Ok I'm hot off a fresh read in Sport Compact about Custom Exhaust. I want to run an idea or two by you all.

1) The article says 1500cc-2000cc engines should use 2-inch pipe, 2100cc-2500cc engine should use 2.25-inch pipe. Should I follow this rule?

2) The article also says to use the longest muffler that will fit my car for the quietest sound (I want quiet) and the same rule applies for the resonator/pre-silencer. What do you think?

I'll stop here, I know I can get long winded.

 

y2k you should know better than to listen to those honda mags smile.gif Those
are general rules ut fairly correct ( it was meant for riced honda
boyz puting 3" pipes on their 1.6L ) we know that for quiet you do
want long muffler/resenators and that 2.25 is a good size for the tib,
2.5 is ok if you have lots of front end mods ( CAI, BTB, cams,
headders, AFC etc. All of it not just one ).

 

So I should be ok with my 2.5" press bent piping for now? I'm looking into a mandrel bent mid-pipe but HDK is the only source I have found so far & you know the story on those guys.

 

You should be able to get mandrel bend exhaust done at most large exhaust places. It's just super expensive since they have to weld all the pieces together. On my car I got a quote for $505 for the mandrel and $295 for a press bent system.

 

When the pieces are welded together are there any rough edges/welds on the inside of the pipe that can cause turbulence/distruption to the exhaust flow?

 

Not if done properly. That they SHOULD do, is weld flanges into the ends of the exhaust and connect the flanges with gaskets and bolts. However, some shops do a "slip joint" where they crush one end down so it will fit INSIDE the other pipe, then weld the seam between the 2 pipes. It looks really nice from the outside, and you can't tell what they did, but it causes backpressure. Ask your local shop what kind of joint welding they do...and if you can...stand around and watch it being made.

 

That would be a lot of flanges
We're talking about a lot of beds on a 2K Elantra exhaust.

 

They should be able to do it in 3 or 4 sections max. They can do multiple bends per section.