how they working that out then?

[White2505 0]

Saw one of these gadgets you fit onto the windscreen of your car.

it measures your 0-60 , standing 1/4 and (if you input the cars weight) somehow gives a hp figure.

 

there are NO connections to the car other than power.

 

What equation are they using to give a hp figure?

I realise it is going to be inaccurate (they quote +/- 1%) but I am intrigued at how they think they can work it out with time and car weight only

[conleycrew3 0]

havnt a clue mate!!!

 

interested though, what is this thing called and do you know where to buy it? how much etc?

 

ta

[White2505 0]

http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... %3AIT&rd=1

 

ebay link for the g-tech unit although there are several different ones out there.

 

frankly if you knew the equation they used for working it out you could do it yourself with nothing more than a £3 stopwatch.

 

like i said probably woefully inaccurate but an amusing way to spend 1/2 hour in the car ragging up and down a quiet straight back road!

[Trig 0]

LOL, well put White2505, I would say it's about as acurate as tying horses to the back of your car and doing a tug-of-war. :)

[Kevin Bacon 5]

I think it uses a mercury type switch thingy, or even a yaw sensor type whatsit to measure G's etc and regarding the bhp, there is a rough equation that can 'calculate' BHP based on the car's weight and how quickly it does the 1/4 mile. There's a website somewhere where you can input the weight and power and it gives you a 1/4 time, so it must be a similar thing all done in the unit.

[dinkus 10]

My boss used to have one of these and it was actually, surprisingly accurate.

 

They have a gyroscope thingy in so when you accelerate, it measures the g-forces and can tell you how fast you're going and how hard you accelerated.

 

You have to calibrate it by doing a 5th gear run-down or somesuch too I think.

[White2505 0]

google is my friend

 

http://www.dsm.org/tools/calchp.htm

 

will calculate based on 1/4 mile time or final speed on 1/4 mile run

 

of course this all depends on your launch technique etc

 

would be interesting to see if there was a way of using this type of formula whilst accelrating from say 20mph to 60 mph without the need to change gear.

this would remove the constraints of traction loss off the line,differences in gear changes on multiple runs etc.

 

All hypothetical stuff but good for a laugh in nothing else!

[White2505 0]

using 2423lbs as the unladed weight plus another 100 lbs for the driver and a standing 1/4 of 14 seconds gives 182hp

 

so whose done a standing 1/4 recently AND had their car dyno'd?

[conleycrew3 0]

ha ha that calculator link seems nonsense to me!!

 

interesting results though, look through this form using the search and you can find other peoples 1/4's and speeds, using knowledge base you can estimate there weight. some dude has come out with 732bhp using one method of calculation and 235bhp using the other!!!

 

all fun though eh?!