Don't try running your ZL1 on the dyno without the air filter or this will happen

[[email protected]]

i have been reading a great deal about this new ecu and the torque modeling and the driver demand table smoothing and the new vve table stuff we can now do in the software, but i have NO answer for this.

totally stock 17 zl1 a10. testing 2 things. first higher octane fuel on a stock ecu and the ported katech tb also on stock ecu. both were positive. the red and green you see here are end result of both. ecu needed nothing to adapt to the tb and the 50/50 91&100 octane produced very repeatable runs after only about 6 runs.

we were done and happy and then decided let's see how it does with no air filter. so we took it out and bolted the top back on.

this crazy ecu pulled timing from the start (vs runs with filter in) and then proceeded to chop the throttle as well. the orange run wasn't a one off either, it'd do it every time until you put the filter back in, then it was happy again.

any ideas on wtf is happening here? no file because we didn't license it yet, this was a stock ecu test. and given good results no tuning, owner may not. but the logs should have all you need to see and maybe there's a stock zl1 file already out there to reference.

[Higgs Boson]

erratic maf

[pjs]

Curious...Where does one read about the new ecu and the torque modeling and the driver demand stuff?

TIA,
Pj

[[email protected]]

so just pulling the air filter makes the maf go nuts? how is that?

to learn, just start clicking on every post in the gen 5 forum and read it all the way through. the first 20 pages should give you a good idea

[Higgs Boson]

Curious...Where does one read about the new ecu and the torque modeling and the driver demand stuff?

TIA,
Pj

https://www.hptuners.com/help/vcm_ed...vanced_e78.htm

that is the only thing out there I have seen, the rest, as mentioned, comes from reading the forum and testing.

[[email protected]]

higgs, you have something with an lt4 in it don't you? have you tried this with no filter? i know an LSA wouldn't do this. biggest difference is the ecu.

[Higgs Boson]

higgs, you have something with an lt4 in it don't you? have you tried this with no filter? i know an LSA wouldn't do this. biggest difference is the ecu.

yes but I haven't started it in quite a while, we got a new baby in the house and she doesn't like catless headers. ;-)

[HackAbuse]

so just pulling the air filter makes the maf go nuts? how is that?

to learn, just start clicking on every post in the gen 5 forum and read it all the way through. the first 20 pages should give you a good idea

Your air filter sort of acts like a large flow straightener, making the airflow over your MAF fairly uniform and consistent.

Removing that filter likely induces a ton of turbulence, causing the MAF to misreport flow. My Cruze does exactly the same thing when the air filter is removed and can cause STFT swings as much as 35% in both directions during steady state operation.

[8850]

https://www.hptuners.com/help/vcm_ed...vanced_e78.htm

that is the only thing out there I have seen, the rest, as mentioned, comes from reading the forum and testing.

I bumped my 100% DD table a tad in an effort to keep my throttle open at WOT and got a lot of kr. Now I see why. Still working on a way to keep the throttle fully open at WOT.

[KonigWolf]

https://www.hptuners.com/help/vcm_ed...vanced_e78.htm

that is the only thing out there I have seen, the rest, as mentioned, comes from reading the forum and testing.

I bumped my 100% DD table a tad in an effort to keep my throttle open at WOT and got a lot of kr. Now I see why. Still working on a way to keep the throttle fully open at WOT.

That link has been the best information on driver demand i've been able to find in searching. I'm kind of surprised no on has wrote better information on how to properly keep our throttles open.

[8850]

That link has been the best information on driver demand i've been able to find in searching. I'm kind of surprised no on has wrote better information on how to properly keep our throttles open.

It's a great link for showing the workings but doesn't show us how. My 2017 Z06 starts closing at about 80-90 mph. Not completely as I've shown in another thread but I would think some et loss.

I wonder if this pressure control table would keep it open. The info says for better responsiveness use 20-40 kPa. I've changed it to 20 to give a try.

[Redline MS]

Your air filter sort of acts like a large flow straightener, making the airflow over your MAF fairly uniform and consistent.

Removing that filter likely induces a ton of turbulence, causing the MAF to misreport flow. My Cruze does exactly the same thing when the air filter is removed and can cause STFT swings as much as 35% in both directions during steady state operation.

Exactly..... you destroyed the Dyna Air Model and shifted load all over.....

[KonigWolf]

It's a great link for showing the workings but doesn't show us how. My 2017 Z06 starts closing at about 80-90 mph. Not completely as I've shown in another thread but I would think some et loss.

I wonder if this pressure control table would keep it open. The info says for better responsiveness use 20-40 kPa. I've changed it to 20 to give a try.

I've read of people adding 10% to the bottom three lines of Map A - Normal in the driver demand section, but I've also read that there is also three or four other tables that also need changing in order to get 100% throttle.

[8850]

I've read of people adding 10% to the bottom three lines of Map A - Normal in the driver demand section, but I've also read that there is also three or four other tables that also need changing in order to get 100% throttle.

I tried that previously with less than 10% in the bottom 100% line but got a lot of knock retard. Maybe the other tables noted in Higgs info link would fix it but I don't know what values to use.

I tried 20% in the table above but still throttle closed. However much less closure in D and letting the tranny shift.

[pjs]

Thanks all! Good article.

[HeavyChevy305]

I tried that previously with less than 10% in the bottom 100% line but got a lot of knock retard. Maybe the other tables noted in Higgs info link would fix it but I don't know what values to use.

I tried 20% in the table above but still throttle closed. However much less closure in D and letting the tranny shift.

Throttle% varies from one table to another. Some use 100% others use 83.9% for example.

Highlight the last 4 rows and add 10% as an experiment. Worked for me, might work for you.

[HackAbuse]

Thanks all! Good article.

Anytime I alter pretty much anything with the MAF, I immediately run MAF only mode, run it up to operating temp, then log fuel trims (b1+b2) vs MAF hz, then multiply by %-half until your trims are looking really close. I always make sure there is a nice linear profile before writing data too

[[email protected]]

how do you enable maf only on a gen 5 ecu?

[8850]

how do you enable maf only on a gen 5 ecu?

Should be in OL of you max this table out to 32767.

[Higgs Boson]

Should be in OL of you max this table out to 32767.

maf only is not the same thing as open loop