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[goodcookiedrift]

On 2002-04-17 03:54, Tommi Tiardi wrote:
um........well, correct me if I'm wrong

the reason why people use individual throttle bodies is because air and gas can be mixed faster, also, individual throttle bodies increase engine response, because the distance that the air travels decreases significantly where it is very important if you are racing in a track because the re-accleration after a turn depends on engine response as well as handling because a fine throttle can be adjusted easily with the use of your foot (and this of course depends on the driver as well).

Now as for the the cons of individual throttles (which often include a sport injection system) is similar to the carbs where the wheather have a significant affect on performance and has to be tuned very often, because air is not um....how should I say it, kinda like filter because one of the major component that would affect engine performance is moisture where you can't "filter" out from the direct mix of the air (that's why they are sometimes called "direct injection&quot. Also since individual throttle body lacks the "air velocity" where a long tube intake system would have, it would lose low end torque. Also since it is an open structure, dust and other contaminants can go into the engine as well. Heat is another concern since the open structure mainly get hot air that is in the engine compartment.

In a conventional throttle body, where there is a large space in the intake manifold, that is to maintain smoothness of the engine, so is like, you won't feel a big difference in speed even if you go up and down the throttle because air is there for the engine to maintain it's rev, so if you let go of the throttle, you head won't be going forward abruptly. So, it is harder to drive with the individual throttles smoothly



Manufacturer have a way around it, for example the 20valve 4age and the new M3 (I think the old M3 has it too) is to add a box in between the individual throttles and the filter(kinda act like a resonator, again correct me if I'm wrong) to maintain the smoothness yet satify the engine response that it needs, also to maintin air velocity of intake air as well as filtration. Also it is easier to drive too



Of course there can't be the best of two worlds, there are up and downs for both application.

For the cone filter thingy, it depends of what you want, high end or low end, if you want low end, then go with the long intake system, if you want high end, you might want a short system. The reason is similar to what I have just said above

again that's just my 2cents, correct me if I'm wrong

Individual throttles and carbs benefit engine response and power better than a single throttle is because there is an even airflow and even mixture (provided its tuned correctly) to EACH cylinder. As a reult, there is far more predictablity and for more flexibilty to generate power.

Correct, there is a lack of air velocity from the traditional single throttle. However, there is also harder and a stronger suction on individuals or carbs. this combined with the differnt velocity stacks can alter the power band of your car. So the individuals/carbs make up the lost velocity in other areas. The last i nkow of it, ivdiviual throttles ARE NOT affected by atmospeheric change as many if not all individual throttle setups use a MAP sensor or standalone system.

Nick