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The limits of MPX4250AP has come more than once. What are our alternatives to MPX4250AP? What are the challenges of fitting for instance MPX5700AP?

Something with a minimum of 4 bar capability and the ability to have a barometric pressure sensor as well? Worst case offer the ability to upgrade to a different sensor and utilize the mpx4250ap as the barometric sensor.

I've used the MPXH6xxx sensors with great success. They come in a ported version but they're MUCH physically smaller than the 4250AP. They come in 2.5bar (6250) 3bar (6300) and 4 bar (6400). They're SOP8 so easy to solder, very linear, good temperature characteristics, very high quality, generally available.

Aside from the slight loss of resolution involved with 15 - 700 kpa scale, I see no reason not to use the MPX5700AP as a drop-in replacement for higher boost. No personal experience with that one but Freescale now NXP sensors are generally excellent.

The Honeywell stainless body sensors with the (?) metripack 3pin connector on them are also a mainstay of the performance aftermarket for those who care. They come in various body types (NPT, shrader valve for LS style fuel rail, etc.), have both liquid and gas versions. They're also widely counterfeited for those looking for cheap stuff.

GM uses a variety of Bosch pressure sensors in the Gen4/Gen5 stuff, both 3 wire and TMAP/4 wire. OEM Gen5 TMAPs are 4bar, like LT4 supercharged. OEM LSA/LS9 are 3bar. Again, great external sensors with good linearity and temp characteristics. Also good data available.

BeerMoneyMotorsports wrote: ↑

Fri Feb 12, 2021 3:42 pm

Something with a minimum of 4 bar capability and the ability to have a barometric pressure sensor as well? Worst case offer the ability to upgrade to a different sensor and utilize the mpx4250ap as the barometric sensor.

None of the decent pressure sensors I know of have integrated baro. If you were not satisfied with the resolution of the high-pressure MAP setup for a sampled baro approach, you'd need to add a dedicated baro sensor that was intended to operate closer to an atmosphere.

BeerMoneyMotorsports wrote: ↑

Fri Feb 12, 2021 3:42 pm

Something with a minimum of 4 bar capability and the ability to have a barometric pressure sensor as well? Worst case offer the ability to upgrade to a different sensor and utilize the mpx4250ap as the barometric sensor.

NA guys generally like/want the higher resolution available from 1 bar sensors vs a 4 bar the turbo guys may need....external or internal fitted per application is probably best.

blundar wrote: ↑

Fri Feb 12, 2021 3:51 pm

you'd need to add a dedicated baro sensor that was intended to operate closer to an atmosphere.

That's exactly what I did on Proteus v0.5 and we'll probably add to other stuff: Added an i2c LPS25HB. It's super slow (<25hz), but is accurate to +-1hPa (aka aka 0.1kPa) out of the box without calibration. The range is pretty narrow, but it's plenty wide for normal atmospheric pressures. Our driver currently allows it to read 50 to 120kPa which will cover any possible baro pressure you encounter.

^^^ Which is awesome Matthew. Perfect solution.

MPXH6250A6U seems to be an option https://www.nxp.com/docs/en/data-sheet/MPXH6250A.pdf

Here's a few more 3Bar and 4Bar? https://www.mouser.com/ProductDetail/NXP-Semiconductors/MPXHZ6400AC6T1?qs=N2XN0KY4UWUU%252BPOBY5ijDQ%3D%3D
And this one https://www.mouser.com/ProductDetail/NXP-Semiconductors/MPXHZ6250AC6T1?qs=r8OyiFxb6ReKwWRu%2FW%2FVpQ%3D%3D