i got my g8 spring of 2021 it had the dod delete and btr s-2 done already and a tune.its always had issues with take off and breaking up and sometimes not at all and went like a rocket ship.since i have done a cai and long tubes.im looking for some advice and if there is some obvious things that arent correct or could use changing.thanks in advance ill post my tune and logs
2008 G8 GT-dod delete btr stage 2,cai,Lt's and more to come.....
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More logging data would help, there seems to be occasion large chunks of timing are removed, also the MAF curve is not pretty.
If you log using the attached channels this will provide a lot more indication of what is going on. Download these to the folder C:\Users\this computer\Documents\HP Tuners\VCM Scanner\Channel Configs and then open it within the scanner at the channel open folder.
Gen 4.Channels.xml
ok will do thank you so much for the help
2008 G8 GT-dod delete btr stage 2,cai,Lt's and more to come.....
heres an updated log with the gen 4 channels.at almost the end of the log the car finally broke up for me in 1st from takeoff.g8 data log update1-19-2022.hpl
2008 G8 GT-dod delete btr stage 2,cai,Lt's and more to come.....
You are super lean, the narrow band voltages should be around 0.88-0.92 volts under PE enrichment.Originally Posted by g8gtchris413
Your airmass(g) is very high (forced induction numbers) like you have been raising the MAF with no result, something odd going on, looks like low fuel delivery. Have you checked the basics, fuel pressure under load at revs (not idle), plugs (as a misfire will look lean in 02 content).
Airmass(g) should be about 0.8. Id start with the stock MAF curve, check fuel pressure under full noise, it should hold steady 58 psi, back off if it drops.
Lean.PNG
ok thank you ill check all of those and ill start back at stock maf curve and get it back into a non lean forced induction table numbers.
2008 G8 GT-dod delete btr stage 2,cai,Lt's and more to come.....
ok fuel pressure was good through all checks 57.9 psi plugs are new but i pulled and checked them and they appeared to be wet and looked as if they have been running rich.here are two new logs one with the maf curve put to a completely stock curve. and the other with the maf curve that the var had when i acquired it.
tune with stock maf curve.hpl maf curve car was bought with.hpl
2008 G8 GT-dod delete btr stage 2,cai,Lt's and more to come.....
In the stock MAF you can see the fuel trims are much closer, you never enter open loop to see what the mixture is compared to the car when bought which is tragically lean or misreading lean due to misfire. Did you check the fuel pressure on the road at WOT? checking at idle does not demonstrate the pump is working. it looks as though the MAF has been pumped to solve a mechanical issue.
yeah i checked fuel psi at idle and while driving at wot it read steady in the scanner at 57.9 should i hook up my physical fuel psi guage to double check the pcm is displaying correct psi?what do you think about a possible plugged/faulty injector?but im not getting any misfires on any cylinders or misfire codes.
2008 G8 GT-dod delete btr stage 2,cai,Lt's and more to come.....
ok i think i might nbe on to something well hopefully.i was through pe in my tune and my pe min map enable was set to 70kPa.in my logs i very rarely even achieve or reach map 70kPa.could this be my lean issue that pe mode isnt even turning on??
2008 G8 GT-dod delete btr stage 2,cai,Lt's and more to come.....
Does your car have an FSCM and a pressure sensor? If not it will constantly display the desired pressure. Your read does not include one in which case you need to test it with a mechanical gauge.
You should be hitting 90 to 100 kpa with wot... Or whatever your barometric pressure is.
Also do as recommended and check with a mechanical working gauge.
2010 Vette Stock Bottom LS3 - LS2 APS Twin Turbo Kit, Trick Flow Heads and Custom Cam - 12psi - 714rwhp and 820rwtq / 100hp Nitrous Shot starting at 3000 rpms - 948rwhp and 1044rwtq still on 93
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You have not driven the vehicle the same in both logs so its not possible to compare apples, however the fuel trim is better with the stock MAF curve. The modified curve is larger and should be very rich but is not.
The logs are leaner than Stoic in open loop in the Way the car came MAF log. You can see clearly in the MAF the car came with the 02 voltages plummet in open loop, the issue is not the command as we can see that is 12.8:1. The MAF airflow is way too high for the level of modification of the car. You have a fuel supply issue based on the log. The previous tuned has not identified the issue and has pushed the MAF values high in an attempt to richen up the mixture.
ok gotcha i appreciate all of the help.know i dont know much on pcm /tuning side of a car but why would someone waste time overclocking the maf instead of just figuring out the issues?even i know better than that.bunch of aholes right haha.ok so say i have correct fuel psi at the rail from idle-wot then im gonna be looking at faulty injectors or possibly needing a higher lb/s injector?
2008 G8 GT-dod delete btr stage 2,cai,Lt's and more to come.....
Lets cross that bridge if we come to it, you are not out of injector duty, your stock injectors are more than big enough, if fuel pressure is not the issue I'll put my thinking cap back on.
As for why, there are a lot of lazy tuners who don't get out of the car to check the basics, and many who don't understand the fundamentals.
i have a tune for your setup i have done a few. should get you in the ballpark. just keep in mind this setup had a flex sensor. Just open and compare 2008 g8 btr stage 2 lt cai flex tune.hpt
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