51" Nelson muffler !!!!
03-25-2004, 07:22 PM
#46
Registered User
Join Date: Dec 2003
Location: Boise, Idaho
Posts: 5,540
Likes: 0
Received 0 Likes
on
0 Posts
Does anyone know what the max exhaust CFM's of the Cummins HO is? It may not make a performance difference using the 40 or 51 inch mufflers other than sound preference...
03-25-2004, 10:09 PM
#48
Registered User
Originally posted by cquestad
Does anyone know what the max exhaust CFM's of the Cummins HO is? It may not make a performance difference using the 40 or 51 inch mufflers other than sound preference...
Does anyone know what the max exhaust CFM's of the Cummins HO is? It may not make a performance difference using the 40 or 51 inch mufflers other than sound preference...
From what I hear the stock muffler flows about 350 CFM.
Blownaway,
Thanks for the update. I would like to hear your tow report with the new exhaust.
MikeyB
03-26-2004, 08:50 AM
#49
Registered User
Join Date: Jul 2002
Location: Boise ID
Posts: 1,340
Likes: 0
Received 0 Likes
on
0 Posts
I get 1600, using the Fleetguard/Nelson formula. I figure if we're talking about an after market high-flow muffler to reduce EGTs, then we're pushing things to the limit. So I plugged in 3200 rpm and 1200 degrees EGT, using the formula for a turbocharged aftercooled diesel of 361 cubic inches displacement.
At this upper extreem for CTD exhaust flow, the donaldson muff is right in the center of its intended operating range, loafing around at only 1 psi backpressure.
At this upper extreem for CTD exhaust flow, the donaldson muff is right in the center of its intended operating range, loafing around at only 1 psi backpressure.
03-26-2004, 12:30 PM
#51
Registered User
Join Date: Jul 2002
Location: Boise ID
Posts: 1,340
Likes: 0
Received 0 Likes
on
0 Posts
we are using the same formula, only I used 1200 degrees EGT and a factor of 1.6 instead of 1.4. You probably meant to have a couple of parentheses in there; the formula as you typed it is not quite correct. I'm using:
CFM = [Displ x RPM x 1.6 x (1200+460)] / 2 x 941760
The way I interpreted the Nelson formula, 1.6 applies to turbocharged diesels with aftercoolers. That amounts to about a 15% increase in CFM, owing to the higher charge denstity of air as a consequence of the aftercooler.
CFM = [Displ x RPM x 1.6 x (1200+460)] / 2 x 941760
The way I interpreted the Nelson formula, 1.6 applies to turbocharged diesels with aftercoolers. That amounts to about a 15% increase in CFM, owing to the higher charge denstity of air as a consequence of the aftercooler.
03-26-2004, 05:17 PM
#52
Registered User
Ok, I see, the formula I found only showed normally aspirated and turbocharged for efficiency. And for turbocharged only the value of 1.4 was listed.
Yeah, I left the parentheses out while I was typing...
Thanks
MikeyB
Yeah, I left the parentheses out while I was typing...
Thanks
MikeyB
03-28-2004, 11:16 PM
#53
Registered User
Join Date: Feb 2004
Location: Washington
Posts: 156
Likes: 0
Received 0 Likes
on
0 Posts
My trailer is going to be heavy! It is a 33.5 Fleetwood 5er loaded full of stuff, We have been living in it. I hooked up today and couldn't believe a 1 ton could sag like that
04-02-2004, 04:32 PM
#55
Registered User
Join Date: Nov 2003
Location: Coweta, Ok
Posts: 17
Likes: 0
Received 0 Likes
on
0 Posts
Check out these 2 sites has Nelson mufflers brochure.
http://www.fleetguard.com/fleet/pdfs...s/LT32002B.pdf
http://www.fleetguard.com/fleet/pdfs...s/LT32002C.pdf
http://www.fleetguard.com/fleet/pdfs...s/LT32002B.pdf
http://www.fleetguard.com/fleet/pdfs...s/LT32002C.pdf
04-02-2004, 04:53 PM
#56
Registered User
Join Date: Nov 2003
Location: Coweta, Ok
Posts: 17
Likes: 0
Received 0 Likes
on
0 Posts
04-03-2004, 07:12 PM
#57
Registered User
Join Date: Feb 2004
Location: Washington
Posts: 156
Likes: 0
Received 0 Likes
on
0 Posts
I towed my trailer, I would estimate the weight at about 13,000-14,000 Lbs 33.5 Fiver very loaded down. My wife says she doesn't notice any difference while towing and I tend to agree, the funny thing is you can hear more noise coming from the cooling fan and engine than the exhaust, With the straight out stock tailpipe it does echo off of gaurdrails and other cars though. I am still very happy and more importantly so is she
It is still just my opinion, I am sure you are not going to find anything more quit than the stock muffler, which by the way looks like baffles down to about three inch on the inside.... That thing sucks!
It is still just my opinion, I am sure you are not going to find anything more quit than the stock muffler, which by the way looks like baffles down to about three inch on the inside.... That thing sucks!
04-04-2004, 11:34 AM
#58
Registered User
Join Date: May 2003
Posts: 357
Likes: 0
Received 0 Likes
on
0 Posts
Re: 51" Nelson muffler !!!!
Originally posted by draebi
About the same noise level at idle but just a little deeper tone. About 15% louder under acceleration with a very nice deep tone. At highway cruising speed(65-80mph) there is a significant decrease in interior noise.
About the same noise level at idle but just a little deeper tone. About 15% louder under acceleration with a very nice deep tone. At highway cruising speed(65-80mph) there is a significant decrease in interior noise.
It has a 4" inlet with a 5" outlet that might make a nice CAT Back System. Looks like it has good flow vs db numbers.
Thoughts anyone for us that need to keep the CAT?
Great post and tons of good info.... Thanks!
04-04-2004, 02:51 PM
#59
Registered User
Join Date: Aug 2003
Location: Swisher, IA
Posts: 117
Likes: 0
Received 0 Likes
on
0 Posts
If you have a cat and need to keep it, then why not just straight pipe it? With the turbo and a cat, it shouldn't be too loud and you can't get any less backpressure than no muffler at all .
-Muzzy
. -Muzzy