psi?
 

can anyone explain to me exactly what psi is? and how it works or wat it does?

its pressure... pounds per square inch. its a way of measureing the compression of something (air or liquid)

A measure of pressure..

pounds per square inch

apx 14.5psi = 1bar

and it's english units.

okay so when people have turbo and say their running 5psi...wat do they mean?

it should be the pressure of the air inside the piston before the up stroke... am i right?

I am pretty sure that 1 BAR is 14.7psi, not 14.5... not that it makes much of a difference.

14.5 was the number I had in mind..

Anyways, if you want go deeper..
1 bar = 14.5038, rounded off to 1 decimal = 14.5

close enough no?
:hmmm:

lol good enough...:yes:

Thank you kind sir.

I think when somebody says they are running 5 psi or whatever, thats the amount of compression that the turbo is feeding back into the intake. I guess compressed air combusts better/more readily, etc. So the more compression you have, the more combustion you have. But too high and run into detonation issues.

somebody correct me if im talking out my ass.

when talking about turbos, its with how much force air is being fed/compressed into the cylinders.
More air = more oxygen = increase fuel mixture to compensate for the extra air.. = bigger boom!

A turbo's function is to compress air = Compressor.

so the more psi u have the more of a boost you have?

how much psi would be good on a ls motor with 121,000 miles? or does mileage not matter with turbo? If I were to get turbo on my stock ls motor, what would I need to change b4 getting turbo so I dont mess up my motor?

lots^^ lol......rebuild most of it....depending on the boost level..

remember psi is just a unit of measure..

its like clocking a baseball being thrown and saying, "is that 99 feet per second u have?"

:P

So the more boost you run, the higher your x PSI will be.

Sorry if that didn't make sense, but PSI is not a noun.. well.. hmm.

Anyways, I'd suggest not running any boost on an engine with that high mileage, unless you rebuild, resleeve, etc...

To get into the tech aspects of it, you should post this in the Turbo forum. It would get more exposure.

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

^^^^Good explanation of turbos^^^^

Its probably asking for trouble if you want to turbocharge a high mileage engine. I'd say rebuild it and at least get it to factory specs before slapping aftermarket stuff on there.