LNF basics

[Iam Broke]

Total trip today of 85 miles and my LTFT's went to +14.1. Took out 14% from the MAF tables and had a -0.8 after 10 more miles. Put 1% back in and see LTFT's of 0.0 for 10 miles.

STFT's from the last run in the histogram are +3 to -5, I'll leave it for a few hundred miles & check on it again.

Boostking- My MAF went up to 32.7 lb./min with 21.5 psi boost after a spike of 22.3 psi. (Buried the sensor) Stock charge piping, that's the next to go.

I had a MAF of around 30 with the snorkeless intake and a K&N drop in. I'm very pleased!

Thanks for all the help Terminator2!

[Terminator2]

Total trip today of 85 miles and my LTFT's went to +14.1. Took out 14% from the MAF tables and had a -0.8 after 10 more miles. Put 1% back in and see LTFT's of 0.0 for 10 miles.

STFT's from the last run in the histogram are +3 to -5, I'll leave it for a few hundred miles & check on it again.

Boostking- My MAF went up to 32.7 lb./min with 21.5 psi boost after a spike of 22.3 psi. (Buried the sensor) Stock charge piping, that's the next to go.

I had a MAF of around 30 with the snorkeless intake and a K&N drop in. I'm very pleased!

Thanks for all the help Terminator2!

Your welcome. I think I may have a slight CP leak as my LTFT were -3 to -4 with the stock airbox on and about 4% different than yours with the same intake. I dunno though.

[Iam Broke]

I've gone over my stock CP's a few times inspecting the clamps & tightening them up. I also had to cut a chassis bolt off shorter that would have rubbed through the rubber hose part underneath, There was a TSB on the CP's bolts rubbing.

I still have a faint whistle/whine though, I hope it's just the turbo spooling up. If you had a leak would it make your's more negative? I get confused.

[Terminator2]

I've gone over my stock CP's a few times inspecting the clamps & tightening them up. I also had to cut a chassis bolt off shorter that would have rubbed through the rubber hose part underneath, There was a TSB on the CP's bolts rubbing.

I still have a faint whistle/whine though, I hope it's just the turbo spooling up. If you had a leak would it make your's more negative? I get confused.

They were more negative. Yours were +14 mine were +9.

[Iam Broke]

I started modding the timing tables tonight, I loaded 18 degrees in all 4 tables greater than 100% load and 5k & up. Smoothed them about 5 times. I'll load it tomorrow and see if I get any KR on the midwest 93 octane. Saw some places that it actually has less timing than stock now by a few degrees doing a compare. I was seeing 3-4 degrees KR in spots.

Also have my eye on the hot side Injen charge piping.

[Iam Broke]

Tried 18* and had 3-4* KR in the high RPM high load areas. Reduced to 15* >100>5k & smoothed it out a bit. LTFT's went to -1.6 today.

Looks like my LTFT's would have been +11 Term, not +14. I'll tweak it and drive it next week before I adjust again. 10 mile runs aren't enough to really tell it seems.

[EaglePerformance]

Just had a couple of GXPs come into the shop, started following this thread, learning a bunch, trying to wrap my head around the relationship of DALs and max air load torque, one of the cars has a GMPP tune in it along with some bolt on stuff. There is a spike right off the bat when I go WOT, to about 23 psi, levels off to about 20 psi. It would be nice to eliminate the spike by having the boost NOT fall off, any ideas? This is being done on a Mustang dyno.

[mkriebs]

I believe that is pretty much the nature of the turbo... but someone with more experience could correct me on that.

[Spinner]

Adding timing isnt going to make more power on this motor.

[mkriebs]

Actually, i believe that Terminator found out it was good for a couple hp. Not a whole ton, but some is better than none.

[Terminator2]

Adding timing isnt going to make more power on this motor.

I have to repectfully disgree. I made 10 whp more on 91 octane adding 3-4* up top. 18 whp up top on 93 octane with the timing I am running right now. It makes only a small difference in the midrange and low end but up top there are good gains.

[Iam Broke]

I'm up to 15* advance up top on 93 octane but saw 3*KR today (90* out) on a 3rd gear pull to redline. No KR in 2nd so I'll leave it for now.

Term, I had to take another -0.8% out of my MAF tables to get the LTFT's to zero today. Started the day at -1.6, ended this afternoon at +0.8 after 85 miles. I calculated the numbers from the stock MAF curves and I'm just a hair under +9% total MAF with the AEM CAI on it. Close to yours isn't it?

[mkriebs]

I just adjusted my Maf for my fuel trims as well. LTFT's were -2%, so that means I add 2% to the MAF tables, right?

[Iam Broke]

Nope, multiply them by 0.98. When my LTFT's were 14.2 I mukltiplied them by 1.14 (14%)to get them close. Yours are -2 so a 2 % increase would be multiplying them by 0.98

[Terminator2]

I just adjusted my Maf for my fuel trims as well. LTFT's were -2%, so that means I add 2% to the MAF tables, right?

If you are adjusting your calibration table you would multiply by 0.98. If you were using your correction table you would subtract 0.02 from the cells in that table.

[Terminator2]

I'm up to 15* advance up top on 93 octane but saw 3*KR today (90* out) on a 3rd gear pull to redline. No KR in 2nd so I'll leave it for now.

Term, I had to take another -0.8% out of my MAF tables to get the LTFT's to zero today. Started the day at -1.6, ended this afternoon at +0.8 after 85 miles. I calculated the numbers from the stock MAF curves and I'm just a hair under +9% total MAF with the AEM CAI on it. Close to yours isn't it?

Mine is at +8 to +9 so yes it is about the same.

[MattD]

Anyone got any good .cfg's that I can use on an 09 Cobalt SS that will work with the beta?

[mkriebs]

Anyone having problems logging their wideband? I mean, I had it in my old config, reinstalled the software, and it won't recognize the wideband, nor the boost sensor. I know i have to have them in my table, and I have them in there, but once I plug it into the car, it says unsupported parameter.

[mkriebs]

Oh, and this is the .cfg I use. If anyone wants to try it and see if I have overlooked something concerning the wideband and the boost. Is there something that would have gotten deleted when i reinstalled the program?

[SSpdDmon]

Here's my current tune. I consider it a relatively great place to start on the LNF Cobalts.

Timing is up a touch - but still safe. Also, you'll notice that the last row of the valve timing and ignition timing tables are stock (or near stock). The reasoning behind this is, if I'm NL shifting at 6K rpm - why push the motor to the limits in & above those ranges? If I miss a shift, then it'll be a touch easier on the engine as well. Again, trying to keep safety and longevity in mind.

Other changes - I've tweaked the MAF for my fueling requirements (K&N drop-in + catless downpipe), removed the speed limiter, and altered the rev limiter to my liking. AFR's are a safe 12.5:1 at WOT and adjusted for non-WOT, high load scenarios. Lastly, I've left some torque managment in to help try and save the stock clutch as long as possible. Technically, I realigned the RPM columns to limit how hard boost hits in lower RPM WOT application.