Exhausted !!!

[Booie]

Anyone have a good suggestion on what kind of exhaust to run on my 79.
I was thihking of go to dual exhausts from the manifolds back the car currently
goes from the manifold into the y pipe into the cat then to a y pipe out the dual
mufflers. I was thinking of headers but do I need two cats to pass emissons
inspections in NY should I use the stock Manifolds. Should I go with Stainless
steel pipes and mufflers. And what mufflers will give the best sound. Thanks;help

 

[KANE]

Anyone have a good suggestion on what kind of exhaust to run on my 79.
I was thihking of go to dual exhausts from the manifolds back the car currently
goes from the manifold into the y pipe into the cat then to a y pipe out the dual
mufflers. I was thinking of headers but do I need two cats to pass emissons
inspections in NY should I use the stock Manifolds. Should I go with Stainless
steel pipes and mufflers. And what mufflers will give the best sound. Thanks;help

Technically... you'll need a 2-to-1 y-pipe and then back to 2 again after the cat to be truly EPA compliant.

However, many inspectors either don't know the details as to what "OEM" was in '79 or don't care so as long as the car passes the sniffer.

I'd go with true duals, a crossover pipe, and two high-flow cats. Run 2 1/2 inch pipe- don't go any smaller (restrictive) or larger (not enough back pressure) if the engine is relatively stock. Go with mandrel bends if you can afford it. I don't think there are any performance gains in stainless- just preference, cost, and longevity. A downside to stainless is they really hold the heat in and will likely raise inside temperatures in the car.

As for mufflers- whatever your preference is. Borla looks good and sounds good but I could never justify the price. IMHO Flowmasters sound like everyone else's Mustang. You could go with the Borla bullet style mufflers as they aren't pricey; however they don't look stock at all. It is up to you. I'd listen to some Vettes with different exhaust pipes at a Corvette club meet or show and see what you like.

If you have picky inspectors- scuff up the pipes, get them wet, and leave them in the sun for a few days before you install them. A little salt water will help "weather" them with some oxidation so they don't look so new. It is a good cheat!

FYI- if you wanted to run side pipes and the inspectors really don't look or care... you can run high flow cats on the pipes between the down pipe and the muffler portion.

Good luck- hope that helps!

 

[bmotojoe]

I would really research your states resent history on emission testing and also any upcoming bills that may go in front of the legislature in your state. New laws are going into effect all over the country and may vary from state to state but most states are adapting some sort of sound decibel level limit associated with after market exhaust systems.
I know here in Washington State we do have a sound level limit but it is rarely enforced for the time being anyway.
I installed with the help of a friend that owns a muffler shop the Mid America 2.5” all stainless system. The high flow catalytic converter is not stainless nor is any of the hardware that comes with it. I also had my friend order 2 mandrel bent 90’s for rear Y to inlet of muffler and 2 mandrel bent 45’s for the tips then cut them so the opening was parallel to the ground. 2.5” stainless steel mandrel bent 90’s and 45’s run about $45.00 each piece. The bender most muffler shops have will not bend a stainless 90 or 45, it will just crush the pipe. I matched the system with the Dynomax Ultra Flo polished mufflers. The Mid America stainless system took over 5 hours to install on a rack so it would sit nice under the rear of the car. All the flanges including the cat had to be cut and re-welded to fit correctly, so it’s not going to be a bolt on application, but I am real picky.
The below link may give you some incite where some states are headed with aftermarket exhaust systems.
http://www.moparmusclemagazine.com/techarticles/mopp_060130_sema_michigan_exhaust_law/index.html
Brian