Fast 90/92 which maf and what size?
02-05-2018, 04:16 AM
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Fast 90/92 which maf and what size? Im sure this has been asked a million times but I still haven't found a clear answer so hoping some one can chime in.
Forged ls1, ported 243's, ported fast 90mm/92 nick Williams, speartech standalone harness for gen 3 engines. Couple classified ads right now for 85mm ls6 screenless/screened mafs, truck 90mm maf, 90mm granatelli maf, and stock ls1/ls6 maf. Which would be the best choice and is it as simple as buying the adapter harness to go from a 3 pin to 5 pin for the truck and granatelli maf?
intake will be a 90 degree elbow off the throttle body to a straight pipe (opinion on tube size recommended ?) To a cone style filter.
The efi deal is all new to me so learning all of this stuff from the forum and internet, any info is greatly appreciated
Forged ls1, ported 243's, ported fast 90mm/92 nick Williams, speartech standalone harness for gen 3 engines. Couple classified ads right now for 85mm ls6 screenless/screened mafs, truck 90mm maf, 90mm granatelli maf, and stock ls1/ls6 maf. Which would be the best choice and is it as simple as buying the adapter harness to go from a 3 pin to 5 pin for the truck and granatelli maf?
intake will be a 90 degree elbow off the throttle body to a straight pipe (opinion on tube size recommended ?) To a cone style filter.
The efi deal is all new to me so learning all of this stuff from the forum and internet, any info is greatly appreciated
02-05-2018, 09:07 AM
#6
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As far as the OP question goes, if you really want to run the MAF, then it will depend on your computer and harness. If you have a separate IAT sensor, then three wire MAF. If not, then go for the built in IAT, 5 wire MAF. There are adapters out there to convert 5 to three. I don't think it goes the other way though, unless you like repining things.
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02-05-2018, 10:16 AM
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02-05-2018, 10:18 AM
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02-05-2018, 10:25 AM
#11
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I'm sure you know what they mean. And the most confusing military acronyms are the ones that have multiple meanings. Like IDF.
02-05-2018, 10:37 AM
#12
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Yeah, wasn't sure you were pulling our collective chain! lol I fell for it! Gullible me... Yeah I knew most of the military ones too(not all...) but it all gets to be alphabet soup after a while... And when I DO learn a new one, I'm like, WTF....
02-05-2018, 11:28 AM
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This whole swap is still being put together so I'm open to changing stuff up if possible. I already have a nick Williams 92mm so I'm good there. As far as speed density how does it work and what do I need to purchase to do it?
My speartech harness is for gen3 ls1/6/5.3 etc so it has the 3 pin plug style maf and I would assume it has the iat but the harness is still bring shipped to me do can't verify yet.
I don't have any kind of a tune yet so that will be starting from a clean slate for the tuner, everything I've read speed density is more for boosted cars rather than street daily driven cars and is harder to tune but the guys running can you tell me wether that's true or not ?
My speartech harness is for gen3 ls1/6/5.3 etc so it has the 3 pin plug style maf and I would assume it has the iat but the harness is still bring shipped to me do can't verify yet.
I don't have any kind of a tune yet so that will be starting from a clean slate for the tuner, everything I've read speed density is more for boosted cars rather than street daily driven cars and is harder to tune but the guys running can you tell me wether that's true or not ?
02-05-2018, 11:41 AM
#14
TECH Fanatic
My favorite military acronym is probably LPC's... leather personnel carriers.
02-05-2018, 12:15 PM
#15
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This whole swap is still being put together so I'm open to changing stuff up if possible. I already have a nick Williams 92mm so I'm good there. As far as speed density how does it work and what do I need to purchase to do it?
My speartech harness is for gen3 ls1/6/5.3 etc so it has the 3 pin plug style maf and I would assume it has the iat but the harness is still bring shipped to me do can't verify yet.
I don't have any kind of a tune yet so that will be starting from a clean slate for the tuner, everything I've read speed density is more for boosted cars rather than street daily driven cars and is harder to tune but the guys running can you tell me wether that's true or not ?
My speartech harness is for gen3 ls1/6/5.3 etc so it has the 3 pin plug style maf and I would assume it has the iat but the harness is still bring shipped to me do can't verify yet.
I don't have any kind of a tune yet so that will be starting from a clean slate for the tuner, everything I've read speed density is more for boosted cars rather than street daily driven cars and is harder to tune but the guys running can you tell me wether that's true or not ?
The difference is SD is based on a theoretical fuel value that uses MAP and rpm, and some other things. Climate and altitude can affect it. Street cars are best off using MAF IMO. I'm sure some die hard SD guys will probably chime in and say it's the best thing ever, but in reality, MAF is just a more effective way to measure air, and not a theoretical table to calculate fuel.
02-05-2018, 12:20 PM
#16
You don't need anything extra for speed density. It is harder to tune, but a good tuner will tune it anyway, then tune the MAF.
The difference is SD is based on a theoretical fuel value that uses MAP and rpm, and some other things. Climate and altitude can affect it. Street cars are best off using MAF IMO. AGREED I'm sure some die hard SD guys will probably chime in and say it's the best thing ever, YES THEY WILL but in reality, MAF is just a more effective way to measure air, and not a theoretical table to calculate fuel.THATS WHAT IM STICKING WITH
The difference is SD is based on a theoretical fuel value that uses MAP and rpm, and some other things. Climate and altitude can affect it. Street cars are best off using MAF IMO. AGREED I'm sure some die hard SD guys will probably chime in and say it's the best thing ever, YES THEY WILL but in reality, MAF is just a more effective way to measure air, and not a theoretical table to calculate fuel.THATS WHAT IM STICKING WITH
02-05-2018, 12:35 PM
#17
You don't need anything extra for speed density. It is harder to tune, but a good tuner will tune it anyway, then tune the MAF.
The difference is SD is based on a theoretical fuel value that uses MAP and rpm, and some other things. Climate and altitude can affect it. Street cars are best off using MAF IMO. I'm sure some die hard SD guys will probably chime in and say it's the best thing ever, but in reality, MAF is just a more effective way to measure air, and not a theoretical table to calculate fuel.
The difference is SD is based on a theoretical fuel value that uses MAP and rpm, and some other things. Climate and altitude can affect it. Street cars are best off using MAF IMO. I'm sure some die hard SD guys will probably chime in and say it's the best thing ever, but in reality, MAF is just a more effective way to measure air, and not a theoretical table to calculate fuel.
I recommend the 4" 22 deg intake hose part number 22B-400X4
02-05-2018, 12:56 PM
#18
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The only real "problem" people usually end up having with a MAF, is when you put a big cam in there with a lot of overlap. This will cause fresh air to enter the exhaust and fool your O2 sensors into a false lean condition, causing your Short Term Fuel Trims (STFTs) to chase themselves around at idle. It causes surging and bucking.
Easy fix for this is to do an open loop (OL) idle using Power Enrichment (PE). PE disables fuel trims, so all that needs to be done is enable it through 1200 or 1600 rpm and set the Equivalence Ratio (EQ) to 1.0 in those rpms. Obviously you'll want to leave PE alone in the higher rpms and shoot for your 12.5 air fuel ratio (AFR) in PE (N/A cars).
Then you have a hybrid tune that uses both SD and MAF.
Easy fix for this is to do an open loop (OL) idle using Power Enrichment (PE). PE disables fuel trims, so all that needs to be done is enable it through 1200 or 1600 rpm and set the Equivalence Ratio (EQ) to 1.0 in those rpms. Obviously you'll want to leave PE alone in the higher rpms and shoot for your 12.5 air fuel ratio (AFR) in PE (N/A cars).
Then you have a hybrid tune that uses both SD and MAF.
02-05-2018, 02:36 PM
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The only real "problem" people usually end up having with a MAF, is when you put a big cam in there with a lot of overlap. This will cause fresh air to enter the exhaust and fool your O2 sensors into a false lean condition, causing your Short Term Fuel Trims (STFTs) to chase themselves around at idle. It causes surging and bucking.
Easy fix for this is to do an open loop (OL) idle using Power Enrichment (PE). PE disables fuel trims, so all that needs to be done is enable it through 1200 or 1600 rpm and set the Equivalence Ratio (EQ) to 1.0 in those rpms. Obviously you'll want to leave PE alone in the higher rpms and shoot for your 12.5 air fuel ratio (AFR) in PE (N/A cars).
Then you have a hybrid tune that uses both SD and MAF.
Easy fix for this is to do an open loop (OL) idle using Power Enrichment (PE). PE disables fuel trims, so all that needs to be done is enable it through 1200 or 1600 rpm and set the Equivalence Ratio (EQ) to 1.0 in those rpms. Obviously you'll want to leave PE alone in the higher rpms and shoot for your 12.5 air fuel ratio (AFR) in PE (N/A cars).
Then you have a hybrid tune that uses both SD and MAF.
02-05-2018, 04:13 PM
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All the SD cars Ive done have no drivability differences then MAP cars Ive done. Its undetectable to you behind the wheel, and they seem to be fine in the long term as far as hitting the target AFR. I dont change climates/altitudes when driving though.