dual TBs?

[Murphy]

There as an Avalon at the shop today with 2 throttle bodies and it made me wonder if there would be an advantage to runnig dual TB's on our cars? Maybe something simple like a Y where the stock TB would go or maybe even something crazy like 1 for 1 and 3 and another for 2 and 4. What are your thoughts?

[BadAssPerformance]

There may be some advantages over running one huge TB in the throttle control department, kind of like a 2-stage 2 barrel.

I just received my 75mm TB... now all I need to do is make the intake, lol.

[Una]

Yeah, VW had the 2 barrell TB way back in the late 70's.. Always seemed like a better idea.. Most modern cars that have multiple TB's have the second one setup to change the size of the plenum to improve low end response/torque.

[altered7151]

I think the only way to really take full advantage of it is to put it on a custom manifold designed for it. You could set it up so the 2nd throttle body doesn't come on until higher throttle positions. Would definitally be cool though.

[Putter]

All the twin throttle body Fords I've ever seen open the first plate then about 15 degrees behind the second plate will open.

[Tony Hanna]

I'd been kind of wondering about welding a second elbow onto the passanger side of an intake and running a second throttlebody that way. It would be a simple matter to put a "Y" in the cable. or if you were running a standard, use the tranny side of the lever on the original throttlebody to work the cable to the other one. A setup like that would have to help overall flow, but I have no idea how it would affect the balance between cylinders.
Tony

[altered7151]

I think the problem with that would be alot of turbulence caused by the air rushing in from both sides and running into each other in the plenum. You want to try to get the flow in the plenum as laminar as possible.

[The S is Silent]

I could see it as an advantage on TBI cars, just because it's really hard to increase the size of the TB. Two TBI units that put in half the amount of fuel.

[Ondonti]

One guy pulled off a twin TB 3.0 where he had 1 on both ends of the plenum. The 3.0 runs lean on the rear cylinders so this is a good idea IMO, but the TD's have special fueling for different cylinders so this probably would be bad unless you fixed the Cal.

I guess it would work differently when you are under boost too....NA its just vacuum pulling air instead of a turbo pushing air into the plenum.

[The S is Silent]

It might be an option if you are getting a custom cal. How would you get the throttles to open the same?

[Tony Hanna]

Adjustable cables would be the easiest way. That's the way they do it with motorcycles. You just adjust the cables until both throttle blades start to open at exactly the same time.

[87 charger]

I just received my 75mm TB... now all I need to do is make the intake, lol.


75 mm ?

WOW :eek: Are you serious ?
If so what is it off of.

[BadAssPerformance]

Yep, very serious. Off of eBay as an upgrade for a 5.0L ferd.

Just need to make the intake now ;)

[looneytuner]

i think it would be good for manageable high hp street use. Progressive linkage as in the old four barrel carbs. Second one starts to open at 1/3? throttle???? Mechanical linkage for two parallel shouldn't be hard to fab. You could probably use carb linkage. I LIKE this idea.:nod:
Heavier spring for second tb so you can feel the resistance in the pedal.

[Tony Hanna]

Yep, very serious. Off of eBay as an upgrade for a 5.0L ferd.

Just need to make the intake now ;)

I'm curious how you're going to get the IAC and TPS working.
Changes in the cal to work with the Ford parts?

[BadAssPerformance]

I'm curious how you're going to get the IAC and TPS working.
Changes in the cal to work with the Ford parts?

I have a FAST system on the car... dont use IAC and should be able to use the mopar or ford TPS with the T-body.

[Tony Hanna]

I have a FAST system on the car... dont use IAC and should be able to use the mopar or ford TPS with the T-body.

Makes sense.
I wonder if it would be possible to make something like that work with a stock ecu?

[BadAssPerformance]

Makes sense.
I wonder if it would be possible to make something like that work with a stock ecu?

Should be able to use the mopar TPS and it has an adjustable idle stop so no need for an IAC.

[glhs875]

Two throttle bodies vs. 1 big one could work better, especially on the street. As the dual smaller plates would have better throttle response over 1 huge plate. I would like to try out a 4 butterfly setup, one for each cylinder.

[BadAssPerformance]

Have you seen Warren Stramer's intake? 4 valves works well for him :thumb:

[glhs875]

Have you seen Warren Stramer's intake? 4 valves works well for him :thumb:

Yea, that's very nice! I bet it feels like a motorcycle engine on steroids!!

[BadAssPerformance]

Yea, that's very nice! I bet it feels like a motorcycle engine on steroids!!

It sure runs like one!

[86Shelby]

Two throttle bodies vs. 1 big one could work better, especially on the street. As the dual smaller plates would have better throttle response over 1 huge plate. I would like to try out a 4 butterfly setup, one for each cylinder.

Acutally, I was looking at a setup from a bike last night and this thought crossed my mind. It had 4 38mm(?) throttle bodies, each with it's own injector boss. The TBs were not controlled by a single shaft like Mr. Stramer's setup; each had thier own shaft and stiff spring loaded and adjustable linkage that moved the one next to it. The spacing appeared pretty close to the spacing needed to mount it on a 2 piece intake.

For the progressive TB idea, take a look at the mid-late 80's VW 1.8L(or is it 1.9L?) engines. Both the 8V and 16V engines had dual throttle openings that were staged,

[glhs875]

Acutally, I was looking at a setup from a bike last night and this thought crossed my mind. It had 4 38mm(?) throttle bodies, each with it's own injector boss. The TBs were not controlled by a single shaft like Mr. Stramer's setup; each had thier own shaft and stiff spring loaded and adjustable linkage that moved the one next to it. The spacing appeared pretty close to the spacing needed to mount it on a 2 piece intake.

For the progressive TB idea, take a look at the mid-late 80's VW 1.8L(or is it 1.9L?) engines. Both the 8V and 16V engines had dual throttle openings that were staged,

Something like that could work, but when using individual butterflies, they need to be larger than one would normally think. On an 8v, I feel that each one would need to be in the 46mm to 52mm range.