Originally Posted by twinring
a B18 requires more water volume than a B16, if you look at the differences between the radiator of an SIR and a teg they are very different. Honda spec`d a larger radiator for a reason. even though you are running boost, the water volume is still the same, so I do think that this is an "exscuse"
The SIR came with a dual core radiator, which in essence is like folding the GSRs single core radiator in half...soo the dinky SINGLE core radiator prob. wouldnt hurt to replace, along with checking fan switch and thermostat.