[RobZL1]

I decided I'd do something a little different that I haven't seen before on the forum. I'm going to do a "build thread" for tuning my car, with screenshots of all the changes I'm making, with detail of everything I'm doing and why I did it.

This thread relates to my build thread here:

2017 ZL1 1000hp Daily Driver Build

The build has morphed a bit, and it's no longer going to be a daily driver, but I'm still building it in such a way that it could be.

I know there are many approaches to tuning, and this thread will probably spark some discussion. I'm no professional, but I am comfortable tuning the car based on my background and prior tuning experience. This is my first car with a torque-based Gen 5 ECM, but I'm fairly familiar with it now after my first rounds of mods.

On to the tuning.

[RobZL1]

I'll start by documenting my base tune to get it to start and run, and then go from there.

An easy one to start off. On the Engine>General tab, I'm disabling the Clutch Protection. The build has a Monster Triple Disk clutch, and I'm not interested in torque management intervening on launches.

[RobZL1]

On the Idle>RPM tab, for the base tune, I'm just going to bump up the idle tables by 200RPM across the board for now, compared to where it was when I had a 2650, intake, 103, and headers. This will set an idle of 850RPM to start, and I'll perhaps adjust later after dialing in the airflow.

Here is the RPM tab, showing what has changed from stock:




And here are the Idle RPM tables after adjustment:







I adjusted the Launch Assist table also. Again, I added 200 rpm versus where I had it for my last round of mods. This is a different profile from stock on a 2017 tune, as I changed it to make the car more drivable when it was bone stock.


Then, I added 50 RPM to the "Maximum" field, simply to match with the current maximum in my revised tables. I don't think this is even necessary, but I did it anyway. I'll never see that area of the idle tables, so it really doesn't matter, but I like things to match.


I didn't touch the idle adaptives at this point. Once the airflow is dialed in, I'll probably end up relaxing both the immediate (spark) and predicted (throttle blade) values depending on how much cam chop versus lope I've got.


.

[RobZL1]

For the base tune, the only thing I'm changing is the Torque Limit, in order to give the car a little more leeway to idle when the airflow models aren't fully correct yet. I bumped it up by about 20 lb-ft for now.

This will likely get adjusted again, along with the tables on this tab, once the car runs and the airflow and virtual torque models are corrected. I'm sure the Zero Pedal Torque will be off, and these tables will change once the real tuning begins.

[SOCAL.M6.ZLE]

Originally Posted by RobZL1

I decided I'd do something a little different that I haven't seen before on the forum. I'm going to do a "build thread" for tuning my car, with screenshots of all the changes I'm making, with detail of everything I'm doing and why I did it.

This thread relates to my build thread here:

2017 ZL1 1000hp Daily Driver Build

The build has morphed a bit, and it's no longer going to be a daily driver, but I'm still building it in such a way that it could be.

I know there are many approaches to tuning, and this thread will probably spark some discussion. I'm no professional, but I am comfortable tuning the car based on my background and prior tuning experience. This is my first car with a torque-based Gen 5 ECM, but I'm fairly familiar with it now after my first rounds of mods.

On to the tuning.

Brilliant, with all of the bright minds on this forum this should be exciting!!! What a benefit to the group also!

[RobZL1]

Originally Posted by SOCAL.M6.ZLE

Brilliant, with all of the bright minds on this forum this should be exciting!!! What a benefit to the group also!

Thanks, Gabe. You guys will be along for the entire journey. I'm sure there will be some good discussion along the way.

[beowulf556]

Very cool discussion so far I look forward to seeing your progress and learning!

[Enslaved]

Originally Posted by RobZL1

I decided I'd do something a little different that I haven't seen before on the forum. I'm going to do a "build thread" for tuning my car, with screenshots of all the changes I'm making, with detail of everything I'm doing and why I did it.

This thread relates to my build thread here:

2017 ZL1 1000hp Daily Driver Build

The build has morphed a bit, and it's no longer going to be a daily driver, but I'm still building it in such a way that it could be.

I know there are many approaches to tuning, and this thread will probably spark some discussion. I'm no professional, but I am comfortable tuning the car based on my background and prior tuning experience. This is my first car with a torque-based Gen 5 ECM, but I'm fairly familiar with it now after my first rounds of mods.

On to the tuning.

You, sir, are a gentleman and a scholar. There needs to be more of this. If for nothing else but enduser knowledge of how the ECM's operate.

I missed an opportunity to get first hand experience with these ECU's when they were under development. Worked at the powertrain engineering facility in Pontiac for over 10 years. Worked hand in hand with the folks responsible for its design (and of course all the engines) and testing. Spent a lot of time with ETAs and dSpace. Just simply wasn't something I was interested in at the time.


Excited to watch your adventure unfold here, and maybe I can learn something.

[RobZL1]

Originally Posted by beowulf556

Very cool discussion so far I look forward to seeing your progress and learning!

Originally Posted by Enslaved

You, sir, are a gentleman and a scholar. There needs to be more of this. If for nothing else but enduser knowledge of how the ECM's operate.

I missed an opportunity to get first hand experience with these ECU's when they were under development. Worked at the powertrain engineering facility in Pontiac for over 10 years. Worked hand in hand with the folks responsible for its design (and of course all the engines) and testing. Spent a lot of time with ETAs and dSpace. Just simply wasn't something I was interested in at the time.


Excited to watch your adventure unfold here, and maybe I can learn something.

Me, too, and thanks. I had a blast tuning my last cars and a couple for friends (and even my current Civic Si daily). Looking forward to this one. I've been through all the basic stuff with this one already. Now just adding the cam and the fueling, and E85, etc. And redoing most of what I already did. Lol.

[vince3]

Awesome. I will keep an eye out for updates to the post.

[Patriot Motorsports USA]

Awesome thread and thanks for sharing!!

[RobZL1]

Thanks, guys.

On we go to the next tab: Engine>Airflow>General

Here I am modifying 4 tables and 1 value from stock.

First is the estimated MAP maximum value. I don't think this makes the same difference on a Gen 5 OS that it did on a Gen 4 OS, but I'm maxing it out to 255kPa anyway.



Next is the IAT sensor calibration, because of the IAT sensor provided with the 2650. These values are simply the transfer function for the sensor that I have been running since installing the 2650. The values were provided by Magnuson, so I trust they got it right for that particular GM sensor- I never checked. The sensor hasn't changed with my current build, so no changes needed.

Then we have the MAF curve. I'm going to leave it where I had it with the last round of mods. Since I'm keeping the same MAF tube and throttle body, it should be fine or only require minor tweaking to get the torque reporting to play nicely at idle. I'm certain I will also have to tune the upper regions once I begin WOT tuning, of course.




The final two changes are to the cranking airflow. I'm adding 1.5g/s to the entire base airflow table for starters and will modify from there later.

I'm also taking the VVE charge bias down to 90% from 100%, again for a starting point.

[RobZL1]

Engine>Airflow>Dynamic

This is an easy one. I'm only changing the VVE cutoff limits from stock values of 4000rpm with a 3800rpm hysteresis value, to 3000rpm with a 2800rpm hysteresis value.

I'm dropping it by 1000rpm for easier tuning, but staying within the typical around-town-driving, part-throttle rpm band. Basically, I want to use a blended VVE as much as I can, but don't want to have to tune it perfectly up to 4000rpm.



.

[RobZL1]

For the next tab, we'll be setting a base VVE.

In this photo, you see the actual tables that have been changed, but these don't mean much to most humans.




This is where the VVE editor comes into play. It translates some long equations into a graph that looks like an old-style VE map. It has some oddities and is not smooth, due to things called zone boundaries and also the suspicion that HPT's calculations are not necessarily represented entirely correctly in the VVE editor's graph.

I'm going to take the easy route and leave it the way it was before this round of mods. I'll need to tune it again, but I just need it to start and run for now. My changes to the tables from stock already moved the character of the curve around to better suite the 2650. For this round, I'll most definitely need to spend some time reshaping it again with the changes to the cam and heads.

Here is where it sits now, versus the stock VVE shape. I was really closely dialed in for the last round of mods. I'm sure I'll get there with this build, too. It just takes a little time.

The first graph is current state, and the second graph is stock. You can see that I already changed the profile of the curve to better match the 2650 airflow characteristics versus the stock 1740 data.