Forged L76 LSA supercharged BTR PD3 camshaft, help with tune

[old4door]

To prefix this, I've done a lot of research, reading, watching Goat Rope on YT and have a good general understanding of tuning. I'm still getting used to HPtuners platform, came from DSM world.

I've got a G8 with a stock LSA charger on it. Stock motor had a rod bend so it was fully forged. 6.0 block, K1 crank, K1 H-beams, Diamond -3cc .005 pistons, ARP all around, LS9 HG, BTR PD stage 3 cam w/ BTR .660 spring kit, LS7 lifters, no porting, just performance rebuild on the heads.

6l80 is fully built except for a billet planetary gear, running a factory ZL1/CTSV converter.

I'm trying to dial in the idle and low RPM cruising and feel like I'm chasing my tail. My primary issues are the false lean condition at idle causing fuel to dump and I get a decent amount of push when decel as the transmission goes from 2nd to 1st. There is a little push while sitting in gear but I don't think it's not undrivable or causing issues really.

I've tried the technique using PE to force idle AFR to be less than 14.7 but I keep getting very lean conditions that don't get better when I add more PE. I'm currently tuned MAF only and haven't touched the VVE table. My car was originally tuned MAF only by a shop.

Anyone got some pointers or things to try? Maybe someone who's running the same cam, what are your setting for idle stuff if you don't mind sharing. I've uploaded my most current tune (maf tuned) and an attempt to use PE. Also added a couple logs (idle 3 while attempting PE idle). The other is a log with the maf tuned uploaded and driving around.

Thanks in advance!

[kevin87turbot]

I suspect the problem that you're fighting is the injector characterization data isn't correct. Do you know what brand they are?

That's some big injectors for that application on pump gas. You didn't datalog the injector PW and DC, but I'd say that you probably never get over 50% DC.

Make sure you get all of the correct injector data and I'd also return the injector tip temp table back to stock.

[cadillactech]

I suspect the problem that you're fighting is the injector characterization data isn't correct. Do you know what brand they are?

That's some big injectors for that application on pump gas. You didn't datalog the injector PW and DC, but I'd say that you probably never get over 50% DC.

Make sure you get all of the correct injector data and I'd also return the injector tip temp table back to stock.

Yes, if you don't have the right injector data you will chase your tail, especially with idle tuning since the pulse widths are so low. With a build like this, spend the money on some ID injectors so you get the right data.

I didn't look at the cam specs on this cam but if there is increased overlap over the stock one then you may need to modify your end of injection targets to keep your fuel from shooting out the exhaust during the overlap period and then you getting a lean reading on the wide band because no fuel made it into the combustion chamber to buirn.

[old4door]

I didn't mention injectors in the post but I'm running ID 1050x with all the data from the factory added. They were installed on the stock motor and everything was in line and running well.

[kevin87turbot]

How did you go about diagnosing the false rich condition?

[old4door]

How did you go about diagnosing the false rich condition?

All my reading on tuning bigger cams has led to having false lean at idle due to the overlap and amount of unburned oxygen flowing through at low RPM. It also smells super rich at idle so I have no doubt it is rich. The cam specs are 231/248 .617"/.595" 120+5, -2 overlap and it installed at 14* per my engine builder (15* is what it lists on sheet).

This is my first experience attempting to tune a cam so my knowledge is pretty limited and there honestly isn't a lot of information I've come across that tackles this.

[kevin87turbot]

You're overthinking this one a bit.
Go ahead and tune it to idle at Stoich. Just like Cadillactech indicated above, you can adjust your EOI to clean up the raw fuel smell a bit. There are some pretty good threads on here about fine-tuning it for your application.

[old4door]

So I got the idle in park looking good. I adjusted the injector timing with the help of the huge thread on here and their awesome spreadsheet. That helped a bunch with fuel smell and adjusted AFRs a bit.

I still have some work to do on the in gear stuff. The timing jumps all over the place when coming to a stop at approximately 25mph and under. I haven't found anything that specifically addresses this issue. Any suggestions on where to start? I've attached a log that shows what I'm talking about.

[07GTS]

u have alot of idle spark 25 deg isnt always needed especially with the PD cam id be in mid to late teens if that and it also leaves some room for the idle spark correction

[RobZL1]

Agreed. Try 18 or 19 degrees. Also, see this thread if you haven't already:

https://forum.hptuners.com/showthrea...e-tuning-guide

[old4door]

u have alot of idle spark 25 deg isnt always needed especially with the PD cam id be in mid to late teens if that and it also leaves some room for the idle spark correction

Agreed. Try 18 or 19 degrees. Also, see this thread if you haven't already:

https://forum.hptuners.com/showthrea...e-tuning-guide

Thank you both for the tips and that link, they helped with everything I was needing! I've got it idling even better and have cured the pushing and coasting issues. My timing was too high and my base air table was too high as well.

I'm now going to start moving on to getting the MAF fully dialed in and then attempt to tackle the VVE table.

Here's the latest tune I've got loaded up.

[Lakegoat]

Since you are using double stoich, You forgot to halve the IVT Terms (AFR). Also, Check the ID website for GM characterization for those injectors. I believe that minimum pulsewidth should be .300 across. You have some other numbers. Check the makeup pulsewidth as well. Under Idle--RPM--Proportional--make that 50 rpm or something, not 4096. I guess you had it turned off for some reason. Under Idle adaptive spark, make the -12 in the overspeed -8. Change Overspeed from 11 to 7---in all of the areas--idle, gear, coast. That will tighten up your timing and get rid of some of the surging. I think the inaccurate data in the injectors is giving the most fits.
Do you have a boost referenced regulator on this setup?

[old4door]

Since you are using double stoich, You forgot to halve the IVT Terms (AFR). Also, Check the ID website for GM characterization for those injectors. I believe that minimum pulsewidth should be .300 across. You have some other numbers. Check the makeup pulsewidth as well. Under Idle--RPM--Proportional--make that 50 rpm or something, not 4096. I guess you had it turned off for some reason. Under Idle adaptive spark, make the -12 in the overspeed -8. Change Overspeed from 11 to 7---in all of the areas--idle, gear, coast. That will tighten up your timing and get rid of some of the surging. I think the inaccurate data in the injectors is giving the most fits.
Do you have a boost referenced regulator on this setup?

Thanks for the quick check over. I changed the IVT terms and min pulse width. Everything else matched up to the ID website, not sure how I missed the .300 min when I first set them up.

The proportional I left off as the idle tuning thread suggests doing. I may mess with the idle adaptives further, thanks for the suggestions.

I'm running a ZL1 pump with vaporworx regulator, still returnless setup with a zr1 rail. The next upgrade will likely be a double pump setup and 2.45 upper pulley but I want to get the current tune pinned down before that. Keep it a bit simpler and easier to track down issues changing a few things at a time.