^ 5/16...

 

1/2" gives you more power (less than 4hp) in the higher rpms but 5/16 gives you the hp at the lower more usable rpms.

 

What is the biggest difference bwtween

COPPER ISO THERMAL PLENUM SPACER
and
ISO THERMAL PLENUM SPACER

 

Test pipes gave me a good amount of power that I could feel for sure.

 

From what I understand, the Copper ISO Thermal Plenum Spacer's recommended for any region that sees temperatures that hit near or below freezing anytime during the year, it's a "set and forget" feature. The non-copper ISO Thermal Plenum Spacer's adjustable and is recommended for more temperate regions... I'm a fan of Motordyne Engineering

Hope that helped, you should check out Motordyne's website or do a search on here...

Peace

 

Test pipes or High Flow Cats will be the best bang for the buck and after hearing more about them i would get either one over the 5/16 spacer

 

NA mods on the VQ = worthless. Go FI

 

The 5/16 and 1/2 Spacer make more power than test pipes or high flow cats...

 

???