Apl 240
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understanding housing sizing: a/r
a/r (area/radius) describes a geometric characteristic of all compressor and turbine housings. technically, it is defined as:
the inlet (or, for compressor housings, the discharge) cross-sectional area divided by the radius from the turbo centerline to the centroid of that area (see figure 2.).
figure 2. illustration of compressor housing showing a/r characteristic
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the a/r parameter has different effects on the compressor and turbine performance, as outlined below.
compressor a/r - compressor performance is comparatively insensitive to changes in a/r. larger a/r housings are sometimes used to optimize performance of low boost applications, and smaller a/r are used for high boost applications. however, as this influence of a/r on compressor performance is minor, there are not a/r options available for compressor housings.
turbine a/r - turbine performance is greatly affected by changing the a/r of the housing, as it is used to adjust the flow capacity of the turbine. using a smaller a/r will increase the exhaust gas velocity into the turbine wheel. this provides increased turbine power at lower engine speeds, resulting in a quicker boost rise. however, a small a/r also causes the flow to enter the wheel more tangentially, which reduces the ultimate flow capacity of the turbine wheel. this will tend to increase exhaust backpressure and hence reduce the engine s ability to breathe effectively at high rpm, adversely affecting peak engine power.
conversely, using a larger a/r will lower exhaust gas velocity, and delay boost rise. the flow in a larger a/r housing enters the wheel in a more radial fashion, increasing the wheel s effective flow capacity, resulting in lower backpressure and better power at higher engine speeds.
when deciding between a/r options, be realistic with the intended vehicle use and use the a/r to bias the performance toward the desired powerband characteristic.
here s a simplistic look at comparing turbine housing geometry with different applications. by comparing different turbine housing a/r, it is often possible to determine the intended use of the system.
imagine two 3.5l engines both using gt30r turbochargers. the only difference between the two engines is a different turbine housing a/r; otherwise the two engines are identical:
1. engine #1 has turbine housing with an a/r of 0.63
2. engine #2 has a turbine housing with an a/r of 1.06.
what can we infer about the intended use and the turbocharger matching for each engine?
engine#1: this engine is using a smaller a/r turbine housing (0.63) thus biased more towards low-end torque and optimal boost response. many would describe this as being more fun to drive on the street, as normal daily driving habits tend to favor transient response. however, at higher engine speeds, this smaller a/r housing will result in high backpressure, which can result in a loss of top end power. this type of engine performance is desirable for street applications where the low speed boost response and transient conditions are more important than top end power.
engine #2: this engine is using a larger a/r turbine housing (1.06) and is biased towards peak horsepower, while sacrificing transient response and torque at very low engine speeds. the larger a/r turbine housing will continue to minimize backpressure at high rpm, to the benefit of engine peak power. on the other hand, this will also raise the engine speed at which the turbo can provide boost, increasing time to boost. the performance of engine #2 is more desirable for racing applications than engine #1 where the engine will be operating at high engine speeds most of the time.
tirado da turbobygarrett
por isso que tipo, a t2 que eu tenho que é .47 .48 é menor que a t3 que eu tenho, .42 .48….
naum dapra analizar a/r por si só já que tá longe de ser algo linear
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ctrl c + ctrl v não explica muita coisa, ainda mais em outra lingua.
se alguem tem dúvidas, telefone pro mack…denovo, ja que eu falando o q ele me ensinou não ta adiantando.
to fora desse tópico, acreditem no que acharem mais bonito e sejam felizes.
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ctrl c + ctrl v não explica muita coisa, ainda mais em outra lingua.
se alguem tem dúvidas, telefone pro mack…denovo, ja que eu falando o q ele me ensinou não ta adiantando.
to fora desse tópico, acreditem no que acharem mais bonito e sejam felizes.
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naum sei se tu entendeu o que eu quiz dizer com isso….mas tipo, em outras palavras: a/r por a/r, naum dapra comparar um caraca?a com outra só por isso....? um valor que acaba sendo muito subjetivo....
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1.8 original com apl 240, não passe de 1,2 bar e não pense em por o comandão pra girar la em cima como antes.
rode com essa config só até conseguir pelo menos uma caixa quente .63 e um rotor (frio) maior.
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pois naum… caixa quente .70 e coletor pulsativo já aki emcima da mesa.
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to vendo que alguem gostou do que viu num certo videozinho ontem
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opa q video em??? rsrsrs…
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ja viu aquele programa da discovery onde dois rapazes colocam a prova (e derrubam) varias lendas urbanasó
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myth busters né? mas oq rolou no programa? ou era só brincadeira e eu to aqui perguntando pq não entendi a brincadeira??? rsrsrs…
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myth busters né?? mas oq rolou no programa?? é ou era só brincadeira e eu to aqui perguntando pq não entendi a brincadeira??? rsrsrs…
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hehehe é q muita gente acredita nas lendas, até chegar alguem e mostrar que as tais lendas são tudo papo furado, estária (não história) de pescador, papo de quem não sabe fzr direito.
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hehehe é q muita gente acredita nas lendas, ai precisa chegar alguem e mostrar que as tais lendas são tudo papo furado, estária (não história) de pescador, papo de quem não sabe fzr direito.
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ah…
hahahaha... e é oq mais acontece mesmo
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to vendo que alguem gostou do que viu num certo videozinho ontem
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isso pq todo mundo ainda me fala q .70 é mto grande…
mas vai virar ainda com zba ( curto pra caramba esse comando... lisinho q ate dá gosto ) e 2e e 0,7 no pe / 1,2 no booster, como estava.
vamos ver q caldo sai desse caramujão