EFI conversion on a old doner

[the shadow]

In the future I plan to do a engine rebuild or refresh, and will want to change to either a TBI/4 barrel intake set up or just a carb? Just pondering how Im going to go about removing the electrical harness's. Since its a running car I'm planning on just cutting out what I dont need off the old harness and altering whats there (engine bay and dash harness). Im going to be replacing the tach/speedo on the dash with aftermarket so I presume a lot of wiring will be removed back there. Does anyone have any opinions or advise as to that plan...maybe someone out there has done the same thing?
Paul

[steno]

Honestly...pulling out the old EFI harness is pretty easy! Go to YouTube and check out Holley Terminator X installation. Lots of great info out there. Took me two hours to have it out and on the floor.

[steno]

BTW...The A9L computer is worth a couple hundred!

[weendoggy]

I agree with steno, pretty easy to do. Engine is simple, even if you kept the "salt-n-pepper" connections. The rest is how you wired it to the ECU. I removed mine about 12yrs ago when I switched to a HP Terminator (not X) factor. Get rid of it all. If you go Holley, it'll come with it's own harness for the engine and any other item you can wire in.

[gbranham]

Check out Edelbrock ProFlo4, too.

[Mike.Bray]

Check out Edelbrock ProFlo4, too.

+1 on the ProFlo4

[steno]

I was thinking of the sensor for the computer...my bad. The gauge sensor is on the driver side toward the front.

[the shadow]

this is the kind of info I was looking for and I will definitely check out you tube and vendor videos. Other then my daily drivers all my hot rods have been carb'd for the last 40 years so I'm no EFI/ECU tech person but I like the efficiency of the modern set ups on a 4 barrel intake plus they keep the look & seem to be user friendly for someone like me. since I didn't build this cobra I figured I'd ask guys that have and had already done this Mod. Thanks again!

[Mike.Bray]

I'm no EFI/ECU tech person but I like the efficiency of the modern set ups on a 4 barrel intake plus they keep the look & seem to be user friendly for someone like me.

By far your best bet is the ProFlo. It has the 4 barrel look but is sequential port injection (way better than throttle body injection) and dead easy to install and setup. Connect through Bluetooth with your phone, enter a few parameters, and go. It's literally that easy.

[Badfish]

I posted this just the other day on our other forum! Hope this helps. And I’m sure somewhere on these forums I have some old posts on the conversion.

I did the EFI to carb conversion about a decade ago. I couldn’t be happier. This link was very helpful: EFI to Carburetor Conversion (https://carbdford.com/fletch/tech/efi-carb/efi-carb.htm). I had a donor harness, but trimmed out a lot! My Crane ignition box recently died, so I went with the Duraspark red grommet. Some good info on the Pantera website on that specific wiring.

[MikeHolt]

By far your best bet is the ProFlo. It has the 4 barrel look but is sequential port injection (way better than throttle body injection) and dead easy to install and setup. Connect through Bluetooth with your phone, enter a few parameters, and go. It's literally that easy.

I asked the question on our ProM page, if anyone has thought of switching over, given ProM seems to be going dark. Almost everyone responded with “stay away because it’s Speed Density based”.
I’m not a big tuner guy. But, if I change out my ProM, I want something I’m not going to continually have to fiddle with. Got burned with that on the “self learning” ProM! :rolleyes:

So, the question becomes….is there anything other than ProM or an OEM system that is Mass Air?
I see that the Sniper and the ProFlo are both Speed Density.

The benefit of the ProFlo is, I already have the sequential rails, injectors, and throttle body. I’d just need their ECU and wiring etc. Whereas the Sniper requires me to swap out the manifold.

[Mike.Bray]

I asked the question on our ProM page, if anyone has thought of switching over, given ProM seems to be going dark. Almost everyone responded with “stay away because it’s Speed Density based”.
I’m not a big tuner guy. But, if I change out my ProM, I want something I’m not going to continually have to fiddle with. Got burned with that on the “self learning” ProM! :rolleyes:

Did anyone say why to stay away from Speed Density?? Speed Density uses manifold pressure (vacuum in an NA application) and RPM to calculate fuel flow. The base fuel map uses MAP (vacuum or load) and RPM and looks something like this.

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It also takes into account air temperature, coolant temperature, and throttle position to make adjustments to the main fuel map.

Speed Density is fine and works well, I'm running it on my stack EFI setup Windsor and it runs great. Anyone that says you have to constantly fiddle with a Speed Density setup I would immediately discount.

Self tuning should be called "fine tuning" as it's not going to get you there if you're miles away. The good thing about the ProFlo is the initial setup, if you answer the questions honestly it will get you very close. Edelbrock has done a great job with the system.

FYI, your other options are Alpha-N and Mass Airflow.

MASS uses a sensor in the air inlet, usually a heated wire, to measure the amount of air passing across it. MASS sensors are good but typically reserved for OEM applications. They can also be bulky and ugly IMO. They can also be a little tricky to install as the sensor requires laminar flow across the wire so you need some straight sections before and after.

Alpha-N builds a base fuel map using throttle position and RPM for cases where a MASS sensor is not available or a good vacuum signal cannot be obtained. My first venture into EFI in the 90's was with stack injection and because of the design of the manifold I could not get a MAP sensor to work so I went to Alpha-N. Tuning is a bit tricky but the throttle response was off the chart. Fuel mileage was not so great.

The vast majority of aftermarket EFI systems are Speed Density because it's simple and it works.

[MikeHolt]

Mainly, comments were based around those with an aggressive cam.
I’m running an E cam and 30# injectors. So, nothing too radical.

Sounds like Pro Flo might be the way to go if I convert.

I’ve finally got my ProM running well (knock on wood). But, there are a lot of rumors floating that the company is folding and customer support is nig impossible. Add to that I’m running the older software…..

[gbranham]

I asked the question on our ProM page, if anyone has thought of switching over, given ProM seems to be going dark. Almost everyone responded with “stay away because it’s Speed Density based”.
I’m not a big tuner guy. But, if I change out my ProM, I want something I’m not going to continually have to fiddle with. Got burned with that on the “self learning” ProM! :rolleyes:

So, the question becomes….is there anything other than ProM or an OEM system that is Mass Air?
I see that the Sniper and the ProFlo are both Speed Density.

The benefit of the ProFlo is, I already have the sequential rails, injectors, and throttle body. I’d just need their ECU and wiring etc. Whereas the Sniper requires me to swap out the manifold.

If you buy ProFlo4, you get an intake manifold with fuel rails, injectors, etc. Not sure you can just buy their ECU and wiring, and why would you, when they've engineered a complete system that works so well?

[Mike.Bray]

Yep, you've got to have a decent vacuum signal for a Speed Density system to work.

Between Holley and Edelbrock/Comp they've just about stitched up the aftermarket EFI market. And now Edelbrock is about to release their throttle body system that is aimed at the Sniper.

[MikeHolt]

If you buy ProFlo4, you get an intake manifold with fuel rails, injectors, etc. Not sure you can just buy their ECU and wiring, and why would you, when they've engineered a complete system that works so well?

Because I already have an Edelbrock intake manifold with fuel rails and injectors.

[Mike.Bray]

This might interest you then. https://www.edelbrock.com/pro-flo-4-efi-ecu-and-electronics-kit-for-small-big-block-chevy.html

If you need the throttle body it is P/N 4150 https://www.summitracing.com/parts/edl-4150

[MikeHolt]

That’s what I was eyeballing.

[gbranham]

That's kind of what I was saying, Mike. Those two packages are within $400 of the all-in ProFlo4 package that was designed and engineered to work together. Seems like the extra $400 is worth it to get a system that plugs and plays.

Greg

[MikeHolt]

Clearly, I have more investigating to do!

I wonder if my ProM throttle body would work with it.

[Mike.Bray]

I wonder if my ProM throttle body would work with it.

It probably would, a throttle body mainly just regulates airflow. I think the only question would be the TPS sensor but that's not insurmountable.

[bobl]

In the future I plan to do a engine rebuild or refresh, and will want to change to either a TBI/4 barrel intake set up or just a carb? Just pondering how Im going to go about removing the electrical harness's. Since its a running car I'm planning on just cutting out what I dont need off the old harness and altering whats there (engine bay and dash harness). Im going to be replacing the tach/speedo on the dash with aftermarket so I presume a lot of wiring will be removed back there. Does anyone have any opinions or advise as to that plan...maybe someone out there has done the same thing?
Paul

I've done this on a couple of MK 1 builds. The last one I bought a Universal Painless harness and rewired the whole car. That's what I would do in the future. Not much more work, if any and you've got everything new. The painless harness has every lead clearly mark and is not very expensive.

Bob

[Valkster]

Another here with the ProFlo4, on an old 428FE. Pretty easy to install but it is $$

[Mike.Bray]

Another here with the ProFlo4, on an old 428FE. Pretty easy to install but it is $$

I wouldn't agree that it's expensive if you break down what you're actually getting. Intake manifold, throttle body, injectors, all sensors, ECU, harness, and distributor for a sequential port injection EFI. You'll be at least double that building your own system with a Terminator.

[Papa]

I could have bought four ProFlow4 systems for what I have in my EFI. :p. And I wouldn't change a thing!!!

https://thefactoryfiveforum.com/attachment.php?attachmentid=168959&d=1656945690

[rich grsc]

I just priced a new Borla 8 Stack, just the hardware costs more than my complete old setup..thats only like an 93.65% increase. :eek: :rolleyes:

[Mike.Bray]

I could have bought four ProFlow4 systems for what I have in my EFI. :p. And I wouldn't change a thing!!!

https://thefactoryfiveforum.com/attachment.php?attachmentid=168959&d=1656945690

I'm with you Dave!

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