Slp loudmouth

**wanna_lS1** · 07-07-2010, 09:15 AM

So I love that the loudmouth is loud but I don't like how it sounds like it's flowing too fast during idle. How can i change that so it doesn't sound like this and also what can i do to keep some back pressure?

**derbs** · 07-07-2010, 05:16 PM

WTF do you mean????? the loudmouth 1 sounds bad ass. If you don't like it get a magnaflow catback or replace them with LM 2's.

**wanna_lS1** · 07-07-2010, 05:35 PM

My main concern is the back pressure i don't wanna lose a lot of low end torque

**derbs** · 07-07-2010, 06:46 PM

guess I'd have no idea because I'm running my LM1 with lt's.

**cammed goat** · 07-08-2010, 03:23 PM

Running LM1 catback and love it. Getting catted LTs in the future.

**ne0fiend** · 07-08-2010, 04:10 PM

I'll play the devil's advocate here -
In 2005 the only performance exhaust available for the 04-M6 was either Flowmaster (around $1,500) or SpinTech ($90 a can).
I opted for the SpinTech with a true-dual style build.
I deleted the resonators, and both cats and did away with all intention of running an off-road pipe. The back pressure I lost with the SpinTech build was negligible and I reduced stock exhaust manifold temperature by 15%; cooler exhaust, cooler engine bay, cooler air feed and we all know cooler air = a denser fuel:air mix = more horse power.

If you are worried about the back pressure, but want to stick with the SLP setup, I suggest adding an H-pipe/off-road pipe. That will restrict the output a little and slow down the exhaust flow.
Of course another option is to use a 2 1/4 exhaust pipe and have the muffler shop bend a transition/taper into the pipe just after the header/manifold flange. This restricts and slows down flow.

Hope that helps.

**wanna_lS1** · 07-09-2010, 01:59 PM

But I run the loudmouth 1 with LT's won't it get raspy?

**cammed goat** · 07-09-2010, 04:08 PM

I have heard catless LTs will be raspy with the LM-1.

**derbs** · 07-09-2010, 08:44 PM

I like the sound of mine with the yank pro thruster 4k the car doesn't sound like I'm running coffee cans like some cars I've heard.. Tomorrow I'll be taking a nice road trip and maybe I can get a vid of how it sounds for you guys.