bringtherain

so i finished getting my xpipe installed and planned on getting a muffler delete as well as quad tips finished today. However, my dad brought a pickup trunk to the same shop yesterday to get the cat back fixed. He chatted with the owner who told him that muffler deletes and xpipes are bad specifically for bmw's and mercedes. I don't see how it could as most of what those things do are regulating outflow of air and noise suppression. So long as air is coming out it should be fine shouldnt it? I still wanna go through with my setup but now my dad insists for me not to get a muffler delete. any inputs to set aside his worries?

snarlingchicken

Well, I wouldn't say it's bad for your car, but I wouldn't necessarily call it good either. I think the drone would be pretty bad unless you have several layers of sound-deadening/anti-vibration material. And sure, with the mufflers you get more airflow, but as a result, you lose back-pressure, meaning you'll lose low-end torque. The M272, along with a good amount of other euro cars, are known for their low-end torque that enables the car to get to speed quickly. Without that backpressure/torque, your car will just be making a lot of noise while not really getting anywhere as quickly :3

(Just what I've learned from being on these forums though. If anyone else has anything else to offer, or would like to correct me for something that I may have gotten wrong, feel free to chime in.)

Also, I believe the lack of backpressure does give you HP in the high-end, but honestly, how often are you gonna be driving at 5k-7k RPMs? You'd be attracting a bit too much attention without mufflers.

jctevere

The myth about burning valves because of straight pipes (no muffler) is because cold air can be sucked into the combustion chamber when you shut the motor down, causing the valves to warp or bend.

Now, this is entirely true... 30+ years ago with leaded fuels and non-hardened exhaust seats. You needed the back pressure back then so lead would be able to coat the valve seats.. With today's engines and modern engineering with the cast iron manifolds and cats in place, that is not going to happen. Futhermore, since leaded fuels haven't been used in the States in a while, you have no problem!

I guess you can chalk this up to "not being able to teach an old dog new tricks".

As far as backpressure and decreased power goes:

Exhaust manifolds are usually pretty restrictive to the flow of exhaust gas, and thus waste a lot of power because your pistons have to push on the exhaust gasses pretty hard to get them out. So why does virtually every new automobile sold have exhaust manifolds? Because they are cheap to produce, and easy to install. The performance alternative to the exhaust manifold is a header. Where a manifold usually has several holes converging into a common chamber to route all your gasses, a header has precisely formed tubes that curve gently to join your exhaust ports to your exhaust pipe. Exhaust gasses must be treated gently for maximum horsepower production.

Again, you may hear a few people tell you that "Borla mufflers make horsepower!" Or "An engine needs some backpressure to run properly!" Nonsense. A muffler can no more "make" horsepower than Wile E. Coyote can catch roadrunners. Any technician with any dyno experience will tell you that the best mufflers are no mufflers at all!

To gain a more complete understanding of how mufflers and headers do their job, we must be familiar with the dynamics of the exhaust pulse itself. Exhaust gas does not come out of the engine in one continuous stream. Since exhaust valves open and close, exhaust gas will flow, then stop, and then flow again as the exhaust valve opens. The more cylinders you have, the closer together these pulses run.
Keep in mind that for a "pulse" to move, the leading edge must be of a higher pressure than the surrounding atmosphere. The "body" of a pulse is very close to ambient pressure, and the tail end of the pulse is lower than ambient. It is so low, in fact, that it is almost a complete vacuum! The pressure differential is what keeps a pulse moving.

Just as Paula Abdul will tell you that opposites attract, the low pressure tail end of an exhaust pulse will most definitely attract the high-pressure bow of the following pulse, effectively "sucking" it along. As long as you don't just HACK off the mufflers and resonators and not replace it with anything, and replace it with a straight pipe, it can only help you out. By adding in an x-pipe (you accelerate the exhaust gases as they hit eachother out of the tailpipe, and the straightpipe provides less backpressure to allow it to flow out faster (but it doesn't sound nearly as good).

Bottom line: Your not doing any harm, your actually making your car more efficient, keep it up!

Mixedfruits

all I can offer is not technical specs but my opinion of this mod .... I had them off for around 6 months now half a year, no cel or anything, down the road I heard it can dry you head..... of the car not yours out. But other than that yeah make alot of noise but go no where, the sound gets time to get used to now I think my cars too quite... but just becasue my ears are a customed to them.

wnunez89

get magnaflow mufflers (around $60ish each) and run quads from that, that way you lose no back pressure.

bringtherain

got everything finished up today and its so freakin loud... and my tips are crooked so im gonna have to go back and have the guy fix it. Would the magnaflow muffs reduce the noise a bit or should i just install 2 12inch resonators in the straight pipe?

jimmythegreek

It will get a little bit quieter, but will still be loud. Its the drone thats bad, not so much the sound it puts out. If you get the smallest magnaflows it will end up being halfway between stock and what u have now, thats what I kinda did w my setup when I had them

wnunez89

the magnaflows will reduce the noise and drone but it will still have the deep tone.

Benz-o-matic

Yo jimmy, im in NNJ and im lookin for a good exhaust or speed shop that wont take me for a ride when it comes to xpipe + res and muffler delete. You got any suggestions? Anyone else in the NNJ area feel free to chime in. I gotta guy but he does body only

bringtherain

what if i were to put back on my resonator? would it eliminate the drone?

snarlingchicken

The resonator might help a little bit, but most of the drone and vibrations will still be there as a result of you not having any mufflers. I would spend the money you would be using on re-welding the resonator in on some sound deadening material if I were you.

burnteggroll

x-pipe and add in the exhaust tips. You don't have to delete the muffler. save a little gas.

Mixedfruits

I get average of 15-16 mpg with semi agressive in city with this set up what do stock c300s get? burnt just wondering if I drive normal around 17

bringtherain

what kinda materials?

already done. at this point im just gonna put my mufflers back on. the sound outside is fantastic but inside the cabin its terrible.

snarlingchicken

Either second skin sound dampening or dynamat.

bringtherain

I was wondering about dynamat. would I just lay it down in my trunk or would I have to do the entire floor of the car?

Sportstick

https://mbworld.org/forums/c-class-w...d-you-use.html

Take a look at this thread, and the solution I tried in post #14. You might want to try this first and gauge the results.

jctevere

WTF... I would check your tires for proper air inflation and some other crap, that is just terrible. I can drive my car around the city FULL out aggressively (red light racing full WOT at EVERY stop light, and still not get 15mpg. The lowest I have gotten in 17mpg. And when I drive "normally" I get about 20mpg city. On the highway I mainly use cruise control and get like 28-30mpg, but when I drive with my light foot I get about 25-27mpg. And I have a c300 4matic...

jimmythegreek

I do most of my own work, I did my magnaflows and then I changed to meisterschafts, wasnt too hard to do. I do know that alot of meineke's have pipe benders, u need one if your doing muffler delete. I personally think U should try resonator delete or X pipe first, I couldnt take the drone when I did straight pipes even w mufflers, just too loud inside car. I did a smaller resonator, and meisterschafts and its perfect, sounds awesome. I have the meisterschaft straight pipes (kinda like X pipe but doesnt cross over) thats bolt on, easy to do and gives u some nice growl, but it does drone a little. The resonator is the biggest recuction in noise, if you remove it the drone is loud.

Benz-o-matic

Thanks for responding man. Theres no TIG welding or welding needed to install the xpipe? idk it was bolted together. Is it clamps?

bringtherain

saw that as well as read through the entire thread. how much of an improvement did you get? The two things that annoy me right now are the drone and the vibration. I have 3 obvious routes right now.

1. be a ***** and throw back on my mufflers

2. add 2 resonators from the xpipe to my tips for noise reduction (i dont know if this will help vibration however)

3. dynamat and luxury liner my trunk (fixes both but dont know to what degree)

optional 4th - Do 2 and 3

I honestly miss that silence I had when it was all stock. now it sucks cus my exhaust is all hacked up. I do love listening to it from the outside though, not too loud to make it obnoxious.

itsLoonie

I'd say do option 3 and if you don't feel the drone and vibration is gone then you can go ahead and do option 2 and put the resonators.

wnunez89

welding is required

Sportstick

I got a significant improvement vs. the stock exhaust. Both exhaust and road noise were reduced, as the plastic spare tire well had been acting as an amplifier. Of course, now I am quite used to it, but I recall my first response as being very pleased. It is the easiest first step to your concern.

bringtherain

btw wnunez do you have a video of the magnaflow muffler setup?