Re: SL55 "Y" & hose install w/pic's & results
The Y beneath the intake is for the intercooler.
Take a look at HDDP's SRT Engine Transplant thread. He has some pics of his torn apart, and it helps to look at them if you are trying to see how it all works. It's a pretty in-efficient design, to be honest...but it is what it is.
SQ