[DivineCL9]

if you're building a block for a supercharged set up, would you run low compression pistons or stock compression ratio?

 

[gyang401]

Sure u would...more boost....more power...some cams n head work = MORE POWER....!

Sent from my SAMSUNG-SGH-I997 using AutoGuide.Com Free App

 

[TSimon]

I'd only drop the CR if your planning to run more than 20psi (hard to do with sc)

My tuner and I both agree that stock cr is fine upto around 1-bar boost.
K24 rods are the biggest issue.

 

[littlebo]

if you gonna SC then NO !

 

[DAYTA]

if you're building a block for a supercharged set up, would you run low compression pistons or stock compression ratio?

Depends on what type and size of S/C you're running (Roots vs twin-screw vs centrifugal), but generally it's recommended to stick with stock CR.

As TSimon mentioned, you typically only want to lower CR on high-boost applications where peak output is the goal. However, if this is a DD, keep in mind that lowering your CR negatively affects driveability as off-boost power is decreased.

 

[DivineCL9]

I'll be using the magnum powers mpx90 with 3" pulley and sending it to jmercado so he can fabricate an aftercooler for me

 

[TSimon]

Your stock cr will be fine.

Boost vs Atmospheric pressure:

Over here in Perth Australia, our average altitude above sea level is 90ft.
With a CR of 10.5:1 and a positive boost pressure of 8psi.
My CR is 15.2:1.

There's a formula for calculating it online too.
The mechanical limits are around the 19-20.0:1 before parts need to be replaced.

+1 for Merc, I have it and it's a damn fine product.