Max boost on a supercharger
 

What's the highest boost being run on stock blocks with supercharger ....I seen a few post with 11 lbs ....is that average ?

I guess what is the reason you ask? Are you looking to copy the max boost? Are you trying to figure out rod strength?

boost is boost; a supercharger just robs power to spin it.
i've seen people on here advertising close to 15lbs. (+ or -) my car is N/A so i haven't a clue what the most one can withstand.. ;)

Well, psi is meaningless without knowing airflow. 5 psi out of a huge turbo/sc is more air than 15 psi out of a tiny one.

Putting a boost gauge in the intake w/same piping from large or small turbo changes nothing; but maybe the temperature of the air. 10psi is 10psi....explain Chuck33079 ?
I know a tiny turbo/supercharger will get hotter than a larger one (resulting in hotter air & power loss) but the pressure of boost is the same.... :)

Boost is a measure of restriction. 10 psi out of a huge turbo is a whole lot more airflow than 10psi out of a small turbo.

I agree with that statement: but put the gauge in the intake & 10psi is still 10psi, it could be a 50mm turbo or a 150mm turbo...still ,adjusted to 10psi at manifold they are = ...yes,you have plenty to spare w/a larger one...but entering the combustion chamber is still 10psi.

I don't know about that. 10 psi on my ST made 533whp where 10psi on my SC made 489.

Yep; because your sc was robbing power; but was still 10psi.


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I can see that.

Well I was trying to decide on a pulley size .. I'm looking at a 85mm pulley for the stage 2 gamma kit ... I'm thinking on setting the rev limiter to 7k and I should be around 11-12 psi

I apologize for contributing to steering your question in a different direction: hopefully no harm/foul.... But I see Top Gun Z has had both- so he may have better insight.

It boils down to CFM. A small turbo at 10 psi may put out 1000 CFM. A large turbo at 5 psi may put out 2000 CFM. So which one puts out more air? ;) Or look at it this way. You have a 2 garden hoses. 1st one is a 1/2" hose. The 2nd hose is 1". You know the water pressure is 55 psi. Normal household psi. Which one will fill the water bucket up faster?

So,what you are saying is: that with a boost gauge plumbed in the intake plenum & both super chargers/turbo's,big or small/ set at 10psi of boost (reading on gauge)-the larger Forced induction feeders will put more air into the combustion chamber?
I say that they are very capable to;but 10psi of boost (constant) is still just 10psi of boost.
that's why there are waste gates & blow off valves/in case of over boosting with the larger air pumps.
we're feeding air through the same intake at 10psi....not a firetruck doing a pump test w/multiple size hoses.

Rusty is correct. Different forced inductions units at the same PSI can have widely different air flows. If you're curious, pull up flow charts for different turbos and compare their CFM at the same PSI.

I used to work with axial and centrifugal compressors. And worked with flow dynamics for a little bit. ;) Believe me. It gets weird at times. Try and figure out flow accelerated corrosion in steam piping. :eek::confused::confused::icon14:

You're oversighting what I am saying also; I'm not talking about cfm,flowcharts,efficiency,of various turbos!
I'm simply stating that on a 370Z/ with equal intake manifolds,throttle bodies,piping,etc...a given boost pressure (measured at intake) is the same/ regardless of 50,150,350mm turbos (1,2,4 or 6 turbos) same difference.....yes, I agree that a larger displacement turbo/turbos have to work less harder to achieve same boost; but anything above 10psi is wasting(dumping out exhaust) the smallest,harder working device will get hotter/ producing hotter air (less power output) but reading boost pressure going into the cylinders will be equal = 👌

i thought psi is psi, just bigger compressor would spin less to produce it

Maybe it's the efficiency then but a good twin turbo setup alwys nets bigger numbers at the same psi as a single.

I think you guys are putting the PSI on a pedastool. (40 year old virgin reference anyone?)

PSI is just a by-product from Forced Induction (and an undesirable one at that).

The original question was what were the upper levels of boost being ran on superchargers.....not how boost is compared from one to another.....any info that pertains to that question ???

Some people just need to read before they post...................or spew information (or mis-information, whichever applies) all over the forums. How about watch an "engineering explained" or "how things work video" first?

I see not much has changed since I was last on the forums

Yeah. What a crime it is we started talking about other supercharger applicable content. Might as well lock this thread up.


OP. There is a sticky that has all boost applications, power made, kit used, and psi.