ignition timing

dave_f · Jul 30th, 2005, 10:41 AM

I have a question for those of you who have a GA16DE and a TECHTOM (or any other way to monitor live ignition timning)...

what are some typical timing settings for light load crusing at around 30 mph for a stock GA?

I know what the base timing should be, but I am interested in the live ginition advance the ECU uses durring crusing under light load.
can anyone help me out?
-dave

psuLemon · Jul 30th, 2005, 03:37 PM

check out sentra.net, it might help... but if you are askin what you can set the timing at, its 15 degrees

dave_f · Jul 30th, 2005, 05:21 PM

Aer you talking about the base timing?
I am interested in the live timing the ECU uses durring light load? Crusining around 2 to 3K RPM under light load. I am trying to adjust my ignition table for better emissions. I have an emissions test coming up, and I dont know what my original ECU used for a stock value.
-dave

Quote:

Originally Posted by psuLemon

check out sentra.net, it might help... but if you are askin what you can set the timing at, its 15 degrees

wes · Jul 31st, 2005, 12:54 AM

Quote:

Originally Posted by dave_f

Aer you talking about the base timing?
I am interested in the live timing the ECU uses durring light load? Crusining around 2 to 3K RPM under light load. I am trying to adjust my ignition table for better emissions. I have an emissions test coming up, and I dont know what my original ECU used for a stock value.
-dave

Mine shows about 35 degrees at that RPM and very light throttle. It actually fluctuates but 35ish is probably the average.

dave_f · Jul 31st, 2005, 08:37 AM

Thanks Wes,
thats exactly what I was after...
Just curious what is your max timing on the top end at boost? I have monitoring EGTS and A/F and currently I have it set to 23 on the top end.
-dave

Quote:

Originally Posted by wes

Mine shows about 35 degrees at that RPM and very light throttle. It actually fluctuates but 35ish is probably the average.

wes · Jul 31st, 2005, 07:08 PM

Quote:

Originally Posted by dave_f

Thanks Wes,
thats exactly what I was after...
Just curious what is your max timing on the top end at boost? I have monitoring EGTS and A/F and currently I have it set to 23 on the top end.
-dave

I hit around 12-14 degrees of timing on the top end under boost. EGT's in the 1400's and at the end of 4th around 1500. Probe in the center of the collecter pre turbine.

aminidab · Aug 1st, 2005, 02:10 AM

I have a consult cable/software I got from here http://www.plmsdevelopments.com/consult_if.shtml

It allows monitoring/data logging of a ton of parameters. I have a bunch of data saved and a few graphs made with timing data. I'll try and post some data/graphs over the next couple days.

My EGTs are a bit higher than Wes'. I haven't done a full 4th gear run since I replaced my fuel pump( when I was running lean) but I'd estimate my EGTs to be at about 1550 at the end of 4th.

Katana200sx · Aug 1st, 2005, 07:51 AM

i haven't paid too much attention to my timing under load, but at idle mine stays between zero and -8. is this normal?

wes · Aug 1st, 2005, 11:10 AM

Quote:

Originally Posted by Katana200sx

i haven't paid too much attention to my timing under load, but at idle mine stays between zero and -8. is this normal?

Yes, it pulls or advances timing to maintain a 14.7:1 AF ratio IIRC.

dave_f · Aug 1st, 2005, 03:28 PM

Thanks Wes, thats a big help.. it gives me a ballpark to shoot for. My plan is to tune to pass emissions this week, I had to take a few steps back since I got my new injectors.

aminidab,
I would love to see some plots, I have a consult port tool too. What software are you running? I currently have SR talk and the free version of Conzult. I havent been able to get the rom trace feature to work correctly... can you trace your ignition anf fuel table?

-dave

Quote:

Originally Posted by wes

I hit around 12-14 degrees of timing on the top end under boost. EGT's in the 1400's and at the end of 4th around 1500. Probe in the center of the collecter pre turbine.

wes · Aug 1st, 2005, 04:14 PM

Quote:

Originally Posted by dave_f

Thanks Wes, thats a big help.. it gives me a ballpark to shoot for. My plan is to tune to pass emissions this week, I had to take a few steps back since I got my new injectors.

aminidab,
I would love to see some plots, I have a consult port tool too. What software are you running? I currently have SR talk and the free version of Conzult. I havent been able to get the rom trace feature to work correctly... can you trace your ignition anf fuel table?

-dave

What injectors did you switch too and also what MAF are you running?

dave_f · Aug 1st, 2005, 05:54 PM

370cc injectors up from 257cc I ran last year.
the MAF is from a 300ZX
I am running a JDM S13 sr20DE ECU with a biki daughter board.
I still havent had a chance to install my sheetmetal intake... but hopefully soon.

-dave

Quote:

Originally Posted by wes

What injectors did you switch too and also what MAF are you running?

aminidab · Aug 1st, 2005, 08:32 PM

Quote:

Originally Posted by dave_f

aminidab,
I would love to see some plots, I have a consult port tool too. What software are you running? I currently have SR talk and the free version of Conzult. I havent been able to get the rom trace feature to work correctly... can you trace your ignition anf fuel table?

-dave

The software is called Nissan Datascan, it comes with the cable I ordered. It's a pretty good program, it let's you monitor 12 sensors in real time
and do data logging.
It also has active tests and stuff like tracing the fuel maps, like you mentioned.
I haven't really used the features like rom dump and fuel map tracing though so I couldn't really tell you how well they work.

Here is a plot of timing/injector duty cycle vs RPM at 12 PSI.

Here is a plot of timing/injector duty cycle vs RPM one time when I accidentaly maxed out my injectors. Notice the fuel cut once it gets over 100% duty cycle.

One thing about these graphs though, they assume a base timing of 5. So you need to subtract 5 to get the total advance.

I can post some plots of timing at around 30 mph with my car, but it's not quite a stock GA

I also have a stock GA I could get some data from, but I wouldn't be able to do that for a week or so.

Oh also, this is with a JWT ECU and the 370cc/S14 MAF program.

wes · Aug 2nd, 2005, 01:21 PM

So you have a total of 10 degrees advance...

The techtom reads actual advance AFAIK, so I have a bit more timing than you up top bewteen 2-4 degrees.

Dave was running 20+ degrees of advance up top which is just awesome, I bet it is so responsive that way..... What kind of boost are you running Dave? I can't imagine that the motor would like that much timing with a GT28RS and 10+ PSI, but then again I have never tried...

aminidab · Aug 2nd, 2005, 02:09 PM

Quote:

Originally Posted by wes

So you have a total of 10 degrees advance...

The techtom reads actual advance AFAIK, so I have a bit more timing than you up top bewteen 2-4 degrees.

Dave was running 20+ degrees of advance up top which is just awesome, I bet it is so responsive that way..... What kind of boost are you running Dave? I can't imagine that the motor would like that much timing with a GT28RS and 10+ PSI, but then again I have never tried...

What I meant is the timing would be 10 degrees above whatever the base timing was at that point. So if I was running 10 degrees base the timing would be 20 at the top end.

It would be interesting to play with the timing and see what the results were on the dyno. I adjusted the base timing a little when I dynoed from 8 to 10.. I didn't see any difference but I was also getting detonation so it's likely the computer was pulling timing anyway.