#76252, "is this typical for boost to look like this...?" Sep-08-04 11:23 AM by tim97rs
this is on my wideband with my boost sensor i built to record boost. what i notice is that the trace is very jumpy although i dont notice or feel anything while driving. my boost gauge says 10psi, my boost controller somtimes says a ful 1-1.5 psi lower than my gauge, and now this tracing says all kinds of shit.
whatcha think about this? which one should i beleive to be the most accurate? gauge? controller? or wideband trace?
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#76254, "RE: is this typical for boost to look like this...?" In response to Reply # 0 Sep-08-04 01:03 PM by admin2
I'd go with the gauge, personally... but no, technically boost is never 100% steady, so on a more sensitive device (read: electronic) expect the variations to be much more apparent. As well, sensitivity may be different between different devices, so some things may read the exact same input as two different results.
Where is the sensor located that is reading this pressure? That can have a whole lot to do with how smoothly it reads.
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#76255, "RE: is this typical for boost to look like this...?" In response to Reply # 1 Sep-08-04 01:11 PM by turbo8u
the gauge is 100% mechanical, so go with that
edit: i was boost spiking on the dyno and my boost gauge didnt even see it though...so really, i dont know what to say. i found an inline check valve and that removed the spike as well as perked up the boost gauge in accuracy, so who knows
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#76312, "RE: is this typical for boost to look like this...?" In response to Reply # 0
If the boost sensor has a dependable source voltage, good wiring, and you calculated its output in psi in relation to its source voltage, then its output is "correct". Additionally, Motorola will likely give you the accuracy of the unit. However, it may not be what you want to see. You may wish to add a mechanical or electronic damper to smooth out the output.
Corbin
'95 ESI-T Now with more power and fewer leaks
Gimme fuel...Gimme fire...Gimme that which I desire
#76321, "RE: is this typical for boost to look like this...?" In response to Reply # 5
Originally posted by Corbin You may wish to add a mechanical or electronic damper to smooth out the output.
tell me more....
USED TO HAVE...Everything you wish you had, and then some...
You are somebody special Tim, you matter! - from the admins (but nobody likes you, because your username is just like that other guy's, and you whine a lot)
#76323, "RE: is this typical for boost to look like this...?" In response to Reply # 6
I didn't see the picture you posted, but I'm assuming that the reading jumps around alot (like there is alot of noise). The S-FMU uses an orifice to smooth out its response. My Profec-B uses something that looks like a lawn mower fuel filter to smooth its readings. Distancing the sensor from the source would help too. Those are the easy things.
Corbin
'95 ESI-T Now with more power and fewer leaks
Gimme fuel...Gimme fire...Gimme that which I desire
USED TO HAVE...Everything you wish you had, and then some...
You are somebody special Tim, you matter! - from the admins (but nobody likes you, because your username is just like that other guy's, and you whine a lot)
#76382, "RE: is this typical for boost to look like this...?" In response to Reply # 8
I hooked my Zt-2 up to the eclipse this weekend and I noticed the same thing. It could be the signal line from the intake the the sensor. I just tapped into my MAP sensor from the SAVCR and it consistantly reads 5 psi less so I just have to add 5 to the output.
I'm actually surprised how well I tuned the EIC with just the EGT, it's almost spot on until 20 psi where I tuned it a but rich to be safe. I was hitting 10.9 at 25 psi, so I just need to tweak that. Widebands are cool.
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