LS3 Manual Trans Camaro Boosted PE Delay causing lean/knock during Shift

[Area47]

here is a suggestion.
your car may absolutely hate this and piss itself, but it's worth a shot.

do a full write with the stock file. {put the stock file back in the car} shut it off for 10-20 seconds after the write. fire it up and try to get it to idle for about 5-10 seconds. just enough time for the ecm to check all the sensors and crap. shut the car off. it works as a hard reset. load the file you're currently working with in the car as a write entire. fire up car and go see what it does after this.

instructions per GM r&d engineering friend. seemed to help out a lot on my truck with this issue and other issues i was fighting. think of it more of a refresh of the ecm than anything else.

as far as i know hpt is only system that doesn't shut down the ecm on a flash, but the write entire does.

[bbrooks98]

Good to know

[10_SS]

Anybody get anywhere with this? IDRIVEAG8GT, while I tried your settings for awhile, I was afraid to smack it to WOT while at higher RPM, not because of your settings, but because I was tuning VE tables, so I reduced the throttle opening rates, and spent time tuning WOT VE tables.

Now I have the WOT VE tables in check, then last minute decided to throw the ZL1 Transient settings in there with full throttle opening rates on a final test tune before re-enabling MAF since the ZL1 transients were populated AND far different than my/any other NA LS3 type engine...

Anyway, long story short, VE's are good, and still I had a a bit of audible knock+max retard at the instant of smacking WOT at about 4200rpm (on a whipple, SD tune, stock LS3, 200kpa+ burst - ZL1 Transient settings and full throttle opening rates). This makes a total of two times now I had knock transitioning to WOT at higher RPM with a manual trans. I'm 100% sure these are the only two times i had knock as I log everything. Starting to think putting a restrictor in the bypass valve or simply leaving the Throttle opening rates slower.

So I will be returning to MAF soon (which I hear helps transition fuel) and going back to your Transient settings)

also curious how many LS3's were toasted just by the transient knock on a boosted setup? Probably not easy to pinpoint, but probably mostly relevant to manual trans as automatics don't transient very often and are relatively easy to tune.

[pmj]

So I will be returning to MAF soon (which I hear helps transition fuel) and going back to your Transient settings)

10_SS, did you clear up your KR while shifting at WOT? I've read through this entire post and wasn't clear if you got your desired results. If so, can you share details on what you did to fix it.

[10_SS]

Yes I did.
1) Went back to MAF.

2) I noticed some stock supercharged GM cars including a 2013 CTS-V has the PE enable MAP set low, around 20KPA... and they trigger PE based on TPS which is also low like 16%... just make sure on your car that 16% throttle is below 95-100kpa at all RPM's or you should lower the TPS enable point even lower. I have my PE enable still at 85kpa, but now may lower it like the CTS-V. There is a PID called PE TPS, or something like that to log and this value is what is referenced in the TPS PE.

3) Also to avoid the pressure spike, I reduced the throttle opening rate just slightly, but you have to take it down below 8 (from 100) to see any reduction is opening rate. Doing this removed all of my pressure spikes when going WOT between shifts.

4) I also played with some of the "Warmup Transient Fuel" and "Transient... Impact factor" as suggested by others on here but I think right now they are adding just a bit too much fuel sometimes... but it doesnt stumble so I'm ok with it.

I've used the attached tune on 2 1hr long road courses and no problems with knock, tip in, etc.

2B071 68 cranking leanout from 60+degrees MAF Leanout .hpt

[pmj]

I was hoping your solution did not include #3. I agree that would resolve the lean tip in, but I think at the cost of some performance in the 1/4 mile. I see you set the Opening Rate to 3...did you try 4 and it resulted in KR?

I can see putting this setting into my street tune, and I can see using on a road course like you are, but I struggle with it on the 1/4 mile...I'm still holding out hope I find a solution for my lean tip in w/o sacrificing throttle response.

Thanks.

[10_SS]

I was hoping your solution did not include #3. I agree that would resolve the lean tip in, but I think at the cost of some performance in the 1/4 mile. I see you set the Opening Rate to 3...did you try 4 and it resulted in KR?

I can see putting this setting into my street tune, and I can see using on a road course like you are, but I struggle with it on the 1/4 mile...I'm still holding out hope I find a solution for my lean tip in w/o sacrificing throttle response.

Thanks.

Actually it should increase 1/4 mile performance since lean/knock rob power. I just beat on a 2013 CTS-V for the weekend and logged MAF/MAP as I made multiple high rpm throttle jabs... and sure enough, the MAP/MAF ramp up... they don't spike high and come down like mine were doing. I don't think you have to slow it down as much as I did... just less than stock since now it's supercharged.. it's just to fast. I just set 3 since it slowed down the throttle but not enough for me to really notice it.

[pmj]

I had to set it to 2 to get rid of the KR. I'm running a 2.75" pulley at 17-18# of boost. I plan to head to the track in a few weeks, we'll see the results...

[10_SS]

I had to set it to 2 to get rid of the KR. I'm running a 2.75" pulley at 17-18# of boost. I plan to head to the track in a few weeks, we'll see the results...

18psi, wow you must have it way worse than I did. I guess you can thank Whipple for that... I don't like how it spikes when the TPS is opened... my remote mounted Procharger never did this. OEM's don't do it either. I wonder if there is something we can do to the bypass valve to help this.