Exhaust fabrication question

[JustJohn]

Nice drawing. I would guess that changing the 45’s to 30’s would get close to a 1” offset. I always wished I knew how to use CAD but never had a need.

It's the bend radius that drives some of it. You can't have a negative "B" length.
Somebody mentioned 15 degrees? Not my choice to work with but:

2.5" Mandrel Bend Radius, 15 Deg Bend Angle
Offset A	Section length B
0.5	0.944
1	2.875
1.5	4.8
2	6.74
2.5	8.67