Funky RPM Readnigs

DMKMM
Posts: 103
Joined: Thu Apr 17, 2008 12:12 pm
Location: Lincoln, NE

Funky RPM Readnigs

Postby DMKMM » Wed May 28, 2008 5:04 pm

Something happened to my RPM signal. I'm using a DASH1 and a DL2; about 2 weeks ago it worked excellent, then i switched it to a identical but different vehcile. For some reason, with out changing any settings, now it reads wrong. (i have a second RPM reader for verifacation)

i have the pulses per rev set at 2, and the maximum rate of change set at 2000, i have the averaging set to 1.

i have RPM lead wire coming from the low voltage side of the coil.

about 2 weeks ago it worked excellent, i made no changes, and i tried switching it back to the original vehicle, and got the same results.

the problem is:

it reads way to high, the Dash1 shows a correct RPM reading at idle (900-1050) but when you start to accelerate, its like it just adds them together? you can start off at idle and end up at 200,000? over 20 seconds while holding the gas pedal at like 2500 rpm. (this is what the readout on the dash1 says)

sorry the graph is a lil hard to read. the most i took the rpm to was 3500, idk why the chart says 8000...

any help with this would be awesome

the test here, shows;

1) Idle for 15 seconds
2) Instant acceleration to 3500 and held for 30 seconds
3) Instanlty back to idle for 20 seconds
4) Slow acceleration to 3500 over 30 seconds
5) Slow deceleration back to idle over 30 seconds
6) Idle for 5 seconds
7) Instant acceleration to 3500 for 5 seconds
8) Instant to idle for 5 seconds
9) Instant acceleration to 3500 for 5 seconds
10) Instant to idle for 5 seconds
11) Instant acceleration to 3500 for 7 seconds
12) Instant to idle for 10 seconds - end

Image

DavidRowley
Posts: 43
Joined: Fri Mar 28, 2008 8:01 pm
Location: westmidlands
Contact:

Postby DavidRowley » Wed May 28, 2008 8:39 pm

yup been here got the badge.

was told the -coil feed had interferance and i should try to get a better signal

went down the line of fitting a Gear tooth sensor to a bracket and located this in front of the crank and then spent a week trying to work out how to display the information i was getting

cut a long story short the dreaded max RPM has returned also to me. i put it down to the configuration in the dash as monitor shows 60 pulses constant and increases as i rev the engine but my dash 2 and dash 1 both FLash peek and act confused i belive the best setting is 2x sample or 3 and 600 in the delay but ill let Support answer why as i belive they put it better.


dave

faraday
Posts: 267
Joined: Sun Feb 25, 2007 1:18 am

Postby faraday » Thu May 29, 2008 4:44 am

Extremely frustrating :evil:

There are several similar user inputs to different pieces of software you could be talking about.

Dave has mentioned at least one that is specific to his Dash2 and not your setup.

You think/assume that you have changed nothing significantly, but this may not be so to the hypersensitive RPM reading hardware or in the confused R-T software.

1) Hardware
a. Is the wiring identical?
I mean the location and bundling, etc of all the two vehicles' looms, not just the routing of the RPM trigger wire.
I know the problem is persisting in your car. If you didn't have to disturb the trigger wire in yours other than unplugging it, I'd be tempted to discount this point.
b. Are the ignition components the same?
They might be the same make and model, but unless you removed your distributor, etc...
Please don't laugh :roll:
As above, back in your car, things are still stuffed, so...

2) Software
a. Is the software the same?
I.E have you updated to a new version?
I make this as a general point, because when you uninstall and install the new version, all the settings go back to default.
b. I'm guessing that you are aware of the above, but have you checked all the areas that change in Analysis?
(i) Vehicle Options - this is a somewhat moot point, as the default is 2, as you require.
(ii) Variable Manager
c. DL2 Configuration: What is the sample rate on RPM?
Is it possible that you have used a different CF card that has a different SETUP.BIN file on it which has without you realising it reconfigured the logger?
If this has happened, it could explain why the Dash is crazy too.

I may have left something out. As I have not worked with any of the R-T displays, I am not savvy to the areas where the possible SNAFUs arise.

:idea: R-T would be well served to append all device configuration details to each log file.

I would not be surprised to learn that you have already attended to all of the above.

WRT the max r.o.c, the higher the number the less that it does. This should be intuitive. In my experience, when the RPM spikes high (and usually stays high), it is normally due to noise. Noise is not a black or white thing, it will always be present to some degree. A lower max r.o.c is needed to filter more noise.
I have been tricked more than once and not checked or changed the Vehicle Option "number of pulses" before I've begun changing the max r.o.c and sent myself crazy. :cry:
It is quite possible to have the max r.o.c too low, in which case the graph looks a bit like yours, with lots of straight lines. There are sometimes horizontal lines as well, where the valid changes are clipped, and RPM is understated when the number is way too low.
Bearing this in mind, I would reduce the max r.o.c before I increased it. You should not need to smooth over a full second (I am assuming that your "1" refers to smoothing in Analysis Variable Manager).
I am used to other systems where any smoothing can be defined in both time and no. of samples. More work for R-T, but it is confusing when in some fields it's time and others, samples.

Hope something here is of help.
:)

Support

Postby Support » Thu May 29, 2008 8:06 am

If you don't get anywhere with this, email a file through to me mhill at race-technology.com and I'll have a look over it for you.

Martin

DMKMM
Posts: 103
Joined: Thu Apr 17, 2008 12:12 pm
Location: Lincoln, NE

Postby DMKMM » Thu May 29, 2008 12:25 pm

well...

i only have one card
both vehicles are Exactly the same,
i didnt take any thing apart, coil, random wires, ect...
im actually using a 12 ga. EMF shielded wire, routed the same place on both vehicles (have these nice lil mounted, plastic, quik-relase zip tie things)
i didnt upgrade the analyzer software (unless it auto-updates)
hardwares the same DASH1 DL2
sampling is set at 100Hz

except for the high rate of change, does it seem like i have everything else correct?

the only reason that i have it that high is because, unless its high, it wont register the data fast enough, ex. if you have the roc set at like 500, and then you romp on it and it goes from idle to 5k rpm, it would show it getting there in 10 seconds...

faraday
Posts: 267
Joined: Sun Feb 25, 2007 1:18 am

Postby faraday » Thu May 29, 2008 1:30 pm

Take up Martin's offer, if you haven't done so already.

It seems you have everything correct.
The fact that you had a well behaved system before should give you confidence that you're not at fault and that the system will work again.
How?
Why?
When?
Who knows? I am sure I'm not the only reader who sympathises.

Your roc is already quite low, but does reducing it go anyway towards fixing the problem?

DMKMM
Posts: 103
Joined: Thu Apr 17, 2008 12:12 pm
Location: Lincoln, NE

Postby DMKMM » Thu May 29, 2008 2:58 pm

ive had it everywhere between 100-10k

having it around 2k usually gave me the best results.

im still Investigating......

faraday
Posts: 267
Joined: Sun Feb 25, 2007 1:18 am

Postby faraday » Thu May 29, 2008 3:05 pm

Good Luck.

I admire your perseverance :!:

DMKMM
Posts: 103
Joined: Thu Apr 17, 2008 12:12 pm
Location: Lincoln, NE

Postby DMKMM » Thu May 29, 2008 3:09 pm

well...

its kind of a necessity...
:twisted:

faraday
Posts: 267
Joined: Sun Feb 25, 2007 1:18 am

Postby faraday » Thu May 29, 2008 3:21 pm

I know the feeling :roll:


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