MAF vs Speed Density?
Melting Slicks
Joined: Feb 2006
Posts: 2,753
Likes: 15
From: backwoods upstate ny
need the 89 knock sensor....remove the map sensor fro the the intake mfld and plug the hole .....if you're keeping the 89 MAF, -165 ecm, and wiring harness.
if you want to change to s/d, you will need a new ecm (-730) and rewire or replace harness.
is the new engine modded?
if you want to change to s/d, you will need a new ecm (-730) and rewire or replace harness.
is the new engine modded?
Thread Starter
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
Originally Posted by redrose
need the 89 knock sensor....remove the map sensor fro the the intake mfld and plug the hole .....if you're keeping the 89 MAF, -165 ecm, and wiring harness.
if you want to change to s/d, you will need a new ecm (-730) and rewire or replace harness.
is the new engine modded?
if you want to change to s/d, you will need a new ecm (-730) and rewire or replace harness.
is the new engine modded?
Melting Slicks
Joined: Feb 2006
Posts: 2,753
Likes: 15
From: backwoods upstate ny
the first GM efi's were all s/d...millions (really) were sold in chevy, pont, caddy, pik-ups, etc for tBi and worked great (i owned several and power, gas mileage, and start-up were better than any carb ever)...then for untold reasons (NOBODY will EVER get the real skinny from gm) the l98 got MAF without MAP...then back to s/d 91-93...then both maf and s/d from then on, tho guesses are that maf is primary and s/d is back-up (i can't see in my ecm, i tried)...the controversy continues with each camp claiming superiority.
there is an f-body post that tried maf and s/d on the same car on the same day, same track and the maf was a tiny bit quicker...before chip burning reportedly made the s/d a bit quicker...tiny bits either way.
the MAF sensor is rumored (i haven't checked) to be flow limited in sensing ability (i'm gonna start my 468 big block on maf to see what happens.)
the MAF does report actual airflow to the ecm, maP ''calculates'' stored pressure/rpm to get reqd input...so maF MIGHT be more accurate...IF the programming AND the hardware are perfect..big ifs
street rods, jeep/chevy converts, pik-up tPi , prefer s/d due to space reqd for the maF, and they're getting rewired anyway
there is an f-body post that tried maf and s/d on the same car on the same day, same track and the maf was a tiny bit quicker...before chip burning reportedly made the s/d a bit quicker...tiny bits either way.
the MAF sensor is rumored (i haven't checked) to be flow limited in sensing ability (i'm gonna start my 468 big block on maf to see what happens.)
the MAF does report actual airflow to the ecm, maP ''calculates'' stored pressure/rpm to get reqd input...so maF MIGHT be more accurate...IF the programming AND the hardware are perfect..big ifs
street rods, jeep/chevy converts, pik-up tPi , prefer s/d due to space reqd for the maF, and they're getting rewired anyway
Pro
Joined: Nov 2003
Posts: 692
Likes: 1
From: Peabody Ma.
Not to sure but i hear the map is more user friendly, and the maf is a little tougher with big modifed engines. I used Street & Performance they made me a harness for my set up . They also make add on harrness to make similar changes as you discussed. Give them a call they make a real nice product and will set you straight with what you want.
Thread Starter
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
Thanks guys, he is not into adding performance at this time. We have been working on it for some time now. Just to clarify, all that is needed to make the complete 91 engine work in a 89 vette with stock engine harness and ECM....we will need to change the knock sensor to a 89 and plug the MAP sensor and install the MAF??
BTW redrose, that is very good info.
BTW redrose, that is very good info.
Pro
Joined: May 2005
Posts: 525
Likes: 0
From: San Antonio TX
Originally Posted by bruced267
Not to sure but i hear the map is more user friendly, and the maf is a little tougher with big modifed engines. I used Street & Performance they made me a harness for my set up . They also make add on harrness to make similar changes as you discussed. Give them a call they make a real nice product and will set you straight with what you want.
Please correct me if I am wrong.
Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
Originally Posted by bowtie350_428
I thought it was the other way around. I hear MAP is very picky about mods while the MAF can compensate better to mods.
Please correct me if I am wrong.
Please correct me if I am wrong.
MAF systems have the ability to adapt to certain changes, within reason of course.
Jake
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Thread Starter
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
Very interesting info guys, thanks. I haven't talked to dad in a few days but I think this will be just what he was looking for. More than likely, he will go with the MAF setup.
