03/30/10 07:27 PM

Thank you John, I will make use of it
Posted By: 73swinger

Re: 1/4 mile ET/HP calc - 03/30/10 07:33 PM

COOL
Posted By: sixpackgut

Re: 1/4 mile ET/HP calc - 03/30/10 07:40 PM

its nice but i dont agree with it.

for example, i dont think it takes 640 rwhp at 3650 lbs to run a slow 10.43

maybe i'm using it wrong
Posted By: BSB67

Re: 1/4 mile ET/HP calc - 03/31/10 12:11 AM

Quote:

its nice but i dont agree with it.

for example, i dont think it takes 640 rwhp at 3650 lbs to run a slow 10.43

maybe i'm using it wrong




I like the old "Drag Strip Dyno" by Mopar or the Moroso Power Speed calculator. I mostly use the Moroso calculator any more as that is what most everyone else uses, and that makes it apples to apples when comparing numbers between cars. The Drag Strip Dyno has really good info in the text for understanding, but it seems to generate power numbers that are a little higher.
Posted By: 0x01b8

Re: 1/4 mile ET/HP calc - 03/31/10 01:31 AM

Quote:

its nice but i dont agree with it.

for example, i dont think it takes 640 rwhp at 3650 lbs to run a slow 10.43

maybe i'm using it wrong




The formula I'm using is the same one that's all over the net in other calcs which is the Patrick Hale formula. If you punch in that hp/weight into the calc in the mopart's tech archive you'll get almost the same et. So I don't know what to say about it.

Are you saying the 10.43 was slow or the mph that my program was showing was slower than you expected, or both? The whole deal is kinda ballpark but I'd like it to be as accurate as I can make it.

thanks for the comments
Posted By: sixpackgut

Re: 1/4 mile ET/HP calc - 03/31/10 02:24 AM

Quote:

Quote:

its nice but i dont agree with it.

for example, i dont think it takes 640 rwhp at 3650 lbs to run a slow 10.43

maybe i'm using it wrong




The formula I'm using is the same one that's all over the net in other calcs which is the Patrick Hale formula. If you punch in that hp/weight into the calc in the mopart's tech archive you'll get almost the same et. So I don't know what to say about it.

Are you saying the 10.43 was slow or the mph that my program was showing was slower than you expected, or both? The whole deal is kinda ballpark but I'd like it to be as accurate as I can make it.

thanks for the comments




the rwhp should be actual hp
http://www.wallaceracing.com/et-hp-mph.php
Posted By: 0x01b8

Re: 1/4 mile ET/HP calc - 03/31/10 07:38 PM

Quote:


the rwhp should be actual hp
http://www.wallaceracing.com/et-hp-mph.php




That one gives the same results as mine.
Posted By: sixpackgut

Re: 1/4 mile ET/HP calc - 03/31/10 08:06 PM

Quote:

Quote:


the rwhp should be actual hp
http://www.wallaceracing.com/et-hp-mph.php




That one gives the same results as mine.




it doesnt say its rwhp though.
Posted By: 0x01b8

Re: 1/4 mile ET/HP calc - 03/31/10 08:56 PM

Quote:

Quote:

Quote:


the rwhp should be actual hp
http://www.wallaceracing.com/et-hp-mph.php




That one gives the same results as mine.




it doesnt say its rwhp though.




Alright - now I see what you're saying. 640hp @10.43 is fine, but the hp at the wheels is more like 570.
A different wallace calc makes it more clear
http://www.wallaceracing.com/hpcalculatorquarter.php

thanks for catching that.
Posted By: QWK_ENUF

Re: 1/4 mile ET/HP calc - 03/31/10 08:58 PM

i just tried it on 2 cars that i know the weight and hp numbers from the dyno.if you adjust the hp scale so the hp numbers from the dyno match the hp numbers at the fywheel it is pretty dead on with the actual et/mph for the 2 cars
Posted By: 0x01b8

Re: 1/4 mile ET/HP calc - 03/31/10 09:46 PM

Quote:

i just tried it on 2 cars that i know the weight and hp numbers from the dyno.if you adjust the hp scale so the hp numbers from the dyno match the hp numbers at the fywheel it is pretty dead on with the actual et/mph for the 2 cars




Hey - can you tell me the hp/et/mph for your two cars? That would really help me get this thing dialed in. thanks.
Posted By: QWK_ENUF

Re: 1/4 mile ET/HP calc - 03/31/10 10:35 PM

this is as close as i recall
one dyno has been called happy and the other conservative

car 1

3500 lbs
10.0's @ 134
788 hp

car 2

3000 lbs
10.30 @ 134
620 hp



car 3

2990 lbs
10.96 @ 118
560 hp
Posted By: 0x01b8

Re: 1/4 mile ET/HP calc - 04/01/10 12:33 AM

thanks for those numbers.

I fixed the backwards hp labeling problem but left the calculations as is for now, which means my calc is using pretty much the same formulas as all the other calcs on the net. Basically a mathematical guess.

Oh well. At least you don't have to type in numbers and hit 'submit' over and over and over again. That was my goal.
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