New measuring devices

25th July 2004, 08:17 PM

I was just wondering with all the new gauges that are available to check engine output,temps,pressures and afr.How accurate are they and will there be less need to rolling road a vehicle with so much information already available.

Martin F · 25th July 2004, 09:35 PM

Well thats a pretty good question. A lot of people do recommend tuning on the road (guess that should be private road) using laptop and various readings (as a passenger obviously) as the scenarios are a bit more realistic compared to a rolling road.

As for accuracy of gauges, well IMO they are only as accurate as the last time they were calibrated and how often do you hear of Joe Bloggs sending his boost gauge off for calibration ? Thats not to say they are way off the mark, as you'd probably find that good quality ones would only be reading off slightly anyway, which is fine for us enthusiasts. However i wonder how many of the well known tuners have their various gauges calibrated on a regular cycle ?

A lot of the wideband air\fuel monitors out there have a calibration resistor in them that can be used for perodic calibration which is a good idea.

Unfortunately calibration is one of my pet subjects and something i've had a lot of exposure too throughout my working life so my opinions on it are quite strong.

25th July 2004, 09:42 PM

It would be interesting to run a car fitted with a new afr and compare it on a rolling road to see how accurate it is.These afr devices are quite an expensive add on,so you would expect them to be fairly accurate.well you would hope so anyway.

alex h · 25th July 2004, 10:00 PM

A WB02 sensor is used for tuning so it's as acurate as you're going to get. 1 example I was watching the readings from the other night was rated at being .4 of a second off of real time. which is IMO more than accurate enough.

Martin F · 26th July 2004, 08:14 AM

Hmmmm not sure i'd agree with that, at 0.4 of a second and 6,000rpm your engine will have done a further 40 revolutions, before you may have realised there's a problem. However the tuner trying to react to the reading in less than 0.4 sec may be quite hard.

Where that sort of thing will become an issue is in a closed loop system where the ECU can react in uS but would be reacting on delayed information. But yet another caveat is that i think (not 100% on this) that the measurement system used for detecting the air\fuel ratio is a very slow system. Anything that involves heating something up and maintaining a constant temperature is never going to be the fastest and most accurate in the world.

25th July 2004, 09:35 PM	#2
Martin F Administrator UK Spec - Manual Join Date: Aug 2003 Location: Essex, UK Posts: 10,226	Well thats a pretty good question. A lot of people do recommend tuning on the road (guess that should be private road) using laptop and various readings (as a passenger obviously) as the scenarios are a bit more realistic compared to a rolling road. As for accuracy of gauges, well IMO they are only as accurate as the last time they were calibrated and how often do you hear of Joe Bloggs sending his boost gauge off for calibration ? Thats not to say they are way off the mark, as you'd probably find that good quality ones would only be reading off slightly anyway, which is fine for us enthusiasts. However i wonder how many of the well known tuners have their various gauges calibrated on a regular cycle ? A lot of the wideband air\fuel monitors out there have a calibration resistor in them that can be used for perodic calibration which is a good idea. Unfortunately calibration is one of my pet subjects and something i've had a lot of exposure too throughout my working life so my opinions on it are quite strong. __________________ Martin UK6TT + Bits & Bobs 'Remember folks, the inside lane isn't just for Xmas' MSOC FAQ MSOC Members Discounts MSOC Resources

25th July 2004, 10:00 PM	#4
alex h Old Timer Join Date: Sep 2003 Location: East UK Posts: 887	A WB02 sensor is used for tuning so it's as acurate as you're going to get. 1 example I was watching the readings from the other night was rated at being .4 of a second off of real time. which is IMO more than accurate enough. __________________ Regards Alex H

26th July 2004, 08:14 AM	#5
Martin F Administrator UK Spec - Manual Join Date: Aug 2003 Location: Essex, UK Posts: 10,226	Hmmmm not sure i'd agree with that, at 0.4 of a second and 6,000rpm your engine will have done a further 40 revolutions, before you may have realised there's a problem. However the tuner trying to react to the reading in less than 0.4 sec may be quite hard. Where that sort of thing will become an issue is in a closed loop system where the ECU can react in uS but would be reacting on delayed information. But yet another caveat is that i think (not 100% on this) that the measurement system used for detecting the air\fuel ratio is a very slow system. Anything that involves heating something up and maintaining a constant temperature is never going to be the fastest and most accurate in the world. __________________ Martin UK6TT + Bits & Bobs 'Remember folks, the inside lane isn't just for Xmas' MSOC FAQ MSOC Members Discounts MSOC Resources

25th July 2004, 08:17 PM	#1
Guest Posts: n/a	I was just wondering with all the new gauges that are available to check engine output,temps,pressures and afr.How accurate are they and will there be less need to rolling road a vehicle with so much information already available.

25th July 2004, 09:42 PM	#3
Guest Posts: n/a	It would be interesting to run a car fitted with a new afr and compare it on a rolling road to see how accurate it is.These afr devices are quite an expensive add on,so you would expect them to be fairly accurate.well you would hope so anyway.

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