Speed Density Fuel Injection

[Steino]

I hear that all 5.0L engines in Lincolns have speed density fuel injection systems that limit modifications without converting to mass air systems. Does this make mass air a top priority in power gain?

1990 LSC

[pro-five-oh]

Steino,

All Marks have a SD setup. Converting to MAF is becoming an "age old" question for the 5-liter crowd. It really depends on how serious you plan on modifying your Mark VII.

SD cars are setup fine for intake/exhaust modifications, and even run faster than similar MAF cars.

I heard of SD Marks and Mustangs with bigger fuel injectors with various combinations heads/cam/forced induction that still idle smoothly, though I cannot vouch for it myself. While that may be true, I converted my 1988 Cougar over to MAF because streetability and tuning are much better with a Mass-Air Meter. MAF allows you to calibrate a Mass-Air meter with larger fuel injectors so the computer will know the exact air-fuel ratio...instead of just guessing by speed and density of the incoming air.

It was easy enough on my Cougar, but Mark VII's have a different wiring harness than other Fords. The computers are different and have the Cruise Control built into the computer. If you go mass-air, you will have to get a 89-93 Mustang computer and convert your Mark to Mustang cruise control. Though some have done it, it's not an easy task.

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pro-five-oh

88 Cougar XR-7 5.0 HO
83 Continental 5.0 LO

[stinkin' Lincoln]

mass air is far from paramount when it comes to making power...

the only time speed density gets in your way is when you change the cam duration and lobe seperation... these cars are so heavy, damn near any aftermarket cam would probably slow them down anyhow... and SD combos usually show a solid 10hp advantage over mass air, so I wouldn't worry about it.

for what it's worth, I plan on running 11's w/ the stock cam and speed density setup on my current Mark VII...

it'll be turbocharged... aftermarket heads and intake, bigger injectorse, etc. etc. all w/ the stock SD EEC driving it.

Forrest

[pro-five-oh]

Forrest, good to hear from ya. So there is life after a turbocharged Fairmont Wagon??? is this the same Mark VII we talked about with a T5z and 200lbs less sound insulation?

--Sajeev

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pro-five-oh

88 Cougar XR-7 5.0 HO
83 Continental 5.0 LO

[Lscman]

Hello, Stinkin'. Steino, IMHO..it depends on what you're using the car for and what mods you make. MAF "reactively" tunes the mixture to compensate for air flow. SD "proactively" adjusts the mixture and makes many assumptions. The reactive and proactive terms are important because it's basically why SD cars are more responsive. In a drag racing environment, I'd give the nod to SD for responsiveness, simplicity and less intake restriction. In severe duty road racing, I'd give the nod to MAF for A/F mixture control and resulting engine durability and efficiency. On the street, either will work. One costs more (MAF) and the other requires more tuning (SD). Some SD cars with big cams and heads do not idle well and can have driveability problems that are difficult to correct.

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Rick, Road Track Terror in my '88 Mark VII LSC. See ya at Northeast Events! Pgh, PA

[stinkin' Lincoln]

this is a different LSC.

I got this one in Austin for $800...

103k miles, champaigne w/ the cloth-insert seats... everything works... the only thing that was "wrong" with it was that the ABS was acting up...

I popped in an ABS relay that I pocketed at the junkyard and it works perfectly...

I've got a LOT of parts accumulated for it right now...

tubular kmember
coilover conversion for front and rear (drag rate w/ 90/10's and 50/50's
solid motor mounts
manual rack
SVO master cylinder and booster
Vortech FMU
acufab regulator
24lb injectors
TFS Street intake
Motorsport headers
a pair of .48 T03's
1.72 stud mount rockers
etc. etc.

I'm PLANNING on putting a pair of TFS heads on it, but I haven't brought myself to flexing the credit card that hard just yet!

Forrest

[pro-five-oh]

Steino--after looking at all these comments I think that keeping your SD setup is fine for a street driven Mark. For me, the ideal Mark would include some better heads, a shift kit and a Kenne Bell whipplecharger for big-block style torque...it all depends on the $$$.

Forrest--Another good deal! Yeah, I was pondering adding TFS heads, but I decided on taking my brothers E7's and just cleaning up the exhaust ports. Debt is a bad thing...

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pro-five-oh

88 Cougar XR-7 5.0 HO
83 Continental 5.0 LO

My Mark VII tribute Page (http://www.geocities.com/motorcity/street/3545/mark.html)

[stinkin' Lincoln]

trust me... I know ALL about debt!! LOL!

you still looking for the coaxial badges for your speaker grilles?

I can probably track down a pair for you.

Forrest