Febuary ECU Project

[ductsoup]

February ECU Project

I had an idea for a project, since I'm none too good at the mechanics side and alittle straped for cash (and knee deep in uni work). I thaught it a good idea, and useful, to be able to read the cars ECU data (and possibly later write) without a laptop and that, frankly, expenive program (since I don't have a laptop).
I do however have one of these http://www.gp2x.com/ (http://www.gbax.com UK distributor), which is a portable media divice which has many many uses. It's really easy to create things for. However at the moment the only way I can see of connecting it to the car is via the breakout board (£40 ) and it, as of yet, the GP2x has no car adaptor and the batteries run out fast.

Anyway, I wanted to know if it's possible to calculate HP (wouldn't be at the wheels) using the information recieved from the ECU? I know HP is converted from Watts easily, but, can it be calculated using the RPM of the engine and the size (diamiter?) of the revolving object? I know it's a long shot but any response would be great. Thanks.

 

[59 bhp is more than enough]

dont think you can read the horsepower from the ECU, unfortnatly the only really accurate way is rolling road. I mean there are a ton of calcultions that you can do to calculate the power output of an engine but like i said it isnt really that accurate due to so many variables. There are programs such as RICARDO where you can create a virtual engine so to speak and they are fairly accurate as they take into account everything from friction of the pistons to angles of the air intake etc if thats any use to you

 

[ductsoup]

Hmm I was thinking more of using the data from the ECU to form an, inaccurate, but close-ish HP, it would probably be HP at the flywheel if that's where RPM is read?

 

[Alienfish360]

RPM is read from the crankshaft.

There's no way of measuring power from the engines data.

 

[ductsoup]

Hmm it was just an idea. I'll get my uni work out of the way by feb and start on the main idea... hopefully it'll go well .

EDIT: Watts are Joules/seccond, Hp is converted to via watts (700 and something watts = 1hp). Distance Traveled and the weight of the car will give the power of the engine in joules and if measured over a period of time (time to travel xdistance) so it can be calculated I would have thaught. Wheel spinning will give a dodgey reading but other than that it should work.

 

[Alienfish360]

G-Techs do it from Weight, Acceleration and G-Forces

 

[ductsoup]

Acceleration is easy to calculate, G-Forces requires acceleromiters I think (oh how ironic).

EDIT: hmm Force=Mass*Acceleration, Force*Velocity=EnginePower, in this equasion acceleration is the tricky bit, it would need to be calculated before hand from previous speed. It wouldn't be accurate but it would give a close approximate... I assume.

EDIT2: This also assumes a flat road... damn.

 

[Alienfish360]

IIRC it may also use speed which is calculated from time and acceleration.

For example if you can use an accelerometer to measure acceleration at say (for example) 120 miles per hour per hour (If I remember it right from GCSE Physics) on a linear basis that would be doing 60mph after 30 minutes.

240miles per hour per hour would be 60mph in 15 minutes?

Once you can calculate it and measure it accurately for approx 10 to 15 seconds.

You could weigh the car, and try find a formulae (I know there is one) that should give you a rough estiamte of power at the wheels, however, it's not totally accurate as it doesn't take into account of gear ratios, including wheel sizes either.