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Discussion Starter · #1 ·
I'm going to buy this set up for the 65 mustang, but the question I want to ask is.. I would like to go with the dual quad set up. They say is good for up to 1200 hp.....my little 331 will be in the 390-425 range I wounder how it will run?????? I dont really need the dual quad setup the single 4 is good to 550hp but I want the cool factor of the dual 4s.....
 

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This being TBI Injection, it would be controlled by a ECM. I would think the fuel curve and throttle body/injector(s) sizes would be calibrated to the application, i.e. street or race and needed CFM/fuel volume. You would have to either study their literature or call their TECH LINE for your particular application.
 

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I;m sure the controller would allow the dual set up to be run on a small block, but, how much are they asking for it?
If its the Wow factor you want, you can;t beat the looks of the new Procomp Electronics IR system, 8 stack EFI !
mind you, its going to retail around 3200 bucks, but, you get everything to bolt it on, from the controller right down to the gaskets.
www.procompelectronics.com
 

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With huge intakes on a street car, I've found the simplest solution is to use progressive throttle linkage to tame it. You'll only ever use perhaps half of that flow, so the linkage would scale the throttle opening rate to maybe 50% of pedal travel off-idle, to 100% at WOT. It prevents a touchy throttle and jerky response. Modern cars usually have progressive eccentrics on the throttle arms for this purpose.

David
 

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As turbo says, a dual 2v would be a better choice with the bore size (and standard injectors) those 4v TBs have, if your manifold will flow properly using 4 of 8 bores. That's another work-around. If I were doing this one as a custom setup, I'd use them as-is and simply kill the 'secondary' injectors and fix the plates closed. With 4v, even with progressive linkage, you'll get to about 1/2 throttle and any more pedal will make no difference. The up-sides to using them as 2v are better throttle opening control, better fueling across the range with half the injectors (better fuel control), and yet the ability to simply re-enable the 'secondaries' for more growth later as desired. All win-win. While this is a simple change for a custom EFI controller, I don't know if the EZ unit is that easily configurable.

David
 

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Discussion Starter · #11 ·
I have watched some YouTube videos of guys running them on a tunnel ram on a sbc 400ci and the thing runs great , if the two 4s runs like crap I'll go back to my stealth intake and just run 1 throttle body, but everything have have read and seen I think it will work just fine, I have been wanting to run dual carbs for awhile but didn't want the headache of tuning them
 

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I have done quite a few multible carb set ups. It can be rough. First sending them out to be matched is easiest unless you have the equipment to do so. Single setup not much of an issue. Currently run dual quads on my 302 with stage 5 calibrating bt Nickerson. They are 390 CFM juced to flow about 520 each. Which actually do better than two bigger carbs because of venturi sizes on the smaller carbs providing more responsive metering.
Fuel econmy is actually better than the Victor EFI set up that was on the car at one time so is performance.
Intake manifold is an issue also. I perfer the Blue Thunder dual quad intake.
Flows better than the EDDY one and the distance between carbs is greater.

Air flow with intake bolted to heads. I run 235 CFM at .500 lift ported DOOE heads. Out of the box the Blue Thunder intake flowed between 160 and 175 CFM depending on runner. After 2 weeks of flowing and grinding got the intake to flow 212 CFM out of each port. More than a Victor Jr I was testing at the same time. The Victor Jr had some port work.
So for the most part the intake wont even flow what the TBs can stock.
 

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I am going to try it with a air gap dual quad intake
I have dynoed air gaps back to back with RPM intakes. The Air gap pulled 5 HP more peak but the RPM pulled more total HP and torq. Air gaps are a gimick in my book. Also found dual planes on SBFs flowed better on the lower than the upper runners. Think it has something to do with runner entry angle into the port center lines. Of course if your just out for the looks factor and radical idle
 

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I have dynoed air gaps back to back with RPM intakes. The Air gap pulled 5 HP more peak but the RPM pulled more total HP and torq. Air gaps are a gimick in my book. Also found dual planes on SBFs flowed better on the lower than the upper runners. Think it has something to do with runner entry angle into the port center lines. Of course if your just out for the looks factor and radical idle
the lower section of daul plane intakes flowing better ... in another tread about intakes , that info was just steped into . now you gave it up

makes one wonder about the old hi-rise claims
 

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I have watched some YouTube videos of guys running them on a tunnel ram on a sbc 400ci and the thing runs great , if the two 4s runs like crap I'll go back to my stealth intake and just run 1 throttle body, but everything have have read and seen I think it will work just fine, I have been wanting to run dual carbs for awhile but didn't want the headache of tuning them
I'm sure it will run fine, I am mostly speaking to the drivability and throttle reaction that is commonly an irritating or frustrating part of huge airflow on the street. It will be fine, and there are simple workarounds like I mentioned for anything you want to alter or tweak.
:tup:
David
 
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