So apparently muffler bypass pipes are really loud!

I installed some muffler bypass pipes on my C4S on Saturday. I thought everyone was being a bunch of pansies about how loud they are. I thought "I've had straight piped VR6s and an STi with a 3.5" catless, how loud could it really be?" Boy was I wrong! I live in a pretty thickly settled development and I have to tip toe around which sucks. However on the back roads where I can pretend it's a cup car, it's siiiiiiicckkk! Above 4k rpm it really comes into it's own, rev matches Oh. My. God. But I am probably going to have my stock mufflers Fister modded, like this week. Also, for the record, these DO NOT fit on C4S's I had to cut them substantially shorter and reuse the stock clamps to make them work. Just food for thought for anyone else with a C4S.

I'm all for louder exhaust, but driving around with straight pipes is just insane. I can't even imagine spending an hour on the freeway with that setup. I nearly lost my mind driving the two blocks from home to the muffler shop after installing long-tube headers on my Corvette. I think my neighbors would toss a molotov cocktail into my garage if I installed muffler bypass pipes on the 911...

I started it up when I had my mufflers off; it sounds really cool but no way would I want that for more than the first 3 minutes.

I'll be installing mine soon. Have a supercharged 928 with straight pipes (no converters) so I'm used to loud. I'm looking forward to making the 996 sound like the World is coming to an end too.

Haha! That's pretty much what it sounds like. It does sound like a cup car so I guess it accomplishes that.

if you dont press on the throttle at all, it is almost ok but then you will have to drive slower than slow. As soon as you are on the gas, it is ridiculous indeed. Even on the track it sucks because you can't even hear the engine, it is all exhaust noise. Only plus really is the weight saving, that's about it.

The Fister mod is an excellent choice.

I have a friend that is a fabrication wiz. Hopefully I can get my stock cans modded for a reasonable price

I had bypass pipes on my car for a few days and I couldn't handle it, it was way too damn loud. And I like loud exhaust. I would literally get a headache if I drove on the freeway for more than 15 minutes or so, the drone around 3000 RPM was awful.

I've had mine on with stock cats for at least a year now...I ask my neighbors if it bothers them when I leave for work at 5am and their answer is always, "no, I love the way it sounds!" Which even I find surprising. Yes, it is super-loud when it first starts and the cats are warming up. After that it really is not that loud. Anyone who rides in the car or who has heard it actually on the throttle always tells me how much they love it. For scientific purposes, it was clocked at 99.7db around 35feet at an autocross...that's on full throttle of course.

I get this impression that it's louder in the car than from outside. My coworkers and friends tell me it sounds good. For me its mostly that 3k rpm drone that kills it

Its not the converters warming up that quiets it down a bit but the ECU comes outnof "cold mode" and the engine leans out a bit. Sort of like taking the choke off a carbureted engine.

I've had mine on for about a year and absolutely love them... I soft shoe it around the neighborhood and cops just to be cautious, but those are the times I should not be flying anyway. I find no terrible highway drone that others complain of. My Passenger seat does vibrate a lot more than when those heavy "counterweight" mufflers were attached... my wife does not complain Everyone who sees my car loves it, but when they finally hear the exhaust they lust after it... I feel the same way. I love being able to actually hear my engine for rev match downshifts... just like my bikes. I like the fact my stock mufflers are still stock and I can put them back on in under an hour if I want to get back to OE. To each their own! But for less than $300 (I think I paid $155 shipped) and some easy labor, it makes for a fun and meaningful performance upgrade.

Just removed my cats and muffler after a Limerock DE and back to my race exhaust on my track 2001 996, it sounds awesome, just like a cup car! I may never go back to Limerock again! Not sure on the drone as always wearing a helmet in it and have no interior carpeting anyway. They could sell this noise...oh wait...how much have I spent on this car again...;-)

I've had my FAbspeed bypass pipes for 2 weeks. Will never go back. This is how a 911 should sound!

As I told numerous people asking about this mod, muffler bypass is stupid loud. If you daily drive the car and put 1,500+ miles per month on the car this mod is absolutely intolerable. If the car is your weekend toy and you drive it for fun few times a week, then this mod is a blast.

I have a set for sale in the classified section if anyone is interested https://rennlist.com/forums/parts-ma...l#post11316615

Quotes source post: 11314262

mine was 98db at 50 ft. tried switching the exhaust just for autox, but got tired of doing that for events and ended up using it as a DD exhaust intermittently it can get tiresome as a DD, but sounds awesome with every downshift or acceleration. has anyone tried the NHP bypass pipes? looking for another cheap but light alternative that might be a little easier to live with http://www.maxspeed-motorsports.com/...ass_Pipes.html

Quotes source post: 11317049

I have these and will be putting them on soon again. I had them off temporarily for emissions. Basically a very minor loss in low end to gain a good deal of mid-high end power/torque. The sound of exhaust will increase and if you have aftermarket exhaust, it can lean more towards the raspy/unrefined(hard to explain) side when you get on it. I'll have to shoot a video this time around.

It's clearly a personal choice. Mine is not a DD, so I love them. Great weather + top down + bypass pipes = heaven. (ok, + stripper in passenger seat)

Quotes source post: 11317335

Do you have the NHP cat bypass pipes or muffler bypass pipes in my link above? If you have the nhp muffler bypass pipes, id be interested in meeting up with you to see how they sound.

Sorry, I thought you meant cat bypass.

since balefire brought up the fact that there are a few different brands like fabspeed and the NHP ones, it's worth mentioning that mine are the variety that hollmatt is selling and they look/fit good although I reused the stock exhaust clamps. I don't know what brand they are; I bought mine used on ebay.

It's definitely the exhaust of choice if you like to announce your presence from afar! I had them on my cab and it was way too loud for my taste with the top down. Had to feather the throttle around town for fear of being shot or stopped by a cop. I went with the Mk1 PSE and it is purrrrfect now. Amazing what a little tube can do to change the acoustics. Here's a pic right before the Tequipment tips were installed.

Put mine on yesterday. It is LOUD but I like it. While the engine is in cold mode it is extremly loud but it quiets down to civilized levels when warm.