yes it does change the tune a little,it is fine to run the motor how you tuned it before you added the pipe in
the pipe does not increase the back pressure or slow down the car as it provides no resistance like a divergent cone in an exhaust pipe does .
try it and find out for your self.
you can also try differant fuel types and blends i have tried 5 types to get my motor to idle better and improve exceleration although they all said they have the same or similar contents in their mixes .
the fuels i tried were
extreme sports 15% inconsistent from bottle to bottle 8%caster10%synthetic
cool power 15% run cooler but had to use os8 15%synthetic
hot stuff 15% found it hard to get and realy oily 10 %caster 8%synthetic
boost15% 7%caster 10%synthetic
now using at fuel 16% nitro 6%caster 10%synthetic and happy with it
these are thing you have to try out for your self.every motor is differant even if they come from the same manufacturer and are the same type.
take 1 day to run the car on a few differant fuels to see what one performs to your satisfaction. just food for thaught
tamiya ta05,kyosho tf5,kyosho v1s,ansmann terrier,tamiya lunchbox,hpi cyber 10 b
I JUST WANT TO HAVE FUN ,NOW DAMM IT