Real-Time Automated Calibration System (RTACS)

[John@SDPC]

I was able to visit the Woodward facility with EFI University. I am one of their instructors. I think Ben was going to try to integrate the SmartFire ignition system into his weeklong class or create an advanced class using an engine dyno and incorporate it there.

OEM’s are interested in ion sensing (IMO) for improved emissions control. Essentially, the ion feedback is like an EKG. If there is a flat line (no fire), then the ignition system could fire again in attempt to reduce emissions. With enough intelligence, the system should also be able to better determine knock (this may be tricky) and optimal timing.

There are two distinct interactions that occur after the spark fires. One is a chemical reaction and the other is a thermal reaction. The first reaction is of no significance other than indicating the spark did indeed occur, and that there was enough feedback to measure it.

The second reaction is of more importance. This is where the current being returned through the circuit (i.e. current flow across the plug) can indicate where peak pressure is occurring. IIRC, the current is very low, micro amps. The peak of the second reaction is where peak pressure is occurring. Thus, timing could be altered to maximize pressure at the appropriate crank angle. I don’t believe the magnitude of the second reaction is directly related to a specific amount of pressure.

Knock is not as straight forward as determining peak pressure. Significant knock events are easily recognized. Smaller knock events are more difficult to detect because there is significant activity and motion in the chamber during the burn. There are a certain number of inflections (changes in the current) that occur. At some point, the software must determine what is an acceptable amount of inflections and whether or not knock is truly present. I will see if I have some pic’s to upload.

BTW, I did check with the two most widely used dynos. One indicated they had no knowledge of anything being offered in the way of torque as any type of output. The other indicated that while it was not currently in discussion, that it could easily be done either through a serial stream or even a programmable analog 0-5v reference.

[5.7ute]

A friend of mine has an old dyno that measures torque via an arm that pressurises a brake master cylinder. This then uses the brake pressure to run to a guage to get your torque reading.
I was thinking about running a rod from this torque arm to a TPS which could then give a 0-5V reading for torque. Or maybe even a pressure switch like the fuel pressure sender set up.
While this is a bit agricultural I am sure that it would help in getting a reasonable baseline for spark until they release their own output on the dyno.

[joecar]

Ion sensing is very high tech and difficult to do (spark plugs now become "sensors")... it will be interesting to see the OEMs integrate this new tech into daily drivers.

[Biggsy]

A friend of mine has an old dyno that measures torque via an arm that pressurises a brake master cylinder. This then uses the brake pressure to run to a guage to get your torque reading.
I was thinking about running a rod from this torque arm to a TPS which could then give a 0-5V reading for torque. Or maybe even a pressure switch like the fuel pressure sender set up.
While this is a bit agricultural I am sure that it would help in getting a reasonable baseline for spark until they release their own output on the dyno.

From what my understanding, the later dyno's use a load cell as an output to calculate torque.

Some digital readout scales use similar load cells to measure weight. They can be calibrated to suit vaious load cells. Some of these digital scales have analogue and digital outputs for remote readouts and recorders.

Some of the setups I see get linked with PLC's which can be quite easily programmed (if you know what yer doing) to give you a 0-5v output

Just having some thoughts out loud

[Doc]

Back from the dead. Has anybody ever seen anything like this???

http://www.land-and-sea.com/rotary-s...shaft-dyno.htm

So, if I get all of this right, with this piece of equipment one could make a calculated PID and bingo, you have a real bonafide 0-5v reading from a real torque transducer???

[dc_justin]

Back from the dead. Has anybody ever seen anything like this???

http://www.land-and-sea.com/rotary-s...shaft-dyno.htm

So, if I get all of this right, with this piece of equipment one could make a calculated PID and bingo, you have a real bonafide 0-5v reading from a real torque transducer???

Oooooooooo. Good find.

[Doc]

I'm changing my shorts...

[Redline Motorsports]

Chad and I where doing some tuning this weekend at my shop and we had this same conversation. Our dyno displays real time torque readings while in "load control" mode. If we could get that value into FS we could somehow come up with a calc pid to find peak cylinder pressure. This would be VERY cool!

Howard

[ringram]

Problem is once you have found pk torque, how do you know timing is at its minimum for the pk torque. For example if 20, 21, 22 and 23 show virtually identical results you would want to use 20*

I dont think a calc pid can keep track of that. Might need some RTAC's intellegence in the software to deal with it.

[Redline Motorsports]

Problem is once you have found pk torque, how do you know timing is at its minimum for the pk torque. For example if 20, 21, 22 and 23 show virtually identical results you would want to use 20*

I dont think a calc pid can keep track of that. Might need some RTAC's intellegence in the software to deal with it.

We'll I agree that its not a slam dunk at that point but if you find a point where torque stops climbing (past peak torque) ands know the timing range that this lack of increase of torque took place, I think it can then figure out a value to deduct to where a "filter" might determine over time.

It might have to cycle the timing up and back down to figure this out. The theory is there but the RTAC will have to figure the rest out!

Howard