HUSHPOWER MUFFLER

dieselenthusiast · **Posted:** Sat Jul 05, 2008 12:53 pm

I posted this on the 4x4 section, but I thought I'd post it here also. Anyway, here’s a more quiet muffler that still has full flow. The hushpower is perfect for off-road vehicles and for those who like a quieter muffler and increased performance.

http://www.justflowmaster.com/Hushpower ... fflers.asp

http://www.hushpower.com/index.php

jinstall · **Posted:** Sat Jul 05, 2008 4:26 pm

2.5" IS THE BIGGEST

dieselenthusiast · **Posted:** Sat Jul 05, 2008 5:03 pm

jinstall wrote:

2.5" IS THE BIGGEST

Isn't the factory exhaust 2.5"? Or are you wanting to replace it with all 3" pipe?

jinstall · **Posted:** Sun Jul 06, 2008 1:42 pm

I want to replace it with 3"

DarbyWalters · **Posted:** Sun Jul 06, 2008 1:51 pm

Don't need no stinkin muffler...

Threeweight · **Joined:** Mon May 14, 2007 5:57 pm **Posts:** 679

You'd need to weld in new exhaust from the turbo back to get 3". I think the 2.5 pipe starts all the way up there. Before I went to that expense, I'd be pretty certain a 3" exhaust offers some gain over 2.5 inch in a tiny little 2.8 liter 4 cylinder diesel...

dieselenthusiast · **Posted:** Sun Jul 06, 2008 5:00 pm

DarbyWalters wrote:

Don't need no stinkin muffler...

Didn't you say, at one time or another, that the CRD wasn't any louder without the muffler? If this were true, then in most cases, depending on the type of muffler, the exhaust with a muffler would be louder than running it without a muffler. Interesting………………………………......... So, why would you want a muffler? Has anyone confirmed this?

dieselenthusiast · **Posted:** Sun Jul 06, 2008 5:05 pm

Threeweight wrote:

You'd need to weld in new exhaust from the turbo back to get 3". I think the 2.5 pipe starts all the way up there. Before I went to that expense, I'd be pretty certain a 3" exhaust offers some gain over 2.5 inch in a tiny little 2.8 liter 4 cylinder diesel...

I’ve been told by a high performance exhaust guy, that going too big can actually hurt your backpressure. A little backpressure is good. I would think that 3” exhaust on the 2.8 VM would probably be okay, however I doubt there would be any benefits. It would be cool to see some before and after dyno's.

Sir Sam · **Posted:** Sun Jul 06, 2008 5:40 pm

dieselenthusiast wrote:

Threeweight wrote:

You'd need to weld in new exhaust from the turbo back to get 3". I think the 2.5 pipe starts all the way up there. Before I went to that expense, I'd be pretty certain a 3" exhaust offers some gain over 2.5 inch in a tiny little 2.8 liter 4 cylinder diesel...

I’ve been told by a high performance exhaust guy, that going too big can actually hurt your backpressure. A little backpressure is good. I would think that 3” exhaust on the 2.8 VM would probably be okay, however I doubt there would be any benefits. It would be cool to see some before and after dyno's.

turbo engines get all the back pressure they need from the turbos, anything after that is just a restriction.

tjkj2002 · **Posted:** Sun Jul 06, 2008 6:45 pm

Sir Sam wrote:

dieselenthusiast wrote:

Threeweight wrote:

You'd need to weld in new exhaust from the turbo back to get 3". I think the 2.5 pipe starts all the way up there. Before I went to that expense, I'd be pretty certain a 3" exhaust offers some gain over 2.5 inch in a tiny little 2.8 liter 4 cylinder diesel...

I’ve been told by a high performance exhaust guy, that going too big can actually hurt your backpressure. A little backpressure is good. I would think that 3” exhaust on the 2.8 VM would probably be okay, however I doubt there would be any benefits. It would be cool to see some before and after dyno's.

turbo engines get all the back pressure they need from the turbos, anything after that is just a restriction.

Only to a certian point,even on a diesel.

Turbo Tim · **Posted:** Sun Jul 06, 2008 8:08 pm

Please explain.
I have been involved with the engineering of turbo systems from the initial design to finished product. Some OEM, some aircraft, but mostly race applications.
If backpressure is needed AFTER the turbine, I would be most interested to hear about it.

tjkj2002 · **Posted:** Sun Jul 06, 2008 8:30 pm

Turbo Tim wrote:

Please explain.
I have been involved with the engineering of turbo systems from the initial design to finished product. Some OEM, some aircraft, but mostly race applications.
If backpressure is needed AFTER the turbine, I would be most interested to hear about it.

You may design turbo systems(highly doubt it,your just fabbing pre-existing stuff to work on other items is all) NOT engines.Turbo's do not provide sufficent back pressure in MOST cases.You can build a engine to run on no back pressure but mass produced engines,even TD's,are not designed for low back pressure since they need to pass noise requirements also so the added back pressure was designed into the engine,cylinder heads, from the get go.Lose enough back pressure and you lose your low end.Then you got exhaust harmonics/pulses,disrupt those harmonics/pulses to much and you can lose more power and effeciency.Race and aircraft apps are not the same as DD versions,the amount of $$$ put into those engines far out weighs what a whole CRD cost brand new and then some.

Put a 5" straight pipe,the whole system and not just turbo back,and see what happens to your low end.You can add 3" straight pipe to your CRD but it is not a true 3" system,the inlet/outlet and down pipe to the turbo is not 3" so it doesn't much matter.

Turbo Tim · **Posted:** Sun Jul 06, 2008 8:57 pm

I worked at Garrett Air Research here in Phoenix in the engineering dept. We had to do testing in the test cells from jet engines to the car/diesel turbo turbines on the T02, TO3, and T04’s.
Most turbo’s run at about 11/2 to 1 pressure ratio. This means that if you have 10 PSI of Boost, you will have 15 PSI of exhaust back pressure! (Nothing is for free). Any exhaust restriction, i.e. backpressure after the turbine will kill the pressure differential across the turbine and you lose.
(We won’t even get into the kinetic energy of the exhaust pulse and thermal expansion properties across the turbine wheel).
Fact is a straight pipe produces back pressure after the turbine. The reason is that the air is spinning (like a tornado) and the exhaust will “Pack Up” in a straight pipe. The quickest way to straighten the air flow and improve the flow is to have a 90* turn on the exit of the turbine. You will see this on just about every OEM and aircraft setup.
Next time you get some time to play on a dyno, try it. Most 2.2 Liter engines see anywhere from 15-25 horsepower increase by just putting on a 90* bend on the dump of the turbo.

dieselenthusiast · **Posted:** Sun Jul 06, 2008 9:24 pm

Swapping an exhaust system on a diesel works by free flowing low back pressure and allowing the turbo to move air more freely, thus reducing exhaust temperatures. Dyno’s have proven to show a significant gain in horsepower by simply switching from stock to an aftermarket exhaust system. On the newer trucks, we know that diesel exhaust back pressure has a direct impact on emissions and engine performance. A larger exhaust can increase exhaust flow which will reduce power robbing back pressure. Therefore, there must be some backpressure involved.

DarbyWalters · **Posted:** Sun Jul 06, 2008 10:28 pm

tjkj2002 wrote:

Put a 5" straight pipe,the whole system and not just turbo back,and see what happens to your low end.You can add 3" straight pipe to your CRD but it is not a true 3" system,the inlet/outlet and down pipe to the turbo is not 3" so it doesn't much matter.

Blanket statements like that will get you into trouble. After the turbo, any opening up of the system will help. Even if the first 1/3 is 2.5" and you add a 3" for the last 2/3, you will see improvement. It is the size of the turbo that will dictate the amount of "betterment" a larger diameter exhaust will yield. Once you exceed that "betterment" diameter, you are just adding weight with bigger(heavier) pipe.

Low end is also dictated by the size and/or design of the turbo (turbo/intercooler/placement)...

nescosmo · **Joined:** Sat Jul 14, 2007 11:17 pm **Posts:** 202

The CRD is 3" up to the C converter after that the muffler is 2.5.

I install a Dynomax moffler #D2219392 that came with all that you need for the convertion. It run smoother and more powerfull.

nursecosmo · **Posted:** Mon Jul 07, 2008 12:35 am

Turbo Tim wrote:

Please explain.
I have been involved with the engineering of turbo systems from the initial design to finished product. Some OEM, some aircraft, but mostly race applications.
If backpressure is needed AFTER the turbine, I would be most interested to hear about it.

Thank you Tim! It is good to have folks on the forum with an actual comprehension of physics and engineering.

Nursecosmo. not to be associated with Nescosmo, just watch the spelling.

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