Can i do an SD tune without a wideband?
04-22-2009, 07:38 PM
#1
Can i do an SD tune without a wideband? i ported and polished my MAF, then i got another one at autozone and they are both doing the same thing. The LTFTs go way up and are pegged for most of the time. Then, when i unplug the MAF, things are great. MY question is, can i just unplug the MAF until i get a wideband? I just have bolt ons and a fuel pump upgrade. Nothing internal. ...Nitrous, but havent used it yet. How much will this hurt my gas mileage, performance, streetability, etc? Thanks
04-22-2009, 07:47 PM
#2
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Yeah you can tune without a wideband, just use your fuel trims. When I disconnect my maf my wideband shows decent fuel trims without tuning, however my car is mostly stock except for an intake and catback. Your headers might throw off your VE table but you say it looks good so it should be fine. You are aware that disconnecting the maf will force your car use the low octane tables right? Why not just tune your maf? Do you have a wet or dry nitrous kit?
04-22-2009, 07:55 PM
#4
what does the low octane tables mean? Im assuming it doesnt mean that i can start suddenly running 87 octane on this right? Or does it mean that it will tell my car to automatically detune the car as if it WERE running the lower octane gas?
04-22-2009, 08:04 PM
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correct, it will default to the low octane timing table which is less aggressive than the high octane table.......yeah, don't use 87 octane. Have you tried scaling the maf up like 10% or so?
04-23-2009, 08:02 AM
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You have no idea what ur A/F ratio at wide open throttle is. If it is lean it is hot. I have seen more than few engines with problems from this. Get a wide band do it right. They are not that much.
04-24-2009, 03:23 AM
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You can tune the car for SD without a wideband but it should only be done to allow you to drive the car (no WOT/PE) until you get a wideband.
Try adjusting your MAF Airflow table(s) based on the results of your logging. I recently made a number of changes to my car and the LTFT (when MAF is enabled) go 25%+ right away. I assumed something was wrong but after a bit of logging and MAF Airflow adjustments it appears that my MAF Airflow table might just be that out of whack after my recent modifications.
Try adjusting your MAF Airflow table(s) based on the results of your logging. I recently made a number of changes to my car and the LTFT (when MAF is enabled) go 25%+ right away. I assumed something was wrong but after a bit of logging and MAF Airflow adjustments it appears that my MAF Airflow table might just be that out of whack after my recent modifications.
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04-25-2009, 04:14 PM
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when I ported my maf on my LT1 my trims went way positive also. Its because the maf area has been increased so you are actually flowing more air than recognizes. You have to skew the entire maf curve up to compensate. I'll never waste my time doing that again, gains are minimal and its a hassle. Have you tried adjusting the maf yet?
Oh yeah, post a log already haha.
Oh yeah, post a log already haha.
