3 inch exhaust

My66dodge · **Posted:** Tue Jun 01, 2021 11:41 pm

Finally someone has a turbo back 3 inch mandrel bent exhaust on the market... I called and it will be back in stock in the next few weeks

https://kbdieselperformance.com/Stainle ... p252059272

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WWDiesel · **Posted:** Wed Jun 02, 2021 1:31 am

Dang, does not even include a muffler?
Personally I don't think there is much to be gained by going from 2.5" exhaust to 3" exhaust on this engine.
The head and turbo simply won't flow no more and are the limiting factor.
But this is just my opinion, only a true dyno comparison would tell you for sure.
:2cents:

thesameguy · **Joined:** Sat Oct 01, 2016 8:24 pm **Posts:** 652

A 2.5" exhaust should be good for well over 200hp on a turbocharged engine... I'd agree I don't think there is much to be gained going bigger unless you have a LOT of other stuff going on.

My66dodge · **Posted:** Wed Jun 02, 2021 8:04 pm

But I will tell you from personal experiences the 3 inch sounds a hell of a lot cooler with just a cat converter and no muffler and a 4 in tip...

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layback40 · **Posted:** Wed Jun 02, 2021 8:36 pm

Much of the talk about ehaust size is like 2 little boys trying to decide who has the biggest! LOL!
Unless some one wants to set up on a dyno and measure the pressure and temperature at various points through the system, its all just talk.
If the true EGT (before the turbo) and pressure at that point were reduced some what, it would be fair to say there would be an improvement. No one drives around at WOT all the time so any improvement at the top end is over rated. An increase in torque over the whole rev range especially from 1500 to 2800 RPM is what people should be aiming for.

PZKW108 · **Joined:** Sun Apr 06, 2014 5:23 pm **Posts:** 461

My66dodge wrote:

But I will tell you from personal experiences the 3 inch sounds a hell of a lot cooler with just a cat converter and no muffler and a 4 in tip...

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You are right with that one !!!!It give a nice growl

You don't need a muffler on the CRD, just a cat to get rid of the stink !

WWDiesel · **Posted:** Wed Jun 02, 2021 9:46 pm

My66dodge wrote:

But I will tell you from personal experiences the 3 inch sounds a hell of a lot cooler with just a cat converter and no muffler and a 4 in tip...

That is an awful lot of money to spend just to sound "Cool"! :banghead:

I doubt it sounds any better than mine with 2.5" turbo back with NO CAT and a Flowmaster muffler... :lol:

turblediesel · **Posted:** Fri Jun 04, 2021 9:10 pm

They're sold out already anyway!

03black · **Posted:** Fri Jun 04, 2021 10:31 pm

Well if someone wants to make their own 3" piping from the turbo flange back. I have a few machined adapters for sale. See pics below but basically it has the machined flange for the turbo flange and V-band clamp and then a shoulder flange to weld your 3" pipe to.

Original exhaust pipe on left, adapter on right:

Butted up to pipe to show flanges meet:

3" flange face:

Side view - turbo side on left, exhaust pipe side on right:

These were made up by another forum member in the interest some may want to upgrade their exhaust system. I haven't done it yet since I can't find a good exhaust shop around me that make mandrel bent pipes. PM me if your interested, only have 2 flanges, $50 + shipping by USPS.

Just another option.

PZKW108 · **Joined:** Sun Apr 06, 2014 5:23 pm **Posts:** 461

03black wrote:

Well if someone wants to make their own 3" piping from the turbo flange back. I have a few machined adapters for sale. See pics below but basically it has the machined flange for the turbo flange and V-band clamp and then a shoulder flange to weld your 3" pipe to.

Original exhaust pipe on left, adapter on right:

Butted up to pipe to show flanges meet:

3" flange face:

Side view - turbo side on left, exhaust pipe side on right:

These were made up by another forum member in the interest some may want to upgrade their exhaust system. I haven't done it yet since I can't find a good exhaust shop around me that make mandrel bent pipes. PM me if your interested, only have 2 flanges, $50 + shipping by USPS.

Just another option.

You can buy 90 and 45 mandrel bent pipes, I've use Vibrant in the past.

All you need is a welder !

03black · **Posted:** Sat Jun 05, 2021 10:58 am

PZKW108 wrote:

You can buy 90 and 45 mandrel bent pipes, I've use Vibrant in the past.

All you need is a welder !

Lol, you don't want to see my welds. :oops:

One of a few things I can't seem to get down right.

snakeyez · **Joined:** Fri Dec 23, 2016 7:45 am **Posts:** 15

I just cut the cat and the 2 1/8" flange last week.
now I have a stainless 2.5" --3" reducer welded and have it going to a 3" resonator, which is straight piped to 2 45 degree mandrel bends, for a side exit right before the right rear wheel.
ALL STAINLESS - about 300 spent...

someone commented that the exhaust is a little lower now due to clearing the frame rail.. he also has a Jeep Liberty, ... I suggested he just completely remove his rear difff as that's in the way too .. :mrgreen:

going to tune this next and start rolling coal next.

"Mother Earth"

3 inch exhaust

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