Supercharger Question.

[Lex-aholic]

Hi all,

Not being mechanically minded I was just wondering how a Supercharger works.

Be as easy as you can with the answer cuz I haven't got a clue about engines. :duh:

Cheers

[altezzaz]

I'm not technically minded either, but there are 2 sorts, the stuff you get on the yank tanks - a "roots" type, and the one fitted to the cars here. Both are driven from a belt from the crankshaft - the bit that the pistons drive - they then drive a turbine in the air intake to push more air into the engine. You can then pump in a bit more fuel and get a stronger explosion in the cylinders. Now watch me get shot down!!

[Lex-aholic]

I'm not technically minded either, but there are 2 sorts, the stuff you get on the yank tanks - a "roots" type, and the one fitted to the cars here. Both are driven from a belt from the crankshaft - the bit that the pistons drive - they then drive a turbine in the air intake to push more air into the engine. You can then pump in a bit more fuel and get a stronger explosion in the cylinders. Now watch me get shot down!!

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Thanks for the info. That does help. It was just one of those things that went through my mind last night. :)

[legendswraith]

I'm not technically minded either, but there are 2 sorts, the stuff you get on the yank tanks - a "roots" type, and the one fitted to the cars here. Both are driven from a belt from the crankshaft - the bit that the pistons drive - they then drive a turbine in the air intake to push more air into the engine. You can then pump in a bit more fuel and get a stronger explosion in the cylinders. Now watch me get shot down!!

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lmao

as far as i am aware both superchargers and turbos work on the same principle but derive the energy from different sources.

A supercharger is spun up directly by an engine driven pulley which spins a single entry centrifugal compressor disc which then forces compressed gasses out through the eye into the engine via the induction piping. This provides the engine with a greater mass of air therefore more fuel can be added into the cycle hence more power.

Turbos work on exactly the same principle but rather than being engine driven they utilize the waste exhaust gasses to spin a turbine which turns a centrifugal compressor giving the extra air to the engine.

The main trade offs are costs ease of install and the fact turbos introduce no parasitic drag into the engine

All this begs the question of what if they put a double entry (awaits double entendres) centrifugal compressor into a blower? I think the pressure ratio of a single entry is roughly 3/4:1 and although there are losses you should get a roughly 7:1 compression ratio on a double entry. It would take longer to spin up but when it did

[MacRS200]

All this begs the question of what if they put a double entry (awaits double entendres) centrifugal compressor into a blower? I think the pressure ratio of a single entry is roughly 3/4:1 and although there are losses you should get a roughly 7:1 compression ratio on a double entry. It would take longer to spin up but when it did 

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Just use 2 compressors and you get double amount of air and spin up in the same time, hold on.....................someone thought of that already

[Monster-Mat]

the TTE compressor is a roots type blower

[Lex-aholic]

Another question (which could seem stupid!). Do they cause alot of damage to the engine if they are pushing more "force" through ?

[legendswraith]

All this begs the question of what if they put a double entry (awaits double entendres) centrifugal compressor into a blower? I think the pressure ratio of a single entry is roughly 3/4:1 and although there are losses you should get a roughly 7:1 compression ratio on a double entry. It would take longer to spin up but when it did 

←

Just use 2 compressors and you get double amount of air and spin up in the same time, hold on.....................someone thought of that already

←

i was more on about a twin stage one in effect rather than two seperate ones

[MacRS200]

All this begs the question of what if they put a double entry (awaits double entendres) centrifugal compressor into a blower? I think the pressure ratio of a single entry is roughly 3/4:1 and although there are losses you should get a roughly 7:1 compression ratio on a double entry. It would take longer to spin up but when it did 

←

Just use 2 compressors and you get double amount of air and spin up in the same time, hold on.....................someone thought of that already

←

i was more on about a twin stage one in effect rather than two seperate ones

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Bit like a Tornado engine then.

[legendswraith]

All this begs the question of what if they put a double entry (awaits double entendres) centrifugal compressor into a blower? I think the pressure ratio of a single entry is roughly 3/4:1 and although there are losses you should get a roughly 7:1 compression ratio on a double entry. It would take longer to spin up but when it did 

←

Just use 2 compressors and you get double amount of air and spin up in the same time, hold on.....................someone thought of that already

←

i was more on about a twin stage one in effect rather than two seperate ones

←

Bit like a Tornado engine then.

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nah a tornado engine has an 3 spool axial flow compressor consisting of an LP comp an ip comp and a hp comp can't remember the compression ratio but i think its about 1.4:1 per stage with a centrifugal compressor the twin entry ones are like having the normal centrifual one welded back to back with another

[MacRS200]

All this begs the question of what if they put a double entry (awaits double entendres) centrifugal compressor into a blower? I think the pressure ratio of a single entry is roughly 3/4:1 and although there are losses you should get a roughly 7:1 compression ratio on a double entry. It would take longer to spin up but when it did 

←

Just use 2 compressors and you get double amount of air and spin up in the same time, hold on.....................someone thought of that already

←

i was more on about a twin stage one in effect rather than two seperate ones

←

Bit like a Tornado engine then.

←

nah a tornado engine has an 3 spool axial flow compressor consisting of an LP comp an ip comp and a hp comp can't remember the compression ratio but i think its about 1.4:1 per stage with a centrifugal compressor the twin entry ones are like having the normal centrifual one welded back to back with another

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Was joking about the Tornado engine mate :D Didn't realise the ratio of the stages was that low.

Can see where you are coming from but that sort of level of boost is not really required and a single stage is more efficient as the HP stage would never be properly synced to the LP stage. So single stage spinning faster seems to me the best way of shifting the volume of air required.

[legendswraith]

All this begs the question of what if they put a double entry (awaits double entendres) centrifugal compressor into a blower? I think the pressure ratio of a single entry is roughly 3/4:1 and although there are losses you should get a roughly 7:1 compression ratio on a double entry. It would take longer to spin up but when it did 

←

Just use 2 compressors and you get double amount of air and spin up in the same time, hold on.....................someone thought of that already

←

i was more on about a twin stage one in effect rather than two seperate ones

←

Bit like a Tornado engine then.

←

nah a tornado engine has an 3 spool axial flow compressor consisting of an LP comp an ip comp and a hp comp can't remember the compression ratio but i think its about 1.4:1 per stage with a centrifugal compressor the twin entry ones are like having the normal centrifual one welded back to back with another

←

Was joking about the Tornado engine mate :D Didn't realise the ratio of the stages was that low.

Can see where you are coming from but that sort of level of boost is not really required and a single stage is more efficient as the HP stage would never be properly synced to the LP stage. So single stage spinning faster seems to me the best way of shifting the volume of air required.

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doesn't need to be syncronised the hp will spin up before the lp so it would only be under sustained loads that the lp would come into play

however you are quite right there is no need for that kind of boost but its an interesting theoretical exercise

but if u could use a single stage double entry centrifugal impeller made out of titanium with a ceramet coating you could supply the boost faster :D

but you would be alot poorer

[Rob]

3main types of supercharger-

the roots blower which is just an air pump, doesnt directly compress the air within the casing but provides more air than the engine needs resulting in +ve air pressure being formed in the manifold ( for the TTE kit this starts to happen at above 3500rpm)

twin screw - used in Whipple superchargers, this type does compress the air within the casings, high effiency

certrifugal- used in powerdyne/vortech superchargers high compression ratio about 4:1 again compresses the air with in the casing

[altezzaz]

All this begs the question of what if they put a double entry (awaits double entendres) centrifugal compressor into a blower? I think the pressure ratio of a single entry is roughly 3/4:1 and although there are losses you should get a roughly 7:1 compression ratio on a double entry. It would take longer to spin up but when it did 

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Do you mean a turbo and a supercharger together? There are rumours that VW will do this to a 1.4 in the golf next year, about 170bhp

[stuwood]

Numpty terms for how the difference between tubochargers & superchargers.

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

Stuart

[Rob]

All this begs the question of what if they put a double entry (awaits double entendres) centrifugal compressor into a blower? I think the pressure ratio of a single entry is roughly 3/4:1 and although there are losses you should get a roughly 7:1 compression ratio on a double entry. It would take longer to spin up but when it did 

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Do you mean a turbo and a supercharger together? There are rumours that VW will do this to a 1.4 in the golf next year, about 170bhp

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nope he means a double centrifugal compressor it is 2 centrifugal comressors back to back and the pressure increase is approx 7:1 ( single stage is approx 4:1)

BTW the roots blower compressors are the least efficient of all the types but they are cheap so one offsets the other.