How much boost can i run?

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Mar 22, 2007 | 06:52 PM

#21

SPECIAL-OPS-S2K

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From: Lincoln, NE

so the GT30 is compacting "x" amount of air to 19 PSI while the GT35 (since its larger and moving more air) only needs to compress it to 15 PSI to get the same amount of AIR into the engine...

I understand its not how much pressure the air is under as it enters the intake it is just HOW MUCH you can shove in there... so a larger turbo moving MORE air needs to compress it less to get the same amount...

hope that makes sense to everyone else because it finally does to me!

LOL Thanks!!

Mar 22, 2007 | 06:53 PM

#22

slimjim8201

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From: Gie

There are a lot more factors going on than one may think...

Check it out: Power versus Boost Pressure

Mar 22, 2007 | 06:55 PM

#23

slimjim8201

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From: Gie

Quote:

Originally Posted by SPECIAL-OPS-S2K' date='Mar 22 2007, 09:15 PM

I've always wondered... why is it that I could say run 15 PSI with a GT35 and make X amount of hp to the wheels and if I were to switch to a GT30 I would need to run 19 PSI to make the same HP??? If the PSI into the intake manifold is the same wouldn't the HP be the same as well??? I know that is not the case but I am just curious if anyone can tell me WHY? Never can learn enough about FI IMO... LOL THANKS

The pressure differential across the engine is the same, but since one turbine may be more restrictive (the smaller turbine leading to higher turbo manifold pressure) the boost pressure must be higher.

Mar 22, 2007 | 06:56 PM

#24

m R g S r

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From: Westchester NY

pressure and cfm are two different things

Mar 22, 2007 | 06:58 PM

#25

2QYK4U

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Quote:

Originally Posted by slimjim8201' date='Mar 22 2007, 06:53 PM

There are a lot more factors going on than one may think...

Check it out: Power versus Boost Pressure

AWESOME write-up!

Mar 23, 2007 | 05:39 PM

#26

1BAD4CYL

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I sure do like all the imfo. Thanks to all that have responded.

Mar 23, 2007 | 06:11 PM

#27

Spoolin

Joined: Mar 2003

Posts: 6,507

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From: Sellersburg, IN

I'm running 9.75 psi with a really conservative tune and making 406 whp on a dynojet.

If you have a very good tuner as I do you can take it safely to about 11 psi with a 3.5 BAR map sensor.

Tune is the key.