Progressive throttle bodies
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Progressive throttle bodies So i'm tooling around in my dads garage with him and i notice he went with twin four barrel carbs on his nova project.. we were setting up a progressive system. And for the ones of you who don't know a progressive system works like this in the case of carbs one carb runs normal as the other one runs at idle until you put your foot in the peddle and it opens the other carb up allowing more fuel and air thats the most basic way i can put it.. so i'm thinking to myself what if i do a dual throttle body set up like 1 throttle body at the rear of the intake manifold. Use progressive linkage and boom i have dual throttle body car.. well a few of you may think hmm waste of time.. well think of this your LS could run really mild mannered next to someone and then once u push it past say 3/4 pettle the other throttlebody opens up and u add a few extra ponies.. it was majorly for a sleeper car back in the day..shouldn't be too hard
I don't think the gains you are expecting out of this are actually there. Unless I'm missing something, you plan to hack up your LS1 intake to stick another throttle body on the back. I think this is a bad idea, because the intake manifold wasn't designed to have another TB on it, unlike your dad's nova project. I imagine he has a dual carb type intake manifold, one DESIGNED to flow 2 carbs, but not always at the same time.
Now, if you had a fabricated sheetmetal intake, this might be a totally different story.
Now, if you had a fabricated sheetmetal intake, this might be a totally different story.
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well see i just got back from the junkyard.. i got 2 LM7 intake manifolds and 2 Throttlebodies to match.. yeah their that plastic nylon crap.. well for my experimentation that will work best it will be easier to work with and it only cost me 110 bucks for everything
On The Tree
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From: North Ridgeville (suburbs of cleveland) Ohio
All i can think of with this project is leaning out your fuel mixture in the higher RPM's. Wouldnt you have to increase fuel and what not as the throttle body was opened? A carburetor is a venturi and allows air to pressurize when in the venturi and gas is added to the mixture. A fuel injected car works on a totally different setup.
your heads will still only flow their maximum. you may see some gain from pressure ratio drops but since the throttle body is not the all restricting part of the intake system i don't think you will yield much more than say 15 horse. but do it up i would love to see the set up.
The stock throttle body on the later LS1
F-bodies has a cam that is "progressive"
in that it opens a little for a lot of draw
and then a lot for the last bit. The earlier
years were more linear.
The main point of progressive linkage carb
to keep a decent velocity / vacuum signal
across wide range of airflow. Since we
don't meter fuel based on any throttle
body air velocity, it doesn't matter how
many TBs or what size - bigger is better
and even bigger is even better. Though
other chokes may make the 6" butterfly
valve kind of pointless.
F-bodies has a cam that is "progressive"
in that it opens a little for a lot of draw
and then a lot for the last bit. The earlier
years were more linear.
The main point of progressive linkage carb
to keep a decent velocity / vacuum signal
across wide range of airflow. Since we
don't meter fuel based on any throttle
body air velocity, it doesn't matter how
many TBs or what size - bigger is better
and even bigger is even better. Though
other chokes may make the 6" butterfly
valve kind of pointless.
