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Your Thoughts pls on some AFR results http://www.gt4dc.co.uk/forum/viewtopic.php?f=13&t=6571 |
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Author: | **BETSY** [ Sun Jun 09, 2013 12:00 am ] |
Post subject: | Your Thoughts pls on some AFR results |
Having run my st165 today at SRR i came away wiuth less BHP than expected and a lean running car!? since the car was mapped back in 2009? i have adjusted the TPS into spec re st205 spec, assumed the PFC is looking for this spec to work as its a Plug and Play ecu? also the car comes on and off Idle correctly as it should now. I have also got a better voltage at the ecu and systems since it was mapped, all be it not a huge amount more. Im left with the car running into the 13's for AFR....My question is could me adjusting the TPS have caused this, im thinking the answer is YES.. 375 BHP before adjustment 346 After adjustment Graphs can be found in the link below. It looks like the whole fuel table has shifted? http://www.flickr.com/photos/69betsy69/ ... 007787619/ |
Author: | TrackToyFour [ Sun Jun 09, 2013 12:50 am ] |
Post subject: | Re: Your Thoughts pls on some AFR results |
If you mean that you have changed the TPS angular zero point reference then I can imagine this would potentially offset the fuel map Steve. I'm sure others will be along soon with additional comment! |
Author: | Nibbles [ Sun Jun 09, 2013 9:20 am ] |
Post subject: | Re: Your Thoughts pls on some AFR results |
More likely is changing the voltage at the ecu as it applies dead time correction for the injectors. Higher voltage makes the injectors open quicker so the ecu shortens the injector pulse. normally tps is only used for 'acceration enrichment' not for steady state fueling. this highlights the need for wideband afr gauges in modified cars. Afrs in the 13s are likely engine killers. |
Author: | **BETSY** [ Sun Jun 09, 2013 9:23 am ] |
Post subject: | Re: Your Thoughts pls on some AFR results |
Hi Don, it's the only thing I can think of? Charlie said it was the Fuel pump but I disagree with that. In my experience of fuel curves and failing fuel pumps or FPR is the AFR graph is a bit like a banana in as much as the AFR dives down when the boost comes on but then starts to go back up as the fuel pump can not keep up with demand, or another part of the fuel system. My AFR graph flat lines and actually goes a little richer right at the end. This can also be seen in the AFR graph back in 2009? |
Author: | **BETSY** [ Sun Jun 09, 2013 9:29 am ] |
Post subject: | Re: Your Thoughts pls on some AFR results |
Hi Chris, It's something I'm looking into purchasing, any one have any good or bad experiences with Wide band set-ups? Ryan has an Excel program which I believe he can use to shift fuel maps by imputing your data and it carries out a calculation and spits out the new data to be input. Any one know of such a set-up? |
Author: | two_OH_five [ Sun Jun 09, 2013 10:25 am ] |
Post subject: | Re: Your Thoughts pls on some AFR results |
Possibly a slight leak in the vac line to the turbo pressure sensor as it gets a little richer as more boost is applied I've had experience of Zeitronix wideband kit - seems OK and accurate. I had mine (zt-1) permanentlyinstalled with the Zeitronic LCD display wired up the to the PFC via datalogit so that I could log everything via a laptop when I was mapping mine. It was pretty simple apart from the non linear output of the sensor which required an equation to be fed into the datalogit software - later zt-2 models have a linear output removing this I believe I also have some Xcel spreadsheets for correcting fuelling based on logged AFR and current map - I will try to find them this evening Innovate O2 monitoring kit also seems to have a good rep. Do you by chance have maps saved from the good fuelling period? There are a few things in mapping that could cause this phenomenon - the PFC does have a TPS fuelling correction but there's a stack of others with injector size compensation being the one that jumps to mind - it's also the way to a quick fix too |
Author: | **BETSY** [ Sun Jun 09, 2013 11:16 am ] |
Post subject: | Re: Your Thoughts pls on some AFR results |
two_OH_five wrote: Possibly a slight leak in the vac line to the turbo pressure sensor as it gets a little richer as more boost is applied I've had experience of Zeitronix wideband kit - seems OK and accurate. I had mine (zt-1) permanentlyinstalled with the Zeitronic LCD display wired up the to the PFC via datalogit so that I could log everything via a laptop when I was mapping mine. It was pretty simple apart from the non linear output of the sensor which required an equation to be fed into the datalogit software - later zt-2 models have a linear output removing this I believe I also have some Xcel spreadsheets for correcting fuelling based on logged AFR and current map - I will try to find them this evening Innovate O2 monitoring kit also seems to have a good rep. Do you by chance have maps saved from the good fuelling period? There are a few things in mapping that could cause this phenomenon - the PFC does have a TPS fuelling correction but there's a stack of others with injector size compensation being the one that jumps to mind - it's also the way to a quick fix too I do indeed have the maps saved from the data Logit. Of course I'm still running the same map as 2009 If you have the xcel program that would be awesome! |
Author: | Nibbles [ Sun Jun 09, 2013 11:53 am ] |
Post subject: | Re: Your Thoughts pls on some AFR results |
Did no one spot this Nibbles wrote: More likely is changing the voltage at the ecu as it applies dead time correction for the injectors. Higher voltage makes the injectors open quicker so the ecu shortens the injector pulse. **BETSY** wrote: . . . . I have also got a better voltage at the ecu and systems since it was mapped, all be it not a huge amount more. ...... It could also be that climate conditions have changed and the other correction figures such as IAT aren't quite correct. This is why Toyota leave a large safety margin. |
Author: | two_OH_five [ Sun Jun 09, 2013 12:20 pm ] |
Post subject: | Re: Your Thoughts pls on some AFR results |
I did Chris Would make sense but only if the dead time numbers were set wrong I think I'd also expect the Afr to look different - more of a general slope as dead time vs on time ratio decreases. There is some evidence of this so it's a very plausible idea |
Author: | **BETSY** [ Sun Jun 09, 2013 8:20 pm ] |
Post subject: | Re: Your Thoughts pls on some AFR results |
So the plan is to purchase Wideband AFR gauge, do some runs on the road, then remove the secondary battery cable and see if the AFR changes! The power FC does have inj Vs voltage setting. Sent from my iPad using Tapatalk |
Author: | Nibbles [ Sun Jun 09, 2013 8:36 pm ] |
Post subject: | Re: Your Thoughts pls on some AFR results |
It would be interesting to know the outcome. I had assumed you had beefed up wiring to the ECU only rather than the injectors as well. It's surprising how much difference a volt makes in mixture terms, especially at lighter throttles. |
Author: | **BETSY** [ Sun Jun 09, 2013 9:36 pm ] |
Post subject: | Re: Your Thoughts pls on some AFR results |
I added an extra bigger cable running from the battery's original location under the bonnet to the battery in the rear. |
Author: | two_OH_five [ Sun Jun 09, 2013 10:28 pm ] |
Post subject: | Re: Your Thoughts pls on some AFR results |
I've found the xls file but it's not really very friendly for public consumption. It's a bit of a mix of rocket science and Xcel hacking and I must admit I'm struggling to remember what figures have to be stuck in which tables It's made for logging so it uses a combination of logged values weighted with the number of recorded instances, all compared to the inj and desired AFR to produce a correction and a new map suitable for hand finishing I should be able to yank the calc bit out and make it simple but it'll be tomorrow |
Author: | **BETSY** [ Sun Jun 09, 2013 10:39 pm ] |
Post subject: | Re: Your Thoughts pls on some AFR results |
That's all good, thanks matey I have purchased a wideband so will report back with my findings later in the week Sent from my iPad using Tapatalk |
Author: | two_OH_five [ Mon Jun 10, 2013 12:01 am ] |
Post subject: | Re: Your Thoughts pls on some AFR results |
Sod it, Maybe someone else can work it out Also might prove useful when you get the wideband set up and do some logging https://www.dropbox.com/s/cupe19cr1q7x0 ... 1_21xx.xls This is using live data from my last session Things that need to be filled in in the Calculations tab:- Measured AFR table Taken from FC log file :- Open Map Watch Open log file Select AFR table Select Average Copy table and paste into Xcel Samples From above chart select samples copy table and paste into Xcel Target AFR Taken from FC-Edit Select Inj Map Choose AF Ratio Copy table and paste to Xcel Current Basemap Taken from FC-Edit Select Base Map Choose Base (mSec) Copy table and paste into Xcel Sample Threshold Manually Entered Determines the weight of the correction applied Corretions based on measurements with samples < sample threshold will be scaled down I used 10 so cells which only have one measurement make little difference but with 10+ samples I was applying the whole correction Output New Basemap Corrected version of the basemap based on the AFR samples Then copy new basemap table and paste special into "new fuelling map" table. Select Values Switch to Graphical Comparisons tab Look at the new fuelling map chart. You might well see that it's a bit peaky as in the example data. Smooth it by hand - lower peaks and raise points either side to achieve a smooth curve. Again look at the example data in the xls, Original Fuelling Map was previously hand smoothed by me When you're happy switch back to the calculations page, copy the values from the "New fuelling map" table and paste into the Base map (Base msec) in FC-Edit What I'm trying to achieve Recalculate the base map so that the measured AFR closely matches the AFR table plotted in the INJ map. Once you've done that AFR changes are as simple as typing in the desired AFR in the INJ map in FC_Edit I also have a spreadsheet for calculating IGN timing but that's really really complicated |
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