title is the easiest short way to describe my question.lol

1986 na, 5 spd, stock other then coilovers. I need a new cat back system as mine is rusted out. I have a racing beat streetable header I believe and an old style racing beat presilencer with the s4 pick up tube. ( given to me by my brother, pic http://www.dragtimes.com/parts/mazda...809615614.html )

I do not have the RB parts installed yet but wanted to get a single pipe made at an exhaust shop as I am on a budget. would the length from the current stock cat back be right for the rb header+presilencer to bolt up to? I need my car for work and my daily is down for a while so can't really find time to install parts and measure myself. Can I get away with 2 bends for a single pipe, even if that means running the muffler crooked?lol, trying to save money. welding hangers on myself but don't feel like welding a ton of pre bent sections and what not. thanks guys.

Side note, how bad will the weld be strength wise if I use mild steel gas and wire on stainless? might have shop weld hangers after I bend them after all.

 

Which are you trying to do? Custom single catback from your header + presilencer, or stock catback from your header + presilencer? RB catbacks are direct replacements for the stock system, so you can interchange the two. But pipe diameter will be different, so you may end up with an exhaust leak.

 

oh, sorry! I want to make a single 2.5" pipe to the muffler from the rb header and rb presilencer. not sure on what muffler I'm getting yet but I can cut that end of the pipe myself and either weld it myself or bring it back to the shop. the rb and other aftermarket systems are too expensive for me right now. my stock system has broken apart several times but is just too rusty to keep fixing so I decided this would be the cheapest way to upgrade.

 

Yes, the RB Header/presilencer [single outlet style, like your link] are the same length as stock manifold+cats. I ran a RB Header/presliencer with a stock catback for a year or two.

Oh and remember: Do Not use glass pack mufflers ^_-

 

thank you very much. and thanks for the heads up on the muffler but already know to use a rotary specific muffler.

 

really stupid question as I'm searching for mufflers, unless it specifically states its a glasspack muffler then its something I can use right? its going on the end replacing the stock muffler. I was looking at magnaflows, but most seem to be 2.25" inlet and not 2.5". could I just run an adapter since I'l be running 2.5" piping? that won't hurt the muffler will it? sorry, noob to all this stuff.