Timing advance
10-16-2005, 08:41 AM
#1
Timing advance
My high RPM ignition timing went from 22º to 30º according to the OBD-II scanner. 
I also seem to have alot more low end torque now, but an 8º advance at the top is probably too much and I might have to back it off a bit. I do not know what the timing curve looks like
More to come later, after I can really prove it worked.
The base timing has not been changed and is still at 17º.
I also seem to have alot more low end torque now, but an 8º advance at the top is probably too much and I might have to back it off a bit. I do not know what the timing curve looks like
More to come later, after I can really prove it worked.
The base timing has not been changed and is still at 17º.
10-16-2005, 02:36 PM
#9
Originally Posted by SR20DEN
My high RPM ignition timing went from 22º to 30º according to the OBD-II scanner.
I also seem to have alot more low end torque now, but an 8º advance at the top is probably too much and I might have to back it off a bit. I do not know what the timing curve looks like
More to come later, after I can really prove it worked.
The base timing has not been changed and is still at 17º.
I also seem to have alot more low end torque now, but an 8º advance at the top is probably too much and I might have to back it off a bit. I do not know what the timing curve looks like
More to come later, after I can really prove it worked.
The base timing has not been changed and is still at 17º.
10-16-2005, 03:06 PM
#11
Originally Posted by SonicDust187
Now I see how you getting so much timing. Leaning out those injectors does wonders. 
I gained power and torque everywhere on the dyno except the peak which takes a huge dip down before going back up. I can only attribute this to WAY too much ignition advance. Soon I'll try a much thicker concentration of 110 octane and the colder NGK plugs.
10-16-2005, 04:50 PM
#14
Ah, interesting. I thought perhaps you had gotten the EU because I seem to remember you making mention a while ago of testing it out eventually, but now I see what you're doing.
Will you be posting before/after timing curves when you're done dyno testing? This would be good information to take a look at...
Will you be posting before/after timing curves when you're done dyno testing? This would be good information to take a look at...
10-16-2005, 05:36 PM
#16
Originally Posted by i30dvr
so how do you advance the timing on our engines? different injectors? tuning?
10-16-2005, 05:49 PM
#17
Or you could just run +0.5 BAR of fuel pressure which is easier to do on return style fuel systems.
I will also have some data on a DE-K or two within the next few weeks. I want to see the timing curves but they will be text logs from OBD-II data logging. Perhaps I can throw them into an excel spreadsheet and spit out a line graph.
I will also have some data on a DE-K or two within the next few weeks. I want to see the timing curves but they will be text logs from OBD-II data logging. Perhaps I can throw them into an excel spreadsheet and spit out a line graph.
10-16-2005, 07:29 PM
#19
Originally Posted by SonicDust187
How can we run 0.5 extra bar of fuel? We cant exactly use a FMU. Well the NA guys cant.
http://cgi.ebay.com/ebaymotors/Megan...spagenameZWD1V
This is what we are going to install on Sloppymaxs car when we convert it to returnless and raise his FP to 3.5 BAR.
10-16-2005, 07:47 PM
#20
Kind of OT, what OBDII scanner do you use? I have been interested for a long time to get one. I was tempted to buy the one that used the Consult port, but I rather get the OBDII one so I can use on other cars.
And what kind of Dynojet does the place you go to have?
And what kind of Dynojet does the place you go to have?
10-16-2005, 08:51 PM
#21
Originally Posted by SR20DEN
http://cgi.ebay.com/ebaymotors/Megan...spagenameZWD1V
This is what we are going to install on Sloppymaxs car when we convert it to returnless and raise his FP to 3.5 BAR.
This is what we are going to install on Sloppymaxs car when we convert it to returnless and raise his FP to 3.5 BAR.
Originally Posted by i30dvr
so how do you advance the timing on our engines? different injectors? tuning?
Originally Posted by SonicDust187
Run bigger injectors then stock and then use SAFC to take out fuel.
So if you do the 3.5 swap, you're already using bigger injectors, all you would need to do is adjust the A/F ratio??
10-16-2005, 09:26 PM
#22
advancing timing by using an AFC, that's interesting. i may just have to get rid of my jwt ecu (does TS make L-spec ECU's for '95 max?) and get an AFC.
so sr20den, to lower the timing up top, do you just add more fuel w/ the AFC?
so sr20den, to lower the timing up top, do you just add more fuel w/ the AFC?
10-16-2005, 10:45 PM
#23
Originally Posted by aznsap
advancing timing by using an AFC, that's interesting. i may just have to get rid of my jwt ecu (does TS make L-spec ECU's for '95 max?) and get an AFC.
so sr20den, to lower the timing up top, do you just add more fuel w/ the AFC?
so sr20den, to lower the timing up top, do you just add more fuel w/ the AFC?
http://www.technosquareinc.com/limited.htm
They feature:
- 7100 Rev Limiter (500rpm Increase)
- Speed Limiter Removal
- Drive By Wire Re-mapping
4th gen SE's don't have a speed limiter and don't have drive by wire.
10-16-2005, 10:45 PM
#24
Originally Posted by SR20DEN
Or you could just run +0.5 BAR of fuel pressure which is easier to do on return style fuel systems.
I will also have some data on a DE-K or two within the next few weeks. I want to see the timing curves but they will be text logs from OBD-II data logging. Perhaps I can throw them into an excel spreadsheet and spit out a line graph.
I will also have some data on a DE-K or two within the next few weeks. I want to see the timing curves but they will be text logs from OBD-II data logging. Perhaps I can throw them into an excel spreadsheet and spit out a line graph.
Originally Posted by SR-71 Blackbird
I wasn't aware that you could simply get bigger injectors, then adjust the A/F via the SAFC to advance the timing. How does that work? I don't understand how using bigger injectors and adjusting the A/F ratio would affect ignition timing.
10-17-2005, 03:35 AM
#25
The self-learn fuel trims take effect in closed-loop only. Both the a/f ratio and ignition timing both use a feedback system during closed loop so any change you make on the s-afc below 40% throttle will be useless. In open loop X millisecond injector pulse width and Y RPM will get you Z degrees advance @ BTDC based on a stored map. Less MAF voltage via pulling fuel with the S-AFC means smaller injector pulse width which means more timing advance. So to compensate for the smaller injector pulse width, you need to either get injectors that flow more or bump up the fuel pressure.
10-17-2005, 05:35 AM
#26
Originally Posted by Kevlo911
Kind of OT, what OBDII scanner do you use? I have been interested for a long time to get one. I was tempted to buy the one that used the Consult port, but I rather get the OBDII one so I can use on other cars.
And what kind of Dynojet does the place you go to have?
And what kind of Dynojet does the place you go to have?
We don't have a DynoJet and that is partially why I don't post numbers from it. Once I get to a certain point on this dyno I'll go to an Internet Dyno (DJ248) to get numbers I can post.
Our Mustang Dyno reads much lower than a DynoJet, which most do. However there is a Mustang Dyno somewhere in NY that reads much higher and there area few .org members posting numbers from it, thinking they've done something miraculous.
www.p1auto.com
10-17-2005, 05:42 AM
#27
Originally Posted by nismology
The self-learn fuel trims take effect in closed-loop only. Both the a/f ratio and ignition timing both use a feedback system during closed loop so any change you make on the s-afc below 40% throttle will be useless. In open loop X millisecond injector pulse width and Y RPM will get you Z degrees advance @ BTDC based on a stored map. Less MAF voltage via pulling fuel with the S-AFC means smaller injector pulse width which means more timing advance. So to compensate for the smaller injector pulse width, you need to either get injectors that flow more or bump up the fuel pressure.
This is the answer folks.
But you do wan't to adjust the low throttle settings with the piggyback to get the fuel trims as close to zero as you can.I have been trying to prove this for quite some time but none of you people wanted to sell me a set of DE-K injectors to test this.
However the SAFC-II isn't complicated enough to get all of the tuning points where I need them to be. I still have a few lean spots at certain RPM ranges under part throttle. And sometimes when the car is cold started I have to run around with a 10-11:1 A/F ratio at low throttle/low RPM as if the long term fuel trims have been reset. But it only takes a few minutes for the short term fuel trims to correct themselves.
10-17-2005, 05:47 AM
#28
Originally Posted by aznsap
advancing timing by using an AFC, that's interesting. i may just have to get rid of my jwt ecu (does TS make L-spec ECU's for '95 max?) and get an AFC.
so sr20den, to lower the timing up top, do you just add more fuel w/ the AFC?
so sr20den, to lower the timing up top, do you just add more fuel w/ the AFC?
Also my fuel computer now averages between 35-45mpg.
10-17-2005, 08:03 AM
#29
Originally Posted by SR20DEN
I was at -8% on the SAFC-2 from about 6400 on and with the 75cc injector difference I am now at -28%, which added approx. 8º of timing advance in that area.
10-17-2005, 08:10 AM
#30
Originally Posted by SR20DEN
Originally Posted by nismology
The self-learn fuel trims take effect in closed-loop only. Both the a/f ratio and ignition timing both use a feedback system during closed loop so any change you make on the s-afc below 40% throttle will be useless. In open loop X millisecond injector pulse width and Y RPM will get you Z degrees advance @ BTDC based on a stored map. Less MAF voltage via pulling fuel with the S-AFC means smaller injector pulse width which means more timing advance. So to compensate for the smaller injector pulse width, you need to either get injectors that flow more or bump up the fuel pressure.
But you do wan't to adjust the low throttle settings with the piggyback to get the fuel trims as close to zero as you can.I have been trying to prove this for quite some time but none of you people wanted to sell me a set of DE-K injectors to test this.
However the SAFC-II isn't complicated enough to get all of the tuning points where I need them to be. I still have a few lean spots at certain RPM ranges under part throttle. And sometimes when the car is cold started I have to run around with a 10-11:1 A/F ratio at low throttle/low RPM as if the long term fuel trims have been reset. But it only takes a few minutes for the short term fuel trims to correct themselves.
This impression was based on doing some comparisons of WOT a/f data before/after my 00VI swap, meaning that although I switched to larger injectors, my WOT a/f ratios seemed to be roughly the same as with stock 4th gen size. If no correction was taking place, wouldn't I have been richer under WOT after switching injectors? However I'm not 100% sure as my FPR seems to be acting up recently and it's possible I may have had slightly different fuel pressure even back then.
Either way I got the gist of what you were doing... the basic principle is getting the ECU to move to a different point on the timing map (ie for the same rpm move to a pulsewidth where there is more advance).
And ya that was one thing I was going to ask in my previous post and forgot - whether the SAFC-II could provide enough resolution to get beyond a coarse level of tuning. Sounds like maybe not... you only have 8 setpoints to work with, right?
10-17-2005, 08:43 AM
#32
Oh ok you're right.. Apexi's site says 12. Last time I just googled it and it went to some speed shop's page where the description said 8.
Also, I just edited my last post to include a little explanation of why I was under the impression the LT fuel trims are applied to the base WOT table... here's what I said (I'll repost it since we're now on another page):
Any comments? I understand what SR20 is doing but this question of fuel trims being applied or not applied to WOT has been lingering in my mind for a while now...
Also, I just edited my last post to include a little explanation of why I was under the impression the LT fuel trims are applied to the base WOT table... here's what I said (I'll repost it since we're now on another page):
Originally Posted by DandyMax
I was under the impression that the basic LT fuel trim learned during closed loop is still applied to the base WOT table to provide some compensation for changes to the system over time. Are you positive this is not the case?
This impression was based on doing some comparisons of WOT a/f data before/after my 00VI swap, meaning that although I switched to larger injectors, my WOT a/f ratios seemed to be roughly the same as with stock 4th gen size. If no correction was taking place, wouldn't I have been richer under WOT after switching injectors? However I'm not 100% sure as my FPR seems to be acting up recently and it's possible I may have had slightly different fuel pressure even back then
This impression was based on doing some comparisons of WOT a/f data before/after my 00VI swap, meaning that although I switched to larger injectors, my WOT a/f ratios seemed to be roughly the same as with stock 4th gen size. If no correction was taking place, wouldn't I have been richer under WOT after switching injectors? However I'm not 100% sure as my FPR seems to be acting up recently and it's possible I may have had slightly different fuel pressure even back then
10-17-2005, 08:58 AM
#33
Hmmmm...that's interesting. I see what you're saying now. Yea, if there was no correction made and the injector pulse width stayed the same the a/f ratio should've been more rich with the DE-K injectors. If that's the case, this whole idea could go down the tube.
:goes to reread the EFI section of FSM:
Do you think removing battery power to the ECU resets the long term fuel trim corrections? If it did you could do before and after tests of the a/f ratio at WOT.
:goes to reread the EFI section of FSM:Do you think removing battery power to the ECU resets the long term fuel trim corrections? If it did you could do before and after tests of the a/f ratio at WOT.
10-17-2005, 09:07 AM
#34
Refresh my memory...which cars use 335cc and 390cc stock? Or are these modified OEMs?
I have a set of 350Z/DEK injectors I'd loan you, but not sell.
I have a set of 350Z/DEK injectors I'd loan you, but not sell.
Originally Posted by SR20DEN
Yup, and this is why I wanted the 335cc injectors (FBJC100), because these 390cc injectors are too big and my ignition is advanced too much.
I gained power and torque everywhere on the dyno except the peak which takes a huge dip down before going back up. I can only attribute this to WAY too much ignition advance. Soon I'll try a much thicker concentration of 110 octane and the colder NGK plugs.
I gained power and torque everywhere on the dyno except the peak which takes a huge dip down before going back up. I can only attribute this to WAY too much ignition advance. Soon I'll try a much thicker concentration of 110 octane and the colder NGK plugs.
10-17-2005, 09:46 AM
#35
These 390cc injectors were part of a Turbonetics 350Z kit which was being upgraded to 440s. I ended up with these 390s because Sharif forgot to drop off his 335cc stockers for me to purchase. I"ll probably get the 335s from him this week.
VQ30DE: 259cc
VQ30DE-K: 290cc @ 3.0 BAR (FBJC100)
VQ35DE: 315cc @ 3.5 BAR (FBJC101, FWD versions)
VQ35DE: 335cc @ 3.5 BAR (FBJC100, 350z etc.)
The '05 350Z (not the rev up engine) have a different injetor part number and I do not know if they're still 335cc.
The SAFC-II is 12 points but it's only a 12x2 map. I really need something more fine such as a 18x4 like on the DTEC-FC. www.turboxs.com
But it does do the job pretty well considering the circumstances.
VQ30DE: 259cc
VQ30DE-K: 290cc @ 3.0 BAR (FBJC100)
VQ35DE: 315cc @ 3.5 BAR (FBJC101, FWD versions)
VQ35DE: 335cc @ 3.5 BAR (FBJC100, 350z etc.)
The '05 350Z (not the rev up engine) have a different injetor part number and I do not know if they're still 335cc.
The SAFC-II is 12 points but it's only a 12x2 map. I really need something more fine such as a 18x4 like on the DTEC-FC. www.turboxs.com
But it does do the job pretty well considering the circumstances.
10-17-2005, 10:05 AM
#36
Originally Posted by SR20DEN
VQ30DE: 259cc
VQ30DE-K: 290cc @ 3.0 BAR (FBJC100)
VQ35DE: 315cc @ 3.5 BAR (FBJC101, FWD versions)
VQ35DE: 335cc @ 3.5 BAR (FBJC100, 350z etc.)
The '05 350Z (not the rev up engine) have a different injetor part number and I do not know if they're still 335cc.
VQ30DE-K: 290cc @ 3.0 BAR (FBJC100)
VQ35DE: 315cc @ 3.5 BAR (FBJC101, FWD versions)
VQ35DE: 335cc @ 3.5 BAR (FBJC100, 350z etc.)
The '05 350Z (not the rev up engine) have a different injetor part number and I do not know if they're still 335cc.
Good specs Matt, I couldn't remember these numbers to save my life. Thanks, I'll be looking into this.
10-17-2005, 01:50 PM
#38
Originally Posted by SR20DEN
That is the theory, however it may require adding more fuel than you wish to use. I was at -8% on the SAFC-2 from about 6400 on and with the 75cc injector difference I am now at -28%, which added approx. 8º of timing advance in that area.
Also my fuel computer now averages between 35-45mpg.
Also my fuel computer now averages between 35-45mpg.
10-17-2005, 03:08 PM
#39
Not to mention he could modify injector pulse width directly to correct for some of the timing advance due to MAF conditioning.
I'd really like to see what SR could do with an EU especially once we can directly advance timing.
I'd really like to see what SR could do with an EU especially once we can directly advance timing.
Originally Posted by DandyMax
The EU is 16x16... 
10-17-2005, 05:39 PM
#40
I just changed the LO/HI throttle points to 15% and 85%, from 39% and 50%. That seems to have ironed out the A/F MAP quite a bit. I am now running a zero correction across the entire low throttle map which seems to work fine with my 77mm MAF. Later on I might try setting it to 10% and 90% to see if it smooths out even more. And I am looking into getting an Auterra so I can do more data logging. Their system looks better than any of the other ones I have seen.
www.auterraweb.com
www.auterraweb.com