[Real1LE]

been thinking about an exhaust. came across muffler delete. its cheap, sounds great but i feel there is more to it.

Can someone shine light on the whole "LOSS OF POWER" or "BACK PRESSURE" issue i've been reading about?

What is it? and how does it affect the car? should i just get a full exhaust instead? i know cheap isnt always a good thing

also, i track my car, its a 1LE. a guy at the shop doing a cage for the car said, it will make the car slower because of aero drag. by removing the muffler you create an opening for air which will slow the car down somehow... Confused on this topic

expert advice is appreciated guys. thank you

[Gunkk]

Muffler deletes and catbacks can make the car louder, but do nothing for performance. There is no "back-pressure issue" with the exhaust on our cars that you will fix with a muffler delete. When you are WOT, the NPP valves open and you're straight piped. See pic below.

For the track, don't bother investing in any mods other than a driver mod (a couple HPDE events with an instructor). Save your $ for tires, brakes and gas practicing what they teach you. If your tracks have sound checks, then spend your exhaust mod $$$ on laguna pipes to pass sound. Making the car louder is not what you want at Laguna and its brethren of <100 dbA-limited tracks.

re: slower w/o muffler
That cage-shop guy is talking about "parachuting," a much debated and unproven concept. Here's how the theory goes: Removing the big suitcase-muffler from our cars without modifying the diffuser makes a big hole under the back of the car. The diffuser acts as a wall at the back of this hole and becomes a parachute, preventing air from exiting from under the back of car easily. Similar to driving a pickup truck with the tailgate up (vs. down) -- also much debated and I think has been proven via testing to be bogus, FWIW.

What is more likely, however, is that this hole will result in the formation of an eddy, increasing air pressure under the back of the car, creating lift, and reducing net rear downforce. Such a thing, if it were to occur, could reduce rear wheel traction at high speeds and create an instability. Hard to tell without an instrumented wind-tunnel test, and AFAIK such a test hasn't been done.

[SJFGTO]

From a pure sound perspective, muffler deletes sound like complete ass. Your ZLE deserves a better sound than a rusty dump truck. Replace your muffler with a cat/axle back and x-pipe if you are going to modify the factory exhaust, don’t just delete the muffler and replace it with straight pipes. Regardless of what you do, remember that many tracks have decibel limits.

[Real1LE]

Originally Posted by Gunkk

Muffler deletes and catbacks can make the car louder, but do nothing for performance. There is no "back-pressure issue" with the exhaust on our cars that you will fix with a muffler delete. When you are WOT, the NPP valves open and you're straight piped. See pic below.

For the track, don't bother investing in any mods other than a driver mod (a couple HPDE events with an instructor). Save your $ for tires, brakes and gas practicing what they teach you. If your tracks have sound checks, then spend your exhaust mod $$$ on laguna pipes to pass sound. Making the car louder is not what you want at Laguna and its brethren of <100 dbA-limited tracks.

re: slower w/o muffler
That cage-shop guy is talking about "parachuting," a much debated and unproven concept. Here's how the theory goes: Removing the big suitcase-muffler from our cars without modifying the diffuser makes a big hole under the back of the car. The diffuser acts as a wall at the back of this hole and becomes a parachute, preventing air from exiting from under the back of car easily. Similar to driving a pickup truck with the tailgate up (vs. down) -- also much debated and I think has been proven via testing to be bogus, FWIW.

What is more likely, however, is that this hole will result in the formation of an eddy, increasing air pressure under the back of the car, creating lift, and reducing net rear downforce. Such a thing, if it were to occur, could reduce rear wheel traction at high speeds and create an instability. Hard to tell without an instrumented wind-tunnel test, and AFAIK such a test hasn't been done.

thank you for sharing, this is great information. i dont mind the current exhaust sound, i was curious as part of my learning process. I prefer and always prioritize spending where it enhances my driving skill and experience before anything else. I think i will likely keep the current exhaust until i have a good reason for replacing to (whatever the option might be) as i still need to learn more. Thanks agian

[Real1LE]

Originally Posted by SJFGTO

From a pure sound perspective, muffler deletes sound like complete ass. Your ZLE deserves a better sound than a rusty dump truck. Replace your muffler with a cat/axle back and x-pipe if you are going to modify the factory exhaust, don’t just delete the muffler and replace it with straight pipes. Regardless of what you do, remember that many tracks have decibel limits.

Thanks for the tips. I am not cheap when it comes to my car, far form it actually. this is why im so skeptical of a $200 mod vs $2,000 (i,e: Corsa Extreme). However, i still dont know much about them so i wont be doing anything anytime soon. as i find reasons to upgrade things i will do accordingly vs. upgrading just because....

love the signature btw

[GunMetalGrey]

Originally Posted by SJFGTO

From a pure sound perspective, muffler deletes sound like complete ass. Your ZLE deserves a better sound than a rusty dump truck. Replace your muffler with a cat/axle back and x-pipe if you are going to modify the factory exhaust, don’t just delete the muffler and replace it with straight pipes. Regardless of what you do, remember that many tracks have decibel limits.

Totally agree, I took the mufflers off for 1 day and it sounded horrible

[datboi448]

my first thought would be more about the weight balance. taking the suitcase off would make me think there would be more weight on the front reducing the rear wheel torque throughput

[TheRealJA105]

First of all a muffler delete does not sound like crap, it sounds way better than the NPP. No need to spend 2 grand on an exhaust, a muffler delete is the way to go. Just make sure where you cut the pipes that you can bolt the NPP back on if you head to a track with sound restrictions. I do think there is some aerodynamic negative, but I haven't had any issues going 158 mph at Watkins Glen or anywhere else and I am making a custom diffuser.

Datboi's comment about weight distribution is hilarious Weight reduction is a good thing and removing 20lbs from the rear doesn't negatively effect anything.

[ssmofo]

Listen to all the 5.bros when they delete the muffler, sound like complete dookie.

[Checkmate1]

Yes a muffler delete also creates a lot of drone (and not the pleasant kind).

Simply do a Secondary Cat Delete and leave the rest stock.

[SSallday]

From my perspective, the muffler delete sounds good. It produces drone but I can live with that. Here's mine:

[GunMetalGrey]

Originally Posted by Checkmate1

Yes a muffler delete also creates a lot of drone (and not the pleasant kind).

Simply do a Secondary Cat Delete and leave the rest stock.

That's right, tons of drone! I forgot to mention that.

It also seems to create a lot more vibrations, things were shaking and rattling that never shaked or rattled before.

I have a loud 105db Borla Atak, so I'm not afraid of a loud system, but with no muffler it sounded so cheap and so bad.

[Real1LE]

Originally Posted by SSallday

From my perspective, the muffler delete sounds good. It produces drone but I can live with that. Here's mine:

thanks for sharing

[TheRealJA105]

I think some of you guys need your ears calibrated to sound not $$$$$$$. Not sure I've ever heard a street car that sounded better than my buddies muffler and resonator deleted 5.bro and some loud ass GT350 I've seen around town a few times.