Anyone experimented with a restrictor plate?

[Formula413]

I don't see what the benefit would be. A restriction is a restriction. You need to restrict airflow to use an ICE, that's what a throttle does. You will still end up with the same amount of restriction in the intake tract to obtain a given amount of power, all things being equal.

[Christ]

Thats' why I was asking about putting the hole in a specific place... maybe you could tailor the airflow so that it wouldn't be so "spoiled" by the throttle plate... but then again, any gains would be minimal at best, and it doesn't really seem like it would be worthwhile.

[Rarist83]

If you could restrict the air intake at a position farther away from the intake then say the throddle body, you could extend the vacume ( negitive pressure ). By doing this the intake charge would cool sooner ( air cools in a vacume and heats under pressure) and allow for a more effitian warm air intake application. In other words, a increase in the volume of the vacume should enable the air to absorb more heat and still maintain a lower temp. this will expand the air and thin out the o2 content requiring you to open the throddle body more for any given power setting. the increase in cylender pressure should provide better vm effitiancy and fuel econamy. This is the same princible that gives a desile higher effitiancy then a gas engine where as the deasil does not have to worry about detonation or o2 content and can obtain full cylender pressure at idle, given that it does not have a turbo.

[vtec-e]

What about on a diesel?

[bgd73]

I found a way to restrict a carb...
progressive two barrel runs on vacuum. while engine is below 195, it is only allowed 1 barrel via a thermal vacuum switch attached to the intake near warm source.

I could only guess at a couple of things for each individual fuel injection, but all systems have something that can hold it back...no plates needed.

[Rarist83]

deisel has no intake restriction due to its nature of operation. Instead it uses fuel to obtain diffrent power settings. This leaves the Pressure in the cylender at tdc on the copresstion stroke the same despit the rpms or load. Not only is the p.s.i the same but the volume of air is the same as well. The more air you have in a cylender when the fuel is ignited the more heat that is asorbed by the air rather then the block, oil, and coolant. This is why a deasil can achieve 40% thermal effitiancy where as a gas engine can only achieve 25%. At the throddle body in a gas engine there is a vaume created as the engine tries to suck in air but is denied due to the throddle boddy being closed. This is required to controll the engine rpms or the power output. If you tried to control this with the fuel mixture in a gas engine the motor would detonate. This is not a problem in a deasil because the fuel is not introduced until it is ready to burn. Because of the vacume that is created in the gas motor the volume of air is decreased as well as the p.s.i. during the copresstion stroke. The detonation temp of a fuel decresses with an increase in oxogene as well as temp. So the Idea is to put in a large volume of air with a low volume of o2 at low temps so that you can open the throddle body all the way without leaning out the ratio between oxogene and fuel. When you heat air you expand it creating more volume with less oxogene. Remeber that fuel detonates with temp increase as well so you can,t heat it to much. In a vacume however the air is stretched and cooled allowing it to absorb more heat with out increasing the temp. So if you take the vacume that is created after the throddle body and extend it to a restrictor plate found before the air filter ( the higher volume of vacume the better) your wai might work a litle better and given the the cpu in you car can componsate it should spray less fuel. You might haved to adjust you throddle body position sensor but be carful doing this because it could void warrenties and damage the engine.

[nayeliesuncle]

I've thought about installing a 2nd throttle body just after the air filter to have a better control of engine RPM. I think it would help with keeping the engine speed steady for those without cruise control (like me).