86 5.0 Efi smog/ emissions delete

[Madtikicustoms]

Hi Everyone!

Just curious. I would like to free up some clutter in my engine bay and hope to grab a bit more power from less static drag. (5-10 hp possible?)

86 Bronco xlt 5.0 efi, OD trans, 9” rear 4.10 gears. All stock except lift and tires.

How big of a headache is it to remove the system. Is it worth the trouble?

Thanks!

 

[Gary Lewis]

I'm pretty sure there's essentially nothing you can do that won't cause problems if you are retaining the EFI system. And, it is a "system", with everything tied together and the computer in control and monitoring things.

The ECU recognizes when things like the TAB and TAD relays aren't there and at least throws codes if not goes into limp-home mode. And you can read here what Jim explained to Pizzadude about the AIR system.

I recommend that you keep the system stock.

[85lebaront2]

I agree with Gary, unless you want to go to a newer system (which will clear some of the stuff off behind the battery) best thing you can do is better heads, the heads on that engine are some of the worst Ford ever used. A late 5.0L Explorer (or clone) has very mice heads, early versions are GT40, later GT40P (identified by a "P" stamped on the end).

[Gary Lewis]

I agree with Gary, unless you want to go to a newer system (which will clear some of the stuff off behind the battery) best thing you can do is better heads, the heads on that engine are some of the worst Ford ever used. A late 5.0L Explorer (or clone) has very mice heads, early versions are GT40, later GT40P (identified by a "P" stamped on the end).

Bill - Can the speed density accommodate the better heads?

[85lebaront2]

Bill - Can the speed density accommodate the better heads?

Yes, as they flow better, the system will compensate for that.

[myrl883]

Yes, as they flow better, the system will compensate for that.

Speed density responds well to better flowing heads, and minor exhaust work. It cannot compensate for cam changes, even something as mild as a stock HO cam.

[Gary Lewis]

Speed density responds well to better flowing heads, and minor exhaust work. It cannot compensate for cam changes, even something as mild as a stock HO cam.

Thanks, guys. I didn't know.

[Madtikicustoms]

Thanks guys!

I figured there may be an issue because of the efi being its own system run off the computer.

Change of heads was something i was considering in the future. I wasn’t sure if the efi was able to adapt. Looks like it can.

I am a bit concerned about the cam though. I was considering a mild cam. A step more aggressive than an RV cam. Nothing crazy.

But it looks like the efi wont work with that. Any work arounds on that without replacing the whole system?

Carburetor is out of the question. I take this rig on trails, so efi is mandatory for me. It keeps the rig from stalling on off camber situations.

Future goals are to be in the mid to upper 300 Torque range around 200-2500 rpm. Any advice?

[85lebaront2]

Thanks guys!

I figured there may be an issue because of the efi being its own system run off the computer.

Change of heads was something i was considering in the future. I wasn’t sure if the efi was able to adapt. Looks like it can.

I am a bit concerned about the cam though. I was considering a mild cam. A step more aggressive than an RV cam. Nothing crazy.

But it looks like the efi wont work with that. Any work arounds on that without replacing the whole system?

Carburetor is out of the question. I take this rig on trails, so efi is mandatory for me. It keeps the rig from stalling on off camber situations.

Future goals are to be in the mid to upper 300 Torque range around 200-2500 rpm. Any advice?

The speed density issue is lobe separation, somewhere I have seen a chart showing what lobe separation is tolerable, I'm recalling something like 110° lobe separation. Also too "lumpy" a cam will drive a speed density system craze.

On off road, even a TBI system might do well, one of the old choices was the "piss pot" Holley of the mid 50s, the float bowl sits above the main body and it will almost run on it's side. Basically if you can get gas to it and you are not at such and angle as to starve the oil system, it will run.

[ArdWrknTrk]

Thanks guys!

I figured there may be an issue because of the efi being its own system run off the computer.

Change of heads was something i was considering in the future. I wasn’t sure if the efi was able to adapt. Looks like it can.

I am a bit concerned about the cam though. I was considering a mild cam. A step more aggressive than an RV cam. Nothing crazy.

But it looks like the efi wont work with that. Any work arounds on that without replacing the whole system?

Carburetor is out of the question. I take this rig on trails, so efi is mandatory for me. It keeps the rig from stalling on off camber situations.

Future goals are to be in the mid to upper 300 Torque range around 200-2500 rpm. Any advice?

**Bank fired Speed Density** definitely has its limitations.

But there are cams ground to make the best they can.

Remember, Ford used this system for over a decade, and the 5.0 was a popular engine across their range.

You're not going to get a lopey idle but I doubt you'd want that in an off road rig (hill climb excepted)

It's not only angle that is going to affect carburetors.

I think another consideration for EFI is that the system runs much higher pressures than a carb, so vapor lock and fuel boiling is far less of an issue if you're crawling in the Arizona heat.