even if they have gone up in price with everything else, sensors remain the single cheapest item on the FD buy list. proper sensors tell you what is happening and can solve problems before they become PROBLEMS. prior to digital, in the analog world, you actually needed to know what you were doing. today, with proper sensorization (o k, instrumentation) a look at the data and most problems are I D'd.

i bring you good tiding$...in the Pressure Department.

first off, pressure?

yes, pressure. one of the most important FD metrics is fuel pressure. if your base fuel pressure is set at 3 BAR, 43.5 psi, and you are under boost at 15 psi your fuel pressure at that moment needs to be 43.5 plus 15 or 58.5. if you have an occluded fuel filter, or a weak fuel pump your fuel pressure will be less. if you have a problem in your return line your pressure will be more. perhaps you have a a fuel pickup problem and are momentarily sucking air which will clearly show on your pressure log. i had such a problem under acceleration with 7.2 gallons of fuel in my tank. i know have the Radium surge tank. during a recent dyno session running 69% ethanol (thank you ethanol sensor) i found my differential fuel pressure had dipped. this was inspite of running the largest Walbro Hellcat pump. thanks again to my pressure sensor. i now have an additional 274 pump. you may never run into these problems but you certainly will know if your fuel filter actually needs a refresh.

besides fuel pressure we have boost pressure and oil pressure. i also run a pressure sensor for my exhaust backpressure.

the primary reason for this post is to alert you to the introduction of the new Honeywell pressure sensor. Honeywell's 2022 annual revenues exceeded $35 Billion and their industrial products are top shelf. i have run their pressure sensors since 2008.

AEM offers a look a like (157) as well as a cheaper (63) pressure sensor.

here's what AEM has to say about their two pressure sensors:

"Which Pressure Sensor is right for you? There are many different tools that can be used for measurement, but the degree of accuracy is dependent upon the tool. For example, a ruler can measure distance with a good degree of accuracy, but for a more precise measurement a caliper should be used. The difference between a brass pressure sensor and a stainless steel pressure sensor is similar if we think about it in these terms: Brass Pressure Sensor = Ruler Use a Brass Pressure Gauge Sensor where you need a good reference to what pressure is being seen. Example: Brass Pressure Sensor used for a Boost Gauge - Reference/Information for knowing manifold pressure, not for ECU calibration. Stainless Steel Pressure Sensor = Caliper Use a SS Pressure Sensor where you need exact details of the pressure. Example: MAP Sensor information for the ECU - Calibration/crucial information for the ECU."

so the stainless steel sensor is like a caliper and the brass option is like a ruler... yet they have the same plus or minus 1% as to accuracy??

thanks but i will pass on the cheapie sensor and am not excited about the $157 item with unknown lineage.

as i mentioned, i bring you good news.

Honeywell has just introduced their new line of pressure sensors.


here are the specs:

Honeywell 150 PSIG Stainless Pressure Sensor - PxL
Honeywell's new product which replaces the older PX pressure transducers that were either brass body, or large stainless body, with a lower cost, compact stainless sensor body and sensor membrane, available in pressure ranges up to 500 psig and ok to use with fuel. For applications above 500 psig (such as brake pressure) or for use with gasoline / petroleum fuels above 500psi, please continue to use AEM's stainless sensors.

Features below will be updated with new information at a later date
FEATURES:

• •Rugged, stainless steel construction
• • Operating temperature: -40°C to 125°C
• Total Error Band ±0.75 %FSS to±1.0 %FSS (-40°C to 125°C)
• Excellent Accuracy
• Mis-wiring protection
• Industrial Grade Design Ideal for Harsh Environments
• Use with gasoline, diesel fuel, engine oil, brake fluid, coolants, CNG, O2, N2, CO2, N2O, air, refrigerants (butane, propane, ammonia, CO2, R134A, R407C, R410A, R448A/Solstice® N40, R32 and R1234ze, R1234yf, glycol + water, water, hydraulic fluids compressed air food, beverage, oil, gas, steam

Specifications:

• 1/8 NPT Sealing Thread
• 0.5 to 4.5 volt ratiometric output (0 psi at 0.5 volts and 150 psi at 4.5 volts, linear between these points)
• 3-way circular GT150 / MP150 connector
• Requires 5 volt DC supply voltage and analog ground
• Accuracy: ±0.15 %FSS typ.
• Temp Drift: <0.50% Full Scale
• Stability: <0.25% Full Scale/Year
• Operating Temp: -40C to 125C
• Burst Pressure: 1000PSI
• Response Time: 1 ms (10% to 90% step change in pressure)
• Wetted Materials: 304L Port & 316L Stainless Steel diaphragm
• Vibration: 20G’s peak to peak sinusoidal
• Weight: <30g
• Supply Current: 5mA MAX. at 5 Vdc
• Installation torque: Two to three turns from finger tight

the two seal the deals for me is that it is a Honeywell and that it is $81.

BTW, most newer ECUs have a math channel. if you have such an ECU welcome to your new MAP sensor. buy one of the HON sensors and set the MAP sensor input up so as to read the absolute pressure. write a simple equation (A minus B). A is the pressure reading and B is Barometric pressure. Bingo, Gauge (Boost) Pressure.

i have used Ballenger Motorsports for lots of good stuff, especially their AFR500v2 Air Fuel Ratio system that employs the superior NTK O2 sensor... here's the link to the sensor@Ballenger

https://www.bmotorsports.com/shop/pr...ue1n1fmpkrn5e7





,

 

missed mentioning another important pressure sensor, my AI system.

 

Thanks for sharing Howard

 

Looks like a great option!

Do you know if these are rated for direct mounting (engine block/fuel rail/etc)?

The more expensive TI and Variohm sensors, which are fairly common, advise against direct mounting. The spec sheets are very similar in terms, especially vibration resistance, but I'm not sure what qualities play into the mounting suggestion. Remote senders look cool but I'd much rather spin one into the block and be done.

 

The Honewell sensor does look like a good option. The AEM stainless sensors have used a few suppliers including Honeywell, and the original manufacturer is usually under the AEM sticker. I don't know if rotary engines need to worry about remote sensor mounting since there's less vibration than most piston engines, has anyone heard of vibration-related sensor failures on rotary engines? I've had an AEM stainless sensor mounted directly to the fuel rail on my car since 2009 (about 13k miles). Also whatever 'street' polyurethane engine mounts that were available from Himni in 2010. I added an AEM stainless oil pressure sensor mounted directly to the Banzai oil filter pedestal a couple of years ago. Both have been reliable, no leaks or failures. I think the oil pressure sensor is the harshest use case, since that experiences both higher pressure and temperature than a fuel pressure sensor. I used some sort of thread sealant on both. Not threadlocker like Locktite, but something like Permatex 59235 intended to avoid leaks.

 

This is enticing. I'm using AEM sensors, and I know at least my fuel pressure sensor is off by about 6psi, reading around 37psi instead of 43psi, using their calculations. And I verified it's 43psi in the same location right off the FPR.

Is this sensor accurate with the given calculations?

 

If you're using the gauge itself for your data, that is the whole problem. AEM and other tuner brand gauges are for reference only, not applicable usable reliable data. The widebands are about the only thing that are exempt from this.

If you're using a standalone that allows for sensor inputs then you simply compensate the calibration table to read measured. Considering the variances in "lower quality" sensors, for critically applied data it's best to do exactly what you did and independently verify the data vs what's being displayed. Calibration tables aren't always 100% so you can just make your own by logging voltage or resistance vs sensor scale. There is a post here on an example of this with a map sensor.

Higher quality sensors like anything stainless and name brand will likely be accurate within whatever percentage claimed and be reliable throughout the scale.

 

i have used 4 Honeywell pressure sensors on my car since 2003.

fuel pressure
oil pressure
AI system pressure
turbo manifold back pressure

when i switched to Link in 2013 i added another Honeywell pressure sensor, for boost.

it is just another 150 psi sensor like the other four... tapped into the UIM. the ECU subtracts barometric pressure to give me both MGP. as well as MAP.

i just ordered from Ballenger Motorsports a new Honeywell 500 psi sensor for my AI system as i am changing it to 100% ProMeth and adding a higher pressure pump.

as to efficacy, Honeywell is a 40 billion dollar rev company mostly serving the global industrial market. what you see as to specs is what you get. FDAuto is 100% correct as to gauge readings. i view my readings thru a digital dash that reports from the ECU. no slippage since it grounds to the ECU..

the only sensor i have replaced is my backpressure sensor that is exposed to exhaust gas. i do have the FFE cannister that helps a bit.

1badFB raised the vibration question. i am pretty sure Honeywell did their best re this challenge as the sensors have to work in many less than ideal locations. i still have the same sensor reporting on my oil pressure that i installed in 2003.

 

FYI you can find these at mouser/newark/sager even cheaper and arguably in a better pressure range (100 psi)

MIPAN2XX100PAAAX
MIPAN2XX150PAAAX

 

No it goes straight to the ECU, then to my display through CAN. Even on the ECU it reads low, and I'm not sure if the oil and coolant pressure sensors are correct either, although coolant pressure is so low I wouldn't really know anyway lol. I know I can change the calibration table, but I figured there might be something wrong if it's that far off with their own cal data, or maybe it's just not as good as other sensors. I think I'll pick up a few of these and see if they're any closer.

Thank you gentlemen!

 

That's good to try but you may very well run into the same issue. There are a lot of variables in between the sensor output and the ultimate "thing" that is displaying the data (to include variances in manufacturing of the sensor). This is not only the case with metric sensors but other ecu settings as well. This is why there are offset tables such as the all so important but ignored, base timing offset.

You simply HAVE to calibrate for actual. Calibration tables are ideal values from the bench in a lab but not always translated 1:1 in application.

I would suggest re scaling your sensors before replacing them. It sounds like that's all you need. The base deviation is off quite a bit yes but so long as the max/min register according to the sensors indicated max/min ranges, then everything else in between the 0-5v will register correctly if scaled.

Using a higher quality sensor will likely just have a smaller deviation or you may get lucky and it will be dead on. A re scale is free though lol and you already have 3 data points and a mechanical gauge to give you more of needed. No tools or money spent, just time and some key strokes.