FE Power Forums
FE Power Forums => FE Technical Forum => Topic started by: Jb427 on January 18, 2018, 09:30:51 PM
-
Like to know Peoples thoughts and experiences on duel carb Throttle Linkage set ups Progressive and 1 to 1 ratio's
-
What is the application, street, strip, single plane, dual plane? I always used the progressive on my 660s simply because the trans stalled best at the exact placement where the secondaries started to open. Dual plane still needs progressive IMO for street. Race only is up to combination. Joe-JDC
-
I've never had any problem running a pair of 4150's @ 1:1. I'm planning on that with my 390 I'm building.
-
For a street car, I think the factory progressive is hard to beat. Super nice that you can feel with your foot when you get to that second carb.
For race or max performance, feed the beast :P
-
On the ones I have done 1 to 1 worked great not fighting lean cylinders, but I do not have as much experience as some here but the ones I have done worked good on the street. Leny Mason
-
What is the application, street, strip, single plane, dual plane? I always used the progressive on my 660s simply because the trans stalled best at the exact placement where the secondaries started to open. Dual plane still needs progressive IMO for street. Race only is up to combination. Joe-JDC
Street and Strip 482 700 lift roller cam bbm intake 2x 750's or now I am thinking of going 2 throttle bodies now auto 3000 or 3500 converter
-
What is the application, street, strip, single plane, dual plane? I always used the progressive on my 660s simply because the trans stalled best at the exact placement where the secondaries started to open. Dual plane still needs progressive IMO for street. Race only is up to combination. Joe-JDC
Street and Strip 482 700 lift roller cam bbm intake 2x 750's or now I am thinking of going 2 throttle bodies now auto 3000 or 3500 converter
Two TB's no need for progressive anything...
-
I know no progressive for throttle bodies. I was going to make a second post asking about carb's vrs Throttle bodies feel free to let me know what people think.
-
I have dual throttle bodies, with progressive. Works fine.
2 of these:
-
Carb progressive linkage works great - Ford got that one exactly right. On a throttle body deal I like a progressive secondary just for smooth driveability - or they can get really abrupt. Probably depends on the engine combination and the size of the throttle body. I know that my big single blade deal on my car is overly throttle responsive - just a touch of pedal travel makes a huge change in RPM - not an easy car to stage at a consistent RPM.
The FiTech 2x4 we dyno'd recently had one to one with all eight barrels opening at once. It sure sounded really crisp - wont know how it behaves in traffic until its in a running car - if I get the feedback. I know of at least a couple folks that have used an eccentric to change pedal reaction on EFI stack systems - slower at first and then faster in the latter portion of travel.
-
I run 1:1 on the two Ed 600s on the 302. Granted it's not so much a putt-putt show grounder - 4000 stall converter, 4:11 locker or 4:56 spool depending on mood, locked timing at 36. However, the Ed primaries have smaller bores and more efficient boosters than a box stock 1850 so considering the motor as two 4 cylinder engines you could run a vacuum secondary unit on a 4 banger no problem. The 1850s might be a little more sensitive to the car setup because the primary bores are larger and the boosters less efficient. But on a dual plane, remember that the engine sees about half of the carb size at any particular time. If you are running vacuum secondaries, those are not even in the picture. Now we've gone from "1200 CFM!" to more like 600 and on a dual plane around 350 for any particular intake valve that needs some juice. And that's with the pedal floored, not just driving down the street. You'd not have a problem with 600 DP on a 390, 351 or even a 302 so a 1:1 with a pair of 600 VSs is not much of a leap.
If the car is low gear (3:25, 3:50) with a tight 11" street converter you may have to play with progressive to get the tip-in performance you think you like. With a high stall converter still building heat while you're cruising at 3400 RPM/55 MPH you really don't care so much about "tip-in" LOL.
660s are 1:1 internal and the other DPs use a progressive link between primary and secondary so running those is another thing entirely.
-
My 660s have a curved throttle lever that pulls the secondaries in at approximately 40% opening. Joe-JDC
-
Used to operate progressive, but about 8 years ago changed over 1 to 1. Had to find optimum squirter size and tried several different pump cams. My engine runs great. Off idle is spot on and low speed acceleration is more crisp. Street use.
496
Tunnel Wedge
2 QFT 750’s
Solid roller