In response to the demand to extend our Phenolic Spacer lineup to include some of the older subaru models, we now have created intake manifold thermal spacers for Impreza/Legacy/Forester 99+ 2.5 N/A and 99+ 2.2 N/A 'Phase 2' engines.
Thermal spacers lift the intake manifold off the super heated engine to lessen the transfer of heat. Both the intake manifold and engine block are aluminum so the high heat transfers very quickly, these spacers stop that. The cooler the intake charge the more HP and TQ your engine will make.
In addition to cooling your intake charge, these will also give you larger intake volume similar to that of a throttle body spacer.
What it does:
How it works:
Temperature Testing Data: Testing at 1/2 hour intervals. All testing was conducted fairly in Fahrenheit measurements on ONE day at a consistent outside temperature.
Test #1 - OEM measurement from IM without spacers, 152 degrees.
Test #2 - with 3mm phenolic spacers the temp dropped to 134 Degrees
Test #3 - With 8mm phenolic spacers the temp dropped to an outstanding 108 Degrees!!!
That is an OVER 44 Degree drop with the largest Phenolic Spacers!
Impreza, Forester 1999-2008 2.5L N/A
Impreza 1999+ 2.2 N/A
Legacy 2000-2009 N/A
Like our other thermal spacers we suggest putting GrimmSpeed gaskets on top and bottom of each spacer to allow for proper sealing.