3" vs 2.5" tail pipes

[john108]

68 Charger R/T.  505 engine, Auto.
TTI 1 7/8 headers with 3" collector.
20" Dynomax Ultra Flow Mufflers w/ 3" in and Out.

QUESTION:
What is your take/opinion of transiting to 2-1/2" aft of the mufflers (tail pipes).
What do you see as the Positive or negatives.

Thank You,
John

[cdr]

68 Charger R/T.  505 engine, Auto.
TTI 1 7/8 headers with 3" collector.
20" Dynomax Ultra Flow Mufflers w/ 3" in and Out.

QUESTION:
What is your take/opinion of transiting to 2-1/2" aft of the mufflers (tail pipes).
What do you see as the Positive or negatives.

Thank You,
John

if you have an x pipe there wont be much if any difference , that said I prefer the 3" pipes

[Mike DC]

  
Maybe a slight loss of HP at 5000+ RPM but not in the usable revs.  It might even give a slight low/mid torque improvement.

It will probably be a little bit quieter.


Stick with 3" tube for the actual mufflers.  Don't bring down the size until after them.  

[john108]

I guess I wasn't totally complete and clear.

I will be getting a 3" H-Pipe.
Any reduction in pipe size would be AFTER the Muffler.

One reason for considering the 2-1/2 tail pipe was that I couldn't find a Mopar type double loop hanger for the 3" pipe.
Accurate stopped carrying them because of lack of demand.  Also 2-1/2 is easier to install.

[cdr]

I guess I wasn't totally complete and clear.

I will be getting a 3" H-Pipe.
Any reduction in pipe size would be AFTER the Muffler.

Well really wont know unless you did a dyno or track test, I prefer the x pipe over the H pipe for making power , just my opinion no proof . my junker runs pretty good for a low compression street car

[c00nhunterjoe]

I prefer the sound of 3 inch pipes over 2.5 and the sound of an h pipe ov3r an x. The gains/ losses are pointless to discuss and you will never feel on the street. 3 inch is deeper, x pipes are tin sounding.

[INTMD8]

What are your priorities? As mentioned 2.5 would be quieter but could also cost you some power depending on what it's making.

If it was mine I would want 3" tailpipes if it was making 550+ at the crank.

[BSB67]

I guess I'm always the only guy that voices a different opinion on this subject.

600 HP is no big deal with 2 1/2" exhaust system.  You will give up a little, but not that much, depending on the rest of the build.  And if you are talking just the tail pipes, it will be even less, if at all. 

If you have 600 HP, and you don't want to leave 10 HP on the table, go 3" tail pipes.

[john108]

Thank you for all the input.  I do see both sides.
The engine is just about 550 HP with a little over 600 torque.
I have been restoring this car for so long that my motives have changed some.
At my present age, what's 10 HP.
I was once very happy with 375 HP.
Some of the parts I need are more available for the 2-1/2 tailpipes, I think I should go that way.
I appreciate the help.
John

[gtx6970]

IMO, the loss will be negligible if at all . Unless its a car that lives in high RPMs all the time. On a street car, I have serious doubts you could even tell

BUT, Ive done a car with 2-1/2" and another with 3" tail pipes, 1st hand experience  it gets real tight from the mufflers back with 3"

[c00nhunterjoe]

Pretty sure thats what i said. Decide on the sound you want. The power on the street will be un measured

[john108]

Thanks again.
The comments and advise helped me a lot,
John

[c00nhunterjoe]

For a decent comparison, 1st video is my car with 3 inch tailpipes, 2nd is 2.5. Same mufflers on both cars.
https://youtu.be/9gpncCxfZ44
https://youtu.be/cC4QY0zkdC0

[john108]

Thanks.  I agree that the 3" has a nicer tone at idle.  The 2-1/2 did sound different but the rpm was mostly higher.
John

[c00nhunterjoe]

https://youtu.be/j6pvgS9xf9Q

Very old video of mine so lower quality but has some rpm to it.

[70phil]

What type of mufflers are you running and length, cOOnhunterjoe?

[c00nhunterjoe]

What type of mufflers are you running and length, cOOnhunterjoe?

They are flowmaster 50 series suv. They have been renamed super 50. 3 inch, there is only 1 length. They are pretty long. Dont recall offhand. The other car in the video i posted has the same muffler but in a 2.5