liam.mccaffrey
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| posted on 13/5/11 at 10:58 AM |
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Data Analysis challenge
I sub to Racecar Engineering Mag and every month they run an article on data aquisition where they have a feature on interpreting telemetry. I must
say I really enjoy this and really look forward to it.
This is the one from the current issue, I reckon I have it sussed out but just wanted to share with you guys and see what you thought and whether you
enjoyed it as much as I did.
The traces are as follow:-
RPM
Speed
Throttle angle
Throttle pot Voltage
Throttle pedal % depression
 
Description
[Edited on 13/5/11 by liam.mccaffrey]
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Agriv8
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| posted on 13/5/11 at 11:12 AM |
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Throttle pot not calibrated/setup correctly or picking up interferance .
How from - the Spkes on :-
Throttle angle
Throttle pot Voltage
and nothing on :-
Throttle pedal % depression
It hard to tell on there but from the diagrame is the Throtle Pot showing 100 % open ? which it should be at full Chat thus down on power.
Regards
agriv8
Taller than your average Guy !
Management is like a tree of monkeys. - Those at the top look down and see a tree full of smiling faces. BUT Those at the bottom look up and see a
tree full of a*seholes .............
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TMC
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| posted on 13/5/11 at 11:34 AM |
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Cant really see the scale figures on the left of the graph, but it seems that 100% throttle pedal depression is not equating to 100% throttle opening
at the business end.
If the car is fitted with a pedal stop then it needs to be moved and better set up, if its drive-by-wire then it needs better calibration.
http://www.tmcmotorsport.co.uk
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liam.mccaffrey
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| posted on 13/5/11 at 11:41 AM |
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I have the benefit of a clear pic in the magazine, so I'll add a piece of information. The buz on the flat part of the throttle angle trace
oscillates between 75 deg and 90 deg.
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TMC
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| posted on 13/5/11 at 11:43 AM |
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quote:
Originally posted by liam.mccaffrey
I have the benefit of a clear pic in the magazine, so I'll add a piece of information. The buz on the flat part of the throttle angle trace
oscillates between 75 deg and 90 deg.
In which case I'm definitely going with my diagnosis: Throttle pedal movement isnt translating to throttle angle correctly.
http://www.tmcmotorsport.co.uk
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NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
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bigruss
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| posted on 13/5/11 at 11:50 AM |
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quote:
Throttle pedal movement isnt translating to throttle angle correctly.
That was my answer too.
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MikeCapon
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| posted on 13/5/11 at 12:33 PM |
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Bumpy track, poor seating + pedal position = lifting off???????
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Agriv8
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| posted on 13/5/11 at 12:56 PM |
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quote:
Originally posted by liam.mccaffrey
I have the benefit of a clear pic in the magazine, so I'll add a piece of information. The buz on the flat part of the throttle angle trace
oscillates between 75 deg and 90 deg.
If it alwayd 75 - 90 possible Throttle pot not attached correctly and rotating missreading could also account for spikes at the other end
regards
Agriv8
Taller than your average Guy !
Management is like a tree of monkeys. - Those at the top look down and see a tree full of smiling faces. BUT Those at the bottom look up and see a
tree full of a*seholes .............
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sebastiaan
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| posted on 13/5/11 at 03:57 PM |
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Gearing's too tall.
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Paul (Notts)
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| posted on 13/5/11 at 05:27 PM |
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With the pedal fully down -100% the throttle is only opening 82.5% BUT engine vibrations pull on the cable and produce a spike from 75 % to 90% as the
engine vibrates from side to side.
Paul
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Liam
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| posted on 13/5/11 at 07:03 PM |
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I'm thinking the spikes on throttle angle/pot that aren't seen on the throttle pedal are automatic throttle blips from the management
system for downshifts, so this could be drive-by-wire. The fact the throttle is not fully opening and seems to be fluttering would explain the lack of
speed, but not sure what the reason for that would be - mechanical play somewhere or an electrical problem. The fact that the flutter is on the
throttle angle trace but not the throttle pot trace may be the key, but I'm not 100% sure what those traces are exactly. I.e. surely the
throttle angle must be measured by a pot. If so what is the throttle pot trace? Another throttle pot? Hmmmmmm.
Anyway - 1,000,000 points if I'm right about the auto throttle blips thing, please!
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MakeEverything
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| posted on 13/5/11 at 09:36 PM |
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My guess is a poor linkage between the throttle pedal and body, a bad earth or voltage loss, or a problem with the butterfly.
Kindest Regards,
Richard.
...You can make it foolProof, but youll never make it Idiot Proof!...
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MikeCapon
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| posted on 16/5/11 at 07:48 AM |
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Well come on then Liam....
What's the answer please?
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