3inch exhaust

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04-08-2008, 07:56 PM

#11

hotairgypsy

3rd Gear Member

Join Date: Jan 2007

Location:

Posts: 813

RE: 3inch exhaust

i was told i lost some boost with the LTs

04-08-2008, 08:13 PM

#12

onederful100

6th Gear Member

Join Date: Jul 2007

Location: Honolulu, HI

Posts: 6,130

RE: 3inch exhaust

i didnt lose any boost w/ the LT's. i think w/ 1 3/4" primaries and 3" exhaust thereafter would be the best setup for FI running big boost over 10psi. this is just speculation, i want to see someone w/ actual dyno numbers w/ a comparison between 3" and 2 1/2, otherwise we are all guessing.

04-08-2008, 08:22 PM

#13

kolb02

2nd Gear Member

Thread Starter

Join Date: May 2007

Location: Montana

Posts: 312

RE: 3inch exhaust

Thats very true Onederful,I would like to know if it's worth it when your up to big boost #'s.

04-09-2008, 05:55 AM

#14

Norm Peterson

6th Gear Member

Join Date: Feb 2007

Location: state of confusion

Posts: 7,635

RE: 3inch exhaust

Quote:

ORIGINAL: acdc163

, they said you need a certain amount of back pressure.

It's not back pressure, per se. Using the inertia of the "column" of exhaustgas to help extract the next cylinder requires exhaust gas velocity. This velocity requires some amount of pressure difference (aka "back pressure"), but just how much pressure difference you end up with depends on how well the system was designed with respect to flow.

Norm