ZT-2 wideband O2 with stock boost sensor (+)

Mr. Y

New Member
Mar 31, 2005
363
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40
80 miles away from Kremlin
Hi, people.
I want to discuss some problems using stock boost sender.
I connected stock boost sensor to my ZT-2, and hit gas pedal really hard, so on my mechanical gauge I saw 0,5bar of boost (aprox 7psi), but on my notebook I saw almost 13 psi of boost.

So, the question: how stock sensor differs from ZT-2's native? I mean, can I just divide my readings approx by 2? Or there are other kind of dependence? (logarithmic, for example ;-)

PS: stock sensor works fast enought (not like stock gauge), I think that it can be used with ZT-2...
 

Milenko

New Member
Mar 31, 2005
83
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45
Mifflinville, PA
From my research, the stock sensor is 1.5 bar or 21.7 PSI. The ZT2 is configured for a 3.5 bar or 50.7 PSI sensor. I think both are 0v to 5V, so the relationship should be linear.

So it looks like dividing the ZT2 reading by 2.33 should give a semi-accurate reading.

I have NOT tested this, although I do plan to. This is just the result of 10 minutes of web surfing, so use at your own risk.

If you test this any further, please post back with results. I'm planning on using a setup like this also (if I can figure out what the conversion is).
 
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Milenko

New Member
Mar 31, 2005
83
0
0
45
Mifflinville, PA
I tried this out today and at 9 psi on my mechanical gauge the ZT2 showed 19. That works out to be 2.11 for a conversion. There's definately some weirdness though regarding vacuum. It seems that the stock sensor doesn't read 0 PSI at 2.5V, which I understand is what most sensors read.

AKA - it should read it's maximum vacuum at 0V - 0PSI at 2.5V - and maximum boost at 5V. This does not seem to be the case with the stock sensor.

I don't think there's going to be a reliable way to use the stocker. :( Does anyone know if there are any other options from other cars? I'm not going to pay $130 for a boost sensor from ZT.....
 

encomiast

boosted kraut
Mar 31, 2005
192
0
0
germany
The stock sensor doesn't seem to have the same scale above and below 0 psi. From what I've figured out some time ago, the voltage-pressure-relationship is as follows:
0.20V ~ -6 psi
1.40V ~ 0 psi
3.50V ~ 12 psi
From -6 to 0 psi should be linear, and so should 0 psi to 12 psi. Just -6 to 12 psi is NOT linear.

It's only a rough figure, I didn't take much time fiddling around with it back then.
Also, I don't know if there are differences/tolerances between the stock units since I never compared mine to another one.