What is the ideal clearance between the silencer and the heat shield.?

I'd start at 1/2" or 13 mm gap between the silencer and the can myself.


ETA...that said I never fitted a guard on my MK Indy and never burnt myself on the exhaust (Pinto engine so drivers side exhaust).

[Edited on 25/8/16 by nick205]

I find the hot exhausts on both sides of my car are a nice surprise for touchy feely member of the public