GeorgeSmooth

Has anyone with LTH measured the internal diameter of their pipes?

Merc63

3 inch minus the thickness of the stainless.

GeorgeSmooth

I am asking about the primary tubes, not the collector. So the the question is the 1 7/8 or 1 3/4 that is advertised is external diameter?

c32AMG-DTM

AFAIK, tubing is typically advertised by its outer diameter, not inner.

So when MHP says they use 1 7/8", or MBH says they use 2" primaries, they mean the tubing they source is that size, respectively, i.e. the outer diameter.

Could be wrong, though.

CampioniShop

SuperSprint uses 45mm OD primaries and 70mm collectors. This has shown the most gains on stock engine cars. I would go 3" with cams for sure.