Hi Anji, Is yours a Short or Long Stroke stroke A7?
I was looking into making some (or have made) a while ago for my Plunger A10, and did some calculating, based on my old pipes (origin unknown).
I laid them on a piece of ply and drew around them, and calculated the radii as best I could. If I'm not working tomorrow, I'll dig it out, but from memory, the top radius was maybe ~3,1/2", flowing (no straight) into the bottom radius of maybe ~ 11" (or and a half) with a ~40º(or ~50º, depending on datum and memory ) offset into the head.
I probably don't need to tell you how to suck eggs, but as I discovered from a crap set of pipes, there's a need for ~40mm (30+~10mm) straight before the top bend starts to allow for the finned 'deco-clamp' to sit square
I expect there will be a height difference (distance from Ex port to bottom run beside frame
) between the Short/Long stroke, and A10 ?
I had some header pipes made for my Gutzzi, a while ago and the measurements were way out of whack, but it wasn't too hard to realign them
, as they are in the same vertical plane (re-cut 'n re-weld)
Hope that's a bit of help? (I'v erun out of steam)