turbos & superchargers... comparo question!!!
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turbos & superchargers... comparo question!!!
Ok, i hate to make this sound DUMB... but, as with a turbocharger.. at certain boost pressures, on any turbo, you run out of "efficiency" say a t25 for example... ive heard its useless to run more than 14 on one of these bad boys looking for any more than hot air... ok, with that said, compressor design/sizing A/R, and trim all have something to do with it...... given.
with a centrifugal supercharger, do you run into the same thing? of so, please someone explain? gear driven half turbo?
As with Roots type too.. if these things have a certain applied efficiency, please explain, why and how!! ive never thought about this before, now i want to know
thanks
~ mark
with a centrifugal supercharger, do you run into the same thing? of so, please someone explain? gear driven half turbo?
As with Roots type too.. if these things have a certain applied efficiency, please explain, why and how!! ive never thought about this before, now i want to know
thanks
~ mark
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same thing as a turbo. the faster the wheel spins the more heat it makes. thus at a certain rpm it will lose efficiency. this all depends on the size of the wheel, and the type of cooling sytem used to cool the air
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a circle depending on size can only spin so fast i think its called terminal velocity, that is why they have gear reduced blowers to get more spins or power out of them, a roots type blower is designed to make the most Hp at a certain point, spinning it faster will not make any more power. that is why people use different pullies. as for a turbo a 14b may make 15 psi, where as a T3/T4 may make 10psi. just because you make a bunch of psi, doesnt mean you are making more power.
a mitsubishi evo runs 19psi. thier turbos are alsmost maxed out from the factory, and need a MBC because a greddy profec wont even read boost past 20psi.
its all crazy wacky crap huh?
this is why i cant sleep at night too many moving parts!!!!!!
a mitsubishi evo runs 19psi. thier turbos are alsmost maxed out from the factory, and need a MBC because a greddy profec wont even read boost past 20psi.
its all crazy wacky crap huh?
this is why i cant sleep at night too many moving parts!!!!!!
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10.02@149.5 Bullseye Power Turbos
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www.tdcperformance.net
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Centrifugal blowers are the compressor side of a turbo w/ a pully attached to the "exhaust" side of the "turbo". its JUST Like a turbo; itll go past its efficiency just like a turbo will if yofu try to run more boost than the wheel is sized for. The problem is that the Centrifugal blower is linear.. meaning you make more airflow with crankshaft RPM.... its directly proportional to the pully rpm... you cant get more boost at a lower RPM even if you wanted to
now w/ a turbo, that of course has problems if you try to overboost the compressor beyond its limits. but, when a turbo hits boost, it SPOOLS up... its NON-linear and does not depend on crankshaft speed...necessarily. You can get FULL boost by 3500 or whatever.. whereas the crank drivin supercharger will make more airflow as the rpm's increase... it doesnt really SPOOL per se. a turbo can go from a few psi to full boost in a few seconds depending on what RPM the engine is at. it only boosts when you need it too.... but a pully driven compressor is trying to push air any time the pully is being turned... even if you are at 10% throttle and cruising.
a Roots type, doesnt really Compress the air like a turbo or centrifugal unit does... it simply MOVES the air. if you ever look at a roots blower, it just grabs air and spins it agains the case, and down into the lower half of the blower manifold and into the engine. the "Boost" comes from the air's resistance to flow as its being MOVED into the cylinders... i mean, it sort of compresses i guess, depending on how you look at it. but not in the same sense as a centrifugal or turbo.
idunno, my traine of thought just derailed... i hope i answered your ?
now w/ a turbo, that of course has problems if you try to overboost the compressor beyond its limits. but, when a turbo hits boost, it SPOOLS up... its NON-linear and does not depend on crankshaft speed...necessarily. You can get FULL boost by 3500 or whatever.. whereas the crank drivin supercharger will make more airflow as the rpm's increase... it doesnt really SPOOL per se. a turbo can go from a few psi to full boost in a few seconds depending on what RPM the engine is at. it only boosts when you need it too.... but a pully driven compressor is trying to push air any time the pully is being turned... even if you are at 10% throttle and cruising.
a Roots type, doesnt really Compress the air like a turbo or centrifugal unit does... it simply MOVES the air. if you ever look at a roots blower, it just grabs air and spins it agains the case, and down into the lower half of the blower manifold and into the engine. the "Boost" comes from the air's resistance to flow as its being MOVED into the cylinders... i mean, it sort of compresses i guess, depending on how you look at it. but not in the same sense as a centrifugal or turbo.
idunno, my traine of thought just derailed... i hope i answered your ?
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Originally posted by flubyux2
Centrifugal blowers are the compressor side of a turbo w/ a pully attached to the "exhaust" side of the "turbo". its JUST Like a turbo; itll go past its efficiency just like a turbo will if yofu try to run more boost than the wheel is sized for.
a Roots type, doesnt really Compress the air like a turbo or centrifugal unit does... it simply MOVES the air. if you ever look at a roots blower, it just grabs air and spins it agains the case, and down into the lower half of the blower manifold and into the engine. the "Boost" comes from the air's resistance to flow as its being MOVED into the cylinders... i mean, it sort of compresses i guess, depending on how you look at it. but not in the same sense as a centrifugal or turbo.
idunno, my traine of thought just derailed... i hope i answered your ?
Centrifugal blowers are the compressor side of a turbo w/ a pully attached to the "exhaust" side of the "turbo". its JUST Like a turbo; itll go past its efficiency just like a turbo will if yofu try to run more boost than the wheel is sized for.
a Roots type, doesnt really Compress the air like a turbo or centrifugal unit does... it simply MOVES the air. if you ever look at a roots blower, it just grabs air and spins it agains the case, and down into the lower half of the blower manifold and into the engine. the "Boost" comes from the air's resistance to flow as its being MOVED into the cylinders... i mean, it sort of compresses i guess, depending on how you look at it. but not in the same sense as a centrifugal or turbo.
idunno, my traine of thought just derailed... i hope i answered your ?
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95 Supra Turbo 6 speed
11 SWP STI sedan
95 Supra Turbo 6 speed
11 SWP STI sedan
