WOT Short Term Fuel Trim

p4ndiamond · January 2nd, 2012, 02:50 PM

Been doing some data logging . and it seems at wide open throttle the car is requesting a value of 20.1 short term fuel trip at around 5k RPM. is there any way to richen that up some. This is on P.I intake/cam swapped motor.

FLEX4.6 · January 2nd, 2012, 03:04 PM

Want to tune mine? Lol

p4ndiamond · January 2nd, 2012, 11:45 PM

heres the specs on it and what its requesting right now.

Tang Stang · January 3rd, 2012, 09:21 AM

STFT's aren't reliable data to look at when in open loop (WOT). You can use STFT's to tune in closed loop, but you'll need to use a WBO2 to do your WOT tuning.

p4ndiamond · January 3rd, 2012, 11:44 AM

Ya just got my wideband ordered . should be here friday.can't wait.

97S281 · January 3rd, 2012, 12:31 PM

If my car was running that lean I would shut it down.

Tang Stang · January 3rd, 2012, 12:51 PM

Originally Posted by 97S281

If my car was running that lean I would shut it down.

The STFT's are just that, trims. He isn't seeing a 20:1 AFR.

p4ndiamond · January 3rd, 2012, 01:21 PM

Yeah. im surprised that it trims that hard . Even when i richen the MAF up top its still the same. Once i get my wide band in i will beable to do everything properly of course .just still surprised that stomping in the mine field shows no effect. I would assume the PI swap (intake and cams ) would make things leaner vs rich meaning i have to add fuel .

97S281 · January 3rd, 2012, 01:28 PM

Originally Posted by Tang Stang

The STFT's are just that, trims. He isn't seeing a 20:1 AFR.

Ok. Educate me. What is all this jibberish about. I have no tuning experience other than adjusting screws on carburators to run rich or lean.

I leave all my tuning to the experts.

p4ndiamond · January 3rd, 2012, 01:45 PM

Originally Posted by 97S281

Ok. Educate me. What is all this jibberish about. I have no tuning experience other than adjusting screws on carburators to run rich or lean.

I leave all my tuning to the experts.

Haha, im new to it too. Short term fuel trims are adjustments the ECU makes automatically to target a certain AFR that is defined in its code . So if it sees like a 13.45 AFR and the target is 14.7 it will cut fuel to the cylinder banks in order to target that AFR.

I think i explained that right lol.

FLEX4.6 · January 3rd, 2012, 01:47 PM

Why is it saying that much hp and torque?

Tang Stang · January 3rd, 2012, 01:48 PM

Originally Posted by p4ndiamond

Yeah. im surprised that it trims that hard . Even when i richen the MAF up top its still the same. Once i get my wide band in i will beable to do everything properly of course .just still surprised that stomping in the mine field shows no effect. I would assume the PI swap (intake and cams ) would make things leaner vs rich meaning i have to add fuel .

I wouldn't mess around with the transfer function too much until you have the wideband on it. You won't do any damage by adding fuel, but you'll likely have to straighten it all out later.

Originally Posted by 97S281

Ok. Educate me. What is all this jibberish about. I have no tuning experience other than adjusting screws on carburators to run rich or lean.

I leave all my tuning to the experts.

Short term fuel trims are the immediate adjustments made by the EEC during closed-loop using the narrowband O2 sensors to achieve the commanded AFR. Long term fuel trims are adjustments made by the EEC using the trends seen from the STFT's. There is WAY more to this, but that is about as basic as I can make it.

p4ndiamond · January 3rd, 2012, 01:50 PM

Originally Posted by FLEX4.6

Why is it saying that much hp and torque?

BECAUSE RACECAR !!!

p4ndiamond · January 3rd, 2012, 01:52 PM

Originally Posted by Tang Stang

I wouldn't mess around with the transfer function too much until you have the wideband on it. You won't do any damage by adding fuel, but you'll likely have to straighten it all out later.

Short term fuel trims are the immediate adjustments made by the EEC during closed-loop using the narrowband O2 sensors to achieve the commanded AFR. Long term fuel trims are adjustments made by the EEC using the trends seen from the STFT's. There is WAY more to this, but that is about as basic as I can make it.

Ahh i get it, that puts it in much better perspective. i have a stock MAF table saved. it lets you import and export them at will. just purchased an Innovate LC-1 166 bucks not too bad for gauge and data logging.

FLEX4.6 · January 3rd, 2012, 01:52 PM

Ha. There is no way you make that much unless you added something and didnt tell us about it. Lol

Tang Stang · January 3rd, 2012, 01:57 PM

Originally Posted by FLEX4.6

Why is it saying that much hp and torque?

If the MAF transfer function isn't correct (which effects the load calculation) and/or the MBT table isn't correct, it will throw off the torque calculation. Horsepower is derived directly from that calculation and engine rpm.

FLEX4.6 · January 3rd, 2012, 01:58 PM

Ah. Got ya.

p4ndiamond · January 3rd, 2012, 02:12 PM

Yeah this not dyno tune lol but my other engine will dyno probably about that or much more.

p4ndiamond · January 3rd, 2012, 02:16 PM

Originally Posted by Tang Stang

If the MAF transfer function isn't correct (which effects the load calculation) and/or the MBT table isn't correct, it will throw off the torque calculation. Horsepower is derived directly from that calculation and engine rpm.

Do you happen to know if we can use our cars EGR monitor wires as a wide band port like on the EEC-IV cars . i planned to do that also if possible

Tang Stang · January 3rd, 2012, 02:23 PM

Originally Posted by p4ndiamond

Do you happen to know if we can use our cars EGR monitor wires as a wide band port like on the EEC-IV cars . i planned to do that also if possible

I use XCal2's to tune my cars, so my widebands just plug into the analog port on the handhelds.

January 2nd, 2012, 02:50 PM	#1
p4ndiamond Hardcore Enthusiast 1997 Pacific Green Cobra 14.80 No traction Join Date: May 2010 Location: New Orleans Posts: 1,216 iTrader: 0 reviews	WOT Short Term Fuel Trim Been doing some data logging . and it seems at wide open throttle the car is requesting a value of 20.1 short term fuel trip at around 5k RPM. is there any way to richen that up some. This is on P.I intake/cam swapped motor. __________________ GT ENGINE (temporary) 4.30 Gears , 31 spline Moser axles , Detroit tru Trac diff, Jmod 4r70w , Pi intake Hitech stage 2 cam, Vortech V2 3.33 pulley. Alum drive shaft. Lowering kit x2 ball joints ,screamin demon coils, LCA " Last edited by p4ndiamond; January 2nd, 2012 at 03:11 PM.

January 2nd, 2012, 11:45 PM	#3
p4ndiamond Hardcore Enthusiast 1997 Pacific Green Cobra 14.80 No traction Join Date: May 2010 Location: New Orleans Posts: 1,216 iTrader: 0 reviews	heres the specs on it and what its requesting right now. __________________ GT ENGINE (temporary) 4.30 Gears , 31 spline Moser axles , Detroit tru Trac diff, Jmod 4r70w , Pi intake Hitech stage 2 cam, Vortech V2 3.33 pulley. Alum drive shaft. Lowering kit x2 ball joints ,screamin demon coils, LCA "

January 3rd, 2012, 09:21 AM	#4
Tang Stang Hardcore Enthusiast 2004 Mustang GT Join Date: Sep 2010 Location: Imperial, MO Posts: 1,961 iTrader: 2 reviews	STFT's aren't reliable data to look at when in open loop (WOT). You can use STFT's to tune in closed loop, but you'll need to use a WBO2 to do your WOT tuning. __________________ Rod @ AzzKicker Cars 2004 Ford Mustang GT-The Driver-BBK CAI, PP TB & Inlet, Steeda UD's, SLP LM1, & 3.73's. 1990 Mercury Cougar XR7-The Meth Addict-5.0L DOHC Stroker w/2.1L KB SC. 1995 Ford F150-Mud Toy-5.0L, 4x4, 33's, & Warn 8274 Winch

January 3rd, 2012, 11:44 AM	#5
p4ndiamond Hardcore Enthusiast 1997 Pacific Green Cobra 14.80 No traction Join Date: May 2010 Location: New Orleans Posts: 1,216 iTrader: 0 reviews	Ya just got my wideband ordered . should be here friday.can't wait. __________________ GT ENGINE (temporary) 4.30 Gears , 31 spline Moser axles , Detroit tru Trac diff, Jmod 4r70w , Pi intake Hitech stage 2 cam, Vortech V2 3.33 pulley. Alum drive shaft. Lowering kit x2 ball joints ,screamin demon coils, LCA "

January 3rd, 2012, 12:31 PM	#6
97S281 Rollin' 18/ pushin' 2 1997 Saleen S281 Join Date: Feb 2007 Location: The lost highway Posts: 6,673 iTrader: 13 reviews	If my car was running that lean I would shut it down. __________________ MODS IN GARAGE NCMM ORIGINAL BLOWN 96-98 CREW MEMBER # 1

January 2nd, 2012, 03:04 PM	#2
FLEX4.6 Regular 96 Mustang Gt Join Date: Mar 2011 Location: La Posts: 347 iTrader: 1 reviews	Want to tune mine? Lol

January 3rd, 2012, 01:21 PM	#8
p4ndiamond Hardcore Enthusiast 1997 Pacific Green Cobra 14.80 No traction Join Date: May 2010 Location: New Orleans Posts: 1,216 iTrader: 0 reviews	Yeah. im surprised that it trims that hard . Even when i richen the MAF up top its still the same. Once i get my wide band in i will beable to do everything properly of course .just still surprised that stomping in the mine field shows no effect. I would assume the PI swap (intake and cams ) would make things leaner vs rich meaning i have to add fuel . __________________ GT ENGINE (temporary) 4.30 Gears , 31 spline Moser axles , Detroit tru Trac diff, Jmod 4r70w , Pi intake Hitech stage 2 cam, Vortech V2 3.33 pulley. Alum drive shaft. Lowering kit x2 ball joints ,screamin demon coils, LCA "

January 3rd, 2012, 01:47 PM	#11
FLEX4.6 Regular 96 Mustang Gt Join Date: Mar 2011 Location: La Posts: 347 iTrader: 1 reviews	Why is it saying that much hp and torque?

January 3rd, 2012, 01:52 PM	#15
FLEX4.6 Regular 96 Mustang Gt Join Date: Mar 2011 Location: La Posts: 347 iTrader: 1 reviews	Ha. There is no way you make that much unless you added something and didnt tell us about it. Lol

January 3rd, 2012, 01:58 PM	#17
FLEX4.6 Regular 96 Mustang Gt Join Date: Mar 2011 Location: La Posts: 347 iTrader: 1 reviews	Ah. Got ya.

January 3rd, 2012, 02:12 PM	#18
p4ndiamond Hardcore Enthusiast 1997 Pacific Green Cobra 14.80 No traction Join Date: May 2010 Location: New Orleans Posts: 1,216 iTrader: 0 reviews	Yeah this not dyno tune lol but my other engine will dyno probably about that or much more. __________________ GT ENGINE (temporary) 4.30 Gears , 31 spline Moser axles , Detroit tru Trac diff, Jmod 4r70w , Pi intake Hitech stage 2 cam, Vortech V2 3.33 pulley. Alum drive shaft. Lowering kit x2 ball joints ,screamin demon coils, LCA "

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