underwoodbits

I just ordered the Donaldson M090544. When I get it, is it better to open the center of the baffle. I tow a lot and dont want any drone, will opening the baffle up cause any drone? I am leaving the cat. I might have to register my truck in California next year, will the M090544 pass California laws.

I also want to order a tip. Will the 4" in and 5" out be louder and how much? I was looking at these tips called Force Cannon. I want to get the 15 Degree Slant Cut Rolled Edge 18" long one and replace factory pipe back to where the first bend is.

http://www.dieselpro.net/product.html?pcfid=44


Thanks.

JCLeary

I have the M090535. The muffler appears to be designed similar to an Aeroturbine. My muffler has a section where the diameter is reduced to 4", splitting the air flow around the venturi (for lack of a better word). The exhaust flow then recombines towards the rear of the muffler. I personally would not open the restriction, as this is what I feel is canceling out the noise.

I haven't seen a 4", so I can't comment on that particular model...

alboy

I ordered the nelson 51x5 with 4 inch reducers,the cummins truck shop cross ref with the donaldson, supposed to be the same,love it, great sound yet quiet,pulled my 15000 lb fiver last weekend,no drone and very quiet in the cab ,my wife commented on how quiet it is.I also have the 5 inch tip and did leave the baffle in.I changed from a magnaflow,flow master b4 that.Everyone is happy now.

Cummins Freak

I've got a muffler related ? for this thread...Would a Donaldson Muffler cause my 12v to loose power??? I would like a muffler just dont really want to loose power

cconrad331

I have the 51" x 5" in/out and I opened it up with a 4" cap off of 100lb propane bottle and I have no drone. That is with no converter and 5" turbo back. If you plan on leaving the cat in place you will have no problem with drone. Here's what it sounds like: http://www.youtube.com/watch?v=i0E6J3FxNCI

2003Ram

One thing to consider is: Will a 51" fit with the CAT still in place? I Just put a 40" on my '03 SB and kept the CAT. Very good fit bordering on tight fit.

BTW: No smog on diesels in Cali.

js091899

My 2 cents....keep the kitty no problem......remove said kitty and it roars under load.....well mine any way. Here kitty kitty where did I put that thing

high bid

Good info. I'm guessing I'd have to use the donaldson 41x5 for a shortbed truck w/5" exhaust. Now searching for a 5" exhaust w/out muff, see how it sounds and then throw in the donaldson. any ideas? thanks.

underwoodbits

No smog testing diesels in California, that is great. I can't believe of all states they don't make you do one.



Measure first, I have a shortbed and the 51" will fit. There is probably 55" or a little more between the cat and the first bend where the exhaust goes over the axle.

JCLeary

Don't kid yourself, it's coming. California is also considering making DPF filters mandatory on pre-emissions vehicles. Basically they want to force people to retrofit their diesel vehicles. You can bet there will be a lot of smog shops popping up around when the testing starts. Look forward to it in 2010.




I was holding mine up there, and it would be a very tight fit. I'm not sure how you would be able to accomodate the offset in the stock muffler w/o a pipe bender. I can't find a shop to mandrel bend 4".

underwoodbits

I am not positive, but I think it will work without bending the stock pipe. If you look right behind the cat about 3" you will see it start to bend down for the offset in the stock muffler. I think if you weld the Donaldson 2" behind the cat it would be fine. Like I said, not for sure but will find out this week or next when I put mine on. I just measured it and if you weld the 51" muffler 2" behind the cat you will have about 54" of space. If it doesn't work, they sell 4" S bend pipe.

2003Ram

Smaller cars like TDIs and Libertys are definitely on the list. There is still a big gray area when it comes to larger vehicles.


My 40" x 4" was installed using two 45* bends right off of the CAT adjusted such that the straight though Muffler was installed up near the bed and lined up with the tail pipe section nicely.

levigarrett76

i run a 4" 51" donaldson that came without the baffle and no cat and i dont have a lick of drone or interior noise...this is with my 5" stack coming up right behind the cab

tburks

Hey levigarrett76, can you tell what the part number was on your 51" Donaldson muffler you order and where is the best place to get you...

levigarrett76

honestly i dont have it, i found the number off of here searching around then took it to a kenworth dealer and had the muffler the next day

There was a post somewhere on here that spelled out the part numbers for the ones with and without baffles..i cant find it anywhere on the muffler itself and the box is long gone