chamber pressure
- Thread starter trevrosborough
- Start date
I've been working on an update to the original chamber pressure setup for a while. I've solved some of the issues with the pressure probe and the injection signal capture, but the software needs to be gone over some more. Specifically, the Windows 7 version.
I'm looking to put out a new release mid-December provided all the new parts work out.
Thanks for asking!
I'm looking to put out a new release mid-December provided all the new parts work out.
Thanks for asking!
Hey Fingers, care to share what kind of cylinder pressure a max effort stock turbo tune runs? From what I saw when I was at Cummins Im guessing 4k+
It is all in the tuning. Well that and delivery rate.
Peak pressure always hovers around TDC,but that is where it does the least good for power production. However, there is a lead time on the fuel burn. So you have to deal with the pressure there to get good value as the piston moves down. It is a tradeoff.
Now, you also have to add that you need at least a minimum pressure to light off the fuel and a couple dozen other small factors.
To answer the question; it depends.
I've observed pressures that have maxed out my 5000 PSI sensor that did not make good power and 3500 PSI peak that made more than most. Stock/Stock engines tend to stay below 3000 PSI on purpose since this reduces emissions.
Moving the injection 1 degree can reduce the chamber pressure 500 PSI
Peak pressure always hovers around TDC,but that is where it does the least good for power production. However, there is a lead time on the fuel burn. So you have to deal with the pressure there to get good value as the piston moves down. It is a tradeoff.
Now, you also have to add that you need at least a minimum pressure to light off the fuel and a couple dozen other small factors.
To answer the question; it depends.
I've observed pressures that have maxed out my 5000 PSI sensor that did not make good power and 3500 PSI peak that made more than most. Stock/Stock engines tend to stay below 3000 PSI on purpose since this reduces emissions.
Moving the injection 1 degree can reduce the chamber pressure 500 PSI
I know there are variables, thanks for the info :thumb:
Do you mind me asking what transducer you use? Ive been around AVL stuff mostly, and 5kpsi does sound like it would max out most of them, not sure if they make a 7.5k or not...
Do you mind me asking what transducer you use? Ive been around AVL stuff mostly, and 5kpsi does sound like it would max out most of them, not sure if they make a 7.5k or not...
Jon I cannot get through to you on the phone number listed. Says your voice mail box not set yp. Could you pleas call me? 714 870 7300 thanks
5 K is the highest I could find in a dynamic pressure sensor. There are higher, but the slew rates are much too slow.
Figure this:
6000 RPM = 100 Rev/sec (my guideline)
Full scale = 5 V
You need .25 V/sec or a response time of 1mSec
And that is to even see the peak pressure let alone any variation in the curve. I use one that has a response time of 1 uSec. Response on this one is more like that of a microphone.Full scale = 5 V
You need .25 V/sec or a response time of 1mSec
In fact, that was an issue I had as one point. I managed to get the sensing chamber of the probe within the harmonic of the pressure pulse such that it whistled. The sensor picked it up and it threw everything off.
6krpm?! I can see that being a hold up :rofl:
Ever thought about just selling a kit with a simple peak-to-peak box for the average joe?
Ever thought about just selling a kit with a simple peak-to-peak box for the average joe?
Thought about it. But Peak pressure alone isn't telling you much. Besides, it takes almost as much hardware for that as it does for the whole system.
Yes, I'm wondering about updates also, before I dyno this fall. I'd really like to see timing effects on this!
We us OSIRIS at work and we mount an encoder motor on the front of the crank that hits 1080 times in on crank rotation, for 1/3 degree precision...
We us OSIRIS at work and we mount an encoder motor on the front of the crank that hits 1080 times in on crank rotation, for 1/3 degree precision...
I still have the stuff to look at pressures. I refer to the data frequently as do others. Only recently I have started looking at the old data, and new, to determine crank velocity changes. (new project)
Ultimately, the rig, as a product, has been a failure. For me, it has been a wealth of information.
Ultimately, the rig, as a product, has been a failure. For me, it has been a wealth of information.
I agree whole heartedly and still want mine that I ordered like two years ago...:hug:
Jon, do you mind saying why the product has been a failure? Obviously I understand you haven't sold any and that would be considered a failure, but why didn't you finish it.
Never even came close to recovering the development costs. --failure
The installation is less than smooth on Windows 7, and later computers. As a result, I have to go and install the software and drivers manually. I could wrap it all in an install package, but that would be more work on a losing cause.
The pressure probe, as it is now, has a very finite service life.
The installation is less than smooth on Windows 7, and later computers. As a result, I have to go and install the software and drivers manually. I could wrap it all in an install package, but that would be more work on a losing cause.
The pressure probe, as it is now, has a very finite service life.