Final exhaust adjustment

[mpyle007]

I have the GMPP axle back with newly installed headers, high flow cats, and stock h-pipe on L99. I was told to keep factory center because it doesn't restrict air flow. Car sounds good but not great. Since nothing else exhaust related will do anything for power, will swapping out just mufflers give it a better sound? I want a deeper yet louder sound from the tail pipes.

Opinions?

I was thinking cut out GMPP mufflers and weld in some new mufflers? Ideas?

[Frid]

Borla S type is a good one. I'm going to be running ARH mufflers thought.

[geaux_tigerss]

The L99 has a HUGE (http://www.camaro5.com/forums/showthread.php?t=59704) resonated center that not only deadens sound volume bud adds considerable weight to the car. Since you're tuned and don't need to worry about AFM I would replace that mid section. The only risk is that you may get some drone out of your current axle back. It is the equivalent of the Borla touring which has a droney reputation when paired with headers.

[mpyle007]

So if I replace this mid-section what will it do to the sound you think?

[geaux_tigerss]

Make it louder inside the car and out. Some borla guys will have to weigh in on drone level vs. rpms.

[mpyle007]

I shouldn't get any drone since I have AFm tuned out right ?

[The Stig]

Originally Posted by mpyle007

I shouldn't get any drone since I have AFm tuned out right ?

Drone isn't from AFM (though AFM does make a pretty annoying sound), it's from the vibration of the exhaust. Example, I have drone around 1800 RPMs. I have Bassani's exhaust.

[geaux_tigerss]

Drone and AFM aren't the same thing. Drone is a resonant frequency that occurs in certain rpm ranges on certain exhaust setups. It's hard to explain if you haven't heard it. For example, I used to have a civic with really loud exhaust. At certain rpms you couldn't talk on the phone, hold a conversation, the noise almost made my teeth rattle. Some exhausts do this, some don't.

[mike.nite]

I have a similar setup:

- L99
- GMPP
- Kooks 1 7/8 LTs
- Highflow Cats


And it realy is just slightly louder than stock (but way more definded). If I ever want to change the sound I'll just remove the resonator.

A friend with a bone stock L99 just removed his resonator and now his stock exhaust sounds meaner than my GMPP!

As for the drone - I only had drone in 4Cyl mode. Since I have tuned out AFM I never had any drone with my setup.

[mpyle007]

This is awesome. Thank you for the feedback. So it sounds like removing the mid section will wake it up more. Now the question, is there anything out there x-pipe wise that will connect my gmpp axle back to my texas speed long tube headers with high flow cats?

Once I go that route if it isnt loud enough i will have to go a different route on the mufflers.

[geaux_tigerss]

Originally Posted by mpyle007

This is awesome. Thank you for the feedback. So it sounds like removing the mid section will wake it up more. Now the question, is there anything out there x-pipe wise that will connect my gmpp axle back to my texas speed long tube headers with high flow cats?

Once I go that route if it isnt loud enough i will have to go a different route on the mufflers.

There are aftermarket x-pipes (for an example: http://www.jegs.com/p/JEGS-Performan...40216/10002/-1) available that you can get welded in line at any local shop. Check this thread out: http://www.camaro5.com/forums/showthread.php?t=82786

As an alternative, you could buy a catback and sell your GMPP mufflers.

[mike.nite]

I'd do it step by step.

You can just delete the resonator and temorarly use straight pipes with clamps. If you like what you hear you can either weld in straight pipes or a resonated X-pipe (if you want to tame the sound just a lil bit).

Either way: A before- and after videoclip is a must!

[S-eatin-grin]

My car is actually very loud with all my mods and the drone is BAD. I am considering switching to GMPP. Is it really a drone free axle back? Can't seem to find anyone with headers and LS3 with GMPP

[The 2010 Sin]

How deep do you want to go?