ninobrn99

iTrader: (8)

Ok, i keep hearing that the PE should be set at 14.7, but why does everyone have 14.63 or so?? it may not even be the PE, but you all know what im talking about... i hope

soundengineer

iTrader: (16)

no... PE(power Enrich) should be set to something around 12.9:1 ish For NA engines...richer for FI and Spray
stoich is mathematically 14.62857

ninobrn99

iTrader: (8)

so where is the stoich a/f set in tuners?? im just trying to make sure ive got a general understanding of what im doing before i do it. My friend thats gonna help me out with the tune is very familiar with the "old edit" ways and doesnt mess with the VE's at all. He uses the IFR's to adjust ltrims. Im trying to avoid that and use the newer methods is all. thanks again scott!

WS6FirebirdTA00

iTrader: (33)

that is the afr to keep the equation balanced (remember donig those in chem? lol) you have to change the ve, ifr tuning is BS, that will not do anything for you thta is helpful.

slow

iTrader: (7)

The Stoich A/F should relate to the actual stoich point of the fuel being run, without changing the fuel, there is little reason to change this value.

PE and IFR tuning, is a clear lack of understanding of the control system.

IFR should only be changed when you change the fuel delivery system.

PE is your "commanded air fuel ratio" you should "set" this to what you want, not "tweak" it to get desired results. You need to change the value that is incorrect, after the fueling is correct, your commanded air fuel is what you want, then the airflow tables need the adjustments.

Ryan

ninobrn99

iTrader: (8)

commanded would be 12.xx-13.xx correct? or is that the stoich?

slow

iTrader: (7)

Commanded is whatever air fuel ratio the pcm is calling for at that time, it could be anything from stoich to 11.0x or richer.

Stoich is the point where you want to be in closed loop, typically around 14.6x on a gasoline fuel.

Dave F

Back to basics, Stoichiometric is the Theoretical maximum fuel ratio that a given amount of oxygen can burn. Less fuel, and you have extra oxygen going out of the exhaust, more fuel, and you leave extra fuel being. 14.7 is the ratio that theoretically burn ALL of the fuel and air, basic chemistry.

In reality, trying to make power, stoichiometric is bad due to 2 reasons. 1. Heat: putting a little extra fuel in (10% or so, knocking the AFR down to 13ish) helps cool the compustion chamber and prevent burning up your valves and plugs. 2. Efficiency: distributing the exact amount of fuel evenly so that every drop gets used is difficult, so putting a little extra in makes sure that all of the air (oxygen) is used.

It's a trade off. For part throttle, you want fuel economy and clean emmissions, so you run Stoich. At WOT, you want max power and a SAFE combustion temperature, so you run rich.

torchredfrc

So part throttle is closed loop and wot is open loop correct?

RedHardSupra

iTrader: (1)

dave, what AFR do you run for your tracktime? I tried to log my car after some HPDE runs and it went ~7-10% leaner than normal, just because of high temps (i guess).

soundengineer

iTrader: (16)

No WOT is not necessarily Open Loop...Just PE..and its only PE if commanded so by the PE vs TPS table
Open loop is defined by Engine Coolant Temperature...when it exceeds a certain temp as defined in a tabel in the PCM it goes into closed loop
upon entering closed loop your car commands whatever PE is at WOT
when your car is still in open loop(example being cold start) it comands whichever of the 2 tables is richer...IF open loop commands 1.17 at 90kpa for your current ECT, and PE is only commanding 1.14 then it will use the open loop value of 1.17

SSpdDmon

iTrader: (10)

The way our cars come, WOT is open loop unless you change the closed-loop enable settings. Open loop fueling simply means the PCM is not getting feedback from the O2 sensors (because they only work around stoich) and therefore it is unable to make corrections. When you close the loop (think circular), there's feedback and the computer adjusts accordingly. Open loop is not only influenced by coolant temps, but throttle position as well. So, there's more than just cold starts that put your vehicle into open loop.

Bombguy99z28

The only reason you should ever change stoichmetric is if you change the fuel you are running. Just change stoichometric to whatever the lambda rating is for the fuel you are using.

To figure out what you are commanding, divide stoich by PE ratio. So if your stoich is 14.63 and your PE value at a given rpm is say 1.18, you are 'commanding' ~12.4 afr when you enter PE mode.

Nino, what year car do you have? I can always double check stuff for you if ya want.

ninobrn99

iTrader: (8)

99. Im taking it over to Ed's this weekend to complete my install and then begin tuning it. Im going to use my old bin and work from there. I was comparing my VE to what marcin has on his blogspot. My **** is off compared to his. Im pretty sure he got the numbers from AdamSS who is running the same cam i was. what do you think?
His are the 2 enclosed pics. the lower numbers belong to the f10 and the others to the x1 i believe. these are mine for the f10 114 following the same suite as his:
43.99997 47.99853 44.99763
43.99997 47.99853 48.99619
43.99997 48.99619 51.99708
43.99997 49.27331 54.22202
46.00321 50.90441 56.20151
47.99853 53.00266 57.99888
48.99619 54.00032 58.99654
50.99942 56.00356 60.00212
52.41674 57.42879 59.97836
55.31470 57.90386 59.82001
56.32820 58.91736 60.84934
57.34169 59.93086 61.88659
58.35519 60.94435 62.92384
59.36868 61.95785 63.95317
60.38218 62.97134 64.99042
62.11621 64.62619 67.26287
64.27780 66.78779 68.94147
66.43940 68.94939 70.62007
66.43940 68.94939 70.62007
ideas?

ninobrn99

iTrader: (8)

oh yeah, this also leads me to ask my next question. which should be tuned first? PE or OLFA? when should the DFCO be done? does it need to be done on a m6? i think i asked that, but dont remember. Please dont flame me

ninobrn99

iTrader: (8)

here's my spark tables relative to my ve:
19.01099 22.00000 27.01099 30.00000 34.00000
19.01099 22.00000 27.01099 30.00000 34.00000
19.01099 22.00000 27.01099 30.00000 34.00000
19.01099 22.00000 27.01099 30.00000 34.00000
17.01099 22.00000 28.00000 31.01099 34.00000
20.00000 23.01099 25.01099 28.00000 31.01099
24.00000 25.51648 24.00000 27.01099 28.00000
22.00000 23.75824 22.00000 26.00000 27.01099
20.00000 22.00000 21.01099 24.00000 26.00000
18.00000 20.00000 17.01099 22.00000 23.01099
16.00000 18.00000 13.01099 17.01099 21.01099
14.50549 16.74725 11.01099 15.01099 18.00000
13.01099 15.51648 8.00000 12.00000 15.01099
12.02198 14.76923 7.01099 10.00000 14.00000
11.01099 14.02198 6.00000 9.01099 13.01099
10.50549 13.51648 6.00000 9.01099 13.01099
10.00000 12.98901 6.00000 9.01099 13.01099
9.75824 12.74725 6.00000 9.01099 13.01099
9.49451 12.48352 6.00000 9.01099 13.01099
9.25275 12.24176 6.00000 9.01099 13.01099
9.01099 12.00000 6.00000 9.01099 13.01099
8.76923 11.75824 6.00000 9.01099 13.01099
8.50549 11.49451 6.00000 9.01099 13.01099
8.50549 11.49451 6.00000 9.01099 13.01099
-4.00000 2.00000 6.00000 9.01099 13.01099
-4.00000 2.00000 6.00000 9.01099 13.01099
-4.00000 2.00000 6.00000 9.01099 13.01099
-4.00000 2.00000 6.00000 9.01099 13.01099
-4.00000 2.00000 6.00000 9.01099 13.01099

Bombguy99z28

The steps I use to tune:

1. Maf unplugged dial in VE.

2. Plug MAF in, dial in MAF.

3. Do some WOT testing, I don't have a wideband so I just check that my A/F is around 890-900. I might adjust PE slightly, but without a wideband or on a dyno it doesn't really matter because you won't know if you're making better power or not.

4. Kinda in conjunction with 3, I want to keep an eye on my timing. Generally you won't gain anything trying to add more timing. In my case at 11.8:1 compression I had to pull a bunch of timing anyway, no big deal.

Thats all I do. Granted I do a LOT of logging for each step. Once I've done those 4 steps, if I were so inclined it would be a good time to go dyno.

Real dyno tuning can only be done on a brake dyno with bi-directional controls, but if you just want to check your WOT AFR and timing. In general you will reach a point were timing doesn't increase power. Usually this is about 5-6* BEFORE you start to get knock. Don't run as much as you can without getting knock, run the least amount of timing it takes to reach the point of negligible return. Same with AFR. Find your point of negligible return, and run the richest AFR you can without giving up a lot.

Ain't much to it, I've never really messed with most of the other stuff. I have tuned the idle stuff, and can give you a hand with that if you need. I rum a 110 lsa cam so I've had to play with it a lot.

Bombguy99z28

I wouldn't mess with DFCO unless you think its causing you a problem. The car runs mainly off of only a couple tables, in general these are the only things you should touch UNLESS you are trying to troubleshoot something.

ninobrn99

iTrader: (8)

to my understanding (JimMuller pointed this out to me) there is a histogram in 2.0 that will take once or twice to do, but that should get my RAF in order. If you look under this forum, i think ive just reached enlightenment i know i made a thread about it, but since your in here When tuning the ve, do i do it cell by cell or a few at a time? or is it just a matter of preference?

ninobrn99

iTrader: (8)

ok, i just thought they were something you "had" to mess with. if its one less thing i dont have to do, so be it!! Oh btw, my cam came in today :