inside a modified 300kpa pressure transducer
02-26-2007, 06:17 AM
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inside a modified 300kpa pressure transducer
for the archives, here's the guts of a 250kpa pressure transducer thats been modified for use as a 300kpa pressure transducer:
<img src="http://www.theswansonfamily.us/modules/gallery2/d/47447-1/IMG_2902.JPG">
From the color bands on the resistors the two on the left side of the picture from bottom to top are 12K and 680K or 692K total, and the bank on the right are 470K and 15K or 485K total. Unless I'm missing another mod on the board somewhere this would be a reasonably easy mod to a 250KPA PT for those looking to skip the expense of a VMAP or a 'real' 300KPA PT...
<img src="http://www.theswansonfamily.us/modules/gallery2/d/47447-1/IMG_2902.JPG">
From the color bands on the resistors the two on the left side of the picture from bottom to top are 12K and 680K or 692K total, and the bank on the right are 470K and 15K or 485K total. Unless I'm missing another mod on the board somewhere this would be a reasonably easy mod to a 250KPA PT for those looking to skip the expense of a VMAP or a 'real' 300KPA PT...
02-26-2007, 06:39 AM
#3
MIhnea used to modify 250s into 300s but he said it took too much time to be profitable.
For him. For DIY, its worth around $150 to $200 (the cost of a VMAP less the price of the resistors).
Of course, you don't get the adjustability of the VMAP.
Of course, you don't get the adjustability of the VMAP.
02-26-2007, 06:43 AM
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right, it doesn't necessarily make sense from Mihnea's perspective
But for someone willing to put the time in themselves it could be a reasonable cost savings.
As far as adjustability is concerned, If you were to install trimpots in place of the fixed resistors you would get the ability to tweak the range a bit...
As far as adjustability is concerned, If you were to install trimpots in place of the fixed resistors you would get the ability to tweak the range a bit...
02-26-2007, 11:32 AM
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Each sensor is calibrated independantly of others, each one of them ends up with different resistors
And 250kPas aren't a good place to start.
Hey, do you also reverse-engineer all my chips by any chance?
Hey, do you also reverse-engineer all my chips by any chance?
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02-26-2007, 12:54 PM
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ah, that makes sense
actually I think there were some subtle differences inside the pressure transducer you modified and another (stock 250kpa) transducer I opened earlier. Care to share with the group what transducer you started with in this photo?
And no, I haven't reverse engineered any of your chips. Not much point since on my S6 altering my fuel maps simply involves booting my laptop up
And no, I haven't reverse engineered any of your chips. Not much point since on my S6 altering my fuel maps simply involves booting my laptop up
02-26-2007, 01:14 PM
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Sorry, the chip thing was sarcasm...
About the sensors, they started their life as 200kpas originally. Cody used to buy them for me frmo Hoppen 
Hey Cody, I'll shoot you an email in a bit 
I have probably done about 30 or 50 of them until I got to use VMaps, nearly 3 years ago (sheesh, that's when I came to the US to do that crazy tuning trip). Honestly there's too much hassle involved and I've also ran occasionally into sensors that would lose any sort of linearity at around 280kPa, so I just gave up on this crap. Until very recently I still had in my hands one of the best ones I had ever done, which was 100% true to the original 300kPa I had used as a model, but that was very rare and I seriously got pissed off of wasting my time doing this when I could just email Feico and ask for 10 VMaps (even if cost is higher).
The principle is easy, it's a voltage divider in essence, but it's really tricky and those resistors are obtained after recalibrating the sensors using trim pots of course!
HTH,
Mihnea
Hey Cody, I'll shoot you an email in a bit I have probably done about 30 or 50 of them until I got to use VMaps, nearly 3 years ago (sheesh, that's when I came to the US to do that crazy tuning trip). Honestly there's too much hassle involved and I've also ran occasionally into sensors that would lose any sort of linearity at around 280kPa, so I just gave up on this crap. Until very recently I still had in my hands one of the best ones I had ever done, which was 100% true to the original 300kPa I had used as a model, but that was very rare and I seriously got pissed off of wasting my time doing this when I could just email Feico and ask for 10 VMaps (even if cost is higher).
The principle is easy, it's a voltage divider in essence, but it's really tricky and those resistors are obtained after recalibrating the sensors using trim pots of course!
HTH,
Mihnea