Quad throttles - why bother?

[Ben Wilson]

would ITBs that are 90degees to the block be better than ITBs at say 110-120degrees to the block?

The only reason you commonly see them at 90 degrees is if they are mounted on a carbie manifold.

[merc-blue]

The only reason you commonly see them at 90 degrees is if they are mounted on a carbie manifold.

also the most direct flow helps,

Im running ITBs on my 2TG for a few reasons, 48mm
1. hard to get parts for solexs
2. webbers are expensive
3. constantly tuning carbies (track work)
4. I know 2 guys who can get 2x DCOEs running good,
5 I know 100s of guys who can get ITBs running well

I saw a 2x DCOE mechanical slide injection system in a box at work today, i got excited, that would be sweet on the 2TG.

If ITBs werent good then they wouldnt use them, there are enough computer simulations and engineers around and top cars are still using them,

[myne]

I've often wondered if there might be a better way of regulating throttle than a simple butterfly.

What about some sort of wedge type thing that raises and lowers within the inlet tube
Wouldnt the increased velocity improve torque at lower rpm?

[WindeX]

I've often wondered if there might be a better way of regulating throttle than a simple butterfly.

What about some sort of wedge type thing that raises and lowers within the inlet tube
Wouldnt the increased velocity improve torque at lower rpm?

Thas a very very interesting idea, I wonder if someone here has a reason why this hasnt been done

[river]

Hi,

Because it's complicated. A butterfly is simple, uses a single cable (or servomotor), and is easy to manufacure without air-leakage on the pivot points.

The movable wedge would require more effort in design for controlling the unit, as well as making it air-tight to avoid air leakages around the mechanism that makes the wedge move.

Of course, this is just off the top of my head, and I may be totally wrong in my assumption.

seeyuzz
river

[skiddz]

im with the old guy on this one, the actuation of a butterfly is alot easier although i cant see how a wedge type thing could increase velocity. as with the butterfly there will be a region of low pressure on the area just under the partially open plate

here is a pic, the red bit is low pressure air (low pressure = turbulance= lower velocity)


the same would apply for a wedge type thing with a low pressure area behind the wedge

[MWP]

Surely you only worry about restriction at WOT.

Anywhere else doesnt matter.... at lower throttle you have to block the air so there is always going to be turbulence/low pressure points.

[V-Na]

I've often wondered if there might be a better way of regulating throttle than a simple butterfly.

What about some sort of wedge type thing that raises and lowers within the inlet tube
Wouldnt the increased velocity improve torque at lower rpm?

That would not generate an effective increased air velocity unless the stream could be directed over the valves and into the combustion chamber almost undeflected. The increased air velocity drops off immediately after the narrowest point of the wedge.

Regardless, torque would be increased at low throttle not low rpm.