Exhaust benefit..

briano · September 25, 2004

again, I may be bringing up old topics so I apologize.

I got a bonus at work so I am thinking of getting the full exhaust done on my duramax. The thing is, I want the bigger, better pipes for many reasons, but I do not want the added sound. I like how it sounds right now.

my question...is it even beneficial to replace all the exhaust from down pipe to tailpipe while keeping the stock muffler? I just don't want it loud. my other HD with the 6.0l I had a flowmaster 40 series on it and d**n it was loud.

just how loud are those aftermarket systems..like banks, or some other ones?

edit: I was doing some searching and it looks like most of the systems delete the catalytic converter, is this true? If so does it make the MIL come on or anything?

thanks again

B.

GMC6000 · September 28, 2004

Go over to The diesel Place. This is dedicated to diesel trucks, maybe they can give you some info.

Machine · September 28, 2004

The stock muffler is pretty restrictive. So restrictive that folks just using the stock 3.5" pipe and a replacement muffler report a nice decrease in EGT's. You're going to spend alot of $ if you just decide to go with a 4" look with the stock, restrictive muffler. The benefits just aren't there with this approach. You could also just put a 5" tip on your stock exhaust...my DPPI exhaust exits at the same angle as the stock setup. The only visual difference is that my pipe is 4" and I have the 5" tip.

In my opinion, all aftermarket diesel exhausts are louder than stock. It's the nature of the beast when switching to a straight through muffler. DPPI and Kennedy make some of the more tolerable mufflers that don't resonate.

By the way, chances are you don't have a catalytic converter

briano · September 29, 2004

actually I do have a Cat on my truck.. the newer Duramax's all have them. the LLY motors that is.

are you in Austin? i see the longhorns avatar!!

highchevy · September 29, 2004

I used two Flowmaster 40 series 3" mufflers in place of the stock muffler and still used the two 3" into one 3.5" stock reaer section and it works really well!

Machine · September 29, 2004

actually I do have a Cat on my truck.. the newer Duramax's all have them. the LLY motors that is.

are you in Austin? i see the longhorns avatar!!

<{POST_SNAPBACK}>

Hi,

Yes, our family splits our time between Austin and S. Texas.

odoh · October 1, 2004

again, I may be bringing up old topics so I apologize.

I got a bonus at work so I am thinking of getting the full exhaust done on my duramax. The thing is, I want the bigger, better pipes for many reasons, but I do not want the added sound. I like how it sounds right now.

my question...is it even beneficial to replace all the exhaust from down pipe to tailpipe while keeping the stock muffler? I just don't want it loud. my other HD with the 6.0l I had a flowmaster 40 series on it and d**n it was loud.

just how loud are those aftermarket systems..like banks, or some other ones?

edit: I was doing some searching and it looks like most of the systems delete the catalytic converter, is this true? If so does it make the MIL come on or anything?

thanks again

B.

<{POST_SNAPBACK}>

I just installed a Banks Monster CAT back on my 02. My concern in shopping around has been w/noise. The vocal market wants loud. The missus is sensitive to noise and if she's unhappy ~ well, ......

Assessment by others is subjective ~ their judgement may not be yours. Best to hear for yourself and even then, may misjudge as under load it may have different/undesireable characteristics. In my case, we're not disappointed ~ friends advice to the contrary, perhaps because Banks is using a different muffler now. Or perhaps its because I left the CAT in? Its been pretty much established that 4" piping in itself really isn't that much of an enhancement for stock eng (because of this, some manufactures don't even bother producing a 4" down/front pipe) ~ the OEM muffler is restrictive and and gain is to be had w/a high flow muffler. Until recently, CA Dmax owners were the only ones w/CATs. Very little effort was made to determine just how much effect it had on overall performance ~ in fact, most would just take it off and be done w/it. Now, all the newer trucks comes w/CATs and some states have/will be inspecting on a routine basis. Hopefully, some useful information may come of all of this ~ as for myself, I elected to leave mine in as unlike gassers, I believe the diesel CATS are of a high flow rate design.