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Re: Bigger Throttle Body, TPS reference changes!
Posted: Wed May 25, 2011 11:20 am
by charlay86
You could try changing the TPS % scaler...
check out my attached spreadsheet.
I haven't tested this yet, but if you try it please let us know how it goes.
Re: Bigger Throttle Body, TPS reference changes!
Posted: Wed May 25, 2011 12:35 pm
by charlay86
The calculations for TPS Percentage are:
16bit_TPS_% = ((((raw_TPS_voltage - TPS_zero_offset_voltage) * TPS_voltage_scaler) + 32 ) * 4) This value is limited to 65355
8bit_TPS_% = (16bit TPS % / 256) in reality it just truncates the low byte
"TPS_voltage_scaler" = 0x60 is default value (byte 0x35F9 in CKUL, 0x36F2 in CNPM)
Increasing this value should compensate for the larger TB, without having to change all of those trans settings (might still have to tweak a few)
Re: Bigger Throttle Body, TPS reference changes!
Posted: Wed May 25, 2011 3:11 pm
by gbonola
Wow, i'm am new to this, can you please simpilfy what you just sent,thanks
Re: Bigger Throttle Body, TPS reference changes!
Posted: Wed May 25, 2011 3:49 pm
by charlay86
well if the required change is 12.7% as yoda69 pointed out earlier in this thread, you can try adjusting the value from my last post from 0x60 to 0x6D.
What bin are you using?
Re: Bigger Throttle Body, TPS reference changes!
Posted: Wed May 25, 2011 3:55 pm
by The1
Hi charlay i missed that one, i have it listed as TPS Throttle Gain % calc X/163.84 and it's 8bit, so ckul stock is 0.59% gain, ive still got the TB on mine here ill give it a run this arvo and try that one out, if it works then it'l be simplier than those tables, which are working but are very fidley as there default or base tables
Re: Bigger Throttle Body, TPS reference changes!
Posted: Wed May 25, 2011 4:05 pm
by charlay86
Yeah this should have an effect on everything that uses the TPS % in the calculation.
Re: Bigger Throttle Body, TPS reference changes!
Posted: Wed May 25, 2011 4:15 pm
by Jayme
possibly including Power Enrichment... could have a negative affect there.
Re: Bigger Throttle Body, TPS reference changes!
Posted: Wed May 25, 2011 4:27 pm
by charlay86
the TPS percentage is a correlation between voltage and the size of the throttle opening.
By adjusting the gain we are just telling the PCM that the throttle is more open at a lower voltage output from the TPS.
I can't see there being too much of a problem with PE, although the Go pedal will be a bit more sensitive
Re: Bigger Throttle Body, TPS reference changes!
Posted: Wed May 25, 2011 5:33 pm
by The1
well i just did a 20min drive home, no PE but normal Trims seem the same, throttle % was different, for my usual lazy foot it usually sits at 16% but it was about 22% now, i changed that scaler from stock 0.59% to 0.69%, it's put the shift times more in sync and slip RPM seems to be better controlled, ill have to get the log off my laptop and have a look, can post up if you wish.
Re: Bigger Throttle Body, TPS reference changes!
Posted: Wed May 25, 2011 6:17 pm
by charlay86
So it had the desired effect then?
Yeah that would be good, so we can see before and after.