People with SECS moniters...
01-10-2006, 05:26 PM
#1
People with SECS moniters...
What is your map reading at idle?...and what does your boost gauge read at idle?
...i seem to be SECS saying -6.5psi and gauge -10psi at idle does that look ok?
...i seem to be SECS saying -6.5psi and gauge -10psi at idle does that look ok?
01-10-2006, 05:35 PM
#5
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The SECS monitor is NOT a super accuarte measurement device
as stated in the instructions.
It is a guide and more used for diagnosing faults.
It is ONLY as accurate as the map sensor which isnt that good by todays
hi tech standards.
Besides, put 2 gauges side by side and they will always read different
especially during transient changes.
as stated in the instructions.
It is a guide and more used for diagnosing faults.
It is ONLY as accurate as the map sensor which isnt that good by todays
hi tech standards.
Besides, put 2 gauges side by side and they will always read different
especially during transient changes.
01-10-2006, 05:42 PM
#7
Originally Posted by SECS
The SECS monitor is NOT a super accuarte measurement device
as stated in the instructions.
It is a guide and more used for diagnosing faults.
It is ONLY as accurate as the map sensor which isnt that good by todays
hi tech standards.
Besides, put 2 gauges side by side and they will always read different
especially during transient changes.
as stated in the instructions.
It is a guide and more used for diagnosing faults.
It is ONLY as accurate as the map sensor which isnt that good by todays
hi tech standards.
Besides, put 2 gauges side by side and they will always read different
especially during transient changes.
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01-10-2006, 05:49 PM
#12
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Phil,
Are you ignoring me
Rich,
Unless your inlet manifold is the same as Phils, any tests at idle
are irrelivant.
Nick,
The monitor reads RAW data from the map sensor and performs
limited digital filtering.
The ECU internal value is highly averaged.
In any case the ECU only has 8 bit resolution and the map sensor isnt
that accurate anyway otherwise it would cost much more to buy.
Are you ignoring me
Originally Posted by SECS
Phil, the map sensor signal will NOT be accurate at idle with a large
plenum chamber due to air pulse and volume sizes.
plenum chamber due to air pulse and volume sizes.
Rich,
Unless your inlet manifold is the same as Phils, any tests at idle
are irrelivant.
Nick,
The monitor reads RAW data from the map sensor and performs
limited digital filtering.
The ECU internal value is highly averaged.
In any case the ECU only has 8 bit resolution and the map sensor isnt
that accurate anyway otherwise it would cost much more to buy.
01-10-2006, 05:56 PM
#13
Testing the future
SECS
i know all of that, but worth pointing out to others
my point is, that if you are interested in knowing what pressure that the ecu is seeing, and hence using to look up stuff from the maps, is to use the datastream. although the monitor (for thicko phil
) tells you more or less what the ecu should see, there could be an internal fault (very unlikely) meaning that it doesn't
i know all of that, but worth pointing out to others
my point is, that if you are interested in knowing what pressure that the ecu is seeing, and hence using to look up stuff from the maps, is to use the datastream. although the monitor (for thicko phil
) tells you more or less what the ecu should see, there could be an internal fault (very unlikely) meaning that it doesn't
01-10-2006, 05:58 PM
#14
...i have a swedish plenum so that accounts for the -2psi defficit on my gauge to his
...i know it aint accurate the fooking boost gauge told me that i was merely asking as i want to make sure my vaccuum is correct.
...i know it aint accurate the fooking boost gauge told me that i was merely asking as i want to make sure my vaccuum is correct.
01-10-2006, 06:03 PM
#16
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Originally Posted by Bosch-Man
...i have a swedish plenum so that accounts for the -2psi defficit on my gauge to his
...i know it aint accurate the fooking boost gauge told me that i was merely asking as i want to make sure my vaccuum is correct.
...i know it aint accurate the fooking boost gauge told me that i was merely asking as i want to make sure my vaccuum is correct.
I wasnt joking.
Due to the large internal volume of the plenum you get pulses of air
at low rpm. This is measured by the map sensor and averaged.
The result is that the ACTUAL cyclinder charge pressure will be different
on that the map sensor as it reacts much quicker.
Mechanical gauges are dampened to stop them vibrating and jumping
around making them hard to read.
The ecu corrects this internally to provide a stable value for map value
selection but this will ALWAYS lead to an averaged value as you cannot
measure it accuartely no matter what ecu you have.
01-10-2006, 06:18 PM
#18
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CossieRich,
The accuracy problem I menationed related to low rpm,
How did you measure that ?
Was it the peak reading ?
Unless you can hold the pressure steady accurate for a period of time
you cant compare the values as both will update at different rates.
Do both read zero when the engine is switched off ?
If so, then its ok as you are implying a larger difference.
(0 psi is not actually 0 volts on the map sensor wire)
The accuracy problem I menationed related to low rpm,
How did you measure that ?
Was it the peak reading ?
Unless you can hold the pressure steady accurate for a period of time
you cant compare the values as both will update at different rates.
Do both read zero when the engine is switched off ?
If so, then its ok as you are implying a larger difference.
(0 psi is not actually 0 volts on the map sensor wire)
01-10-2006, 06:21 PM
#19
Originally Posted by SECS
CossieRich,
The accuracy problem I menationed related to low rpm,
How did you measure that ?
Was it the peak reading ?
Unless you can hold the pressure steady accurate for a period of time
you cant compare the values as both will update at different rates.
Do both read zero when the engine is switched off ?
If so, then its ok as you are implying a larger difference.
(0 psi is not actually 0 volts on the map sensor wire)
The accuracy problem I menationed related to low rpm,
How did you measure that ?
Was it the peak reading ?
Unless you can hold the pressure steady accurate for a period of time
you cant compare the values as both will update at different rates.
Do both read zero when the engine is switched off ?
If so, then its ok as you are implying a larger difference.
(0 psi is not actually 0 volts on the map sensor wire)
I reset the peak data on the monitor. I then floored it in 4th until the needle got to 2 bar on my boost guage. I then checked peak data under MAP and it said 26.4 psi
I know my gauge reads 0 when engine is off. Never actually looked at he monitor though. Will check it out
01-10-2006, 06:26 PM
#20
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The peak data will ALWAYS read higher than a gauge.
For the reasons explained above.
I.E. The monitor reacts MUCH quicker that a gauge and records the peak.
Check the ZERO points are about the same.
Zero is actually 14.5 psi in absolute pressure terms
(The pressure of the atmosphere).
For the reasons explained above.
I.E. The monitor reacts MUCH quicker that a gauge and records the peak.
Check the ZERO points are about the same.
Zero is actually 14.5 psi in absolute pressure terms
(The pressure of the atmosphere).
01-10-2006, 06:31 PM
#21
Originally Posted by SECS
The peak data will ALWAYS read higher than a gauge.
For the reasons explained above.
I.E. The monitor reacts MUCH quicker that a gauge and records the peak.
Check the ZERO points are about the same.
Zero is actually 14.5 psi in absolute pressure terms
(The pressure of the atmosphere).
For the reasons explained above.
I.E. The monitor reacts MUCH quicker that a gauge and records the peak.
Check the ZERO points are about the same.
Zero is actually 14.5 psi in absolute pressure terms
(The pressure of the atmosphere).
The peak data was lower than my gauge reading, but you are saying that the peak data will always read higher than a gauge.
01-10-2006, 06:38 PM
#22
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Rich,
I missread what you originally said
However, I have yet to find a mechanical gauge under Ł200 that
has any sort of reasonable accuracy.
However....
2 bar = (2 x 14.5 psi) = 29.0 psi
(rounded down to one decimal place before anyone moans)
29.0 - 26.4 = 2.6 psi
If you allow 1% for monitor accuaracy (0.9 psi for a 2 bar scale/3 bar map)
That means the gauge at best is 1% in-accurate.
(Assuming all is functioning correctly)
Also, dont forget,, the viewing angle of the gauge will affect how you
read the scale.
I missread what you originally said
However, I have yet to find a mechanical gauge under Ł200 that
has any sort of reasonable accuracy.
However....
2 bar = (2 x 14.5 psi) = 29.0 psi
(rounded down to one decimal place before anyone moans)
29.0 - 26.4 = 2.6 psi
If you allow 1% for monitor accuaracy (0.9 psi for a 2 bar scale/3 bar map)
That means the gauge at best is 1% in-accurate.
(Assuming all is functioning correctly)
Also, dont forget,, the viewing angle of the gauge will affect how you
read the scale.
01-10-2006, 06:52 PM
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r5jame5
When comparing peak data....
Different update rates will yeald different results.
If you apply a static pressure for enough time they will equalise.
jaycos,
Generally, yes.
When comparing peak data....
Different update rates will yeald different results.
If you apply a static pressure for enough time they will equalise.
jaycos,
Generally, yes.
01-10-2006, 07:01 PM
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it was held on full boost for quite a while and there was still 5 psi in between them i was sat watching both from the passenger seat they had plenty of time to equalise . not slating the product in any way because all the other functions are spot on except this one .
01-10-2006, 07:03 PM
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r5jame5,
When ever you get 2 measuring devices side by side, tehre will ALWAYS
be a difference.
Which one is correct....
In my instruction manual, I do quote accuracy percentages.
I bet Pectel dont...
When ever you get 2 measuring devices side by side, tehre will ALWAYS
be a difference.
Which one is correct....
In my instruction manual, I do quote accuracy percentages.
I bet Pectel dont...
01-10-2006, 07:15 PM
#34
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Then your defi is wrong too
Seriously, said this before but the monitor was only ever meant to be a
guide and diagnostic tool and many things can affect accuracy.
If you wanted an officially calibrated accurate device then double
the price and people wouldnt buy them.
They do the job they were designed to do
Seriously, said this before but the monitor was only ever meant to be a
guide and diagnostic tool and many things can affect accuracy.
If you wanted an officially calibrated accurate device then double
the price and people wouldnt buy them.
They do the job they were designed to do
01-10-2006, 07:21 PM
#36
see my zeixtronic gauge reads -16.7 psi normal gauge -15psi my ecu data screen -8 psi so working on what si says about gauge accuracy is right beacause the load points on my ecu start at 0 kpa then the next is -8 (50 kpa) ,and its the second site thats adjusted for idle if i went purely by a gauge which you wouldnt id be mapping the first site at 0 kpa
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