im thinking of doing the dyno mouth mod to my stock exhaust setup....what are the gains!!!

 

Zip Nada zero, Just alot louder but with a 2.25 stock intermediate its going to sound crappy. My .02cents. You might want to check out my signature for a chambered pipe instead. Give Mike a call.

 

ahh....... the stock intermidate pip is not 2 and quarter its 2.75. somebody else...???

 

probably around 3-5 rwhp.

 

The SLP loudmouth exhaust is one of the best flowing system's around and a dynomouth is basically the same thing except with a straight through bullet muffler in place of the hollow expansion chamber "resonator."

Many have dyno'd in the 320s-330s with just lid and LM/DM.
I'm sure it's worth AT LEAST as much, if not more than our typically restrictive "crossflow" designed set-up.

Why not check out LS1tech.com or LS1.com someone had posted flow results from many popular LS1 cat-backs and from what I remember most of our crossflow set-ups flow between 340-800 cfm while the LM/DM was flowing around 2100cfm!

I noticed a considerable jump revability and mid+range push.
And it sounds VERY deep.
I converted an SLP LM into dynomouth and also use SLP's y-pipe.

 

Ahhhh a typo. Besides if all your doing is adding a bullet in place of the stock muffler it wont add all that much. That being said Ive had a LM on my car since it was 2 days old tossed the stock stuff away. Changed out the resonator with a chambered stick gives it a nicer sound. I also used stainless bands so I can change it back to the resonator in about 10 min as my mood changes

 

don't really see how a bullet muffler would really be that much more restrictive than the stock hollow Loudmouth "resonator." The bullet is pretty much a perforated straight shot, no bends, chambers, etc...
So maybe I'm giving up a hundred cfm or so that still puts the DM way ahead of the average crossflow cat-back.

 

He said he wanted to replace the STOCK muffler only with a bullet. Not a complete new system. With the stock Y-Pipe and stock tubing there wont be nearly as much flow gains overall as if he had a set of 3inch pipes and a aftermarket Y pipe.

 

Why isn't this being asked in the LT1 section? Your sig says you have a 97 unless this is for a different car. I am knowledgeable on LS1 exhaust and dynomouth but don't know anything about the LT1's since I never owned one.

On an LS1 the stock pipes are 2.75" stainless steel and mandrel press bent. The full catbacks offer 3" stainless steel mandrel press bent pipes. They do NOT include a Y-pipe. Both dynomouth and loudmouth flow 2200 cmf. The gains will be very close. I have heard 13 rwhp from a loudmouth so figure 10 or 11 on dynomouth. The mufflers are what are so restrictive not the pipes.

To reap 100% full benifits you want to get LT headers, no cats or HF cats, ORY and a catback or cutout. Dynomouth flows great, sounds awesome and is inexpensive. Nothing wrong with that.