ProFlo 4 anyone?

[Mach1 Driver 560]

There is lots of chatter on the forums now about how hard it is to get chips for ailing EFI systems, and a high rate of installs with EMI/RFI noise problems. This is primarily on the TBI units, presumably because the electronics are in the throttle body, and can’t be installed in the cabin.

Edelbrock’s ProFlo4 has good reviews with only one instance I’ve seen where they couldn’t fix the noise issues and wanted to rip it off the car. It didn’t say where the electronics were installed. But speaking of the PF4, I saw a post on Edelbrock’s forum where he had a 69 with 351W:

Mustang 69 Specific issue: the overall height is much bigger and it is impossible to fit any air cleaner under the hood even with drop base air cleaner bottom and/or dropped offset bottom - I decided to cut the hood and install a Hood scoop: no clearance issue and much better Air intake temp.

I’m not wild about the visible fuel rails and injectors, since the PF4 is not a TBI unit, but if the hood really has to be cut out for another larger scoop (my Mach has a scoop), then that is totally unacceptable. Does anyone have experience with a PF4 in a 69 with a 351W?

[ClubSport 29]

Hi

This is my post from the Edelbrock forum.

I cut the hood because I had no scoop at all - Potentially with lowering engine mounts , a dropped filter  base  and using a thin air filter : the PF4 should even fit with a stock hood.

I have chosen to go the scoop because I saw the air intake temperature was very high and with scoop it is equal to the external air temp.

[det0326 179]

Terry, I think we may have talked about the one I used on another project before. I have no knowledge of using one on a Mustang but I can tell u that after we got this thing on the road the learning ability of it is awesome. The more u drive it the better it gets.

[Mach1 Driver 560]

7 hours ago, ClubSport said:

Hi

This is my post from the Edelbrock forum.

I cut the hood because I had no scoop at all - Potentially with lowering engine mounts , a dropped filter  base  and using a thin air filter : the PF4 should even fit with a stock hood.

I have chosen to go the scoop because I saw the air intake temperature was very high and with scoop it is equal to the external air temp.

Yes ClubSport, that was your post, and the only time I've heard the PF4 had height issues on a 351w 69, so I'm sure the same holds true for a 70. That's a good looking car. Your scoop looks to be 3-4" wider than my stock scoop.  Thanks for the pictures.

[Mach1 Driver 560]

19 hours ago, det0326 said:

Terry, I think we may have talked about the one I used on another project before. I have no knowledge of using one on a Mustang but I can tell u that after we got this thing on the road the learning ability of it is awesome. The more u drive it the better it gets.

Hi Dave, yes almost all reviews for the PF4 are very positive- not like the TBIs that at least one professional (EFI System Pro) says run into RFI problems about 10% of time. The chatter on the forums makes it seem much higher, with more people complaining than defending Sniper and FiTech, but I suppose that's human nature.  Edit, a Holley tech claims 10-20%.

[fvike 173]

I haven't got the PF4 in my Mustang, but my brother has it in his '70 'cuda. 340. The throttle body is slightly lower than a Holley HP carb, so issues with the hood on '69 wouldn't be any different from what we're used to with these cars.

That said, The PF4 is in my opinion far better than the TBIs out there. Really, the only thing you need to keep an eye on is that the O2 sensor is online, so the system isn't mis-learing anything. I doubt it'll be a plug and play deal, some issues might be encountered. Sensors can go bad  etc. The huge plus with the PF4 is that it has a pad that you use to tune it, so you can stand outside the car, or sit in it, and put the pad away in the console when you're cruising. 

Still, while my brother is super happy with his PF4, I prefer carburetors.

[Mach1 Driver 560]

Yeah, I agree the PF4 is by all accounts superior to TBIs, but we have at least one example that it couldn't be done without cutting a hole in the hood. Maybe lowering the engine would help, but I'm not going to be the guinea pig. I was hoping that someone on here had already done it to a 69 with a 351w.

The other down side for me are the visible fuel rails. The air cleaner can hide a TBI, but those rails will always be visible. A Summit M2008 carb is looking like the best of several bad options right now.

[Mach1 Driver 560]

FYI, I received this response from Edelbrock on the height of the ProFlo4:

Hello Terry, The Pro-Flo 4 EFI System Air Valve Height for Air Filter On Top is 8.780” Tall, Intake Manifold Alone IS 6.25” Tall, 4V Air Valve is 2.53” Tall Both Equal = 8.780” Tall before Adding any Air Filter…

Also Not enough Real-estate to Machine Carb Pad Down, on Pro-Flo 4 EFI Kits # 35950….

 

So lets compare it to a 2181 Performer manifold with a 4 barrel or Sniper/FiTech, which I know barely allows enough room for the stock big blue bucket air cleaner. This combination is 7.32" from the top of the air horn, and 8.78-7.32=1.46" taller for the PF4. A dropped base filter will give another inch, so now we're down to 0.46" A check of K&N's site says you can get a filter that is 13" OD, and 2.313 high that gets us maybe within 0.25" depending on what filter you started out with. I didn't investigate what that does to air flow. The point is,  it is getting close, and would take some serious measurement before committing. Its worthy of further investigation, and maybe a PF4 could be used on a 69 351w without major modifications. 

[RPM 1,190]

I am impressed with that reply from Edelbrock.

[Mach1 Driver 560]

I explained the problem of the PF4 not fitting under the hood a 69 with a 351w, and they responded to all my questions including my question about milling down the pad. They included the air horn height so they get an extra Brownie Point because I didn't have to look it up ;)

[Mach1 Driver 560]

If I got serious about this system I would see if I could get the part I believe they call the air valve (it has the butterfly and linkage attachments) and a couple of different drop bases for the air filters, then see what will fit for the linkage and distributor on the stock engine. If the mock-up works then I would invest in the entire PF4 system. By the time I'm ready to do this maybe someone will already be successful.

[det0326 179]

Terry, if u need measurements of height of throttle body I get get that for u off the 454. I would assume it would be the same from carb pad up. 

[Mach1 Driver 560]

Thanks Dave,, but I believe that's what they call the "4V Air Valve" and it is 2.53” high according to their email.

[ClubSport 29]

Hi

You cannot use a deep drop base without having issues with the the throttle linkage - I have tried ...it doesn't work without modifying the linkage.

I also tried to use 2-3/4 height KN filter in order to gain some height but still not enough clearance with the hood.

A 2 " air filter my clear the hood but I think it will be restrictive.

I believe it is doable with a shaker hood but some modding of the system will be needed.

Otherwise I am very happy with the system - I re-started my car after 14 months and it has just started as if it was fired one day ago, I think it is the best system in term of driveability and it is very easy to tune.