I found a formula that can be a poor man's dyno.
Weight * Speed divided by distance = horsepower.
At the last race I attended this is how mine works out.
Weight (4690) times speed (106)
Divided by distance in 1/4 mile (1320 feet)
equals 376.62 horsepower.
Wow, not bad for a stock truck with just a chip and filter!

Anyone have any other useful formulas?



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• 2000 Red Lightning
• 13.13 @ 106.40 mph in 1/4 mile
• 8.50 @ 85.43 mph in 1/8 mile (same run)
• Superchip R9, Airaid box with S+B 10" filter
  

 

COOL!

4915 * 101.5 / 1320 = 378

???

 

Never knew that one I like it...

4800x110.15 / 1320= 400.54

Spiro-

 

what does a 95 mph trap speed in the 1/8 equal to in the 1/4???

Ray

 

Just use the same formula for a different distance, I've never seen that formula before, pretty cool.
G

 

OK, let's see how it works out compared to an actual dyno run.

Truck (4696) + me (190) * (105.91/1320) = 392.02 hp
(thanks for the correction, LightStruck)

Actual DynoJet results, similar weather conditions:
366.1 uncorrected, 350.8 corrected.

------------------
'00 Lightning - 13.110 @ 105.91
'92 Stealth Turbo - 13.4 @ 103
'99 Z28 - 13.7 @ 107

[This message has been edited by MarkJ (edited 11-25-2000).]

[This message has been edited by MarkJ (edited 11-26-2000).]

 

sweet....thats cool

we did 95 mph on the 1/8 in the mustang
the formula said we where making 460 hp..we dyno'd at 450.....
pretty damm close

I have seen this formula on a web site somewhere before too

ray

[This message has been edited by BlueL (edited 11-25-2000).]

 

Ray,

95mph in the 1/8th wil more than likely get you ~122 or so in the 1/4...but that's assuming you're not spinning the entire way down the 1/8 mile. IOW, if you were running on slicks or a tire that hooked up pretty good, then you can use the 1/8 mile to estimate what you'd have run in the 1/4. But, if you were spinning badly for 330-400' then the 1/8 mile speed and ET will be artifically low (with relation to the 1/4 mile times).

For instance, I run 102+ in the 1/8 on slicks, but only 98 or so on radials in my '90 LX. However, trap speed in the 1/4 mile is always 133-134 no matter what.

------------------
Wes Tarbox
90 LX 5.0 (10.69 @ 134.7)--597rwhp/590rwtq
96 Cobra (12.34 @ 115.8)--392rwhp/433rwtq
99 Lightning (13.20 @ 103.8)--364rwhp/447rwtq
00 Expedition XLT 5.4
http://members.aol.com/Wa2fst/index.html

 

MarkJ,
Hate to be picky, but I think you're supposed to use 1320 in your equation.

That should make you 392hp. ?

 

4800 x 101.2 / 1320 = 368 HP for me.

------------------
Later,
Chuck
Black 00
Chuck's Lightning Page

 

Guys,

This may help posted on f150online some time ago:
http://www.dsm.org/tools/calchp.htm

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Dunbarton "The Middle Aged Kid" '99 XLT SC SB 4x2 4.6 auto 3.55 ls The occasional Z-71 Eater! Wedgewood & Denim, SuperChipped, Airaid FIPK, HD electrical and cooling, power seat, Rhino Liner, Extang Classic tonneau cover, Mobil 1. Man, I got it all! (New Jersey)

 

Dunbarton,
Thanks for the link. Nice calculator to play with! (I'm guessing the ET formula is closest of the two???)

Ryan2K--you're gonna like this method. Looks like you back ahead of me by at least 30 horses or so!!

 

LightStruck,
You're right. I guess that's why I shouldn't post after my bed time. Thanks for pointing it out.

Mark

------------------
'00 Lightning - 13.110 @ 105.91
'92 Stealth Turbo - 13.4 @ 103
'99 Z28 - 13.7 @ 107

 

Way cool!
I came up with 410 hp for ET and 441 for Speed.
Imagine that!! Man, that R9 kicks a$$ !!
Lightstruck - You too can use "The Force"...haha.


------------------

• 2000 Red Lightning
• 13.13 @ 106.40 mph in 1/4 mile
• 8.50 @ 85.43 mph in 1/8 mile (same run)
• Superchip R9, Airaid box with S+B 10" filter
  

 

Using the ET method, I come up with 494 horsepower
Using the Speed method, I come up with 519 horsepower

------------------
Thomas 'Lightning Boy' Shelton
SVTPerformance.com
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