stock muffler and air filter CFM

[Kubotaorange76]

Does anyone know what CFM the stock muffler and the Stock air filter is capable of flowing at a given restriction?

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[Kubotaorange76]

anybody have any input??

 

[Kubotaorange76]

Any links or articles you can point to other than the duramax article?

 

[DPKetchum]

That has been discussed and threads on it. Don't remember if this site or others. want to say on several sites its been discussed in the past. Way back in the past. Try using the SEARCH function.

 

[Kubotaorange76]

I wouldn't have posted this if i had not searched for an answer on three different discussion forums first.

 

[Kubotaorange76]

I still haven't found anything

 

[ERogers]

If an aftermarket manufacturer claims an airflow of a certain percentage better than stock and they give their numbers, you should be able to figure out what the stock numbers are.

 

[Kubotaorange76]

i dont believe people trying to sell their product

 

[JimB1]

If reliable believeable data is important to you, then consider that anyone making accurate measurements is most likely using said info in a proprietary application and wouldn't give it away.



Installing your own test ports, transducers, multiplexing switch and guage might be best method for meeting accuracy requirements.



I've also been interested, so am hoping you'll post results.

 

[SShafranko]

The CFM at Mid Range of the Donaldson 51 inch 4 in 4 out 9 inch body diameter muffler is 1638. The Dba is 13 to 18 which sounds very low to me. I'm assuming the stocker would be close or a little less since it sounds almost the same. Just an assumption. No facts to back it up but it may be a good starting point.

 

[CToney]

All that I know is that the stock pieces on our trucks flow well relative to Chevy and Ford. The gains to be made from "Cold air intakes" isn't very much like 4 hp at 2900 rpm. The psm buick air box mod opens up the stock box for more flow and cool air (good till 450hp). They have extensive test results on their website. As for the muffler or exhaust 8hp improvement. Quite expensive in terms of hp/$. I know on 2nd gens you were good till 300hp then you needed 4" exhaust. We are probably good till 400hp before mods would really help. Just conclusions I have drawn from stuff I have seen. On trucks with a kitty if it went MIA things would probably improve a good deal.

 

[DPKetchum]

Well it must be a long time back those figures were posted. I want to say like the stock air box if I remember correctly in 03/04? had a flow of like 900/950 cfm ? Not sure. But those figures for intake and exhaust have been in threads before. I bet Banks has those figures. Maybe other manufactures might also.

 

[Kubotaorange76]

I put a stock muffler and tailpipe back on my truck this weekend... . pulling 27000 lbs Egt's still didnt go over 1200 with my Smarty Jr. on 40 horse... no seat of the pants difference in power either? Spools up just as well... and its SILENT inside... . kind of nice

 

[opjohnny]

The flow at a given pressure drop was printed on the box or the filter itself. I wrote the numbers down but cant find them. I will keep looking. This was for a stock filter.

John

 

[AH64ID]

I put a stock muffler and tailpipe back on my truck this weekend... . pulling 27000 lbs Egt's still didnt go over 1200 with my Smarty Jr. on 40 horse... no seat of the pants difference in power either? Spools up just as well... and its SILENT inside... . kind of nice

Do you think that's from the muffler or the lack of a stack?



I am now running a 40" Donaldson with a megacab resonator/tailpipe... As quiet as stock, but I'm sure it flows more and I am seeing a slight decrease in EGT's. .

 

[Kubotaorange76]

muffler... and lack of stack. I love playing with different exhaust setups, if you havent noticed. . haha

 

[AH64ID]

muffler... and lack of stack. I love playing with different exhaust setups, if you havent noticed. . haha

Yeah. . you change yours more than me... But I think I found one I like now.

 

[Kubotaorange76]

its sort of a hobby... you should see the pile of random diesel exhaust parts i have, lets see. I went from stock... to no cat stock muffler, then to small perforated muffler, then a 51" donaldson, Then a 5" stack with 51" donaldson, Then 40" donaldson w/ 5" stack, Then 4" stack with 40 ", then same 4" stack with 40 " and mbrp resonator, Then 5" stack with resonator, then straight pipe, then Stock muffler and tailpipe with mbrp resonator. Now just stock muffler. Haha

 

[AH64ID]

its sort of a hobby... you should see the pile of random diesel exhaust parts i have, lets see. I went from stock... to no cat stock muffler, then to small perforated muffler, then a 51" donaldson, Then a 5" stack with 51" donaldson, Then 40" donaldson w/ 5" stack, Then 4" stack with 40 ", then same 4" stack with 40 " and mbrp resonator, Then 5" stack with resonator, then straight pipe, then Stock muffler and tailpipe with mbrp resonator. Now just stock muffler. Haha

Good lord!!!

 

[Kubotaorange76]

All over a period of just under 2 years... . the 51" donaldson was junked because it blew apart... the only parts i bought were the 5" stack, a few clamps, the 40 donaldson and the small perforated muffler, all pipe and resonator etc were free from my random exhaust pile. I think i have 3 complete 02 powerstroke exhausts left, 1 dodge 3. 5" and 1 4" thats in peices, then random 3. 5" and 4" mufflers, and a stock 97 powerstroke exhaust, and the straight pipe i had on my 97... . along a pile of 4 cummins kitties, and 4 powerstroke kitties.







ANYWAY... when i get the chance i am going to dyno my truck with and without the stock muffler back to back on sw #3... then dyno it SW#1 and SW#1 on 50%.



Does anyone have a link to some number that show before and after removing the stock muffler?



I know theres a thread somewhere on DTR where a guy was making like 800 hp in a common rail with the stock muffler and tailpipe... cut out the muffler and it gave him 15 hp?