dual throttles

[krebs128]

my friend has a 98 civic ex dohc vtec and we wanted to 'add' another throttle to it. now how would i go along doing this? we're gonna put some kind of divider in the intake manifold so one throttle goes to 2 cylinders and the other throttle to the other 2 cylinders. of course the fuel injection will be upgraded and a custom intake manifold. i've seen something like this done before on a ford focus, and i was wondering how i would go through this process of creating it?

[454Casull]

Originally Posted by krebs128

my friend has a 98 civic ex dohc vtec and we wanted to 'add' another throttle to it. now how would i go along doing this? we're gonna put some kind of divider in the intake manifold so one throttle goes to 2 cylinders and the other throttle to the other 2 cylinders. of course the fuel injection will be upgraded and a custom intake manifold. i've seen something like this done before on a ford focus, and i was wondering how i would go through this process of creating it?

Why would you do it?

[Pringles]

Might as well go for four itb's.

[krebs128]

Originally Posted by 454Casull

Why would you do it?

put more air in the engine. it's not forced induction. unlike turbos or s/c which need a source of power. 2 air intake into 2 throttles will result in more air.

Originally Posted by Pringles

Might as well go for four itb's.

itb's?

[sideshowrich]

Individual Throttle Bodies.

[krebs128]

i've thought of that, making 2 smaller intake manifolds and putting a throttle on each. but what else would i need to do to make it work?

[454Casull]

If you think the throttle body is a restriction in the intake (and it probably isn't) why not just get/build a bigger one?

[krebs128]

the biggest throttle out there is someting like 80mm, *correct me if i'm wrong*, 2 air intakes each going to a throttle body-has nothing to do w/ resriction, it's just getting more air in there.

[Sluttypatton]

Actually, 2 TB's will ease up the restriction (if thats where the air is being restricted) because less air will have to flow through each TB in order to provide the same amount of air as through a single throttle body. But chances are, it wont really matter for a stock motor (by stock i mean more than a K&N and a high flow axle-back system).

[454Casull]

Originally Posted by Sluttypatton

Actually, 2 TB's will ease up the restriction (if thats where the air is being restricted) because less air will have to flow through each TB in order to provide the same amount of air as through a single throttle body. But chances are, it wont really matter for a stock motor (by stock i mean more than a K&N and a high flow axle-back system).

I still don't see how his engine isn't getting enough air.

<has nothing to do w/ resriction, it's just getting more air in there.>
How would you get more air than you need? Either you don't have enough air because of a restriction in the intake, or you have enough (excluding cases with really bad intake tuning).

[Sluttypatton]

Your absolutely right, if your engine is already getting enough air, making the intake system less restrictive doesn't really matter.

[krebs128]

ok, yea you're right, the engine is getting enough air, the normal amount a stock vtec would take in. but what i'm looking for is more air. it's like the forced induction thing-more air mixed w/ the right ratio of fuel will create more power and THAT'S what i'm looking for, more power. having an intake and a throttle will give me a set amount of air. by adding another throttle, air intake will double-theoretically. all the while, the car is technically naturally aspirated.

[Pringles]

It doesn't work like that. If the engine is getting all the air it can process then any more air you give it won't do anything. What the dual throttle body system could do, if designed properly, is maybe give better throttle response. Think about it, if this thing worked it would have been done already.

[454Casull]

Originally Posted by Pringles

It doesn't work like that. If the engine is getting all the air it can process then any more air you give it won't do anything. What the dual throttle body system could do, if designed properly, is maybe give better throttle response. Think about it, if this thing worked it would have been done already.

Right. The engine only pulls in air because the pressure inside the cylinder is lower than in the runners (then manifold/intake/ambient air), because of the properties of gases. If the pressure inside the cylinder was higher than 1 atm (what boost is), it would want to go back out the intake.

[krebs128]

ah alright, icic. well thanx for your explanations.

Originally Posted by Pringles

Think about it, if this thing worked it would have been done already.

this kinda of thing has already been done before on a ford focus.