Oil Press/Fuel Press Sensor Compatibilities?

[Schmieder]

Was just wondering if one could measure fuel pressures off the Schrader Valve using an oil pressure sensor. In this case the oil pressure sensor has a range of 0-105 PSI and is aftermarket, not the OEM sensor the PCM relies on for data.

Both fuel and oil are of the same properties, oil products, and therefore should not damage the sensor. As long as the sensor tip is cleaned I see no issues attaching it to the fuel rail, schrader valve, to log fuel pressures. Which can be referrenced against manifold vacuum/boost for tuning the fuel injectors.

Just tossing this idea out there....anyone know or see any potential problems I overlooked please advise. Otherwise this will save me some loot...and get my injectors tuned to a few decimal points. From there tuning the MAF with the wideband and I'll have a really strong tune.

Afterwards I was considering how to measure EGT's for each cylinder. Suppose I used a non-contact IR Thermometer with an accuracy of +/- 1 degree to measure manifold temps. To increase accuracy I will insert a bolt into the Exhaust stream and hold the thermometer the appropriate distance as to read only the bolt head temps.

I'm sure I will not get a proper temp reading but I could get temp offset ratios per cylinder compared to others. I'm hoping this will provide good enough data to effectively skew each injector to balance temps. i.e. make each bolt temp = to the rest.

Which metal would be the best temp conductor? Aluminum?

[Joseph Upson]

Was just wondering if one could measure fuel pressures off the Schrader Valve using an oil pressure sensor. In this case the oil pressure sensor has a range of 0-105 PSI and is aftermarket, not the OEM sensor the PCM relies on for data.

Both fuel and oil are of the same properties, oil products, and therefore should not damage the sensor. As long as the sensor tip is cleaned I see no issues attaching it to the fuel rail, schrader valve, to log fuel pressures. Which can be referrenced against manifold vacuum/boost for tuning the fuel injectors.

Just tossing this idea out there....anyone know or see any potential problems I overlooked please advise. Otherwise this will save me some loot...and get my injectors tuned to a few decimal points. From there tuning the MAF with the wideband and I'll have a really strong tune.

Afterwards I was considering how to measure EGT's for each cylinder. Suppose I used a non-contact IR Thermometer with an accuracy of +/- 1 degree to measure manifold temps. To increase accuracy I will insert a bolt into the Exhaust stream and hold the thermometer the appropriate distance as to read only the bolt head temps.

I'm sure I will not get a proper temp reading but I could get temp offset ratios per cylinder compared to others. I'm hoping this will provide good enough data to effectively skew each injector to balance temps. i.e. make each bolt temp = to the rest.

Which metal would be the best temp conductor? Aluminum?

It'll work, the sender is listed as Oil/Fuel sender for some apps like the one I just purchased for my Fiero.

[Schmieder]

It'll work, the sender is listed as Oil/Fuel sender for some apps like the one I just purchased for my Fiero.

That's great. I figured it would but it wouldn't be the first time I over looked something. Data logging the fuel pressure will be awesome. Using a calculator to achieve maximum accuracy after my injectors are flow tested. Then tuning the MAF against the injector rate and wideband (data logged) will lock the airflow in nice and tight.

I found my 3100 gets the most power from 11.6-11.5 AFR under 6-8 psi. I managed to get a spark map from a GTP3100 and translated it. So for now the spark tables are at a good starting point.

I love tuning, this stuff is fun. I'm trying to fine tune Max Torque vs Gear vs RPM to keep the power just under tire spin out. So I can floor it and reach maximum torque w/o the spin out when boost kicks in. Right now my aging tires start to slip at 255 ft/lbs around 3400 RPM. So I set the max torque at 250/3400RPM and scale it to no torque management at 4400 RPM. It seems to work well as long as the roads are dry.

Anyways, thanks for the reassurance.

[Joseph Upson]

Most boosted code has a desired boost vs. speed or rpm or both so that you can limit it to what the tires can handle as load increases.

[AleroB888]

That's great. I figured it would but it wouldn't be the first time I over looked something. Data logging the fuel pressure will be awesome. Using a calculator to achieve maximum accuracy after my injectors are flow tested. Then tuning the MAF against the injector rate and wideband (data logged) will lock the airflow in nice and tight.

I found my 3100 gets the most power from 11.6-11.5 AFR under 6-8 psi. I managed to get a spark map from a GTP3100 and translated it. So for now the spark tables are at a good starting point.

I love tuning, this stuff is fun. I'm trying to fine tune Max Torque vs Gear vs RPM to keep the power just under tire spin out. So I can floor it and reach maximum torque w/o the spin out when boost kicks in. Right now my aging tires start to slip at 255 ft/lbs around 3400 RPM. So I set the max torque at 250/3400RPM and scale it to no torque management at 4400 RPM. It seems to work well as long as the roads are dry.

Anyways, thanks for the reassurance.

lol. (Weren't you going to ditch the MAF and spray alky into the turbo?)

Interesting ideas, but would it not be easier just to reduce the timing in the lower ranges of the Main Spark Tables, since ultimately that's what Torque Management does anyway?

Are you able to monitor "delivered trans torque"? I've been trying to get people to do that to compare what they are reading to what I came up with.

[Schmieder]

lol. (Weren't you going to ditch the MAF and spray alky into the turbo?)

Interesting ideas, but would it not be easier just to reduce the timing in the lower ranges of the Main Spark Tables, since ultimately that's what Torque Management does anyway?

Are you able to monitor "delivered trans torque"? I've been trying to get people to do that to compare what they are reading to what I came up with.

I was going to ditch the MAF until I discovered how to change the settings in my BIN to use VE with the MAF for a more accurate transient fueling.

Spraying into the turbo will happen down the road. I might even build my own system with LED indicators mounted in the dash. Something like a Red and Green LED light for each monitor. I.E. water/meth level stays green and hits red when low and shuts off spray. Voltage monitor for the systems power, ect. What actually pushed that project back was the wanting to retard spark in the event the spray fails. I considered triggering a "MAF to high" signal to throw the spark table to Low Octane if the system failed one way or the other. Could be a simple relay that will not complete the circuit unless the spray system has no voltage. Then it would apply an appropriate amount of voltage to the MAF signal wire triggering a MAF fail fault. Effectively dropping the Spark through the PCM.

I can monitor delivered trans torque. It's accuracy isn't top notch just yet. Once I log fuel rail pressures at all manifold vacuum/boost then I can tune the injectors true. After that the WB will make the MAF true, which in turn will make the delivered trans torque true.

The MAF isn't that far off really so the torque figures are close atm. I am pushing max 320 ft/lb at 4400-4800 RPM with 7.5 PSI w/o torque management. I average 290-310 per WOT push. With management, which is just like a retarded spark, is a rough method of traction control at WOT from a stand still. I decided to keep my spark tables as they are and let management retard as needed. When I advance the spark one degree to test torque output per WOT run I lower it in the Spark vs AFR table. This way I can reduce 1 degree under WOT only, leaving idle and part load untouched. Afterwards I will translate the best spark degree into the spark map. I'm still building this process as I am attempting the most perfect tune possible w/o a dyno.

I'm even investigating a cheap EGT monitor system. Using Type J Thermocouples ($30), a transformer and a resistor to turn the signal into a 0-1V range and run it through the A/C Pressure Signal Line into the PCM to log EGT temps. Only problem is I want to add one per cylinder so I will need a switching system to toggle each at idle so I can fine tune the Injector Skew. The permanent EGT sensor ($30 Thermocouple) will be placed post turbo and I want to figure out how to trip a relay at a specific voltage (Temp Threshold) to illuminate a Red LED in the dash as a rough EGT overtemp warning.

With a little time I could build a fully functional 4-8 cylinder EGT monitor system which would display 4 decimal voltages for the sole purpose of injector skew tuning. I found this method is cheaper and more reliable then an IR Thermometer.