Tune Help with C7 Stock Grand Sport

[Todd-C7]

I am brand new to tuning, just received my MPVI3 today. The first thing I want to troubleshoot is poor throttle response. Stabbing the throttle results in hesitation and delayed rpm response. It affects the drivability of the manual transmission until you get used to this behavior. My C6 Grand Sport had none of these symptoms. Log and tune file attached, car is completely stock, 2019 Grand Sport 2LT Manual. Car is in the garage for the winter so the log is not under driving conditions. The poor throttle response also occurs when the car is up to operating temperature in normal driving conditions. If I am reading the log correctly, looks like it's losing timing when throttle is pressed. Any suggestions on what/where to look would be appreciated. Thanks!

[GHuggins]

Write entire with this one then grab another driving log using these channels. If you can grab some wot stomps in the log. Hopefully weather will allow you to get it out of the garage for a few mins Make sure to just open and write entire.

[Todd-C7]

Thanks Greg. I will work on this today or tomorrow. What is different about the hpt file you sent? When I compare in the editor I don't see any differences.

[blindsquirrel]

As overwhelming as all that stuff looks in the editor, the settings you can see are something like only 15% of the actual code.

[GHuggins]

If you have the latest hpt version it may or may not have one of the tables I adjusted which is pedal progression. Basically controls how much the throttle opens and how much control the ecm has over that opening via pedal inputs. The other two tables were torque management tables that can limit throttle opening via vehicle speed, so no move = less throttle.

I'm also trying out a DD editor for a gentleman that's come pretty far since starting with it that I was needing a log for. It can do the final touch ups and should be made public for all in the next week or two... There's also some other throttle torque tables you can change, but I don't like messing with those. They always seem to cause other problems if you max them out. They're under your DD tables if you want to mess with them. I can also change your throttle area/rate table for this, but again I don't like messing with that for this problem unless it's a drag specific car. Don't want the throttle being too sensitive!!!

[Todd-C7]

I have HPT MPVI3, VCM Editor version 5.0.4. I did a View Comparison log with my file and your file open, it shows a blank screen, so I assumed no differences. Bear with me as I am extremely cautious until I learn more about tuning. Appreciate your help!

[GHuggins]

Go to hpt's website and download the latest beta straight from it. Yours is very old. You'll also need to change your editor to be in advanced mode and take your emissions BS class to get access to everything. All of that is through the website. Latest beta is under downloads. The BS Class I don't remember but you can youtube search for directions on how to find it.

As long as you save your current tune file you can always write entire with it and go back to what you had so there's nothing to be worried about there.

[Todd-C7]

Great info. I downloaded Beta, took the class and updated the Editor's Parameter Access.

[Todd-C7]

I have download another Beta that just came out today and updated the Parameter Access with code provided by taking the online class. I still cannot see any differences from my original file to the suggested updated file. Any suggestions? Thanks.

[GHuggins]

Guess hpt never added those in on your OS as long as the editor is set to advanced.

[Todd-C7]

I finally got the car out on the road to record a log. Issue is a bad hesitation/stumble off idle pulling out in 1st gear or just sitting in neutral stabbing the throttle. Log and Tune file attached. Issue can be noted where pulling out from a stop at 59 sec, 2 min 45 sec, 7 min 22 sec in the log. Any thoughts on where to begin with changes in the tune or what is causing this behavior? Also, I have many channels in the log. Does that have any negative effect on the program polling for data or receiving broadcast data from the ecm?

[GHuggins]

Did you do the write entire with the one I posted? In other words just open it and write entire?

[Todd-C7]

I did not since a file compare with my original and yours did not show any differences and I wasn't sure what I would be writing to the car. Even with the latest Beta, and viewing in Advanced mode I can't see where your tune differs from my stock tune, so out of caution I don't want to write that one. I read the forum's and totally respect your knowledge and expertise, but I am still new and learning.

[GHuggins]

All you have to do to go back to stock if you don't like it is write entire the stock file back

[Todd-C7]

Could you summarize what is changed in your tune and I can try to apply to mine?

[edcmat-l1]

Could you summarize what is changed in your tune and I can try to apply to mine?

Background throttle tables that you don't have access to.

[Todd-C7]

How do you experienced tuners access and change the background tables? When I do a write entire with the new tune is there any possibility of bricking the ECM in comparison to a write calibration with changes made from VCM editor, which I have done a couple times so far? When the write entire is completed with the new tune supplied previously I assume I can continue making future changes using VCM Editor, but would I do a write calibration or write entire for additional changes. Thanks!

[GHuggins]

How do you experienced tuners access and change the background tables? When I do a write entire with the new tune is there any possibility of bricking the ECM in comparison to a write calibration with changes made from VCM editor, which I have done a couple times so far? When the write entire is completed with the new tune supplied previously I assume I can continue making future changes using VCM Editor, but would I do a write calibration or write entire for additional changes. Thanks!

This is what I changed on yours shown below. These are actually normally available in the vette calibrations, which is why I said an update might show them for you but apparently your operating system never got them added in. You can request these tables and refer them to this thread to request them yourself. Otherwise if you want to be able to play with them you'll need to get user defined access and talk to Will or go to Will's website at Minigeist "google it" to get xdf's made for yourself. Will isn't going to get you anything illegal, so don't bother asking for anything like that... Anytime someone else changes things in the background for you it requires a write entire to get everything to load, otherwise you would only need to do a write cal and can do write cals going forward unless you want to put everything back to stock. At that point write entire to be safe. Then FWIW, I didn't max any of these tables out. I normally run a little more aggressive with these settings personally.

What I changed.jpg

[Todd-C7]

Thanks Greg. I was reading your post "NA to Boost Tuning on Gen V's with Background Tables." I understand a bit more about earlier comments in this post and was able to find Will's website. I will try your tune in the next couple days. Thanks for your efforts on this.

[GHuggins]

I've got to update that write-up. The throttle rate table is actually displayed as area with "possibly" sonic airflow incorporated into it or at least it sure seems that way knowing what I know now. Either way, yes that's the pedal progression table that I changed in yours along with some torque limiters that Verlon helped me figure out. Again all 3 of those are normally in a lot of vette cals from hpt.

You can also change some tables in the dfco section to help and the DD table using Michaels DD tool. AND even though I absolutely hate doing it as it usually causes it's own problems there are the rate tables that you can adjust. Plan on having tranny shifting problems and decel problems if you do