heretic

Now you have me wondering how difficult it would be to fit a fuel flow gauge to a car. Fuel injection would be supremely easy to implement electronically, if you knew your injector size and the duty cycle. Carburetor, not so easy.



Come to think of it, all you would really need would be a ratio of duty cycle to speed, if all that mattered was optimizing a single car for efficiency. It could read in gallons per mile per hour or hogsheads per league per fortnight, all that matters is making the number as low as conveniently possible.







Had a customer who had an airboat. Strangest thing to climb aboard a contraption and then have to reach UP to work on a small block Chevy. As well as climb into the "cage" and work around the 6' prop jungle-gym style. I wasn't in the day we chained it to a couple trucks so we could full-power test the nitrous system. I'm forever convinced that people who run airboats are complete loonies



Glad to have you back aboard.

Lynn E. Hanover

My 99 Dodge van reads out actual mileage at this speed and throttle setting.



Distance remaining on this tankfull at this speed and throttle setting.



Avarage milage, so for, for this tankfull.



Avarage mileage last tankfull.



The gallons per hour is just a common reading that is used in aviation, because fuel remaining is so important. Using just the injector pulse width and the known fuel pressure, gallons per hour can be inturpolated.



In fact, large radial powered aircraft used to have torque meters on the engine mounts as a performance report to the engineer. RPM is known, so you have a running account of HP. A strain gage accross one motor mount could be calibrated against a torque wrench and produce the same information.



If the rolling resistance for each speed were known, the Dodge van could be reporting HP in use already, so it is possible.

We just need an electronics expert to make the great leap forward. (Chinese Communist term).



Then when everybody has a dyno built into his or her car, HP developement could race along at an ever increasing rate. (Pun)



Any electronics experts out there?





Lynn E. Hanover

mazdaspeed7

When I had a Megasquirt on my car, I remember seeing a piece of software for it that was a real time hp calculator. It wasnt perfect as the BSFC was a constant put in by the user, but it was interesting nontheless.

bill shurvinton

It's something I have been thinking about for a while. The ideal system would measure crank torque on the gearbox input shaft. Just recently this has come out http://www.land-and-sea.com/rotary-shaft-d...-shaft-dyno.htm which has the potential to fit the bill.



Where it gets interesting is if the sample rate gets high enough and can be syncronised with the engine cycle, as you can measure peak torque during the combustion cycle. Feed this information back into the ECU and you get 2 very interesting effects

1. auto tuning of spark

2. Knock sensing that starts to work BEFORE you acutally reach the point of detonation.



The technology is nothing new. F1 teams instrument everything from the crank onwards to see what is happening. The problem is coming up with a package that is both affordable AND can be fitted without needing to send chunks of your transmission off to be modified.

Lynn E. Hanover

Google Gami.



George Braly has devloped a full authority engine management system for big airplane engines.



It can adjust timing for each cylinder basd on the previous firing cycle and pressure output. I think he has a sensor for shock wave in each cylinder head. That system in a rotary would be interesting.



Lynn E. Hanover

bill shurvinton

I looked at the Gami stuff a few years back. the spark plug pressure sensing was a nice idea, but very expensive and limited life expectancy. I ought to check what has happened on that front.



Ion sensing has distinct possibilities and is being used in cars other than SAAB since delphi took over and some of the original patents ran out.



One day I'll find the time.

re10

Did you build your motor Jim?