hey guys, thansk for looking at this thread,

first of all i live in california, some of you might have an idea how the law works out here, so i came up with an idea by having a true dual setup for my 305 tpi z28.

1. have to sepreat tubings from the headers
2. getting to cats.
3. or getting a dual cat (picture below)
3. super 40 muffler dual in/out
5. 2 1/2 inch tubing

and having the muffler sitting some where in the passenger are having it tucked in real well and putting some heat shields for proyection.

* for 91 z28 5.0/5.7 came stock with 2 cats*

please let me know what you guys thin or if you guys some ideas or adjustments that i could do to my idea and especially if this setup would pass smog here in california.

* LOOK AT THE PICTURE BELOW FOR REFRENCES*

THANKS FOR YOUR INPUT.

 

Why not just replacement high-flow dual cats? 2-1/2" vs. the 2" of that double cat thing.

Muffler - Not sure of the pipe sizes of the dual-in/dual-out Super 40, but probably the same story - single 3" better.

 

arnt the cats to far down the exhaust stream to help any??? I thought they needed to get hot to perform properly?

 

im not sure how they perform, but hey hopefully i get an answer later.

laterz.
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i thought about a 3inch pipe. at first but i dont have enough power, for that diameter, then again people tell me i have enough back pressure, that if i had a dual setup it would even things up just right, and by the way the muffler shop is charging me 420 with everything.

laterz.

 

That one has an O2 pipe, if you hook that up to an air pump you can place the cat that for down the exhaust, no problem.

 

If you aren't making enough power for single 3" pipe, you aren't making enough power to justify dual exhaust.

This looks like a downgrade to me. $420 is a mighty expensive downgrade.

 

what do you mean when you say "you aren't making enough power to justify dual exhaust."

 

First, I said "If you aren't making enough power..."

And, it was the OP that said...

If you were thinking 3" duals, true, you aren't making enough power to justify that. However, you aren't making enough power to over-power 3" single. And, dual 2" is more restrictive than 3" single.

 

oh jeeze five7kid...you just opened up a can of worms with these guys...seems they'll never understand

 

personaly true duals can be a pain in the *** lol i loved the sound when i had mine but ground clerance sucks and was just too damn loud all the time lol.(i feel old now) best way i see to to true duals on these cars though is basicly like the picture you showed but without using the muffler you posted a 2in 2out muffler defets the purpose of "true duals" imo will not sound the samenow i could see adding cats to that and run the pipes ove the axle with two seperate mufflers at the rear bumper thats what i was gona do minus the cats but i decided to go with a single 3.5 with a cutout into a stock 4thgen muffler for street driving. like i said true duals can be a pain and expensive.