LNF STFT and LTFT Tuning

[gmtech16450yz]

I had the ZZP S252 tune emailed to me from a couple different people and you would be shocked how rich they run their setups if you think .85 is WAY rich LOL!

Yeah and they wonder why they have to modify the cr#p out of the fuel system to get it to run right! Common knowledge for damn near every internal combustion engine made in the last 100 years is if you want to make power you don't dump a ton of fuel into it. I learned that playing with Cox .049 engines when I was 9 years old. You make the most power right before it blows up! I'll never forget talking to drag boat engine builders years ago (long before widebands and fuel injection) they said they lean it out 'till it blows, then rebuild and go back a little richer!

[gmtech16450yz]

I just had another thought about this mixture issue. Has anyone ever seen an LNF that was "blown up" or damaged by running too lean? I personally have NEVER seen or heard of one that was DIRECTLY related to a lean condition. The ring land issue is caused by heat, usually from pushing the stock turbo too far. A super rich mixture will help avoid it, but that's just a bandaid for the real issue. What happens is you might save the pistons, but you're diluting your oil and will end up with lower end problems sooner or later. More power can be made and be safer and kinder to your motor with lower boost and leaner mixtures in that situation.

Another thing to remember, the stock tune runs at .95 PE in the midrange. How many bone stock LNF's, or even ones with the gmpp tune, their lean mixtures and massive KR have blown? A few but certainly not an epidemic. Lean mixtures will burn holes in pistons and burn valves. I've never seen an LNF with either of those.

My point is everyone keeps saying it's "safer" to run these motors pig rich. Can ANYONE show me some proof of an LNF failure from actually running too lean? I believe everyone is worried about something that just doesn't happen, or at least is extremely rare.

[Iam Broke]

ROTFLOL on the Cox .049. I had more than a few. More nitro please! Cox TD .051 was my favorite.

Graduated into 1.2 C.I. 4 stroke O.S. Engines ~15 years ago, still need more nitro.

[cobaltssoverbooster]

i have a K&B 1.o CI haha i smoked a supercharged seadoo last year in lake havasu area

[gmtech16450yz]

Damn! I'm gonna say that radio is late '70's or early '80's?
I had a few that looked like that. I gotta ask, how old are you? I'm a "young" 49. (it's all relative ain't it?)

[cobaltssoverbooster]

yea im 23 haha i got the boat from my boss and it had ghetto radio. i put my motor on it with dual metal servos for steering and upgraded to a blue wireless network style aircraft radio ahhaa
i tossed that stupid radio it was trash

[Iam Broke]

Ghetto radio? Stupid? Why you young whipper snapper! I still have 6 of those state of the art 1980's Futabas. Ha!
They were the most reliable for R/C aircraft then. I got you all beat, Iz 54!

I haven't flown any in about 10 years and all my stuff needs to be updated. Too many toys, not enough time.

[cobaltssoverbooster]

haha well if you feel beter i still have futaba servos in there

[BackyardTurbo_FTW]

There's been a few people that melted pistons.

[cobaltssoverbooster]

i may perform a small swap with the lnf and if i do so i have plenty of room for a compound setup and may send in for some custom J.E. pistons and a install some carrillos or custom order Lunati rods. ill put some upgraded valve springs and maybe put some better valves in it stock size so i dont have to worry about a stem lock snap and dropping a valve. seen 4 of those in the last few months now.

still in idea mode though. at least it would tow what i want and get great gas mileage at the same time. ideas ideas ideas.....at least i can always dream haha

GET ER DONE!!!

[Devilbmxer120]

Whay can i not get the histogram right for this >_< Im on beta 2.23 I just logged MAF frequency and i was getting 4 digit numbers in random spots. There were a lot of empty spots too :/

[Whitmore29]

So I attempted this today for the first time. When I flashed my car with the MAF correction table set to 1s and the purge solenoid disconnected (I just removed the electric connection, not the vac line is this correct?) it idled so ridiculously rough I had to turn the car off and flash back to stock GMS1 for fear of damaging something. It was sputtering and revving up to 2k then falling to 600. Should I just try to wait this out or is something likely incorrect? The other thing is I only have the "base" Maf table set to 1's the other MAF tabled seemed to have values like 50 and high 40s (forget the name of the table and I'm not in front of my tuning laptop). Setting this to 1 seemed a little off (really dramatic change), any help is much appreciated I have a feeling I am missing something so simple.

Thanks,

[Iam Broke]

Leave the MAF frequency table stock, not 1's. Set the MAF correction table to all 1.0's.

Yes, just the electrical connector on the purge sol.

[cobaltssoverbooster]

http://www.hptuners.com/forum/showthread.php?t=35129
Follow this and tell us how it goes

[Whitmore29]

Thank you both for the responses both in thread and via PM. I did as you did in your picture tutorial. writing the "base" table under"MAF calibration" to all 1's once this was done and uploaded to the car as soon as I started it up it acted very odd. Would it matter that my EVAP solenoid was disconnected when I flashed (as per Nick's write up)? It is pouring here today so I likely wont make any headway tune wise but still would like to figure out where I'm going wrong. I have uploaded my tune file which is all stock GMS1 exact for fuel enrichment table and this MAF table, let me know what you think.

Thanks guys

[Iam Broke]

It should work ok from what I see. You do have the 3 bar GMS1 sensors, correct?

It doesn't matter that the sensor is disconnected when you flash as far as I know.

[Whitmore29]

It should work ok from what I see. You do have the 3 bar GMS1 sensors, correct?

It doesn't matter that the sensor is disconnected when you flash as far as I know.

I sure do have the proper sensors. Had gms1 insralled by the dealer before i took ownership of tue car. Ill try with the solenoid connected and see if that makes a difference. Thanks again.

[stromboli86]

I dont know about others but the first time i start my car up after a reflash it will do the same exact thing at idle, especially if its cold outside... Once it warms up after the flash it usually goes back to normal for whenever you start the car cold again

[Iam Broke]

You could disable the cat warmup.
Here's what I ran with it disabled, make the Knock & Cat heating tables the same as the Main ones even though cat heating should be disabled. As was stated, the car may run funky after a flash until it learns a bit.

[Whitmore29]

Thanks for the tips guys. I was just being paranoid at the rough idle I fired it up again today and flashed it again with the same file and no problem once it warmed up. I think I am on the right track now with all the help much appreciated.

@IamBroke:

Thanks for the tables, will these be alright to mess with on a car that still has a highflow cat? I have the MPX DP with Spun metal cat so I can pass inspections here in Canada.


Thanks again,

Chris