How Do The 'new' Carb Throttle Bodies Work?

[89oem]

i really like these throttle bodies... with the proper lower how do they work vs the big runner upper/lower stuff everyone has?

vacuum?

drivability?

would you swap your, factory, cobra, explorer, edelbrock, tfs intake setup for one?

if you were in an 89+ fox sn95 efi car...

thanks!



please educate me !

 

[dnbonds]

They look cool but I don't think they would flow better since they have 4 small openings instead of a single large one.

Edit: I didn't know it was carb instead of MAF

 

[Bullitt347]

The whole purpose of the long runner EFI intake manifolds is to optimize throttle response and torque curve. A short runner manifold will typically make more top end power than a long runner manifold. On a production street car, a intake that promotes throttle response and low end torque will make for better driveability. Also with EFI, since the fuel injector is near the cylinder head and pointed at the intake valve, you do not have to worry about fuel distribution issues with such a long runner path. Which is why you do not see CFI or throttle body fuel injection on long runner manifolds. A throttle body fuel injection system is nothing more than a electronic carburetor, maybe the fuel is atomized a bit better, but that is about it.

Edit: In my opinion, throttle body fuel injection is the poor mans excuse to say you have "EFI" save your money and buy a good carb instead, like a QuickFuel carb. It will make more power than any throttle body "EFI" system.

 

[tannerc91gt]

They look cool but I don't think they would flow better since they have 4 small openings instead of a single large one.

They flow better. By a good bit

 

[tannerc91gt]

The whole purpose of the long runner EFI intake manifolds is to optimize throttle response and torque curve. A short runner manifold will typically make more top end power than a long runner manifold. On a production street car, a intake that promotes throttle response and low end torque will make for better driveability. Also with EFI, since the fuel injector is near the cylinder head and pointed at the intake valve, you do not have to worry about fuel distribution issues with such a long runner path. Which is why you do not see CFI or throttle body fuel injection on long runner manifolds. A throttle body fuel injection system is nothing more than a electronic carburetor, maybe the fuel is atomized a bit better, but that is about it.

Edit: In my opinion, throttle body fuel injection is the poor mans excuse to say you have "EFI" save your money and buy a good carb instead, like a QuickFuel carb. It will make more power than any throttle body "EFI" system.

Maybe I'm misreading you here but it looks more like OP is referring to a 4150 TB with a fuel injector at each cylinder than a throttle body injection system(which I'll agree is crap)

 

[rbohm]

these were designed to be installed on engines that never came with EFI. for instance, find me an EFI intake for a 390 or 428 ford. no? how about a boss 302 or boss 429 ford. no? perhaps a boss 351 ford. no? throttle body injection is also nice when you want to install EFI but dont want to use all the factory rigamarole. as for the factory intakes being designed for low end power, that is true, BUT they are also dry flow systems. you can accomplish the same thing with a throttle body injection system and a dual plane intake like the performer in a wet flow system.

the difference in efficiency is small, the biggest difference is no sefi system with TBI.

 

[tannerc91gt]

Am I losing my mind or is this not what OP is talking about? It's NOT a TBI setup

 

[89oem]

@tannerc91gt yes, yours from the lower intake up - not so sure about the gm aspects

anyway i saw a few 1320 builds on boards and then your build,

guess im old but that setup with a circular filter and maybe shaker hood or boost would be my ideal look/setup for my 89 factory 5.0... wouldnt want to give up street drivability or upscale drivability like any normal factory plus efi/maf intake with hci would yield ......sorry if i wasnt clear...

 

[84Ttop]

Am I losing my mind or is this not what OP is talking about? It's NOT a TBI setup

I'm picking up what your putting down

 

[old_blue]

Tanner is right.

The whole purpose of the long runner EFI intake manifolds is to optimize throttle response and torque curve. A short runner manifold will typically make more top end power than a long runner manifold. On a production street car, a intake that promotes throttle response and low end torque will make for better driveability. Also with EFI, since the fuel injector is near the cylinder head and pointed at the intake valve, you do not have to worry about fuel distribution issues with such a long runner path. Which is why you do not see CFI or throttle body fuel injection on long runner manifolds. A throttle body fuel injection system is nothing more than a electronic carburetor, maybe the fuel is atomized a bit better, but that is about it.

Edit: In my opinion, throttle body fuel injection is the poor mans excuse to say you have "EFI" save your money and buy a good carb instead, like a QuickFuel carb. It will make more power than any throttle body "EFI" system.

Nope the system the OP posted is a direct port system with just the air going through the TB.

these were designed to be installed on engines that never came with EFI. for instance, find me an EFI intake for a 390 or 428 ford. no? how about a boss 302 or boss 429 ford. no? perhaps a boss 351 ford. no? throttle body injection is also nice when you want to install EFI but dont want to use all the factory rigamarole. as for the factory intakes being designed for low end power, that is true, BUT they are also dry flow systems. you can accomplish the same thing with a throttle body injection system and a dual plane intake like the performer in a wet flow system.

the difference in efficiency is small, the biggest difference is no sefi system with TBI.

Again, this isnt a TBI system. These are much more efficient than those old systems that chevy used the heck out of in the 80-90s

 

[89oem]

Exactly! this is not some 'carb' setup its a directly attaching TB sitting on the lower, fuel rails injectors ...

or heck you could have an 8 pack of TB's !! All sitting on an efi controlled engine... but w/o maf etc

this is where i wonder about daily reliability / performance....of the design and the need for things like vacuum..

not the ecu cause thats a different debate.... i see tannerc91gt is running a megasquirt but theres a9l chips, holley, pro-m, etc... ...

 

[tannerc91gt]

Im running a holley EFI system. and while it is GM (ford fuel injectors if that counts ) its identical in most aspects.
the only issue i could see is that its way overkill for a stock 302. you can run the same setup on a performer or a vic JR and maybe pick up some drivability there but the thing is built to suck a lot of air just by design. I could see it being a real dog down low

 

[89oem]

cool, ya i was thinking with a typical hci mod, guess its not what i was wishing...

sorry on the holley ecu .... i misread your thread...