On average ~150-200 degrees of so, nothing you need to worry about melting rubber or anything.
BTW...a little water mist in the motor doesn't hurt anything. Think of it as a poor mans water injection system
Just buy a 3"-4" silicone transition coupler. They're only like $20 from most GOOD turbo shops online....check out
www.vwturbo.com link to part is below
http://www.atpturbo.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=ATP-SIL-053&Category_Code=SIL-TRN