i feel dumb but what is PR and how does it effect everything?

 

Pressure ratio. (boost+14.7/14.7)

Higher it goes efficiency goes bye bye.

 

agreed

 

so with my ported exhaust side of the head, i am running about 25% less boost per pulley than everyone else with the tvs. my pressure ratio is lower than most? i could potentially run more rpms on the SC and be in the efficiency range for longer? if im reading this correctly.

got any websites i could read up on to learn more

 

me likes torquez

 

That is correct, even so if you are running 20 pai your already a 2.36.

Increasing displacement is another way to lower that number.

 

im running 20psi on a 2.8,
i was looking into dropping to a 2.5 just for s&g but i dont wanna go so far out of the efficiency range that my car losses its fun edge and dies off too much up top

 

I ran a 2.5" on my car back in the testing days. For me it offered no gain in horsepower, and 2 ft/lbs.

This was also with the car on 90/10 meth on the 2.5" and pump gas on the 2.75".

Tell you what though it was funny to hit 20 psi at 2k rpms.

 

wow, 20 psi at 2k? Thats nuts.

 

well id like to see a big increase in tq.
i have no heat problems, ive got plenty of flow through the car. i will actually see a big drop in psi when i go to a 3in exhuast from what i have now...

 

if you're only hitting 20psi with a 2.8. you are not ripping the rpms high enough.

 

^^^ that is the understatement of the year