we gained about 20kw switching from a standard 34 GTR cooler to a thicker 100mm unit on my brothers car, which has a 6262 on e85
although the power increase was also a result of another 4-5 psi of boost but our tuner said a thicker cooler was required to utilise the boost
jumped from 420 to 440kw.
and in terms of standard rubber piping... mine keeps tearing with -9s on e85.. I've had to replace the rubber pipe just below the twin turbo pipe 3 times now. Have a hard pipe kit waiting to go in. The rubber ones are 17 years old now and struggle with 25psi running through them.