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Discussion Starter #42

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Discussion Starter #43
So the FiTech Go Port throttle body experiment on the PF4 setup continues with some more backyard shade tree science. Little factoid: The Go Port 1:1 throttle linkage throttle body flows 900cfm. It's not 1000cfm like the Edelbrock progressive linkage throttle body, but close enough for a mild SBC 350. (The Go EFI throttle bodies don't flow as much as the Go Port throttle body. They look similar, but the bores are sleeved differently because the Go Port is not a wet throttle body.)

Moving right along.... I've been thinking about making a set of velocity stacks that I can drop down onto the 4 barrel throttle body, so I put something together with parts I had laying around. The stacks are short adding 1 inch in height to the stock throttle bores. They work really well on my motor on top of the FiTech Go Port throttle body on the PF4 MPFI setup with the addition of a 1-inch spacer under the throttle body. The motor has never run so smooth. Go figure.

I should get the car on a dyno some day and spin it up with and without the stacks to see if the stacks make any power difference. I'm sure they changed something in either a positive or negative way, because the motor sounds different, and seems to run great. Might be placebo effect because it isn't a total fail.

Anyway, below is what the prototype stack set looks like. It is nothing like the goofy air cleaner assemblies with the fake stacks on top for anyone that wants to post a pic and say "Why didn't you just get one of these?". The tiny stacks are doing what velocity stacks would do. Whatever that would be on a 4-barrel throttle body.


 

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Discussion Starter #44
Should have posted these shots a while ago.

FiTech Go Port throttle body with ECU and harnesses removed, simple cover made, FiTech proprietary MAP port blocked off behind the cover, external MAP ready to mount up rear left on the bench.


Mounted prior to setting it up with the stacks and 1-inch spacer.
 
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Can one equate the progressive linkage of the PF4 to a quadrajet type mentality? I may be way off here.
 

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Discussion Starter #46
Can one equate the progressive linkage of the PF4 to a quadrajet type mentality? I may be way off here.
You could think of it that way I suppose. I think it's a different animal myself.

The Edelbrock throttle body flows more (1000cfm), is a square bore, and the secondary throttles are locked at "starting to open" at 65% of the total throttle movement. The stock quadrajet is smaller (750-800cfm), a spread bore, and has vacuum actuated secondary throttles.
 

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Discussion Starter #47
Aside from the velocity stack idea working awesome on the FiTech throttle body, I decided I'd put even more FiTech into the PF4 effort.

I replaced the little 29lb Edelbrock injectors with 40lb FiTech injectors I had from the Go Port setup. Motor is much happier contrary to Edelbrock forum moderator wisdom insisting that I need to make more horsepower to use bigger injectors. Same moderator would also say they are the wrong injectors and insist I use something Edelbrock has tested. For example, their 35lb injectors. Well yeah, that would be correct for guys that don't want to spend any time tuning EFI, but not so much for me. I used one of the 35lb 43psi SBC calibrations that matched my cubic inches, vacuum, and camshaft profile. All I had to do was pull some fuel for Idle and Cruise with the Fuel Modifier function to tame the trims. Pulls like it should now. Much stronger than it was with the 29lb injectors.

I'll be trying the 60lb Siemens Deka injectors in a couple of weeks. Edelbrock forum support said I needed to be making 700HP to use em. I told the moderator they worked on my Go Port setup and he deleted my post. I must have gone outside the lines of the Edelbrock coloring book, along with a few more where my crayon strayed into the experimental zone.
 
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Aside from the velocity stack idea working awesome on the FiTech throttle body, I decided I'd put even more FiTech into the PF4 effort.

I replaced the little 29lb Edelbrock injectors with 40lb FiTech injectors I had from the Go Port setup. Motor is much happier contrary to Edelbrock forum moderator wisdom insisting that I need to make more horsepower to use bigger injectors. Same moderator would also say they are the wrong injectors and insist I use something Edelbrock has tested. For example, their 35lb injectors. Well yeah, that would be correct for guys that don't want to spend any time tuning EFI, but not so much for me. I used one of the 35lb 43psi SBC calibrations that matched my cubic inches, vacuum, and camshaft profile. All I had to do was pull some fuel for Idle and Cruise with the Fuel Modifier function to tame the trims. Pulls like it should now. Much stronger than it was with the 29lb injectors.

I'll be trying the 60lb Siemens Deka injectors in a couple of weeks. Edelbrock forum support said I needed to be making 700HP to use em. I told the moderator they worked on my Go Port setup and he deleted my post. I must have gone outside the lines of the Edelbrock coloring book, along with a few more where my crayon strayed into the experimental zone.
I watch that forum frequently just for knowledge and I see that the moderator “Nate” is like big brother for edelbrock
 
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Discussion Starter #49
Version 2.x of my Short Stack Pack for FiTech 4-hole throttle bodies. Hand made with a jig saw, a file, sand paper, a Dremel, and some other parts I put together.


Does it work? I may be delusional, but the car spins up like a 2 stroke from a dead stop giving it WOT. No time slips or video, so I guess it never happened. ha
 
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You can adjust the TPS a little on the Edelbrock throttle body....Why. Because at start-up. It's at "rest position" is now 0.
So. If you move it a little clockwise ( as you face it ) WOT ( usually 75% of throttle of the TPS ) will now happen sooner.
It would be better to try this trick, instead of adjusting the secondaries first.

Or put another way: WOT can start sooner or later, depending where the TPS sees 75% at.

Other fun facts about Pro-Flo 4:
1. The shuttle wheel in the distributor is the same timing as used in the 1979 system ( aka Ford TFI )
2. The ECU has 4 ignition outputs. So you could use LS truck coils in wasted spark setup.
3. The logo is upside down on the case. But has been fixed on the Pro-Flo 4 Plus.
4. EFI Technology Inc makes the ECU...They made all the ECU's back to Pro-Flo. ( not the first 2 original systems ) Link: https://en.wikipedia.org/wiki/EFI_Technology_Inc
5. The main connector used on the ECU is only rated for 20 insertions....same connector is used on Harley Davidson stereos.
 

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Discussion Starter #51
You can adjust the TPS a little on the Edelbrock throttle body....Why. Because at start-up. It's at "rest position" is now 0.
So. If you move it a little clockwise ( as you face it ) WOT ( usually 75% of throttle of the TPS ) will now happen sooner.
It would be better to try this trick, instead of adjusting the secondaries first.

Or put another way: WOT can start sooner or later, depending where the TPS sees 75% at.
Interesting, but I'd never take that tuning approach, because I don't like the progressive linkage, and it would be time wasted for me. I prefer to concentrate on changes that make a significant difference in power delivery over the entire throttle range.

I fabricated a 1:1 throttle linkage setup for the PF4 Edelbrock throttle body and it works perfectly. I just had to think about it a minute. https://www.chevelles.com/forums/89-efi/1098868-1-1-throttle-linkage-conversion-pro-flo-4-throttle-body.html

I put the 900cfm FiTech throttle body away pictured above your post, even though it worked fine on the PF4. The 1000cfm Edelbrock throttle body works even better than the 900cfm throttle body, since I converted it to 1:1 linkage. And, better than it ever did with progressive linkage. Night a day difference in power delivery from the progressive linkage. Also much smoother throttle feel, because the secondary throttle spring doesn't come in at 65%. It is in use through the entire throttle range.

Jamming the pedal to the floor from a dead stop the two linkage types are the same, but everywhere up to 65% throttle, the 1:1 linkage makes the progressive linkage feel anemic.
 

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77sonic.

You make your own 1:1 or change TB completely?
 

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Made my own. It is sorta in beta, if it performs well I will build it a bit better.
 

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Discussion Starter #55
Completely agree with Schwany here concerning anemic feel with the Proflo progressive linkage. I don't have a lot of time on my PF4 set up yet but response is nothing compared to the Fitech I was running. Just converted the PF4 to 1:1 linkage today. Now I need the snow to melt again so I can test it:surprise:
Does the snow ever melt in MN? :smile2:

Be careful if there is any ice still out there. It'll be very responsive. I would imagine the guys with Pro Flo 4 XT ram intakes and LS style throttle bodies have had crispier acceleration all along. That progressive linkage is flabby.

You might have to do some Acceleration Fuel tuning. I suggest clearing the Self-Learn in the Fuel Modifiers section of the ETuner app. The stored values in the fuel table will be wrong for the 1:1 setup.
 
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Thanks for the tips, Steve. I removed one of the return springs from the primary shaft as the throttle seems quite stiff now with both shafts working in unison.
 

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Discussion Starter #57
Read the help you get if you click on the "?" at the top of Fuel Modifiers page in the ETuner app. While in there, and once the motor is all warmed up, you'll want to check to be sure your Idle Short Fuel Trim looks good or if it might need a nudge + or -. Get it close to 0. Probably kind of an obvious thing to do, but if you haven't tuned it with the 1:1 throttles, it might help to go over the basic stuff again. Enjoy
 

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Here is what my set up looks like.
 

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77sonic. Looks nice.

And looking at the 2 different setups on here, they both appear to be relative simple. I'm confused why edelbrock dont have this an off the shelf option. Seems doable at their level then would could have the option.
 

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77sonic. Looks nice.

And looking at the 2 different setups on here, they both appear to be relative simple. I'm confused why edelbrock dont have this an off the shelf option. Seems doable at their level then would could have the option.
I don't think they want the inexperienced audience that generally expects things to work out of the box messing with the throttle body. It would end up being a support headache. Market for the 1:1 throttle linkage is too small. I'm thinking the majority of Pro Flo 4 4150 kit owners never even think about it.
 
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