i'm having trouble getting a leak-free seal between my midpipe and driver's side manifold.
the midpipe i'm using is a magnaflow 441114 x-pipe with 4 cats. it's a 2.5" stainless system. using a caliper, the pipes are actually ever so slightly larger than advertised. for reference, the stock h-pipe is ever so slightly smaller than 2 1/4" OD. the stock manifold opening is about 2"
the socket of the midpipe will bottom out against the manifold flange before making full contact with the ball of the manifold.
leftover from another project, i have an adapter that was included in a mac prochamber kit that is intended for use with the stock manifolds. the prochamber kit measured slightly on the inside of the tick mark of 2.5" OD, and had thinner walls than the stock or the magnaflow.
i cut the end off the stock h-pipe (sold the cats previously) to make an adapter, and compared it to the mac adapter. the stock socket has a larger 'trumpet', is thicker walled, but has a smaller outside tube diameter than the mac adapter.
i dry fit the magnaflow midpipe to the stock manifold using both the mac adapter and the stock socket adapter. the mac adapter fit flush and snug inside of the mac socket, but loose and slightly recessed inside of the magnaflow socket because of the slightly larger tubing.
the stock socket's trumpet was the same size as the magnaflow's, but the OD of the tube part was smaller and it stuck slightly past the midpipe edge - similar in how the mac adapter fit inside of the mac socket.
the stock socket appears to seal against the midpipe at the very outer most edge of the trumpets, while the mac combo seemed to make full contact near the inner apex of the tubes, not the trumpet parts.
should the critical seal between the midpipe socket and adapter be near the apex of the internal bend of the pipe, or is a seal near the outer edge acceptable?
basically, my options are:
- midpipe with no adapter - leaks/bottoms out against flange
- midpipe with mac adapter - all but bottoms out against manifold flange, seals on inside edge of trumpets
- midpipe with stock adapter - adapter trumpet doesn't contact midpipe trumpet until the outer most edge with most of the ball/socket not in contact
i understand the issue is making a 2.5" socket fit on a 2 1/4" ball. is there an intermediate adapter/trumpet between 2.5" and 2 1/4"?
i currently have it with the mac adapter with some copper RTV between the adapter and midpipie. midpipe bottomed out against the flange on one side, and the other was very nearly but not quite (so the ball might have maxed out against the adapter rather than the midpipe socket which = seal). i question if it actually snugged up against the adapter or not, though.
for comparison - i have 2 1/4" trumpets made by magnaflow and when cut and used as an adapter, the socket didn't contact the ball until essentially the flange and tended to leak. the convex shape of the trumpet walls was too extreme compared to the mac or the stock sockets.
edit: this might just be more of a rant than anything else. either i roll the dice and what i just did actually sealed, or i pull the midpipe and reseal using the stock 'adapter' and at least know where it's making contact.
the midpipe i'm using is a magnaflow 441114 x-pipe with 4 cats. it's a 2.5" stainless system. using a caliper, the pipes are actually ever so slightly larger than advertised. for reference, the stock h-pipe is ever so slightly smaller than 2 1/4" OD. the stock manifold opening is about 2"
the socket of the midpipe will bottom out against the manifold flange before making full contact with the ball of the manifold.
leftover from another project, i have an adapter that was included in a mac prochamber kit that is intended for use with the stock manifolds. the prochamber kit measured slightly on the inside of the tick mark of 2.5" OD, and had thinner walls than the stock or the magnaflow.
i cut the end off the stock h-pipe (sold the cats previously) to make an adapter, and compared it to the mac adapter. the stock socket has a larger 'trumpet', is thicker walled, but has a smaller outside tube diameter than the mac adapter.
i dry fit the magnaflow midpipe to the stock manifold using both the mac adapter and the stock socket adapter. the mac adapter fit flush and snug inside of the mac socket, but loose and slightly recessed inside of the magnaflow socket because of the slightly larger tubing.
the stock socket's trumpet was the same size as the magnaflow's, but the OD of the tube part was smaller and it stuck slightly past the midpipe edge - similar in how the mac adapter fit inside of the mac socket.
the stock socket appears to seal against the midpipe at the very outer most edge of the trumpets, while the mac combo seemed to make full contact near the inner apex of the tubes, not the trumpet parts.
should the critical seal between the midpipe socket and adapter be near the apex of the internal bend of the pipe, or is a seal near the outer edge acceptable?
basically, my options are:
- midpipe with no adapter - leaks/bottoms out against flange
- midpipe with mac adapter - all but bottoms out against manifold flange, seals on inside edge of trumpets
- midpipe with stock adapter - adapter trumpet doesn't contact midpipe trumpet until the outer most edge with most of the ball/socket not in contact
i understand the issue is making a 2.5" socket fit on a 2 1/4" ball. is there an intermediate adapter/trumpet between 2.5" and 2 1/4"?
i currently have it with the mac adapter with some copper RTV between the adapter and midpipie. midpipe bottomed out against the flange on one side, and the other was very nearly but not quite (so the ball might have maxed out against the adapter rather than the midpipe socket which = seal). i question if it actually snugged up against the adapter or not, though.
for comparison - i have 2 1/4" trumpets made by magnaflow and when cut and used as an adapter, the socket didn't contact the ball until essentially the flange and tended to leak. the convex shape of the trumpet walls was too extreme compared to the mac or the stock sockets.
edit: this might just be more of a rant than anything else. either i roll the dice and what i just did actually sealed, or i pull the midpipe and reseal using the stock 'adapter' and at least know where it's making contact.
