hobbsy
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| posted on 8/5/10 at 03:50 PM |
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Logging AFR, RPM, TP (innovate kit? or cheaper option?)
Gents,
I've done a search but not found a great deal, so here we go.
I have a 2003 5PW R1 engine in my Fury (injected) with a PowerCommander 3R (serial connection version that also does ignition as standard). I'm
currently running a map I was given by someone else with a similar setup (4-1 manifold, sausage air filter).
I've just got around to fitting an Innovate LC-1 (wideband lambda) with XD16 gauge. This is nice and pretty and you can glance at it and get an
idea if you're running to rich or lean but to do anything meaningful in terms of re-mapping I need some logging.
The PowerCommander map (as far as I know) can only be changing all at once rather than on the fly on a load site basis. So my plan is to log the RPM
and throttle position (as this is what the x and y axis on the PC3R fuel map is) and then see where I am too rich or lean and amend the relevant
cells.
The Innovate kit gives you a serial daisy chain setup (3.5mm jacks ultimately to a 9pin serial) that works with their Logworks software OR anything
that can deal with a 0-5V output.
The easy (but costly) option to get the RPM and TP inputs logged at the same time seems to be this piece of kit:
http://www.innovatemotorsports.com/products/ssi_4.php
which retails for 129USD (oh why didn't I get this back when it was 2$/£) - I can get it for around £90.
This will let me put 4 other inputs into the same serial "daisy chain" - Innovate call this their Modular Tuning System (MTS).
The RPM input is straightforward but does anyone know what the throttle position sensor output on an R1 is like voltage wise?
I would test it myself with a multimeter but I'm away from home.
Also are there any other decent (cheaper?) alternatives that other people are using?
I don't mind breaking out my soldering iron, I'm ok with basic PCB stuff (not really tooled up for SMT). However there is always the time
spent vs cost saving ratio to consider.
Any experiences you guys can share would be appreciated.
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bram boekestein
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| posted on 8/5/10 at 06:00 PM |
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TPS signal is measured in impedance (Ohm), not voltage. It's simply a potmeter.
[Edited on 8/5/10 by bram boekestein]
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hobbsy
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| posted on 8/5/10 at 06:23 PM |
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I know the TPS is a pot but I thought that in much the same way that a fuel level sender (for example) varies resistance that the output is a voltage
which has been reduced by that varying resistance?
So you'll put 12V on its input then measure the output voltage? It will then give a voltage which corresponds to 0% throttle all the way up to
another (higher or lower) voltage that is 100% throttle.
If its a linear potentiometer then this will be a linear relationship.
What I need to know is the range of voltages that are seen on the 5PW R1 TPS pot to check if they are within the input range of this Innovate SSI-4.
Also assuming that this is the best piece of kit for me to use for this application.
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Moorron
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| posted on 8/5/10 at 06:26 PM |
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i didnt want to spend a load of money either so i got myself a screen capture program and took my laptop out and drove about for an hour. With
logworks displaying real time data for my fueling and power commander showing the throttle and revs i recorded some info. after watching it back i
could sort out the fueling but its not quick. i first did 100% throttle test, adjusted and retested until i was happy with the results, then i did
light throttle stuff to get rid of bunny hopping when cruising. i havent really done much else as it does eat up you weekend but im happy the engine
wont be damaged from running to lean and also happy the car behaves itself around town.
i think i used fraps to screen captur which you have to buy but i thought i was a locost way of doing it.
i will get it tuned on a rolling road this year to get the most power out of it.
just an idea
Sorry about my spelling, im an engineer and only work in numbers.
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hobbsy
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| posted on 8/5/10 at 06:38 PM |
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Moorron,
Interesting locost way of doing it.
But as you say probably a lot more time consuming that what you could do if you got all the data into logworks at once.
I don't know if my old PowerCommander 3R software shows you the revs and throttle in real time when you're connected and driving as
I've never tried it. It probably does.
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matt_gsxr
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| posted on 8/5/10 at 07:54 PM |
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Hey there,
You should be able to pick up a voltage from the TPS sliding contact and it will be linear. One issue will be correcting it for the battery voltage
as it may not be driven by a regulated supply. Presumably if you use 2 of the SSI-4 inputs (one for each of the non-grounded TPS pins).
It may be that the ECU on the R1 contains a resistor in parallel with the TPS. This is a trick to make the TPS non-linear (someone here told me that
trick), but if you sample the TPS wiper voltage it will take this into account.
The alternative is to add an additional potentiometer on the throttle pedal that you log with the SSI-4. I did this when I was using my megasquirt as
a datalogger (trying to get carbs working nicely). You could use a megasquirt for the job you are doing. Same price as Innovate stuff, although
logging rate is slower (70ms) for MS1.
Matt
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MikeRJ
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| posted on 9/5/10 at 06:13 AM |
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quote:
Originally posted by hobbsy
What I need to know is the range of voltages that are seen on the 5PW R1 TPS pot to check if they are within the input range of this Innovate
SSI-4.
This depends entirely on the reference voltage that the R1 ECU uses for the TPS. Very often ECUs use a 5v reference, but I couldn't guarantee
the R1 does so measuring would be the safe option.
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hobbsy
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| posted on 9/5/10 at 09:20 AM |
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TBH dudes the timescales are such that I've already ordered it. If the TPS output is out of scale I can deal with it with some electronics
(worse case scenario).
I'll let you know how I get on.
[Edited on 9/5/10 by hobbsy]
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