[wnta1ss]

Originally Posted by cjperformance

Todo:
- Reduce the timing from 16-17 advance at WOT, and will probably end up around 14-15 from what I'm seeing. Manifold Air Temps def play a role in how likely the KR is. I think there is a scaling factor or table for that I can play with. Much worse KR when it was 88 ambient w/ 130-150 MAT. With 70 ambient and 110-120 MAT, much less KR.
- Try to get PE lambda down to .825 or even .800 without exceeding 6 ms inj pulse width.

Agree that pulling a couple degrees of spark in the area of concern is worth a try.

Your screenshot shows .83 on the wideband, not that far from what you're seeking. Small PE adjustment would probably get there.

Any new track results after your tuning work?

[cjperformance]

Sadly, no. Prob wont get to a track until oct 8th. Wasnt able to do any of the todos today. Hopefully tomorrow or sunday.

[danhr]

Originally Posted by cjperformance

Ok... big temperature change between Monday and today, so hard to compare seat of the pants feel. Obviously feels much more powerful today at 64 deg F instead of 88 degrees, so not quite an apples to apples comparison.

Updated the enable torque tables. PE is now occurring throughout the full RPM range at WOT... or 70% and higher...

Couple of things. Inj pulse width ms is around 5.8 AND there's still some knock retard in the upper rpm range.

Looking for input on how to approach.

Option #1 - Increase PE for that range... try to get closer to .82 lamda. With inj pw already at 5.8... not sure how much further I can push that.

Option #2 - Pull timing from the base table at those rpms/load.

My thoughts... since I'm a noob... start by pulling timing by 2 degrees at those rpms, may actually get more power if I'm already past the peak supportable ign timing? Pulling timing cant hurt at least. It's safe.

After the above, verify if KR goes away.

If yes, then maybe modify the PE tables to increase enrichment by a small amount... maybe .5%??? Not sure what the effective relationship is between a .5% or 1% increase to the PE tables will have on injector PW. My understanding is that above 5ms is "a lot", but could maybe push to 6.2 ms if the SOI is already adjusted (based on input I've received)

Procharger modified the SOI, but not sure if it was modified enough to support 6.2ms inj pulse width.

So... asking myself, what am I trying to get out of this right now???? I think I need to be happy with the power level, whatever it is at WOT until I upgrade fueling.

I want to change a few things so its safe, but effective. Feel like I'm close. With the Knock Retard showing its ugly head, I'm probably at the limit for timing at WOT. Earlier in the thread it was mentioned to zero out the static retard. This was done in the canned tune, so we are good there. I have to think its real knock, and dangerous.

Other than that, would like to "brighten up" the part throttle feel. Thinking I might be able to do that with some small timing experimentation in the part throttle ranges.

Attached a shot of a section of the log. LMK if anyone is interested in seeing/knowing more. My goal is to help others in the same situation.

From my eyes, it looks like you are hitting torque management and your knock is the computer pulling timing to make the shift

and you are running out on your low side. (this could also be a reason it is pulling timing out)

[cjperformance]

Originally Posted by danhr

From my eyes, it looks like you are hitting torque management and your knock is the computer pulling timing to make the shift

and you are running out on your low side. (this could also be a reason it is pulling timing out)

Thanks, I'll look into that. I see where it pulls timing for the shift, but I had thought that would manifest in the actual Timing Advance value, and not in the knock retard.

The more dialed in I get things, the more my low-side fuel is dropping too. Will look at addressing that soon.

[cjperformance]

Updates:

Seat of the pants, and lack of traction, tells me I'm making improvements in power. It's a warmer day today than two days ago when I last tested, and going WOT at 30 to 40 mph is resulting in tire spin at times now. Feels stonger with less timing actually. Have to be a bit more careful

My changes between two days ago and today:
Made some addl changes to retune the MAF at higher rpms. I think some of my other changes, and/or lower temperatures, are causing the engine to suck more air, because I was hitting MAF/RPM values, I didn't hit before way up high.

EQ Ratio/Lamda is pretty much spot-on now between commanded and actual. Commanded is .845 and actual is between .835 and .855 at WOT w/ PE. I know I gotta get that down at least around .825 for safety.

Dropped ignition timing by a couple degrees. Previous canned tune was 13-17 (scaled) between 4200 and 6400 rpm.

I rescaled that to 13-12.5 across the board in that rpm range. See image. Actually decreasing timing in the upper RPM w/ more boost. Engine seems to like that. Did several runs, and settled here as the best of what I tested.

With spark dialed back and knock retard almost completely gone, I can focus on getting the PE down a little, but kinda sketchy if fuel is going to hold out. I'm around .835 at 5200 rpm up to 6400 at WOT, and low side fuel is dropping to 37 psi at the lowest. High side is staying up over 2,000... so.... ???? Not much I can do until I get LT4 fueling I think?

[cjperformance]

Also, my dsx baro breakout w 3 bar just arrived. Who wants to help me open that can of worms?

[wnta1ss]

Originally Posted by cjperformance

Also, my dsx baro breakout w 3 bar just arrived. Who wants to help me open that can of worms?

If your 3-BAR MAP sensor is the red-top GM part from the C6 ZR1 (12592525) then the tune values for it in Engine>Airflow>General are:

MAP Sensor Linear 312.50 kPa

MAP Sensor Offset -11.25 kPa



As far as mounting the breakout harness with a 1-BAR sensor on it, I just made sure that the pressure nipple was open to the atmosphere and was pointing downward.

[cjperformance]

Originally Posted by wnta1ss

If your 3-BAR MAP sensor is the red-top GM part from the C6 ZR1 (12592525) then the tune values for it in Engine>Airflow>General are:

MAP Sensor Linear 312.50 kPa

MAP Sensor Offset -11.25 kPa



As far as mounting the breakout harness with a 1-BAR sensor on it, I just made sure that the pressure nipple was open to the atmosphere and was pointing downward.

Will i need to extend out any of the tables that use MAP? Dont need to do VVE since its MAF only right now. But there are other tables that use MAP.

Its pn 55567257. Basically same thing. Dsx gives same values as the one you mention. Just didnt know if there were tables to rescale or not.

[wnta1ss]

Originally Posted by cjperformance

Will i need to extend out any of the tables that use MAP? Dont need to do VVE since its MAF only right now. But there are other tables that use MAP.

Its pn 55567257. Basically same thing. Dsx gives same values as the one you mention. Just didnt know if there were tables to rescale or not.

Those parameters were the only ones where I had entered those 2 values for mine.

[cjperformance]

Im kinda concerned about running the car with the fuel pressure drop on low side. Especially with cooler weather coming, and more fuel needed at colder temps. Already riding the line.

I am looking at lt4 fueling, but wondering if there are other things i can do for the short term. Been trying to learn about the fscm and whether or not there are tweaks i can do there to band aid things a bit until i get the lt4 fueling. Am i going to need to unlock that anyway if i install lt4 low side pump?

Heard about others using a low side fuel pump voltage booster to make things better, even if its not a perfect fix...

Today's agenda... install the 3 bar map and do some more logging. Going to try a few more ignition timing tweaks, and increase the PE. Watch the fuel pressure.

Anyone know of indepth info you can pointme to about switching to lt4 fueling? I think im going to need the 8 injectors, high side pump, low side pump. Ive also seen mentioned about replacing the hp fuel supply pipe whenever injectors are swapped?

[Joshinator99]

Originally Posted by cjperformance

Im kinda concerned about running the car with the fuel pressure drop on low side. Especially with cooler weather coming, and more fuel needed at colder temps. Already riding the line.

I am looking at lt4 fueling, but wondering if there are other things i can do for the short term. Been trying to learn about the fscm and whether or not there are tweaks i can do there to band aid things a bit until i get the lt4 fueling. Am i going to need to unlock that anyway if i install lt4 low side pump?

Heard about others using a low side fuel pump voltage booster to make things better, even if its not a perfect fix...

Today's agenda... install the 3 bar map and do some more logging. Going to try a few more ignition timing tweaks, and increase the PE. Watch the fuel pressure.

Anyone know of indepth info you can pointme to about switching to lt4 fueling? I think im going to need the 8 injectors, high side pump, low side pump. Ive also seen mentioned about replacing the hp fuel supply pipe whenever injectors are swapped?

Tuning the FSCM can help to some extent but don’t expect any miracles. You could probably add a JMS voltage booster to the LT1 in-tank pump to get more out of that. And you can obviously continue to use that when you change to the LT4 in-tank pump.

The LT4 in-tank pump is pretty cheap and is needed first. You can definitely do that without doing the rest of the fuel system at this point.

The LT4 HPFP will be the next weak link. You should replace the high pressure pipes every time you interrupt them (two pipes, maybe $75 for both, see attached). I would also recommend the LPE high flow check valve to replace the very restrictive LT1 version. You’ll then do the LT4 injectors when you do the LT4 fuel pump because the operating pressure is higher (2900 LT4 vs 2175 LT1). Adding a cam at some point will let you get 32-40% more out of the HPFP.

[cjperformance]

Originally Posted by Joshinator99

Tuning the FSCM can help to some extent but don’t expect any miracles. You could probably add a JMS voltage booster to the LT1 in-tank pump to get more out of that. And you can obviously continue to use that when you change to the LT4 in-tank pump.

The LT4 in-tank pump is pretty cheap and is needed first. You can definitely do that without doing the rest of the fuel system at this point.

The LT4 HPFP will be the next weak link. You should replace the high pressure pipes every time you interrupt them (two pipes, maybe $75 for both, see attached). I would also recommend the LPE high flow check valve to replace the very restrictive LT1 version. You’ll then do the LT4 injectors when you do the LT4 fuel pump because the operating pressure is higher (2900 LT4 vs 2175 LT1). Adding a cam at some point will let you get 32-40% more out of the HPFP.

Awesome info! Thanks!

[KingLT1]

If you have the fuel system module licensed go into the sytem/general/ fuel system minimum and up the voltages from 14.7 to 15.5 from about 159 lb/hr on up.

Next set the Diag System Voltage low to 12.5v.

Then go to fuel system/fuel pressure/ Normal and set it to 50.8psi.

See if that helps your low side out.

[cjperformance]

Originally Posted by wnta1ss

Those parameters were the only ones where I had entered those 2 values for mine.

I always need to know the why's on things... So my question is why dont we need to update all the tables that rely on MAP.

Kind of a random brainstorm here... hopefully my ravings make sense.

So, I think the answer is that you can update the MAP characteristics as described above, and it will read accurately without scaling other tables that rely on MAP.

What keeps from having to adjust all the tables that rely on MAP is the MAP Estimation Max/Min. In another forum, I read that any values above or below those values respectively will get "clipped" back to those values for reading form those tables.

So... with 3 bar reading... say 150 kpa will actually be truncated/clipped/whatever back to 105 for cross reffing in the tables...

Now, if I were to update those min/max values.... then I think there could be some table scaling required, as I imagine it will expect values in those tables that correspond to the actual values. Then again... however... even if those tables are NOT changed along with est max... I suspect that it would still use the highest/last values in the table. So if it tried to look up a value at 150kpa in a table, and the highest value/row in the table is 105kpa... then it would probably use that row.