Mass Air Flow vs Speed Density, plz read
#1
Member
Thread Starter
Join Date: Jan 2002
Location: Ann Arbor,MI
Posts: 182
Likes: 0
Received 1 Like
on
1 Post
Car: 1989 Trans Am GTA
Engine: LB9 TPI with L98 cam (Manual car)
Transmission: T5 5Speed/ 9bolt Borg-Warner 3.45 gears with posi
Mass Air Flow vs Speed Density, plz read
Ive noticed that 3rd Gen fbody owners prefer the Speed Density as an upgrade for their TPI 305 or 350, this seems the opposite of the Ford 5.0 faithful Ive run into.
I own a 1986 Mark VII LSC with the Ford 5.0 HO and from 86 to 88? Ford used Speed Density for these cars, then switched to MAF which with 3rd Gens it seems GM went the opposite route switching to MAP.
The Ford guys say the MAF system allows them more flexibility with modding the motor since the MAF adjusts itself according to what the sensor says, they say the Speed Density is restricted by the programming in the computer and is less mod friendly, but also state a slight edge in stock power vs MAF cars.
Im aware the differences between GM and Ford ecm's might be great but these 2 induction styles (MAF and MAP) are somewhat similar between Ford and GM, why the differences in opinion?
I own a 1986 Mark VII LSC with the Ford 5.0 HO and from 86 to 88? Ford used Speed Density for these cars, then switched to MAF which with 3rd Gens it seems GM went the opposite route switching to MAP.
The Ford guys say the MAF system allows them more flexibility with modding the motor since the MAF adjusts itself according to what the sensor says, they say the Speed Density is restricted by the programming in the computer and is less mod friendly, but also state a slight edge in stock power vs MAF cars.
Im aware the differences between GM and Ford ecm's might be great but these 2 induction styles (MAF and MAP) are somewhat similar between Ford and GM, why the differences in opinion?
Last edited by LetsRock; 08-28-2002 at 02:27 AM.
#2
you have to look at other factors. the ford has larger mafs that can be bought as the power level goes up, the gm doesnt.
the gm ecm is easily cracked to make upgrading with a SD system very easy, the ford isnt. most people that switch to SD do it when they get to a point where the maf is slowing them down and since in gms case the maf system is limited unlike the ford the only route to go is SD.
the gm ecm is easily cracked to make upgrading with a SD system very easy, the ford isnt. most people that switch to SD do it when they get to a point where the maf is slowing them down and since in gms case the maf system is limited unlike the ford the only route to go is SD.
#3
GM does go back to MAF, but that happens outside of the scope of third generation F-bodies. So that leaves the 90-92 SD system as the best CC system available in thirdgens before the change in body style. That, in combination with what was said above is the reason for the switch.
#5
Member
Thread Starter
Join Date: Jan 2002
Location: Ann Arbor,MI
Posts: 182
Likes: 0
Received 1 Like
on
1 Post
Car: 1989 Trans Am GTA
Engine: LB9 TPI with L98 cam (Manual car)
Transmission: T5 5Speed/ 9bolt Borg-Warner 3.45 gears with posi
Ah now I see, thanks for clearing this up guys... funny thing is Im stuck with the lesser prefered system on my lincoln and my GTA lol.. well I can always convert
#6
Supreme Member
Join Date: Jun 2000
Location: the garage
Posts: 1,612
Likes: 0
Received 0 Likes
on
0 Posts
Car: 84 SVO
Engine: Volvo headed 2.3T
Transmission: WCT5
Axle/Gears: 8.8" 3.73
Whats nice about Fords wirng harness is that to change to MAF from SD all you have to add is the correct ECM, and four wires to the MAF. Splice in power, ground, and add signal in and out at the correct location is all you have to do. Unlike GM, Ford doesn't need the harness changed and the pinout is the same, with the exception of the signal in and out. I did this with my 86 GT. cheers, Bob
#7
TGO Supporter
Join Date: Jul 1999
Location: The Bone Yard
Posts: 10,907
Likes: 0
Received 3 Likes
on
3 Posts
Car: Death Mobile
Engine: 666 c.i.
Originally posted by LetsRock
Ah now I see, thanks for clearing this up guys... funny thing is Im stuck with the lesser prefered system on my lincoln and my GTA lol.. well I can always convert
Ah now I see, thanks for clearing this up guys... funny thing is Im stuck with the lesser prefered system on my lincoln and my GTA lol.. well I can always convert
Until the ECMs for 3rd Gen cars were fully hacked, you WERE better off with a 3rd Gen MAF car. But once "eprom tuning" became commonplace on 3rd Gens, then the "fine tuning" capabilities of the SD system allowed it to shine.
FYI, there are guys with 4th Gen LT1s with the 8051 ECM that run faster in "SD Mode only" than "both MAF and SD". Go figure.
Thread
Thread Starter
Forum
Replies
Last Post
eightsixseven
Tech / General Engine
1
08-14-2015 03:09 PM