individual throttle bodies?

[bug killa]

Can you guys explain the advantages of having individual throttle bodies as opposed to a single one? What the theory behind it? Why dont more cars have that setup?

[Chui]

The advantage is better overall flow which should assist combustion.
Better [read faster] throttle response.
Cost.

[bug killa]

do cars w/ indiv throttle bodies still have an intake manifold? or do the throttle bodies just connect to runners straight to the intake ports on the engine? How is the overall flow better? is it cuz there is less surface to cause friction?

[Chui]

There is still an intake manifold. Try looking up BMW E46 M3 engine on the web. You can see pictures of the intake and the six 'bell-mouthed' trumpets.

Flow will be better because you don't have to evacuate this large plenum which must be filled before it dumps air into each trumpet or runner. So it's really a big throttle response advantage.

If the induction system is designed properly it should be theoretically possible to charge each cylinder equally which assists in combustion variability.

[Griffin]

Actually in its most effective naturally aspirated racing applications, individual throttle bodies are sometimes used without any manifold at all, for instance the TRD SCORE motors and the 4A-GE Formula Atlantic Motor.

Griffin

[Chui]

Originally posted by Griffin
Actually in its most effective naturally aspirated racing applications, individual throttle bodies are sometimes used without any manifold at all, for instance the TRD SCORE motors and the 4A-GE Formula Atlantic Motor.

Griffin

WOW, I overlooked the obvious. No plenum, less restrictions at higher speeds, too.

Look at F1 engines, or any truly stressed normally aspirated race engine and you'll see exactly what Griffin has described: Multiple trumpets with nice throttle bodies...

THAT'S my idea of PRON!! :D

[Griffin]

Originally posted by Chui


WOW, I overlooked the obvious. No plenum, less restrictions at higher speeds, too.

Look at F1 engines, or any truly stressed normally aspirated race engine and you'll see exactly what Griffin has described: Multiple trumpets with nice throttle bodies...

THAT'S my idea of PRON!! :D

It's not that obvious - seeing as how you do what you do I imagine that thinking of a completely unfiltered intake airstream is a tad uncharacteristic. A manufacturer would have to be insane or have a 500 mile warranty to get away with it :)

But man oh man - nothing sounds quite like a totally unrestricted intake :)

Griffin

[Blue Bomber]

So, does anyone think this would be possible to do (with enough $$$, of course! :D ) on a Celica?

[autxr]

http://www.twminduction.com/images/chevv8.jpg

Pictures like this make me long for a domestic project car.

8 throttle bodies, fuel injected, a thing of beauty.

If you want to look at nice parts, TWM Induction is on the list of cool sites.

Scott

[icyjaws]

TWM also makes them for honda and mazda. Someone might try talking to them about making something for the 2zz but there not cheap and i would think there would be better ways to make the power.

[Griffin]

Originally posted by Blue Bomber
So, does anyone think this would be possible to do (with enough $$$, of course! :D ) on a Celica?

Yes it would be possible, but once done the car will never again be a daily driver, at that point you are limited use race only. (its also a good idea to set up direct / ram airflow to the intake assembly in this case). The peoblem is you would have to go with a standalone for fuel management and you would loose yout VVTi and VVTLi function.

Griffin