NA to boosted tuning question

[TuneAFish]

Hi everyone – as the title indicates, I am new to boost and have a question about the tuning process. I have a 2015 SS M6 car that I am adding small turbos to; I have HPTuners.

I have done a fair amount of research and am comfortable tuning an N/A car. I’ve rescaled my MAF and tweaked the spark when I changed my CAI. I’ve installed a factory 3bar map sensor and scaled its settings accordingly. Lastly, I installed a ZL1 fuel pump and 90lb injectors and have put the new injector data in.

My issue is how to approach the tune now that I’ve installed the turbos.

My plan was to set it to MAF only and rescale the MAF for the new charge tubing characteristics, then do a SD-only tune, and then let the car run in mixed mode (MAF plus SD). Does this sound like a logical plan? I’m confused because I seem to read about a lot of people that use SD-only tunes and completely ignore the MAF (if I understand correctly).

I have not yet upgraded the OS to the 2Bar Speed Density mode, because I’m not sure if I should go ahead and do that now or wait until after rescaling the MAF (assuming I end up running in mixed mode). I have read a fair amount how to tune using the VE tables, so I feel confident doing it once I am supposed to.

One of my concerns about running in SD-only mode is (I’ve read) that as your weather changes you want to change your tune settings. I don’t have a problem with that at the track when I’m trying to maximize power (or be consistent for ¼ mile runs), but I don’t want to have to change the tune to go to the car show if it’s 30 degrees cooler/warmer today than yesterday (I live in Ohio, this happens a lot).

For disclosure, I know Ted, Ryan, Steve, or several of the other tuners here could fix this super quick and it’d run like a bat out of hell, but I’m really trying to teach myself how to tune, because in the near future we have plans to build an EFI bracket race car, and I’d like to be 100% confident in making the race-day tweaks myself.

Thanks in advance for reading this far and thinking about it.

[Tajefe Couple]

[eLeSthree]

I've paid for a few remote tunes and have had a few dyno tunes on this 5th gen so far. One thing they all have in common (except my current 427 tune) is that they are all MAF only tunes, and no one touched VVE. That being said, they have all run well.

When Jannetty tuned my 427 remotely he massaged my injector data a little beyond what FIC supplied (maybe because my base FP is 60psi) Then we did 2 or 3 quick revisions to the VVE table, then moved onto the maf. He continued tweeking the maf and timing and FF adders for another 15 or so revisions.

In the end though, even with a modified VVE table, the tune has VE disabled at 500rpms. I've been told that even when running a maf only tune, the volumetric efficiency table will still predict airmass calculations. Sounds strange, but

If you arent changing displacement, I would probably knock out the maf tune first, since its easiest. Then you'll have a decent tune you can drive around on while you complete a few heat cycles on the new hardware. Then tackle the ve stuff.... just a thought.

I'm no pro tuner, but I think you have a solid plan. A hybrid tune is always better.

[TuneAFish]

Originally Posted by eLeSthree

I'm no pro tuner, but I think you have a solid plan. A hybrid tune is always better.

Thanks for the input - there's good information there. I'm also glad to hear that, as I thought a hybrid was the best way to go based on what I read, but I wasn't sure it worked with this setup.

I'm heading back to the garage tonight, I'll go ahead and scale the MAF first and see how at least that step goes...

[FrankT]

You shouldn't need to rescale the MAF, the Gen 4 has more than enough room to work just fine. I tuned my 2010 Huron Speed twin setup myself. I am running a MAF only tune, and it works well. I spent hours trying to dial in the VVE tables to run a hybrid tune, but in the end to have a smooth transition going into boost, the MAF only tune just worked better for me. Good luck with whichever road you choose to take.

[Big Biscuits]

You will not find lots of tuning advice here. Hptuner forum is where all of the good info is hidden. For what it’s worth, I have a blended FI tune. I run the custom OS 2 bar and cross from SD to MAF at 4000 rpm. The best advice I will give you is make good filters for your data. Only keep good clean data averages (high hit counts) and make changes slowly. Paste special multi by half is your friend. It will take a lot of reading to gather filters that will net you the best results. If it’s good clean data, you changes to your tune will track your percent added or subtracted.

[Tarendor]

Because of the way I routed my pipes I didn't have enough straight pipe for the maf, even with the honey comb section it just wasn't happy. So I went sd os. You have to do what your car and setup will allow but it seems like you have a decent plan. Hptuners forum has a lot of valuable information for you.

[TuneAFish]

Thanks for all the feedback.

I've spent a good deal of time on the HPTuners forum as well, it's just nice to get some vehicle specific advice from the good people here. And I'll tell you what, this is definitely a community of folks that want to help each other out and I appreciate it!

That's no joke about the filters; I may reach out to you if I have more issues in the logging, but I *think* I have them setup decently now (after a ton of iterations). I took the HP Academy course on EFI Tuning and he walks through a few examples of how to set them up.

One really helpful thing that I stumbled across was to reset the fuel trims in the scanner (not the editor) while logging after significant mechanical (and tune) changes.

I didn't know this was a thing and it caused me serious headaches earlier this week when I initially tried tuning it. My AFR was WAY off (by 70% even at low rpms) on my initial startup.

Once I reset the fuel trims, it immediately made a significant difference. I was down to a 7-10% AFR error. So hopefully that little nugget of info helps save someone else some headaches.

I'll be helping my son put a new cam in his S10 (with an old school Weiand blower) tonight, so it will probably be tomorrow or this weekend before I have a significant update...or more questions :-)

[FrankT]

If you really want to learn to tune, I highly recommend The Tuning School in Odessa, FL. I bought their tuning printed course and later went to one of their hands on schools. They teach a lot there that you won't find on the internet.

[TuneAFish]

Originally Posted by FrankT

If you really want to learn to tune, I highly recommend The Tuning School in Odessa, FL. I bought their tuning printed course and later went to one of their hands on schools. They teach a lot there that you won't find on the internet.

Thanks for the info; I literally just told my wife I wish there was a place I could do in-person learning. I've learned a ton from HP Academy, but I find that I have a lot more 'Ah-ha' moments in-person.