1985 LTD Free Power Gains

[85LTDCrownHip]

Today, my father and i started to dissassemble the throttle body on my 1985 ltd crown vic 2door. This year has the electric carb as i want to call it, but ford calls it CFI (Central port Fuel Injection). Well anyway, we tool aprt the throttle body and noticed, its pretty damn rough in there and can not have good air flow, So long story short, right now we began porting the throttle body to improve the airflow and to improve the flow of gas from the injectors.
Have any of yall ever done anything like this or seen this? My father and i dont see why this wouldnt help but all feed back is appreciated

[gadget73]

I suspect swapping or porting the lower intake for one that flows better would do more.

Honestly not much about CFI is performance oriented. The usual ways to gain power involve converting it to multiport injection or a carb.

[87GrandMarq]

Anything is better than the stock cast iron intake manifold Ford used in 85. Problem is getting one matched to the low powerband of these motors. Most intakes will be overkill.

You could try to swap on an open air cleaner for a carb, though the stocker probably isnt really a restriction.

[DerekTheGreat]

Yah, I wouldn't do anything other than a dual plane type manifold. Cool thing is the bolt pattern for the carb is like a Holley so you can use aftermarket manifolds with a 2 bbl adaptor plate. What I'd be tempted to do whenever I get me another CFI car if that happens. I wouldn't bother polishing the throttle body though. My memory is foggy here but I thought I read something that said a rough surface is actually better for air flow, that air/fuel molecules hang on to the texture of the bore increasing the velocity of the mixture not clinging to the bore. Firing from the hip without glasses on with that one though.

[phayzer5]

I'd put that one back in your holster there chief. The polishing part of "porting and polishing" heads and intakes wouldn't be a thing if airflow followed Derek's Laws of Fluid Dynamics

I wouldn't bother polishing the throttle body though. My memory is foggy here but I thought I read something that said a rough surface is actually better for air flow, that air/fuel molecules hang on to the texture of the bore increasing the velocity of the mixture not clinging to the bore. Firing from the hip without glasses on with that one though.

[kishy]

Anything is better than the stock cast iron intake manifold Ford used in 85. Problem is getting one matched to the low powerband of these motors. Most intakes will be overkill.

Although there are cast iron intakes, I have only seen them on carb-equipped cars (and I own one with it). Both of my CFI cars (84+85) have aluminum intakes, as have junkyard cars. Though, it stands to reason based on the carb and CFI mounting bases being identical that one could mix and match and the factory may have done that too, if the flow characteristics are about equal. I don't know if they are or aren't.

Supposedly there is something you can do involving a baffle inside the intake (adding one that does not exist) to help prevent certain cylinders from going lean at WOT, but trying to get concrete info on that is challenging. Apparently the CFI HO cars (and yes they exist, not on our platform) had it.

[DerekTheGreat]

I'd put that one back in your holster there chief. The polishing part of "porting and polishing" heads and intakes wouldn't be a thing if airflow followed Derek's Laws of Fluid Dynamics

You give me too much credit by calling me chief. I was merely throwing that out there for debate, not as fact or law.

[gadget73]

I've seen both iron and aluminum CFI intakes. Not a clue why different cars got different materials though. Possibly it was just a supplier availability thing. I don't really expect one is better than the other in terms of performance, though an aluminum one would be a lot easier to port.

[87GrandMarq]

My 85 had an iron intake, it was pretty rusty being a midwest car for most its life lol that how I was sure it was iron.

[knucklehead0202]

Best performance enhancement for CFI, is EFI, lol. Put a 4-barrel manifold with the 2x4 adapter and stick a nitrous plate under it? That might wake it up, once or twice. All kidding aside, sounds like you're on the right track cleaning up the TB. I mean, if you lost power with any of this, would you notice? Can really only get better.

[phayzer5]

Best performance enhancement for CFI, is EFI

You misspelled carburetor

[kishy]

Best performance enhancement for CFI, is EFI, lol. Put a 4-barrel manifold with the 2x4 adapter and stick a nitrous plate under it? That might wake it up, once or twice. All kidding aside, sounds like you're on the right track cleaning up the TB. I mean, if you lost power with any of this, would you notice? Can really only get better.

So...my '84 with 3.08 rear gears is a very acceptably-performing car. That isn't me having low standards, that's the car being a very acceptably-performing car. Last year's Detroit meet crew can back that up. This isn't a 2.3 automatic Tempo.

The common thought is that '85 got new heads that flow better, thus '84 should perform worse than '85. All else is equal AFAIK, although '84 and '85 have different computers, and my car does have an '85 computer (not that I suspect it has performance gains, probably just bug fixes).

It is also established that stock for stock, SEFI is not going to offer a performance benefit that you can feel, and maybe just barely one you can measure.

I'm reasonably sure these engines don't max out the power (airflow through the TB, and fuel delivery) potential of CFI. It has shortcomings but should not be the automatic scapegoat that it often serves as.

Mod potential is better for SEFI simply due to parts availability, but stock for stock it's a colossal waste of time and money...IMHO

[DerekTheGreat]

Your '84 kept up with my '88. I think it boils down to drivability, my '85 was nowhere as smooth as my '88. ET times may have been similar but the power delivery of SEFI can't be overlooked. Drive mine next time you're around and you'll see what I mean.

[kishy]

Your '84 kept up with my '88. I think it boils down to drivability, my '85 was nowhere as smooth as my '88. ET times may have been similar but the power delivery of SEFI can't be overlooked. Drive mine next time you're around and you'll see what I mean.

Yes...the fact that 3.08 kept up with 3.27 says (sorry) bad things about your car, or good things about mine, or somewhere in the middle.

I've driven my 91 GM (3.08) and my buddy's 87 TC (unknown gears, but it's a Signature, so...3.27?) so I'm familiar with SEFI. I suspect restricted cats on my 91 and didn't observe any issues with buddy's 87. It's stronger at WOT but still wheezy just as CFI is; about the same elsewhere in the throttle. The issues surrounding getting air into the engine are not a throttle body-specific problem. Intake, heads. I would try to address those in-place in the CFI setup before deciding it was dead-ended. Depends on where one's goals are, though. There is an obvious limitation that can't be bypassed with the bore size in the CFI TB so you can only go so far. Still, "CFI HO" exists and AFAIK uses the exact same TB (different injectors), so there's more to be had.

Reference point from another thread:

I never said the SEFI lopo was sufficiently not-gutless either. I just think these cars should have had more power from the beginning.


The CFI HO was a different cam, larger injectors, and a different ECM tune to play happy with all that. I believe they had the same E5 heads that non-HO CFI cars had in 1985. Mostly it was the cam, the injectors were just because it allowed the engine to move more fuel. I seem to remember Pete playing around with this at one point on his 85, using the HO ECM and throttle body, but it didn't run right because the cam wasn't there to complete the package.

[DerekTheGreat]

I can't speak for the other cars you've driven but mine has a smooth power plant. Maybe the other cars are just as smooth but between my old '85 and this TBI truck I've got vs my '88, power delivery is smoother. Fuel infector for each cylinder precisely timed vs injectors dumping fuel onto throttle plates like a carb essentially does. There really isn't much of a difference between 3.27's and 3.08's. We could run the gauntlet again in the fall or when either car isn't loaded down with passengers. Drive mine after driving your TC.