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Air/Fuel changes

Maybe some guys can give me an insight to my recent Air/Fuel changes. Over last year and a half I wanted more power(who doesn't). I upgraded my turbos to twin 54mm. I upgraded to 96lb injectors and swapped out the 4 Bosch pumps with a aeromotive single pump(good for 1000 hp). I installed a new wide-band O2 in the exhaust pipe as designated by the manufacturer. According to the O2 car was too rich to register everywhere in the map table. Started taking out fuel. Got to the point where all fuel ratios looked good except O2 reading rich at idle(10.6-1) and too rich to read over 19lbs boost. Idle did not change much no matter what I did. But started pulling more fuel out of high boost. I live in Florida and most test days were in the upper 80's- mid 90's. It is now cooler 70's to 80's. Took car out for little blast and in pulled fantastic. But noticed idle O2 now reading 13-1. Took it out again a week later. When I started it, idle read 14-1 and started coming down(richer) as car warmed up. On next blast fuel mixtures at above 19lbs boost up to 23lbs read 11.3-1 and computer was adding 5% fuel to get there. I do not have any warm up enrichments programmed in yet. Is it possible 20 degrees of outside temp. could change the mixture that much. And as for idle why did it change so drastically? It is a twin plug motor and I run regular Bosch plugs in bottom and Bosch race plugs in top. I guess it is possible that I fouled out the race plugs and when the engine mixture got better it cleaned off plugs and they started firing. I checked the O2 for accuracy, I checked fuel pressure, Idle vacuum is better than before. Only thing i can think of is plugs,warm up enrichments, or some type of fuel restriction. Any thoughts?

Old 11-07-2014, 04:10 AM
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What is your base fuel pressure? Did it change when you went to the one, big pump? What is the base fuel pressure now? Do you have a rising rate FPR?
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Brad...930 gt-1 racecar, increased displacement to 3.6L, JB racing Cylinders, JE 8 to1 pistons, stroked crank, Carrillo rods, extrudehoned 3.2L intake, full bay Bell I/C, GT-2 EVO cams, Rarly8 headers, GTX-3584RS turbo, twin plug, P&P heads, Link G4 EFi system, G-50/50 with LTD slip and oil squirters/oil cooler, zork tube, full race coilover system, with carbon fiber body, full cage, E-85 sippin drunk
Old 11-07-2014, 05:40 AM
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Base fuel pressure is 44lbs at idle, this did not change. It is a rising rate regulator. Fuel ratios only changed when temp did and after I made two runs in 2nd gear 23 lbs boost, 7200 rpm 105 mph.
Old 11-07-2014, 05:56 AM
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What air fuel does your car car run at idle turbobrat930?
Old 11-07-2014, 05:57 AM
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I run ID1000 injectors (100 lb at 43 PSI) and I run a base fuel pressure of 50 PSI. Dual 044 Motorsports pumps.... I have my AFR set to be about 14.0 to 14.2 at idle. Any leaner, and the engine sounds lean, and there is really no need for me to go any richer at idle.
I can manually set the cells where the engine idels at in the fuel maps (both with a fuelmap based off of MAP and RPM, and TPS and RPM)

What ECU are you running?
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Brad...930 gt-1 racecar, increased displacement to 3.6L, JB racing Cylinders, JE 8 to1 pistons, stroked crank, Carrillo rods, extrudehoned 3.2L intake, full bay Bell I/C, GT-2 EVO cams, Rarly8 headers, GTX-3584RS turbo, twin plug, P&P heads, Link G4 EFi system, G-50/50 with LTD slip and oil squirters/oil cooler, zork tube, full race coilover system, with carbon fiber body, full cage, E-85 sippin drunk
Old 11-07-2014, 06:12 AM
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Also, coud you have blown off a small vacuum line at that boost level, and your ICV is maintaining your idle, but you are adding extra air at idle, whick would be making you leaner?
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Brad...930 gt-1 racecar, increased displacement to 3.6L, JB racing Cylinders, JE 8 to1 pistons, stroked crank, Carrillo rods, extrudehoned 3.2L intake, full bay Bell I/C, GT-2 EVO cams, Rarly8 headers, GTX-3584RS turbo, twin plug, P&P heads, Link G4 EFi system, G-50/50 with LTD slip and oil squirters/oil cooler, zork tube, full race coilover system, with carbon fiber body, full cage, E-85 sippin drunk
Old 11-07-2014, 06:15 AM
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Ambient temps have a huge effect on AFR's.

What EFI system do you have?

Do you have an inlet temp sensor scale that you can adjust for air temp changes?

According to the ideal gas law, air temp readings may not be completely linear.

My scale is a little slopey to accommodate different ambient air temps to maintain same AFR's.
Old 11-07-2014, 07:09 AM
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I have no idle control valve. I use 962 central plenom to read vacuum. And the vacuum reading actually got better, so no leak and peak boost is also the same as before. The new air fuel ratios are great, better than ever before, just can not figure what changed. Run electromotive TEC3R engine management. Idle only was pig rich, now good. Just watching air fuel to see if continues to lean out or stays fixed at or around the cooler temperatures.
Old 11-07-2014, 07:12 AM
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Tippy is spot on above. I have an Intake air Temp sender (Bosche standard) and it really is an intragal part of the system.

I know you say that you have the Tec-3R system. Do you have a intake air temp sender?
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Brad...930 gt-1 racecar, increased displacement to 3.6L, JB racing Cylinders, JE 8 to1 pistons, stroked crank, Carrillo rods, extrudehoned 3.2L intake, full bay Bell I/C, GT-2 EVO cams, Rarly8 headers, GTX-3584RS turbo, twin plug, P&P heads, Link G4 EFi system, G-50/50 with LTD slip and oil squirters/oil cooler, zork tube, full race coilover system, with carbon fiber body, full cage, E-85 sippin drunk
Old 11-07-2014, 08:30 AM
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Yes I do. Should I tune the car at moderate temperature and add or subtract fuel with the air temp sensor? I pull some fuel out now with it at high boost and higher air temps. I could easily do the same but add it with cooler air temps. This may work well as the map fuel table is pretty well tuned and working well.
Old 11-07-2014, 08:37 AM
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Your ECU should be doing that for you. Obviously, air gets denser as it gets colder, so, in order to prevent a lean condition when colder air prevails, you would need to add a little more fuel... I am not familiar with Tec-3r system, but there should be a user adjustable table there, where you can adjust things...

I just re-read what you said in your last post. You are correct. I would add some when the air temp shows colder. You should be good then!!
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Brad...930 gt-1 racecar, increased displacement to 3.6L, JB racing Cylinders, JE 8 to1 pistons, stroked crank, Carrillo rods, extrudehoned 3.2L intake, full bay Bell I/C, GT-2 EVO cams, Rarly8 headers, GTX-3584RS turbo, twin plug, P&P heads, Link G4 EFi system, G-50/50 with LTD slip and oil squirters/oil cooler, zork tube, full race coilover system, with carbon fiber body, full cage, E-85 sippin drunk

Last edited by turbobrat930; 11-07-2014 at 09:18 AM..
Old 11-07-2014, 08:57 AM
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The ECU only does what you allow it to do on the TEC3R. I can tune by map, engine temp, and air temp, also by TPS. You can also give the computer an authority range for the O2 sensor. Mine is tuned to only change mixtures by 4%. I can change the amount but the better tuned the computer is the less the O2 should have to work. Usually after tuning I turn off the authority range, so if the sensor fails it's not adding or pulling fuel. I will work on air temp tuning now and see where that takes me. Thanks for everyone's help.
Old 11-07-2014, 09:23 AM
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Well, I found after swapping out sensors. My problem is not in my tune, good thing I did not make any radical changes. The AEM wideband O2 sensor is bad after only about 10 runs. Called AEM and they say high EGT's. I use an aircraft EGT set up with 6 individual sensors, I do not have high EGT's. Then they say the sensor needs to be 36" from the exhaust port. Not possible, have they ever seen 935 headers and twin turbo set up. So basicly the sensors will not survive under high boost runs, so I need to find a source where I can buy them at a descent price as it looks like I will be replacing them often or turning off the computers ability to make changes based on the wideband readings. Have seen somewhere a spacer which is suppose to reduce some of the heat to the sensor but can not recall who makes it.
Old 11-11-2014, 03:57 AM
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I have an Innovate MTX-L that has been just fine so far for a few years.

You can fab up a piece of copper sheet to act as a heat sink. Simply drill a hole and mount in between the sensor and bung.

It'll act like a washer and heatsink.
Old 11-11-2014, 04:03 AM
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Innovate Motorsports makes a nice O2S heat sink if you don't choose to fab your own.
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Old 11-11-2014, 05:57 AM
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I purchased the Innovate O2 heat sink. Will see how long sensor lasts with this installed.
Old 11-11-2014, 06:16 AM
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+1000 on the mtx unit. prob one of the best for our cars because it removes the "brain" from the hostile enviroment of the engine bay. also you always need to add fuel for cooler temps, and yes here in so. fla it can go from 90 to 65 in 12 hours which can wreak havoc on a tune without having an active intake temp sensor. i cant imagine a stand alone system not being able to support that vital function.i dont know the system other than replacing one for an ms3 unit but i am sure it can do that function. no carrier and i will be in daytona this week helping pete with the k3 for the hsr races thru sunday if you want to stop by

Old 11-11-2014, 06:28 AM
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