I've decided to build my own 4" cat back exhaust. Mainly due the cost of shipping it the UK. Has anyone else built one in 4" or 3"? What I'm asking is for a materials list, for example, how many of which type of bend, how much straight pipe, which muffler etc. Thanks

 

Long tube headers? Ypipe gonna be 3" into y merge 4" out?

 

Short headers, Ive built a Y pipe, will probably build another in 3". So roughly starting from where a typical Y pipe stops? No cats

 

If you do ypipe in right location starting with flowmaster y merge there should be about a 45 deg bend to angle pipe down driveshaft tunnel. Thats gonna get you 2.5-3 ft of straight before the bend up over axle which will be 1 90 bend you may trim back to a 60-70 deg angle or so? Then another 90 to complete the over axle. 1 more 90 for turning exhaust towards driver side rear fender. Muffler under gas tank. 90 deg off muffler for tail pipe.

Or you go under axle like i did my 5". Still clears well and is abit easier to do in my opinion. Kinda go 3 ft straight back, slight 45 toward pass side then big bend back towards driver side to go into muffler under gas tank.

Various layouts you can run. All in all roughly 1 45, 3-4 90's and 2-3 ft straight aint a bad starting point

 

Wicked, thanks a lot! Ill look at the sizes right away. 5" under the axle? Is your car lowered? Im using a Moser 9"

 

Lowered but on 27-28" tall tires so i get abit more clearance that way.

My pics are down at the moment. Gotta upgrade my photobucket account for bandwidth :rolleyes

 

I did think about oval, but would again have to ship from US. I can get tight radius bends, would these be better?

 

You want the smoothest largest radius that will fit but exact numbers i cant recall on my systems. I did 4" over axle no prob but its tight with upper track bar. Tighter may be better for that region.