I have an old boost/fuel pressure combo gauge made by SPA Technique. I like it when it works, but the senders have been getting sketchy for a while, and SPA no longer sells or supports these gauges at all. I'd like to try to keep the gauge, and just replace the senders. Flipping through the manual, it seems like it's possible (but really tedious with only one button) to reprogram it to use any sender with a linear scale. I have a buddy who's been using these cheap no-name ones from eBay with his Megasquirt setup for a couple years, including for fuel pressure, and his car hasn't blown up in a fireball yet: https://www.ebay.com/itm/125280599941.
What says the hive? Any experience with these? I'm just a little nervous because I'd be putting one of them on a ~58psi fuel rail.
Gauge:
Sender:
I would say just be careful. I know someone who was going to use one as a pressure sensor on the brakes of a race car (to the data logger). Installed it and found the brakes really spongy - after multiple bleedings too it out & brakes were fine. Curious, he opened it up and found it was a mechanical plunger/spring thing that moved an arm on a resistor (plus some circuitry). This was on a 1000 (or 2000) psi transducer!
You are right to be concerned with a fuel pressure sender in particular. In an alternate reality where the CCP wasn't hell-bent on world domination starting by infiltrating the world's supply base, there might be one you could find with different pedigree and therefore more trustworthy. But this reality is not that alternate reality, and these days many of those sorts of components made for the OEMs are in fact made in the same factories as the no-name Ebay items. It's getting really hard to tell the difference, if there is a difference. I'd still be inclined to see if there was a compatible sender on a late-model in a junkyard first.
I have been using this as an oil pressure transducer for over a year now with no issues in my track car, readings are good and no leaks. It looks similar to what you have posted - https://www.amazon.ca/gp/product/B074QPD5RT/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1
In reply to Kendall_Jones:
I would not trust a generic sensor in the brake system but you should be able to find something decent in a u-pull yard (plus you can clip the pigtail at the same time to wire it in). I'm planning on grabbing one of these Bosch sensors at some point that came in a bunch of German stuff - https://www.finjector.com/documents/589822ac0fe60/0265005303.pdf
I put this one on my fuel rail a couple years ago so I could see if my corvette filter regulator was working. No issues and seems to read accurate. Lowdollar Motorsport is the go to in the sloppy mechanics drag world for "quality" chinesium sensors
Last month I had an oil pressure sensor crack in my race car and spray oil all over my engine bay at an astonishing rate. It was a big fire risk and a big cleanup, and if the oil pressure warning light hadn't gone off in time it would have cost me an engine. So I'm pretty focused on sender quality right now, I wouldn't install anything that I felt was "cheap".
Lowdollar motorsports or rife from motion raceworks
Thanks guys. Took a look at "Lowdoller" and despite their spelling issues, this is a killer product. This is going on an LS fuel rail, and I love the idea of a sensor that I can install without any adapters. I'm sold. I'll just stick the eBay cheapo in the intake manifold for the boost gauge since that's way less critical.
The temp sensors from lowdoller are a very strange cal and will likely need a different interface (bias resistor) to work well with most standalone/gauges.
In reply to Paul_VR6 (Forum Supporter) :
Good to know. I'm only planning on using this pressure sensor, which seems pretty straightforward.
Kendall_Jones said:
I would say just be careful. I know someone who was going to use one as a pressure sensor on the brakes of a race car (to the data logger). Installed it and found the brakes really spongy - after multiple bleedings too it out & brakes were fine. Curious, he opened it up and found it was a mechanical plunger/spring thing that moved an arm on a resistor (plus some circuitry). This was on a 1000 (or 2000) psi transducer!
My first thought when seeing this thread title was remembering a big-money race car that went into a wall because a brake pressure sensor (don't know if it was a cheap or expensive model) failed in a way that opened up both sides of a brake hydraulic system at the proportioning valve.
