Instead of having one throttle body taking in air for four of the inlets, with the ITBs, each inlet has it own throttle intake/body, hence Individual Throttle Body/s taking in air individually for each inlet port.
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Instead of having one throttle body taking in air for four of the inlets, with the ITBs, each inlet has it own throttle intake/body, hence Individual Throttle Body/s taking in air individually for each inlet port.
a single intake for each combustion chamber.
Here's an article written by one of the legends of Honda drag racing Bisi Ezerioha. It is part of his build for the Super Street engine builders competition.
http://www.superstreetonline.com/fea...tec/index.html
Thanks for link!Quote:
Originally Posted by grumpy rooster
I read about that engine before because its the engine from my car -.-.. its unbelievable how much potential it has..like WOW...
on top of getting a more balanced amount of air per cylinder, you just get resonance/reinforcement physics as well.
your engine produces vacuum on the intake stroke, which pulls air into the cylinder for as long as the valve is open, however, when the valve suddenly closes, air rebounds off the valve and goes out the trumpet. and then when the valve opens again, the air is drawn in again. according to a certain formula, if you manage to set it up so that the end of your trumpet is exactly a certain distance away from your intake valve, you can hit certain harmonics (at which points the air wave that was deflected away from the valve is drawn in at the same time as new air wave, thus reinforcing the strength of the wave).
im not sure about the specifics of the formula, but it also applies to individual carburetor setups using trumpets. according to a basic calculation using a d series motor as the base, with 13 inches between the end of the trumpet and the valve, you hit the fourth harmonic between 5294 to 5920rpm, the third harmonic between 6790 to 7760rpm and the second harmonic between 9037 to 10966, each with increasing pulse strength.
however, you will have to toss up between what your car is being used for. with trumpets, they only really produce more power when you hit the harmonics. with itbs, the disadvantages of trumpets are minimised due to fuel only being injected into the cylinder when the valve is open. with carburetors in a d series, lets just say that the direction of the carburetors is less than ideal for trumpets, so if you accelerate, fuel will just fall out of the trumpets and you'll run lean.