exhaust difference ph1 172 n 172 cup.

[hoperacing]

bought a back box that came off a 172 cup a magnex one off here and its about half an inch wider diameter that the straight through pipe i bought for my ph1 172?
how come they went to a bigger bore but no hp gains or was there????
dont know wether to sleave it to make it fit as going to a wider pipe that far back shouldnt cost me anything power wise or go get a wider mid section made?
any feed back on this would be appreciated.
the stainless straight through mid section will go with my scorpion back box but wanted to use the magnex one seen as i have shelle out for it! plus prefer the oval magnex to the round scorpion!!!
any ideas boys?....n girls sorry!

 

[hoperacing]

bump??

 

[sh33n]

Go to a custom exhaust place and get them to make a decent centre section that will fit the back box.

 

[stoddie]

this happened with my old car to - a ford!

i had a magnex back box but wanted a cat back.

apparently the back boxes are made a different size than the systems by magnex however that is!

 

[ben_p]

the bore is the same

 

[hoperacing]

i bought the back box off a guy with a cup on here.
its half an inch wider than the standard centre section on my standard pipe and than the longlife stainless straight throgh system i bought (which is for sale if anyone wants it!!)
problem solved anyway.
called a mate who owns wunoff exhaust solutions in west yrokshire.
he is gonna make me up a straight through centre section to fit this bigger bore. is it woth getting him to do a decat pipe while he's at it?