Intake system on a supercharged car

[D_eano]

this is more for my general knowlege than anything else... but am i right in thinking that once air enters the system it starts with an intake pipe taking it into the supercharger by means of an impeller sucking it in... then it gerts pushed through an intercooler and then through the throttle body?

i cant think what happens to the throttle body... does the butterfly open as normal and air is just pushed into the inlet?

cheers for any help guys

[Clairey Fairy]

It would seem logical that way, but quite clearly im no expert!!

[Mike_M]

A supercharger does not have an intercooler as far as I am aware........it simply compresses and forces the air into the engine to make a bigger explosion with fuel and runs off the engines power/cambelt

http://www.gadgetonline.com/Super.htm

[Tallika_Fan]

You're basically correct Dean, you don't have to use an intercooler though it's advised that you do due the the increased temperatures.

air filter > supercharger > (optional intercooler) > throttle body, you'd generally have some sort of dump/recirc valve in there too, just like a turbo car.

Some roots style chargers they use on muscle v8's have a watercooled intercooler directly connected to the oulet flange of the charger then straight to the inlet/throttle bodies of the engine.

[heartagram]

You need some form of cooling. Some people chose to use a charge cooler.

[Niche]

G40's had an Intercooler and they still got ridiculously hot on the standard set-up.

[D_eano]

i figured an intercooler would cool the air down thats getting heated up passing through the hot blower... so you guys rekon the throttle body will operate as normal and just get air forced down past the valves?

[rosscarbry]

correct me if am wrong but some one on this site told me that the air from a super is forced in to the inlet manifold and a turbo is forced through the throttle body so he is maybe talking sh**te but his mate told me that aswell :S

[D_eano]

hmmm maybe... could do with paulbin commenting really lol... where is he

[CasperGTI]

I think the both work on the same principle but use different methods to acheive the compression, Turbos use exhaust gas and chargers use a direct drive. Correct me if im wrong, but dont turbos use an impeller and superchargers use a screw to get there compression?

I would think that it would be the same at the throttle body for bothe chargers and turbos, air is forced towards it and the throttle body butterfly meters the amount of charger air in to the engine. Hence why a blow off of dump valve is needed when the throttle is let off?

Intercoolers are optional on both turbos and chargers, but the general rule is that the more compression or boost you acheive, the hotter the air will be entering the engine, due to boyles/charles/combined gas laws i think.

John

[Unheard]

I think the both work on the same principle but use different methods to acheive the compression, Turbos use exhaust gas and chargers use a direct drive. Correct me if im wrong, but dont turbos use an impeller and superchargers use a screw to get there compression?

There are different types of supercharger but screw are the most efficient if i remember correctly

howstuffworks is always a fantastic place to look, superchargers comes up with...

http://auto.howstuffworks.com/supercharger.htm

turbo

http://auto.howstuffworks.com/turbo.htm

the differacne between turbo and supercharger...

http://auto.howstuffworks.com/question122.htm

I have not looked at any of them but there is usualy good info on them

[jon_273]

Intercoolers are optional on both turbos and chargers, but the general rule is that the more compression or boost you acheive, the hotter the air will be entering the engine, due to boyles/charles/combined gas laws i think.

Thats right. Compressing a gas means work is being done on it, causing it to heat up. As the temperature goes up density decreases, which is not what you want since you are using compression to increase the density of the gas. Therefore an intercooler can be used to cool the gas, this results in an increased compression ratio and higher efficiency.

Basically you want conditions as close to isothermal compession as possible. An intercooler helps you get closer to this.

[paulbin]

hello guys the way i have it at the moment is the air travels through the intake into the blades of the eaton where it gets compressed and then blown out the outlet into the intercooler then into the throttle body. The pressure release valve is always open on half throttle as its being opened with the vacuum created in the throttle inlet, as i press my pedal down further the vaccum is lost the valve closes and the compressed air is then forced into the engine via the throttle body.

if u have a very efficient supercharger like the rotrex you dont really have to use an intercooler but because the eaton isnt the most efficient charger out it does create a bit of heat (doesnt help being placed just over the exhaust manifold either) so an intercooler or a charge cooler (intercooler that is cooled with a liquid, similar to a radiator) is a must.

hope that helps

[D_eano]

Cheers guys... think i understand it a bit better... i was reading up on forced induction at college and didnt get to read what happend towards the throttle body end

[currie]

G40's had an Intercooler and they still got ridiculously hot on the standard set-up.

what? g40 boost temps are very respectable?!

first you have a glader which doesnt get the air hot at all compared to a turbo or roots type blower, then you have a intercooler..

[currie]

correct me if am wrong but some one on this site told me that the air from a super is forced in to the inlet manifold and a turbo is forced through the throttle body so he is maybe talking sh**te but his mate told me that aswell :S

they are the same, they both go through a throttle body and manifold and into the engine.

[noddy]

a little bit of info is that not all throttle bodies take to charging as they can leak and be blow open with low pressures you do have bypass valves for this but some still leak with that never known it on a vw tho

[currie]

a little bit of info is that not all throttle bodies take to charging as they can leak and be blow open with low pressures you do have bypass valves for this but some still leak with that never known it on a vw tho

good point, well made.

also worth note along these lines are that 75% of carbs if not more dont like boost, the r5gtT being one of the few that is suited to it.

and totally the opposite, almost all bike ITBs are fine for boost.

[karl]

AIR enters through the air filter then flows through the throttle plate and then enters the supercharger once it exits the charger it then goes in to the inlet of the engine , the run from the exit of the supercharger to the engine intake port should be as short as possible otherwise there will be lag this is because a supercharger dose not compress air it is more of a pump which turns in relation to the crankshaft ( ie you get a fixed volume of air per rev of the crank )

The boost ( pressure ) that some people refer to is the resistance of the engine to the increased flow of air in other words boost means nothing its the flow of air we look at .

Quick example if we had two supercharged engines one with a restrictive exhaust the boost pressure would be higher on this engine and possibly make a bit less overall power compaired to the other engine which has a nice free flowing exhaust .

[karl]

hello guys the way i have it at the moment is the air travels through the intake into the blades of the eaton where it gets compressed and then blown out the outlet into the intercooler then into the throttle body. The pressure release valve is always open on half throttle as its being opened with the vacuum created in the throttle inlet, as i press my pedal down further the vaccum is lost the valve closes and the compressed air is then forced into the engine via the throttle body.

if u have a very efficient supercharger like the rotrex you dont really have to use an intercooler but because the eaton isnt the most efficient charger out it does create a bit of heat (doesnt help being placed just over the exhaust manifold either) so an intercooler or a charge cooler (intercooler that is cooled with a liquid, similar to a radiator) is a must.

hope that helps

Actually the Eaton M series of superchargers are very good and you will only need some sort of intercooling if they are being over driven .

[noddy]

AIR enters through the air filter then flows through the throttle plate and then enters the supercharger once it exits the charger it then goes in to the inlet of the engine , the run from the exit of the supercharger to the engine intake port should be as short as possible otherwise there will be lag this is because a supercharger dose not compress air it is more of a pump which turns in relation to the crankshaft ( ie you get a fixed volume of air per rev of the crank )

The boost ( pressure ) that some people refer to is the resistance of the engine to the increased flow of air in other words boost means nothing its the flow of air we look at .

Quick example if we had two supercharged engines one with a restrictive exhaust the boost pressure would be higher on this engine and possibly make a bit less overall power compaired to the other engine which has a nice free flowing exhaust .

not really most run the throttle bodie after the intercooler/ chargecooler and i dont know of any turbos that have the bodie befor it

[karl]

not really most run the throttle bodie after the intercooler/ chargecooler and i dont know of any turbos that have the bodie befor it

I was not refering to a turbo set up with a supercharger it is better the way i decribed due to less pipework after the charger = better throttle responce .

could also be that a mass air flow meter is being used rather than a vaccume / pressure type .

Edited July 29, 2008 by karl

[currie]

AIR enters through the air filter then flows through the throttle plate and then enters the supercharger once it exits the charger it then goes in to the inlet of the engine , the run from the exit of the supercharger to the engine intake port should be as short as possible otherwise there will be lag this is because a supercharger dose not compress air it is more of a pump which turns in relation to the crankshaft ( ie you get a fixed volume of air per rev of the crank )

The boost ( pressure ) that some people refer to is the resistance of the engine to the increased flow of air in other words boost means nothing its the flow of air we look at .

Quick example if we had two supercharged engines one with a restrictive exhaust the boost pressure would be higher on this engine and possibly make a bit less overall power compaired to the other engine which has a nice free flowing exhaust .

erm no. the throttle body goes after the supercharger. otherwise you cant accurately control the air entering the engine

[karl]

erm no. the throttle body goes after the supercharger. otherwise you cant accurately control the air entering the engine

yes you can its called MAP manifold absolute pressure sensor / although Honda and most jap engines manufactors dont use a blower they do use a MAP sensor which is located in the inlet manifold on their NA lumps , although they are not as accurate as the Bosch hot wire jobbie but the do work .

[currie]

yes you can its called MAP manifold absolute pressure sensor / although Honda and most jap engines manufactors dont use a blower they do use a MAP sensor which is located in the inlet manifold on their NA lumps , although they are not as accurate as the Bosch hot wire jobbie but the do work .

thats got nothing to do with controlling the air. that tells the ecu how much fuel to supply but it doesnt stop the air.

you need the throttle butterly to stop it otherwise everytime you let off the throttle all the pressure built up would carry on into the engine.