Pontiac G8 GT L76 BTR Stage 2 V2 Tune

[slo5oh]

First timer here and I am not a GM guy or a ECU tuning guy either but I rebuilt my brothers G8 last month and I'm trying to give this car a new life, I have got the tuner working and got the car idling.., but it is not running well and I need help, winter is coming fast up here Michigan but I would love to hear this thing at least idle and drive around the block better than it is now.

Here's what was done and most likely a terrible tune to view:

BTR Stage 2 V2 cam
Texas Speed dual valve springs
New Trunion kit
LS7 lifters
Chromoly stock length pushrods
New High Flow Melling oil pump
.010 cut off the heads
ARP studs and bolts throughout
1 3/4 longtubes
Ebay special exhaust 2.5 inch through


Stock Converter currently and the push through is very noticeable but not over whelming.

G8.Tune_ADJUSTED_After_First_Drive_Rev_1.hpt

[edcmat-l1]

Post a data log of it not running well. A data log most times will tell you more about the vehicle than the tune file.

[edcmat-l1]

Idle spark under/overspeed tables don't make sense. You'd be better off just putting them back to stock.

And this is your idle speed table. First off this engine doesn't need to idle anywhere near 872 RPM in gear. Second, does the table look like it makes sense to you just in general? Why would you have your P/N RPM at 750 regardless of temp, yet your in gear tapers down? Neither of those things make sense.

[slo5oh]

Post a data log of it not running well. A data log most times will tell you more about the vehicle than the tune file.

Here it is when it was driving, I knew i would get on here and get absolutely wrecked but I'd rather be told I'm an idiot and correct it and learn from it than go through life being an idiot.

Fore warning this tune was taken off of the forum by another member and his car was driving or so he said in his posts. I know this is not running well or remotely correct but I am asking for advice on somewhere to start.

I bet this will give you GM guys on here a laugh too... I'm a Ford guy if that tells you anything!

[edcmat-l1]

I just realized I didn't post the screen shot of your idle speed table to go along with what I said. It's in my previous post now.

There's some stuff in there that does not take any amount of experience to know it's not right. The idle speed table for instance. Just do a compare between what you posted and a stock calibration for the year/make/model.

[slo5oh]

I?ll check it out when I get home.

All I did was take the previous stock tune. Save it. And enter in this guys tune into the tables and start and drive the car to see how it felt.

I?ve got an old foxbody with a distributor and a carb, this is new to me. Sorry for being absolutely clueless about setting idle tables and such.

[JasonHSV]

This will get you pretty close for a start up tune. I've also made some adjustments to your VVE & Maf in the idle areas only, but you need to be logging the Mass Airflow Frequency (hz), dial in the MAF, VVE etc .
G8.Tune_ADJUSTED_After_First_Drive_Rev_2.hpt

[slo5oh]

Thank you for the help Jason, I will flash that later this week and give you an update I have the driver header off right now to give some clearance its tapping the steering linkage.. I will take a log with the MAF Frequency and report back with results.

[edcmat-l1]

This will get you pretty close for a start up tune. I've also made some adjustments to your VVE & Maf in the idle areas only, but you need to be logging the Mass Airflow Frequency (hz), dial in the MAF, VVE etc .
G8.Tune_ADJUSTED_After_First_Drive_Rev_2.hpt

You may have helped the idle slightly with your VVE change but that's a helluva step from 1000 to 1200 RPM.

VVE step at 1200 RPM.jpg

And the MAF has a huge drop off right in the range where it will run most of the time.

MAF step 100 Hz.jpg

Both are going to cause driveability issues.

[JasonHSV]

Ed appreciate your comments, but as I stated in post, that was to get him started. I also said he will need to tune both maf and vve.

I also noticed the drop at 4800 hz. That was from his original file. Maybe I helped more than I should if he doesn?t know what he?s doing but I?m not giving him a completed tune, just a base tune to work off which I thought I made quite clear in my post.

[slo5oh]

@jason I do understand the post and I don't plan on adjusting it for actual street driving we have snow in the forecast starting next week. My main reason for wanting a idle tune is so that I can start and warm the car and move it around 10-15 feet at time during the winter months.. November-March up here.. I have to move my M5 and my foxbody and my boat I always have to move around a few times a year, its one of those too many cars and not enough space situations. And this isn't my car I'm just trying to store it for him this winter.

He is trying to figure out who he wants to tune the car but we're running out of time and my M5 needs to get into the garage its parked outside right now under a cover.

Notably I would love to learn more about this type of tuning it potentially could help me if I ever turn my foxbody efi. Maybe if its not too much to ask down the road I can get a cliff notes version of MAF tuning from someone on here, I'm an electrician by trade and I'm in college now for controls engineering so I'm very open to learning..