Originally Posted by boostmonkey

Just to be clear: you can install the 65mm OR 178mm pulley without supporting fuel system upgrades. To do both, you need some upgrades.

For 178/65 stacked, I recommend at least the following fuel mods:

• upgraded fuel pump
• upgraded fuel pressure regulator & filter
• looped fuel rail
• 550cc injectors
• WBO2 or dyno-tuned with WBO2

I also have:

• larger fuel lines
• reworked fuel fail with larger inlet
• conversion from return-less to "regular" return style rail

For intercooling I recommend at least:

• IC pump upgrade
• heat exchanger upgrade

And seriously consider other intercooling upgrades such as:

• Rudy's single-pass IC
• IC insulation (baked potato mod)
• IC reservoir (think of it as a heat sink)

Switching from a 62mm pulley to the stacked pulleys and getting a Eurocharged tune gained me +43 RWHP and +52RWTQ.