Kruz

unclehobart

this is my special title
If I was thinking of taking my 95 5.2liter Dodge Dakota to a dual exhaust system... how much would it cost and what benefits would I gain?
 

Professur

Mushroom at large
You're looking at pulling the manifolds and putting headers to start with. That gets you breathing easier. You'll be increasing your pipe size too, so there's even less backpressure in the system. Do you guys have to pass a smog check? Might get your wrist slapped there.

It that a gas or diesel engine?
 

Kruz

Moderator
Staff member
just about EVERY truck out here has dual exhaust that I've seen.. most are just "cat back" systems, meaning they go from single to a y-pipe after the convertor. any exhaust shop around here will probably do it for you.. there are no emissions problems with cat back systems. I don't know the EPA laws for replacing a single cat system to a dual cat system, I've never seen them check under a car for a emissions test, just what comes out of the tail pipe...
I think you can get the "cool look / sound factor" from a single to dual cat back system
 

unclehobart

this is my special title
But if it went from a split single to a true wide pipe dual exhaust independent system ... would there be any benefits to HP or mileage. Gods knows it would have to sound meatier.
 

Mirlyn

rebmeM
My friend just had it done to his 2000 GMC full-size truck. They cut the Y pipe and did flowmasters to the back. Says he gets a noticeable mileage increase (forget how much though) and the truck even seemed squirrly (sp?) immediately after putting in dual exhaust with the extra getup. A shop here in town did it for 200, and had it done within an hour.

I've heard it adds anywhere from 10-20 HP, depending on the vehicle.

I just called that same shop today about doing it to my Mustang and they said $399. No expert here, but from what I gather it depends if you want new headers and if you want to cut the Y pipe or replace it with an H pipe. I asked for an H-pipe.

This is what I've heard here in Kansas, so it might be different or it might be federal law, but no shop here in town will touch your car without putting or keeping the cats on.

Hope this helps.
 

Kruz

Moderator
Staff member
yes you would get a small to moderate gain in HP...
but ! the problem comes from the emissions side of this.
the EGR (exhaust gas resurculation) Valve is controlled by exhaust "backpressure". if you change the backpressure by creating a free flowing exhaust, you can prevent the egr valve from working , and then failing the emissions test for high N0X readings
 

Professur

Mushroom at large
More horses to be sure. Just going from the manifold to mandrel bent headers would supply that. But you'd have to look into adding a second O2 sensor, and figuring out how to hook that into the computer.
 

Mirlyn

rebmeM
Kruz said:
yes you would get a small to moderate gain in HP...
but ! the problem comes from the emissions side of this.
the EGR (exhaust gas resurculation) Valve is controlled by exhaust "backpressure". if you change the backpressure by creating a free flowing exhaust, you can prevent the egr valve from working , and then failing the emissions test for high N0X readings

Would upping the intake help this at all? Just curious...
No emissions testing here, but I've heard of the backpressure problem.
 

Kruz

Moderator
Staff member
if you don't have emissions testing than dont worry about the egr valve. it's just there to cool the combustion chamber by adding a calibrated amount of exhaust gas into the intake manifold.. which lowers the NOX gasses. but higher combustion temps mean a increase in detonation (pinging)! so you will have to use at least 93 octain fuel to prevent that....
 

unclehobart

this is my special title
Feed me some ideas on how to tinker with my system to get more oomph out of it from cheap to expensive ... that won't send my emissions into the shitter.
 

Mirlyn

rebmeM
Unc, I noticed a difference when I got down on it (like highway merging, etc) after replacing the factory air filter with a K&N. :shrug:
 
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