I have no idea why its that number either. If my data would have came up with 734 or the such, I would have assumed it was really 720 (witch makes more sence) and missing it by 14 would be reasonable error from the way I got the data. But because 784 isn't really close to any real world multiple of 45 or 90, I just went with what make thes observed data match, -784...Originally Posted by soundengineer
Wow, that really shed some light on the makeup fuel pulses. I had always though that the makeup pulses were the ecms ability to breakup the main fuel pulse into mulitiple pulses for better atomization. IE, instead of one 9ms pulse, 3 - 3ms pulses (with each pulse getting its own offset and spa applied seperatly, lol) spread out over a greater amount of time during the engine cycle.
From what Chris said, its basically just a way for the ecm to add fuel due to changes and transients after the main pulse had been delivered. Much like the old gm batch fire setups would go from syncronious to asyncronious fueling when a transient fueling couldnt wait until the next normal pulse.
That also explaines why I never saw but one fuel pulse per engine cylce in my tests... they were all steady state. Well, thats good news to me. That means the whole injector timing schem is much less complicated than I previously thought.
Also It makes me think that the makeup should be a bigger number than the normal, but somthing before the ivc point so that the fuel has time to get there. Anytime the normal matches the makeup is should in effect have the makeup pulses disabled. Also the more we retard the main pulse the less the makeup would matter. The stock tune looks to only use makeup pulses when the engine is cold and main pulse is advanced more. Which makes sence for keeping from a lean stumble on a cold engine transient.
does it work the same on an LS1?Boundary is the latest point in time that fuel can make it into the cylinder for the current injection period. It is measured in degrees AFTER TDC compression. It is also the earliest the injector can fire again after the completion of the last injection event. ie. the boundary defines the start/end of a complete injection cycle.
Normal End of Injection Target (EOIT) is the angle before the boundary (in degrees) that the normal pulse (the main pulse) should finish. The hardware calulates the start of injection time from the EOIT and the desired PW.
Makeup End of Injection Target (EOIT) is the angle before the boundary (in degrees) that the first makeup pulse should finish. Makeup pulses are extra pulses that can be injected to inject more fuel during an injection cycle rather than having to wait for the next cycle. There can be more than one makeup pulse but the makeup EOIT specifies the EOIT of the first makeup pulse.
The makeup PW minimum is a minimum PW for the makeup pulses, they cannot be shorter than this (if they are they don't happen).
So you have the boundary that defines the injection cycle, a normal EOIT that specifies the EOIT for the main pulse, and finally a makeup EOIT that specifies the EIOT for any makeup pulses that might be needed if a fuel increase is commanded during an injection cycle but after the main pulse has occurred.
Hope that helps.
Chris...
If I'm reading that correctly.. does that mean that its backwards?
meaning is normal a Negative value?
boundary is 6.5
normal is 5.55
total EOIT is 6.5-5.55=0.95?
meaning Just like the LS7 tables have 520 crank degrees on start/finish
that 6.5-5.55=0.95 would be like saying finish .95 before the 6.5
so LS1=
Boundary 585
and Normal = 85.5
finish by 499.5* for normal?
Last edited by S2H; 01-12-2011 at 11:04 AM.
-Scott -
stock LS1 cam is IVC 614 @0.006
and IVC 573 @0.050
-Scott -
I think the LS1 stuff is different as the numbers add up for the final value. The LS2/7 stuff is a little more strait forward IMO lol
Sulski Performance Tuning
2000 WS6 M6 - LS6 (long block, refreshed top end), 10.8:1 CR, 90 mm ported FAST, Exo-Skel, 227/232 cam, QTP HVMC, EWP, GMMG, 9" w/4.11s
2018 Sierra SLT 5.3L A8 - Airaid intake tube, GM Borla catback, L86 Intake/Ported TB
per the description on HPT:
Boundary: Fuel injection delivery boundary as a number of reference points after TDC
Normal: The end of injection target measured in reference periods after the injection boundary that the normal injection pulse should finish.
Makeup: [same as normals description]
Last edited by Wnts2Go10O; 01-12-2011 at 04:09 PM.
Just got done with some final checks on my car. The only difference I noted was the fact that this made the car have trouble idling when warm. It also hurt warm restarts. I saw no different in power and no difference in timed runs per gear. Fueling also did not move enough to say "yeah it made a difference". I also could tell no difference in the exhaust smell at idle like some can. I am leaving mine set at stock.
Sulski Performance Tuning
2000 WS6 M6 - LS6 (long block, refreshed top end), 10.8:1 CR, 90 mm ported FAST, Exo-Skel, 227/232 cam, QTP HVMC, EWP, GMMG, 9" w/4.11s
2018 Sierra SLT 5.3L A8 - Airaid intake tube, GM Borla catback, L86 Intake/Ported TB
Did you use new or true normal.
I had similar results with true. Seemed to reduce gas smell though and idle was rough col and warm. Blipping the throttle also caused RPMs to dip below 700 when they fell back down. Throttle response seemed sluggish as well. We have similar cams it looks like.
I'm going to try new normal and add some air to idle and RAF.
I didn't use the spread sheet so I don't know what is what.
I tried several values for EOIT:
-EVC at 0.050" (EOIT in º ~370º) 6.322 in normal table
-EVC at 0.020" (EOIT in º ~385º) 6.488 in normal table
-EVC at 0.020" + 15º to allow injection to start after the exhaust valve is <0.020" open (6.65 in the normal IIRC, EOIT in º ~400º)
The gas smell is hard to tell, car stinks anyway lol
I attempted to adjust the RAF with no luck. The idle airflow was jumping around quite a bit. May be a timing related issue, but I didn't feel like messing with all that when the car was running just fine. If anything I will change cold start, seemed to help there, but I will have to try with the normal tune in there as it may have just been my wishful thinking.
Sulski Performance Tuning
2000 WS6 M6 - LS6 (long block, refreshed top end), 10.8:1 CR, 90 mm ported FAST, Exo-Skel, 227/232 cam, QTP HVMC, EWP, GMMG, 9" w/4.11s
2018 Sierra SLT 5.3L A8 - Airaid intake tube, GM Borla catback, L86 Intake/Ported TB
I noticed that I had to remove about 10% from my fueling when I moved mine up into the low 6's with my cam...
make sure you revisit fueling and see if your results are the same
I'm sure you double checked AFR/fuel trims, but I know that some people may not remember to double check it.
-Scott -
I did, WB was in the whole time and it did not move an amount that I can confidently say it did something. Idle, light load cruising RPM and on a 2000-3000 RPM high load pull it was "the same" for the most part.
Sulski Performance Tuning
2000 WS6 M6 - LS6 (long block, refreshed top end), 10.8:1 CR, 90 mm ported FAST, Exo-Skel, 227/232 cam, QTP HVMC, EWP, GMMG, 9" w/4.11s
2018 Sierra SLT 5.3L A8 - Airaid intake tube, GM Borla catback, L86 Intake/Ported TB
with the SS i saw a ~6-7 point swing (in stft's) from rich to lean.
a thread i ran into doing some searching on the subject. they are asking similar questions we are: http://www.efi101.com/forum/viewtopic.php?t=1341
a document on the Ford system and how they reference off the IVC. they also point out that of course, 1 degree of cam rotation is 2 degrees of crank rotation:
http://fordfuelinjection.com/files/T...tor_Timing.pdf
this one i think is significant because it shines a little light on how we probably should go about it.
Yeah, but most of the numbers we discuss are in º BTDC or ATDC in reference to the crank.
Looking at the efi101 course, it looks like they are injecting near the end where the intake valve is closing and getting better results ending earlier and earlier. That would make sense as the velocity is so low near BDC that you are getting poor fuel mixing.
Still trying to comprehend the Ford document. I have seen that posted before but never really read it in depth.
Sulski Performance Tuning
2000 WS6 M6 - LS6 (long block, refreshed top end), 10.8:1 CR, 90 mm ported FAST, Exo-Skel, 227/232 cam, QTP HVMC, EWP, GMMG, 9" w/4.11s
2018 Sierra SLT 5.3L A8 - Airaid intake tube, GM Borla catback, L86 Intake/Ported TB
ttt to see if anyone has gotten anything definitive
Hitting the dyno Wednesday morning with a vette and my car in the evening....
weather permitting that is
-Scott -
Just an update for everyone.
Yesterday I was able to play with a 2003 Corvette on the dyno...
I moved the Injector Boundary Normal to a later event time.
What I noticed is that the vehicle gained torque until the point where the injectors really were spraying for more time than the valve was open...
it still increase a little as the rpm's went up but it was drastically less improvement in the upper rpm's
we gained around 10~15 ft-lbs of torque down low and 5~7 up top just from pushing the "Normal" value to a higher value
with his car, the cam is a 236 ish duration and it stopped making any improvements past 6.5 normal... I was moving in .25 increments
we still gained a hair more above that, but it could have been tire flex or other small fuel difference factors from run to run.
I didint play with it any more than that as we were already late in the day and I needed to get some street tuning done and we had already for the most part finished up the tune and werent gong to nit-pik over 1 or 2 horsepower
but moving the Injector EOIT to a later point with a cam, improved the torque across teh board...more noticeably down low in the RPM Range
-Scott -
So you weren't moving this based on the formula in the spreadsheet?
Did the end numbers come close to what the spreadsheet calculated for new or actual EOIT?
I didnt have exact cam specs for his cam...he didnt remember it and didnt have his cam card.
It seems to match up with where the valve events should be at
-Scott -
So it should be close to "actual"? Do you remember what value you ended with?
What injectors did he have?
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