Exhaust clamp

[battlecry]

This winter I replaced the rusting Superseal clamp in the rear cylinder down pipe with a lighter all stainless Mikalor clamp.  The new clamp looks great but did not seal worth a d@mn.   Even cranked down, it still leaks.

Looking at the specs for the OEM Superseal, it seals at a torque of 48Nm with a 25mm band, the Mikalor has a maximum rated torque of 16Nm with a 20mm band.  I looked at other stainless bolt clamps with 360 degree support and the bolts look no much bigger than the one of the Mikalor, so I can't imagine they can be cranked down much more either.

The bike is a 2003 M800.  The Mikalor clamps are working fine on the sides where the header meets the Remus slip-ons, but the Remus pipes seal differently.

I'd hate to take down the exhaust again to go back to the Superseal, but I may need to do it. 

Has anybody successfully used any of the 20mm stainless clamps with no leaks on the rear pipe without resorting to shims or goo?  It seems the expansion slots in the vertical pipe are longer than 20mm, so maybe the 25mm Superseal is the proper spec.