1979rx7

how dou figure bost +hp?

i mean if u ruuning 10lb of boost how much hp is that ?

j9fd3s

depends on what you're pressurizing to 10psi!



10psi on a sewer pipe is a lot of water, but 10psi on a stir straw isnt

1979rx7

yea bout im talking about boost not water

how to translate boost to hp?

spaceman Spiff

it all depends is what he is saying, i mean 10 psi on a built engine will make more power than 10 psi on a stock engine... we need more info on the engine

trianglepower

Someone told me that an average 4cyl. 1 psi=7hp, but on a bigger motor or on a rotary you should get more than that. I have heard you will get about 14hp out of 1psi. I don't know if that is accurate or what variables it is based on, but that is what I have heard.

j9fd3s

it depends on the turbo/engine. the 917/30 ran about 14psi and 1100hp, but 14 psi on a stock turbo fc turbo motor will get you about 240

nismo convert

General rule of thumb is 10 PSI is 100 hp, which is 10hp per psi.

rfreeman27

that is such BS



it all depends on the engine and turbo size.

jspecracer7

Mike's analogy is correct. Replace the word water with air and it makes sense.

jspecracer7

Who told you that?



10 psi on a stock turbo vs. 10 psi on a greddy T78. Now 20 psi on a stock turbo vs. 20 psi on a greddy T78. So they both will yield the same HP gain per psi?



HP gain per PSI is dependent upon turbo effeciency in that range of boost. Some turbo's are more effecient down low ...say 15psi and below. Some turbo's are more effecient at "high boost"....say 21 psi and above.