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Discussion Starter #1
Just an FYI, "GoatRope Garage" on youtube has some great Gen IV tuning stuff. I referenced him a lot in my tuning. I figure that after commenting in some other threads, I would post my general tuning approach here for TFNGs to consider:

------------------------- STEP 1: ----------------------------
MAF-Only Tuning: save as temporary file.
** Try to avoid sharp throttle changes for MAF only tuning, so readings are more accurate.

Temporarily disable VVE/SD via the following:
* Airflow / Dynamic: Dynamic Airflow - disable (set disable to 100 RPM, re-enable to 90 RPM).
Temporarily disable Closed Loop:
  • Fuel / Oxygen Sensors - O2 readiness ECT: disable closed loop (set to 400* F).
  • Fuel / Oxygen Sensors - LTFT (Min ECT 400* F, Max ECT 10* F).
  • Fuel / Temperature Control - Catalyst Protection (COT disabled).
Temporarily disable DFCO:
  • Fuel / Cutoff, DFCO - Clutch Fuel Cutoff (disable to 300 MPH, 8000 RPM).
  • Fuel / Cutoff, DFCO - Deceleration Fuel Cutoff (enable 400* F, disable 399* F)
  • Fuel / Lean/Fuel-Saving - DoD disable.

Setup histogram for MAF in Hz and EQ ratio.
1st Parameter, EQ error (Math)
2nd Parameter, MAF for column axis in Frequency
Make sure to copy column axis values from ECM Tuner MAF output frequency

** You may need to create two histograms for Low and High frequency MAF tables **

Once histogram populated, copy/paste "special" as percent change to ECM Tuner tables. Repeat data logs if desired, then copy / paste MAF frequency tables to original tune file.

------------------------- STEP 2: ----------------------------
VVE(speed density) Tuning: save as temporary file.
The goal is non-PE "stoich" tuning. Consider raising PE minimums, and driving in variable conditions in EACH gear to hit more load cells.

Temporarily disable MAF via the following:
* Engine Diagnostics / Airflow - MAF freq Fail (Fail High 2 Hz, Fail Low 1 hz)
* Set P0103 to fail on 1st error.
Temporarily disable Closed Loop:
  • Fuel / Oxygen Sensors - O2 readiness ECT (set to 400* F).
  • Fuel / Oxygen Sensors - LTFT (Min ECT 400* F, Max ECT 10* F).
  • Fuel / Temperature Control - Catalyst Protection (COT disabled).
Temporarily disable DFCO:
  • Fuel / Cutoff, DFCO - Clutch Fuel Cutoff (disable to 300 MPH, 8000 RPM).
  • Fuel / Cutoff, DFCO - Deceleration Fuel Cutoff (enable 400* F, disable 399* F)
  • Fuel / Lean/Fuel-Saving - DoD disable.

Setup histogram for EQ ratio and MAP.
1st Parameter, EQ Ratio
2nd Parameter, Engine RPM for column axis,
3rd Parameter, Manifold Absolute Pressure for row axis.
Make sure to copy column/row axis values from ECM Tuner VVE tables to match.

Once histogram populated, copy/paste "special" as percent change to ECM Tuner VVE tables - all four should match. Smooth out boundaries if needed. Repeat data logs if desired, then reset Closed Loop, DFCO and MAF enable settings equal to original tune file.

Use 2013 Camaro LZ1 Zone boundaries for VVE: VVE zone question, found nothing definitive on a search.
 

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Discussion Starter #2 (Edited)
For idle tuning (assuming a new, larger cam), I'd start at commanding around 15* advance for the cell values at ide range (generally, 6-1000 RPM with "airmass" between .20- .52 (g) in the idle timing table), and start with a reasonable target idle RPM - you can work down later as you dial things in. If you command to little timing, it will skew your airflow requirements in the same way if you command too much timing, it will be harder to dial in. Timing, airflow, fuel and commanded RPM all interplay with one another, so sometimes you just have to start somewhere: and I'd suggest getting your MAF sensor adjusted, commanding 15* idle advance and working from there on airflow requirements. I'd also suggest turning VVE off to help minimize the variables. Your MAF sensor has to be calibrated well for this to work (see above), otherwise you'll have big swings in cold start and closed-loop fuel trims. Bear in mind that for larger cams, your O2 sensor may NOT be accurate due to slow exhaust velocity, cam overlap, and temperature.

You will almost always have to lower your Airflow Final Minimum table a significant amount (20-40%?), as well as the ECT Multi table below it for temps below 60*. Once you feel idle is decent, I'd suggest matching the same idle cell values in your Idle Spark Advance table to the High Octane spark table to avoid big jumps in commanded timing - you can sometimes feel that in the car.

When you data log, you must data log "Idle Adaptive Advance." Every time you touch the gas, this flat-lines, but as soon as the computer realizes your idling (clutch in / neutral for us M6 guys, usually 0mph for Auto Guys); the Idle Adaptive advance starts adjusting: negative values mean it's trying to REDUCE airflow to match your target idle RPM. positive values means it's adding airflow to keep your target RPM. You will almost always be negative: reduce Airflow Final Minimums further. Remember to pay attention to your engine coolant - cold starts are different than fully warmed up and driving around town (ECT multi table vs Airflow Final Minimum table). When you notice massive "negative timing" adjustments in your data log, like JAustin does, this is a second way the computer tries to reduce your idle RPM: pulling timing. Do not add more timing back into the idle timing table; meaning don't command 30 degrees and hope that you get 15* actual - continue to lower your minimum idle airflow parameters and this will take care of itself.

If you get "flare" on cold start, where your motor winds up to 1500 RPM and then settles back down to a more normal RPM range, you will want to lower your MAF S/S Startup table: this assumes a specific MAF frequency based on temperature on cold starts before the airflow in your intake has stabilized; IIRC it's just a few seconds before it transitions to using actual MAF data. If you need to change it, do it 5% at a time. Remember this is indexed to ECT temperatures.

Once you get close and you feel your idle Adaptive advance is within a few degrees of zero oscillating pretty uniformly, your timing should be pretty stable within 5* or so as well when data logging at idle. It's better to run slightly more timing than not enough, both in the heat generated in the exhaust, mean brake torque output and idle stability - but every combo can be different due to cams, head flow, compression, fuel, etc. For Manual guys, if you run too little timing the motor will tend to stall easier. Once you get your airflow tables adjusted, you will likely be able to add another degree or two of timing back in - you can test this using the HP Tuners VCM special functions option while actively data logging.

Another way to think of this is: with the car fully warmed up, on 93 pump gas, once you command a reasonable idle timing advance and RPM (say, 15* advance and 850 RPM); drop your airflow tables by a decent margin (20%) and see what happens. If your idle adaptive advance is negative, lower those tables more. If the car stalls out, and/or your idle adaptive advance is POSITIVE, then revert back to your previous tune and lower the Airflow Final Minimum table half as much. :) If your idle surges, and these parameters are otherwise pretty close to dialed in, you'll likely want to INCREASE your "Enable RPM error" tables slightly - you want to relax the computer's attempt at controlling idle RPM with bigger cams, so wider tolerance with the RPM error tables.

Bear in mind for FLEX fuel idle and part-throttle timing, you will want to pull total timing using the flex fuel modifier table. A rule of thumb is to pull timing at idle and part-throttle ranges by 4-5* advance, as ethanol has a faster flame front than pump gas and thus reaches maximum torque faster (ie with less timing advance). You only use additional timing advance with ethanol when your engine is "octane limited," which for us is usually near or at peak engine load, or when you push the skinny pedal most of the way down. I strongly recommend you get your pump-gas tables perfect before messing with ethanol, as "riding the knock sensor" under ethanol is much more destructive due to higher chamber pressures and bad things happen.

These are my random thoughts on idle tuning, I recommend you ignore them and pay a professional. I'm only posting here so I can save my notes for posterity, etc. :p
 

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Discussion Starter #3
Here is a screenshot of my idle. Its cold out (45* F) so higher air density but the engine bay and sensors are heat soaked which throws a few things off slightly.

But I can turn off the idle adaptive advance (ie the "throttle follower" from ye days of olde) and the idle remains stable. In this scenario, I can command 18* advance and idle advance doesn't increase at all... lowering it to 12* roughens the quality and stall tendency. It just stays around 13-15* advance.

Ergo, my higher compression motor likes 14-15* advance on pump gas. If I want to smooth it out further, I need to likely reduce the response time for RPM error or idle adaptive adjustments to lessen the "hunting" people often get with cammed cars.


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Thank you! I need to get back into tuning my V. I mostly just use HPtuners now to cheat on my emissions test lol.
 

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Goat rope garage is a pretty good reference. It really helps to see him doing it with the program and being able to follow along and learn.
 
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Discussion Starter #6
Goat rope garage is a pretty good reference. It really helps to see him doing it with the program and being able to follow along and learn.
Yes - my first page of notes is basically just writing down what he says in his video on VVE tuning.

But some of our stuff is E38 specific, and that's what I came up with.

I definitely am no PatG and encourage everyone to consider him for remote tuning the bulk of your changes. He worked some magic on my fueling - but the idle was lacking (personal preference) so I did a lot of trial and error.

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Yes - my first page of notes is basically just writing down what he says in his video on VVE tuning.

But some of our stuff is E38 specific, and that's what I came up with.

I definitely am no PatG and encourage everyone to consider him for remote tuning the bulk of your changes. He worked some magic on my fueling - but the idle was lacking (personal preference) so I did a lot of trial and error.

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I like Pat as well. Good dude. I shared all my FPCM tuning findings as they relate to utilizing aux pumps. Basically, completely fix the stock pump draw down under WOT but increasing the desired pressure at various flow settings. I'm about to send him some more $$$ to get the turbo setup dialed in once I change my cam.

Thanks for posting the info you did. People can do some reading and maybe get their stuff dialed in better.
 

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I like Pat as well. Good dude. I shared all my FPCM tuning findings as they relate to utilizing aux pumps. Basically, completely fix the stock pump draw down under WOT but increasing the desired pressure at various flow settings. I'm about to send him some more $$$ to get the turbo setup dialed in once I change my cam.

Thanks for posting the info you did. People can do some reading and maybe get their stuff dialed in better.
Can you share your FPCM tips here? I know its buried in your build thread somewhere. I might need a little more pressure and new rails for the spring.

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So, pulling from my build thread and making a couple edits, here's the info for tuning the FPCM needed (IMO with and without an aux kit) to keep your FPCM from neutering your stock pumps once the aux kicks in. Remember, the FPCM has no idea the aux is installed, it thinks any and all fuel pressure comes from the in tank pumps and it's limited to pressure and pressure vs flow.

To confirm you need this......log FP commanded duty cycle on a WOT pull. If you see your duty cycle drop from 100% (or 90% if you have a bad tuner) then you also notice a fuel pressure drop.....THEN the duty cycle ramps back up because holy fuck, you're about to melt a cylinder under wot because of low fuel pressure.......this fix is for you.

I thought the "fix" might be to command more KPA on the stock pumps....don't do this....at least don't go over 480KPA, perhaps even over stock 450KPA (high flow).

What I did was revert these high pressure settings I had previously played with, back to stock. My high pressure was set to 450KPA (stock). I figured what may need to be adjusted is the FPCM's parameters of what determines high flow, or rather too high flow. When the FPCM see's high KPA it ramps the pumps down. It has no idea the Aux Pump is there so when that bad boy kicks in.....my FPCM commanded the pumps down. What I did was adjust the following:

Fuel System > Fuel Pressure > Mode Conditions > High Flow Upper

I took the ZR1 FPCM settings and pasted in 90% of what those values are. The ZR1 commands higher fuel pressure and has a higher in-basket relief valve so I didn't need 100% of what those values were.

Anyway, I did a couple of pulls and my pumps aren't commanding down at all and I don't have a pressure dip. Best thing is, I don't have to hack up a beautiful pump control harness built by DSX.

CLIFF NOTES: Copy over 90% ZR1 files into your FPCM if you have an aux pump and stop cutting DSX harnesses for hobbs switches....that's like putting a carburetor on a LSX.

I've shared this info with Pat G. and Dave Steck and a couple other tuners. Be sure your tuner knows about this and also, be prepared to pay $50 for the FPCM HPT credit.
 

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So, pulling from my build thread and making a couple edits, here's the info for tuning the FPCM needed (IMO with and without an aux kit) to keep your FPCM from neutering your stock pumps once the aux kicks in. Remember, the FPCM has no idea the aux is installed, it thinks any and all fuel pressure comes from the in tank pumps and it's limited to pressure and pressure vs flow.

To confirm you need this......log FP commanded duty cycle on a WOT pull. If you see your duty cycle drop from 100% (or 90% if you have a bad tuner) then you also notice a fuel pressure drop.....THEN the duty cycle ramps back up because holy fuck, you're about to melt a cylinder under wot because of low fuel pressure.......this fix is for you.

I thought the "fix" might be to command more KPA on the stock pumps....don't do this....at least don't go over 480KPA, perhaps even over stock 450KPA (high flow).

What I did was revert these high pressure settings I had previously played with, back to stock. My high pressure was set to 450KPA (stock). I figured what may need to be adjusted is the FPCM's parameters of what determines high flow, or rather too high flow. When the FPCM see's high KPA it ramps the pumps down. It has no idea the Aux Pump is there so when that bad boy kicks in.....my FPCM commanded the pumps down. What I did was adjust the following:

Fuel System > Fuel Pressure > Mode Conditions > High Flow Upper

I took the ZR1 FPCM settings and pasted in 90% of what those values are. The ZR1 commands higher fuel pressure and has a higher in-basket relief valve so I didn't need 100% of what those values were.

Anyway, I did a couple of pulls and my pumps aren't commanding down at all and I don't have a pressure dip. Best thing is, I don't have to hack up a beautiful pump control harness built by DSX.

CLIFF NOTES: Copy over 90% ZR1 files into your FPCM if you have an aux pump and stop cutting DSX harnesses for hobbs switches....that's like putting a carburetor on a LSX.

I've shared this info with Pat G. and Dave Steck and a couple other tuners. Be sure your tuner knows about this and also, be prepared to pay $50 for the FPCM HPT credit.
Excellent.

With the feedback you got from the online tuners, did they give you the impression it would change their other "tune" settings as far as fueling, or does this just allow for a more consistent rail pressure?
 

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Excellent.

With the feedback you got from the online tuners, did they give you the impression it would change their other "tune" settings as far as fueling, or does this just allow for a more consistent rail pressure?
I didn't get the impression it would cause an issue with their tunes since the drop in fuel pressure happens quickly after WOT and recovers pretty fast. There's really no way to tune for it.
 

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CLIFF NOTES: Copy over 90% ZR1 files into your FPCM if you have an aux pump and stop cutting DSX harnesses for hobbs switches....that's like putting a carburetor on a LSX.

I've shared this info with Pat G. and Dave Steck and a couple other tuners. Be sure your tuner knows about this and also, be prepared to pay $50 for the FPCM HPT credit.
Question: Are the values in the pic you posted at 90% or 100%?

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Question: Are the values in the pic you posted at 90% or 100%?

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Those are at 90%. Those are the values in my tune.

148320
 

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- but the idle was lacking (personal preference) so I did a lot of trial and error.
My car idles very well but the smell is pretty rich, partially unburnt fuel I suspect. With a BTR3 cam and no cats is there a possibility to improve the idle to clean it up or should I live with it? The smell isn't horrible I just think a bit more work could improve it. Thoughts?
 

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My car idles very well but the smell is pretty rich, partially unburnt fuel I suspect. With a BTR3 cam and no cats is there a possibility to improve the idle to clean it up or should I live with it? The smell isn't horrible I just think a bit more work could improve it. Thoughts?
Run ethanol. I think it smells good 👍
 

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My car idles very well but the smell is pretty rich, partially unburnt fuel I suspect. With a BTR3 cam and no cats is there a possibility to improve the idle to clean it up or should I live with it? The smell isn't horrible I just think a bit more work could improve it. Thoughts?
Without seeing some data logs I'm guessing, but I'd wager there is room for improvement. But you also would benefit from tweaking with the injector timing to start after the exhaust valve closes, via the injector timing offset tables. I would only mess with injector timing after your other idle settings are as good as you can get them, as it's somewhat complicated.

This is only for idle, dont fuck around with higher RPM stuff. Reference thread to get you started:


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Without seeing some data logs I'm guessing, but I'd wager there is room for improvement. But you also would benefit from tweaking with the injector timing to start after the exhaust valve closes, via the injector timing offset tables. I would only mess with injector timing after your other idle settings are as good as you can get them, as it's somewhat complicated.

This is only for idle, dont fuck around with higher RPM stuff. Reference thread to get you started:


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When I got my first CTSV I bought HP Tuners with the intent to log at minimum. Turns out my PC laptop battery is junk and I don't want to buy another PC for the rest of my life. Tuning is a pretty complicated endeavor that would take a ton of time for this guy to learn. Right now my passion is flying, any extra time and bandwidth gets spent there.

I don't have the talent nor the desire to invest the time to learn. What is your home address? :)
 

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Discussion Starter #18
So the weather keeps getting colder (32*F today), and I keep pulling minimum idle air at running temps and through the ECT Multi tables - which allowed me to add a bit more timing back in to help clutch-in transitions.

I also smoothed out the Throttle Follower tables to reduce some hunting (my OCD on watching the idle adaptive advance on my laptop, you couldn't really feel it sitting in the car), basically having the corrections start slightly sooner, but more gradually increase. Combined with a slightly wider RPM error tolerance for the cam this seems to work really well.

I also focus timing changes on only the areas where idle RPM and cyl airmass are relevant.

I suspect every car will be very different, depending on the cam, intake, etc. I'd suggesting making 5% changes to airflow tables and testing it before changing again.
 

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I'm in the same boat. Need to tweak min air. It did wind up being the min air tables set too high that cause my car to idle down in the -2 - 0 deg timing advance.....which caused surging, even when fully warmed up. I've since got it to idle smoothly, but the throttle is very touchy....too sensitive IMO.

I definitely have timing to smooth out in those air mass ranges. I'll have to go through and make sure I don't have conflicting data in various tables all competing for the commanded idle and coast down timing.

What did you wind up setting your solid state maff at? I know a lot of variables come into play between our setups, just curious.
 
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Discussion Starter #20
A great day for tuning!


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