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TPS PF4C characteristic curve equation


Meinolf

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Hi,

 

some advise that the (cheaper) PF4C can be used as replacement for the PF3C. To the best of my knowledge the curves are different, so it's not a drop-in replacement. The TPS lookup table in the BIN needs to be adapted. I'm happy to do so and publish it here, but need the characteristic curve equation of the PF4C for the purpose.

 

I couldn't find anything in Google. If any of you has the means to measure angle and resistance (or voltage), then 4 datapoints would be sufficient to calculate the equations. 0°, 20°, 35° and max. ° would be enough. Of course getting the equation(s) would be even better.

 

Cheers

Meinolf

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Hi,

 

Probably not that relevant but this may be of interest, not sure if the section at the bottom of the page is by the seller or CA Cycleworks, the manufacturer of the aftermarket part.

 

Could not work out how to paste the ebay page using this android tablet.

 

http://www.ebay.co.uk/itm/Ducati-Throttle-Position-Censor-TPS-PF3C-Monster-SS-SS750-SS900-ST2-748R-/111784871752?hash=item1a06e5c748:g:tdwAAOSwsB9WCwF5

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I have used the Harley TPS in both a V11 Lemans and Bassa.. I highly doubt you could tell any difference WHEN RIDING which TPS is installed.  for me it was a no brainer  $42 vs $300+

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Meinolf, I have the "Harley-Davidson" TPS fitted to my Sport (Magnetti-Marelli PF4C/00), installed Nov 2008 and can attempt to get these data points.  Only 4 points? Seems we could generate a smoother curve than that?

 

I am expecting to use guzzidiag for the angles of opening and the TPS breakout harness to measure millivoltage with my Triplett meter?

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Me and Meinolf had been e-mailing about this a bit. I asked the same thing as you Docc and Meinolf said: "No. GuzziDiag will give you an angle based on the TPS lookup table in the BIN currently loaded, which is using the values for a PF3C. Catch22,,,,"

Basically it needs to be measured physically.

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Me and Meinolf had been e-mailing about this a bit. I asked the same thing as you Docc and Meinolf said: "No. GuzziDiag will give you an angle based on the TPS lookup table in the BIN currently loaded, which is using the values for a PF3C. Catch22,,,,"

Basically it needs to be measured physically.

Yeah, I was afraid of that. So, I ain't got the poop to get those data points.

 

I remember seeing a PF4C graph (I thought Meinolf had posted it?), and it appeared to "rise" quicker than the PF3.

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Hi,

 

@Docc. Yes, 2 points (angle/voltage or angle/resistance) are sufficient to create the linear equation describing a straigt line. The http://img4.hostingpics.net/pics/484669PF3CPF4C.jpg doesn't show values, so no reverse calculation is possible.

 

@Martin. The drawing in the link is for the PF3C, for which the equations are known, and doesn't include voltage. The poster "Guest_Jeff in Ohio_*" mentioned that he also has a diagram for the PF4C. Does anybody know him?

 

As the PF4C is used on HDs, the info needed might be available in the Harley community. Does anybody have contacts there and could ask the question?

 

Cheers

Meinolf

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"Guest_Jeff in Ohio_*" mentioned that he also has a diagram for the PF4C. Does anybody know him?

Cheers Meinolf

See http://archive.guzzitech.com/HD-TPS-Jeff_B.html

None of the links work, but Jeff's email might still be good.

Also http://mphcycles.com/the-pdf-mike-sent-that-i-dont-know-what-its-about-write-a-real-title/

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I have the Cal Cycle Works TPS on my EV ($75).  Actually, the previous owner had replaced the factory part with the Harley TPS before I bought it.  I got 35k+ miles out of that one before it was replaced.

 

I returned a Harley part & returned another Cal part before finding one that works.  A fellow on WG had a similar experience with a replacement TPS.  I wonder if these replacements are made in China?

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Hi,

 

finding the curves is less trival than one might think. I talked with Marelli in Germany, but they have no clue whom to ask in their operation or even which division to ask. The same with two distributors in Germany.

 

And sent an email to Jeff. Alas, the address is not valid.

 

An easier way might be to contact HD's support and ask the question. The HD part # is 27271-95. Does anybody have contacts to Harley and ask?

 

Cheers

Meinolf

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It seems to me with my failing memory that Mike Haven from MPH posted the difference between the curves many years ago. From memory, it wasn't much.

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Hi Martin,

 

do you know that CTS is the supplier of Magneti Marelli? I won't fish in the dark.

 

I contacted Chris, the owner of CA Cycleworks, and asked if he had data for the PF4C. He made an amazing contraption to check and record the values of TPSs. Really cool stuff!

 

https://www.youtube.com/watch?v=cZK9fVvNaC4

 

Beard (author of the GuzziDiag suite) made an interesting proposal. Which is to use the PF1C. Because it doesn't have the oval holes necessary for rotation, he would modify the contents of the EEPROM and add an offset. And we could adapt the TPS lookup table to the linear curve of it.

 

The PF1C is available for ~11$ from Alibaba, so I went ahead and ordered one.

 

Cheers

Meinolf

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