4" or 5" exhaust

[CUMIN2pass]

I'm getting ready to pull out stock pipes. I'm will be running 275's

EZ, with 14cm2. Should I use 4" or 5" tail pipe. Does it matter?

 

[Bigsaint]

I really don't think there is much to gain in performance over the 4". If you want more 'shock value' bigger is always better



Scott W.

 

[Beast2B]

go for the shock value!

Just based on appearance, go with the 5" system. Obviously, it can't flow any worse than the 4" setup! Probably doesn't need to be said, but get a VERY free flowing muffler (along with the CHROME muffler bearing)

 

[Stroke This 24V]

Go 5"

I did!!! LOL It runs out to the factory location and is a very clean look. I like the What the He** and the Holy Sh*t expressions that I get when refueling and just about everywhere

 

[Jim Nunn]

A diesel engine is an "Air Pump"

I have the 5" exhaust and have no measure of the difference from stock versus the 5"er... BUT it does seem to me that the EGT's are somewhat less, and knowing that this engine needs to suck in and blow out a LOT of air, it seems natural that the engine will do better with less resistance to air going either way.

 

[Mopar-muscle]

other than the 5" system i saw that quaddoorramdiesel4x4ohmygodthelongestnameonfile built , the only 5" i saw on frank noble of JRE fame has on his truck used a 4" downpipe to an 4" to 5" adaptor and the rest was 5" , if you want shock value go 4" to a 5" tip ,makes the ricer guys jealous . when they make a comment to me i tell them at least i'm feeding that tip with a 4" pipe not a 1 3/4" pipe

 

[Archive]

??????

How does that 5 in pipe fit past the spare tire... will it fit with the 265 tire. . 285???? Thanks. .

Bryan

 

[MCummings]

Don't forget, you can go for dual exhaust also, you have to add a "Y-Pipe" somewhere along the exhaust since the CTD is a straight 6.

#ad




I have dual 3" pipe that is Y'ed off the bottom of the stock downpipe, and Chrome 3. 5" tips.

I have heard this setup yields the performance of a 4. 5" pipe.



MerrickNJr

 

[KennyM]

MCummings



I love the looks of the side pipes. Are you running a mufler? What is noise like. The wife might complain if its to loud.



Ken

 

[Fireman Dave]

Me and johnrv4 went straight 4" from the resonator back with a 5" chrome tip that was originally intended for an motorhome. It comes out at the stock location and looks and sounds great. Wally19 did the same as us, but he went straight 4" all the way to the turbo (no resonator). His is the loudest.

 

[MCummings]

I am straight Piped, no muffs

I'll give you a bit of history behind my exhaust, and my so called reasoning.



I have a friend who has a '79 3/4 ton Chevy 4-speed with a 350 motor, he has true dual 2" or 2. 5" pipes with 7" glasspacks (length)

His truck when at WOT can easily be heard from 1/4 mile away, and is actually quiet in the cab, the most prominant noise is the drivetrain.

I wanted his type of setup,, Loud outside, quiet inside.



Well, I didn't get it. The resonance at 70MPH gets bad if you do anymore than about 15-30 minutes of steady 70MPH.

If I travel at 1,500RPMs the exhaust is a ALOT quieter, and above 2K the resonance is not any worse, but is still bad.

The driver side, and Back pass. side are the worst resonating spots, the Passenger side has the least resonance,, it's nearly non-exsistant, the only noise is the actual exhaust while accelerating, and the turbo whistle while decelerating.



*I* LOVE the sound, INSANE Turbo Noise. The Turbo isn't louder than the actual exhaust at WOT, but while slowing down any, the trubo can be heard whistlin' in the wind. .



If I could compare the interior noise to anything, it would be to a vehicle with open headers dumping right behind the cab.



Maybe you could put some mufflers on it, and it would get rid of the resonance.



You can look up TDR member "Brian Hopper" and he has the same exhaust setup, but exits farther back.





Anymore questions? feel free to ask.



MerrickNJr



P. S. I have 600watts of bass underneath the rear-seat, and the resonance is nowhere to be found, if you listen to the radio the resonance will be ALOT less, but for me, the radio is ON (loud) or OFF.

 

[Joseph Donnelly]

At your power level, no difference between 3" and whatever bigger size you choose. At 380 rear wheel hp, you gain 7 hp with 4" and no muffler over 3" with a Walker 21468 muffler. Above 350 hp, the HX40 is valuable to lower egt, and it is designed for 4". Sickly has run 613 hp through 4" on #2 only. If you want bigger for appearance or sound, that is another thing. . .

 

[Todd T]

yah what Joe said!!!

he's da man.



and he would know.