Engine/Transmission (1994 - 1998) '96 exhaust output Cu Ft/minute??

[GGibson]

I'm trying to achieve a "low noise" exhaust system. Trying to determine if 2 mufflers in parallel would reduce noise compared to 1 muffler. Called Donaldson and they need the engine exhaust output range in cubic feet per minute in order to do the calculation. Does anyone have that info????

 

[Bob4x4]

I would think that mufflers in parallel would be louder. I have run mufflers in series when less noise is desired.



Bob

 

[Loren]

The engine displaces 5. 9 liters.



It produces an exhaust stroke on each cylinder every two revolutions. So it will exhaust 2. 95 liters per revolution.



At 3000 RPM, the engine will exhaust 8,850 liters per minute.



One liter equals 0. 03531 liters.



At 3000 RPM, the engine will exhaust 312 cubic feet per minute.



Loren

 

[onestackdram]

you are way to smart, just thought i would throw that in

 

[MWBrooks]

Loren,

Your numbers don't take into consideration the expansion of the burnt fuel.







Mike

 

[Bob4x4]

Remember also that with the turbocharger we are operating at considerably above 100 % volumetric efficiency.



Bob

 

[Loren]

Mike,



You are absolutely correct. Sorry for the incorrect assumptions in the solution.



I figured if I posted something that was wrong, somebody would point out my errors. My calculations will work only if the engine is used as an air pump.



Oh, well. Now GGibson is back to where he started, 'cause I don't know how much extra gas is created by the burning fuel.



I may ponder this issue for a while, but I doubt that I'll be able to come up with anything better than an educated guess.



Thanks for the insight that I missed.



Loren

 

[Loren]

While I was writing my last post, Bob reminded me of the turbocharger. I admit that I didn't take that into consideration either, but I don't know how that will affect the outcome. It's not the same as actually creating gas by burning fuel.



GGibson seeks an answer in cubic feet per minute, so the pressure created by the turbocharger may not matter. If we were after an answer in pounds per minute, it would have a major impact.



Some more numbers:

If you are getting 30 psi boost, that is the pressure of your intake air (above atmospheric). If you compress that at 18:1, you will get 540 psi air. And this is BEFORE you introduce the fuel.



Two things we need to know in order to calculate (rather than just measure) the answer are:

1. What is the volume of gas created by burning the fuel?

2. What is the pressure of the gas as it moves through the exhaust pipe?



I'm afraid that I don't know the answer to either one of those questions. Sorry.



Has anyone thought of sticking a dry cleaner bag on the tailpipe and timing how long it takes the engine to fill it up? How much volume does a dry cleaning bag hold anyway? Maybe a mattress bag would be required.



Loren

 

[GGibson]

Donaldson Muffler ratings

Thanks you guys for taking a shot at this. I tied myself in the same knot with the calculations and then got completely stumped when it came to the fuel expansion. For what it's worth here's the Rated Flow for the Donaldson M085171, designed for the 4" inlet/outlet system.



Rated Flow, Low range 1800 CFM

Rated Flow, Med range 1546 CFM

Rated Flow, Hi range 3119 CFM

Noise Attenuation (dBA) 8-12



For the 5" inlet/outlet muffler, M100465

Rated Flow, LR, 1610 CFM

Rated Flow, MR, 2277 CFM

Rated Flow, HR, 2790 CFM

Noise Attenuation (dBA) 15-20



Yes, I noticed that the Hi Range CFM was greater for the 4" which I don't understand. But the 5" is a lot quieter.

Rated Flow, HR, 2790 CFM



In any case, the guy at Donaldson said he could tell me if a single muffler or "duals" would be quieter if the knew the CFM. One of the earlier posts makes sense to me, He thought 2 mufflers would make more noise than one.

 

[wcjp]

Call this guy. Not affiliated with Rip.



http://membersites.nwbombers.com/riprook/

 

[MCummings]

Don't forget the muffler bearings. .