New DP, low boost

[Scoobum]

When I ran alky I'd always see blips of KR. When I ran race gas...nothing. ..with the 02's being the same. My theory was the alky wasn't staying in a uniform pattern...with the alky pump possibly not staying at an even pressure.

If memory serves, I believe it was Julio that said the air rushing through the TB was something like 200-300 mph. If the alky pressure varied even slightly, I'd be thinking you'd see hints of KR. Just a theory.

[Shimy87]

Map is in stock location on pass fender. log look like mine, gauge reads smooth so I think I'm ok. Alky theory seems sound to me. Will be bumping up the boost on gauge to 24 and will then tune from there. Thanks guys.....more info to follow when I can get some time. Putting in a paver patio so wife has me on a short leash with car fun right now.

[Steve Wood]

We are taking a theoretical constant 5.0 volt feed and supplying it to the map sensor which then sends a proportional analog voltage back to us which gets converted to a digital equivalent and then it is sampled 20+ times a second.  On average, it is a good approximation.  Same with the O2 voltage, fuel pressure sensor if so equipped, etc.  All of them tend to come out with a lot of chatter which makes no sense at all other than we are screwing with the signal in a less than perfect sense.  Ideally, we would apply a smoothing factor to the chatter and make it look more like the original analog signal.

That was a 10.3 run at 129 mph as I recall.

If we look too closely, we may over analyze things beyond the reliability of the data we are looking at.

[Shimy87]

Thanks Steve...im the king of over anaylizing things. Tuning is much better/ more fun than dismanteling this old gal 10 times a day.cant imagine a 10.3, im shooting for upper 11's an fully expect that this year. 

[motorhead]

So why not just put a quality pressure transducer into the plenum and run it straight into the datalogger?  You could then treat that as your constant and just reference the MAP.

Quality transducers are far less sensitive to changes (voltage, pressure pulses, temp, etc) than an OEM MAP.

[good2win22]

I am using an SSI pressure sensor mounted in the plenum.


http://www.ssi-sensors.com/pdfs/Pressure%20Sensors/P51/PS-AN10_LOW%20GAUGE%20PRESSURE.pdf

[motorhead]

I am using an SSI pressure sensor mounted in the plenum.


http://www.ssi-sensors.com/pdfs/Pressure%20Sensors/P51/PS-AN10_LOW%20GAUGE%20PRESSURE.pdf

I knew there was something I liked about you.

[TexasT]

Made in my dad's home town. They were probably a gm supplier before they shut that plant down.

[good2win22]

I am using an SSI pressure sensor mounted in the plenum.


http://www.ssi-sensors.com/pdfs/Pressure%20Sensors/P51/PS-AN10_LOW%20GAUGE%20PRESSURE.pdf

I knew there was something I liked about you.

If I remember correctly, I think you turned me onto their products

[motorhead]

I am using an SSI pressure sensor mounted in the plenum.


http://www.ssi-sensors.com/pdfs/Pressure%20Sensors/P51/PS-AN10_LOW%20GAUGE%20PRESSURE.pdf

I knew there was something I liked about you.

If I remember correctly, I think you turned me onto their products

Maybe.

This is my usual source: http://www.motorsportsinnovations.com/wide_band_o2_files/WB_Pressure.htm