winders

Can the Aim PRS-837 pressure sensor be used as a fuel pressure sensor for leaded race fuel?

Matt Romanowski

Yes

winders

Anyone here have an AiM PRS-837 in stock?

ProCoach

No, but I have RaceGrade units, if you're interested. A little better than the KA's but I estimate it will be at least after April 3-4 before AiM Sports USA has the KA's again.

I bought the last in inventory from Summit, WR, Discovery Parts, OG, Pegasus and a few other vendors to complete large system orders that were missing these.

With the connector and 719 end added, the RG sensors are $208.

I would NOT recommend mounting any on the fuel rail itself. A pigtail of aeroquip will take a lot of the stress off.

winders

I am using one of these coming off the -6 AN fitting on fuel pump in the front of the car:

winders

Peter,

Which RaceGrade sensor are you recommending? The M P75A-E4C would seem to be ideal.

ProCoach

winders

Do you make these pigtails yourself or do you buy them? If you buy them, where do you get them?

My new engine build with a MoTec M130 ECU is going to use the fuel pressure sensor I bought from you for oil pressure. I want to mount it off of the engine so there is less vibration.

ProCoach

Good idea, for any sensor mounted to the engine itself.

I make them up myself, adding NPT male (or metric male) to AN male fittings, then a made up hose with two female AN's on each end, then the appropriate male AN to female accept-whatever-the-sensor-male thread is.

Take a look at this page from Pegasus. https://www.pegasusautoracing.com/gr...=PRESSADAPTERS

The appropriate threaded adapter and copper seal ring at your engine end could then use the Autometer kit on the bottom of the page. Quick, easy and safe.

winders

Has anyone ever had a RaceGrade M APT-G2-DTM-150 (0 - 150 psi) pressure sensor fail when mounted to the engine? After all, 911 flat six engines have perfect primary and secondary balance and are low in vibration. I could understand if this were a V-6, but it i not.

With my previous engine, I mounted an AiM pressure sensor right on the engine and it was fine all the years I had it that way.

ProCoach

No.Over a hundred and fifty and no failures.

I would never recommend any sensor be mounted directly to the engine, always with a short length of braided line.

It's been two years, but I'll replace your sensor if you can send me the old one back.

winders

Peter,

Thanks, but the RaceGrade sensor you sold me is fine. With the old engine setup I used it with my AiM MXL2 dash for fuel pressure and it was at the front of the car by the fuel pump (it should have been after the fuel filter, not before it....). With my new engine I will use it as an oil pressure sensor with my MoTec M130 ECU. I am just trying to figure out if it really is bad to have the pressure sender on a 911 engine. I had an AiM oil pressure sensor directly on the engine and it worked great for years.

I would never mount an oil temp sensor anywhere BUT on the engine right where the oil is flowing. The cam sensor is mounted on the engine. The crank sensor is mounted on the engine. The CHT sensor is on the engine. The knock sensors are on the engine. The TPS is on the ITBs which is on the engine. In fact, the only sensor that it appears you don't want to mount on the engine is the oil pressure sensor....

Scott

Matt Romanowski

I have not had an AiM made sensor fail that was used correctly. They are very robust and get great testing at the factory for calibration of pressures, temps, and operating environment. I did have some KA sensors fail, but I'm not sure exactly how many. Not a handful in the years they made them for AiM.

Temp sensors are a junction, so they are not affected by vibration or operating range temps. Pressure sensors can be influenced by temp and vibration in their readings and life span. I mount them on engines all the time. Everything from multiple V8 manufacturers to off road UTVs, motorcycles, baja buggies, and all sorts of road racing. They live fine on the engine, though "proper" mounting is with a hose in a vibration reducing mount. My 914 with a 2.7 and later 3 liter motor has always had one screwed into the case directly and it's been fine.

ProCoach

Yes, because Scott’s inquiry was about the 0-150 psi RaceGrade sensor, I naturally responded advising that, in my experience, oil pressure sending units should be mounted to the engine using a short length of braided hose as a dampener. Just didn’t add the word “oil.”

As a professional mechanic for decades, I did see a number of bulb-type VDO and Veglia oil pressure sensors, all mounted directly to a threaded port in the block, fail over time, both internally and also leaking externally. Maybe that’s the reason I’m paranoid about those specific sensors.

In the beginning, I sold a few AIM diaphragm type VDO sensors, but as soon as I discovered the MSI solid-state sensors, I never sold another diaphragm type again.

Then, the KA sensors came out and my experience was quite different from Matt’s. Out of nearly eight hundred sold, I had a significant number of external fluid leakage and output failures on the brake pressure sensors (almost always immediately after installation, so if they worked, they worked), and some with no output on the 0-150 range.

This was the reason I started selling the RaceGrade sensors, to avoid issues near the end of KA’s time as a supplier to AIM.

I’ve sold more than a hundred of the new AIM pressure sensors. So far, so good.

As Scott and Matt point out, the PT100 temp sensors and the rotary and string pots sensors mounted solidly work fine, but I’m still recommending fuel rail and oil pressure sensors be mounted remotely using braided line from the main galley. YMMV.

Matt Romanowski

I don't count the VDO sensors in the same category as a Motorsport sensor. Those are far more failure prone and I've never advised them and only ever sold maybe 2.

The AiM sensors are pretty amazing. I've seen all the board design, actual manufacturing of the board (component pick and place to oven), packaging, multiple testing fixtures, and finished product. It's impressive! Part of the reason I was the first dealer to have them and have sold so many.