Exhaust question. Probably stupid.

[safetyfast]

Autozone is running a 15% off sale today, so I thought I might replace my crusty exhaust. The stock muffler inlet and outlet are offset. So, if you install a bullet or glass pack, how do you like the muffler up with the stock intermediate and tail pipes?

 

[quietpeen]

if the new muffler is shorter an exhaust shop can bend and weld in some pipe to match up, if they are same size i would imainge some pipe would have to be cut out to make room to weld in a new pipe with the offset

 

[safetyfast]

I see. Planning to install myself. Any opinion about walker sound fx versus Thrush turbo mufflers. Both should be direct fits.

 

[ParrotHead FA]

You can buy glasspack and bullet mufflers with offset inlet/outlet that will line up and be direct fit if you get the right length muffler. Why not go with true duals from the block back? You'd get a lot better performance and mileage gains than using a single with cat setup.
Dave

 

[05singlecabHEMI]

You can buy glasspack and bullet mufflers with offset inlet/outlet that will line up and be direct fit if you get the right length muffler. Why not go with true duals from the block back? You'd get a lot better performance and mileage gains than using a single with cat setup.
Dave

I always heard true duals were worse. Kills your back pressure and lowers the torque. Which would so hurt milage due to having to work the engine a bit more. Especially without the cats.

 

[talon6]

You can buy glasspack and bullet mufflers with offset inlet/outlet that will line up and be direct fit if you get the right length muffler. Why not go with true duals from the block back? You'd get a lot better performance and mileage gains than using a single with cat setup.
Dave

not true. duals doesnt always mean better performance.

 

[Budakane]

Gonna 3rd this, True duels do NOT = performance. U need back pressure, or u will have no low end torque

 

[Okiespaniel]

I don't know if any of you guys are reading the other threads in the 2nd gen forum, but Parrothead is claming 26-27 mpg hwy and 17-19 mpg city with his true dual setup. So there may be some merit to this...

However, at highway speeds there is no low end torque. It's the city driving where it's needed, especially with big mud tires and highway gears.

Let me say that there's a minute group of people who have achieved great mileage and power from certain mods, while the rest of us who've tried them have fallen way short. I wonder what we've missed.

 

[ParrotHead FA]

Just to clarify things a bit, I'm not claiming that I get that kind of mileage increase from running straight pipe alone. The straight pipe true duals help a great deal, but I have made several other modifications that work along with this to achieve the mileage and hp gains that I have acheived. First of all, when using glasspacks or straight pipe, you use pipe diameter and length to acheive a small amount of backpressure necessary for a proper torque curve. I only use 2" pipe, and run from the header collectors to the rear bumper. This right for the size of my engine (5.2) and the length of the run when using no mufflers or cats. I also use a ram air induction system to supply the engine with cool air from outside the truck, and to force more air into the throttle body the faster you drive. I have removed the thermostat entirely to drop the operating temps to 130-140 degrees. This allows me to advance the timing 4 degrees and run a 92 octane tune while using 89 or at times even 87 octane fuel. Of course in order to make the engine run this cool, I had to use plugs several heat ranges hotter, and reset the temp at which the computer leans out the air fuel mixture. I use an MSD 6AL setup, 8mm plug wires, platinum 4 Bosch plugs (interestingly enough, MSD does not reccomend these plugs with their ignitions, but i find they work great... appearantly they wear much faster than normal, but not a problem for me as I replace them every 20,000 miles) I beleive it is a combination of all these things, and possibly even the use of Amsoil synthetic lubricants, that result in the kind of mileage I can get from my engine. When I'm doing mostly highway driving in the ram, I get from 683-720 miles to a tank of fuel, and I have a 26 gallon tank. So it's well worth the mods I have made if I drive reasonably. A few other noteworthy side benefits of my mods that I have noticed over the years: The engines stay much cleaner, both inside the combustion chambers, and inside the crankcase.
The engines last a lot longer before needing an overhaul, I usually can get 350,000 miles or more with no oil burning
You can rev the engine higher without damage, my rev limiter on the ram is currently set at 6600 rpms
Dave
Dave

 

[safetyfast]

I went the cheap route. Walker exact fit tail pipe and intermediate pipe plus Thrush Turbo muffler ran me $100 on sale. Hope to install this weekend.

 

[safetyfast]

Thrush that supposedly fits wasn't even close. Ended up exchanging it for a walker muffler that looks and sounds like OE. All in all a pretty easy morning's work.