Exhaust questions

[Russ Harris]

I'm looking to upgrade my exhaust to straight pipe, which way do I go to get the max HP, take out the cat and leave the muffler, or take out the muffler and leave the cat.

 

[Cummins12V98]

What year is your truck? I can tell you don’t go straight pipe, you will hate it.

I finally ended up with what I like. MBRP turbo back with big Donaldson/NAPA straight thru muffler.

 

[Russ Harris]

I have a 2001 ram 2500 5.9L 6-speed and my roommate has a 2004 ram 2500 5.9L 6-speed

 

[NIsaacs]

or take out the muffler and leave the cat.

Do this.

It is not a cat, it is a resonator. I ran my '01 like this for years then upgraded to 4" turbo back straight pipe. I didn't like it at all so installed a small muffler, still too loud, so I installed a Walker/Napa muffler. I like it, nice and quiet.

 

[GAmes]

I found the muffler that came with my MBRP was about the same as the NAPA straight thru muffler I had installed years ago. Don't expect any HP increase with either a straight pipe or a flow thru muffler unless you are pushing 500+ HP. Perhaps a decrease in WOT EGTs.

 

[AH64ID]

I have a 2001 ram 2500 5.9L 6-speed and my roommate has a 2004 ram 2500 5.9L 6-speed

What mods are on the trucks?

I don’t think either of those came with cats, maybe the 01 has a resonator. The 04 shouldn’t have either.

Likely there won’t be any increase in power with what you are talking about thou.

 

[MRiley]

I just saw this post. I have an '01 6spd. No cats on the truck. I've run straight 4in pipe for close to 15 years. Its loud but I like the way it sounds. I don't know that there's more HP but the turbo spools faster and therefore the truck will power up quicker.

 

[Russ Harris]

My apologies, I didn't get the right info till 2 days after I made this post, my roommate has straight 4" on his 04 6-speed and it's loud. I'm mainly looking for a good sound for a decent price without braking the bank. The truck originally had a stack coming out of the bed but they put full exhaust back on it before they traded it in.

 

[BigPapa]

MBRP. Their muffler was fine for me on sound. I get compliments about the sound and it’s not too loud. Mine is the standard steel, not stainless, and it’s been on over 15 years. Of course, I’m not in the rust belt, though. As others have mentioned, don’t expect any power gains.

 

[Joe Mc]

Have to agree the MRBP 4" is a nice system. I got the setup in like 03 with aluminized pipes a SS muffler, came with nice SS angled tip. I ran for years without the muffler it was loud. Recently put muffler back on. I think it came with new down pipe but forget because new turbo went on in like 06 or so and had to get different down pipe. Solid system only thing hookey was 2 piece tailpipe right at the center of the loop above the differential but it's still hasn't rusted out.

 

[Joe Mc]

What'd you end up doing?

 

[77w 12valve]

What is the best jake brake are exhaust brake for a stock 12 valve and do I need to upgrade my valve springs

 

[GAmes]

What is the best jake brake are exhaust brake for a stock 12 valve and do I need to upgrade my valve springs

You really should start your own thread, but to answer your question, they all work well. There isn't a "Jake" brake made for a 12 valve, not one like a big truck has anyway. The common "Jake brake" has an actuator that briefly opens the exhaust valve at the top the compression stroke which results in the piston not being forced back down. My exhaust brake, (made by Jacobs by the way) works the same as the others on the market. It has a butterfly plate in the exhaust that restricts exhaust flow, much like putting a potato in the exhaust pipe. The result is engine braking. Mine came with 60 pound springs for the exhaust valves.

 

[Joseph Donnelly]

I found the Walker 21468 (3") and 21471 (4") to sound good and not cost HP.