Originally Posted by jangy

Actually, the E55 has a connection pipe just after the cats.

I have tried all three setups on my cars ('05 and '06 E55). The x pipe helping droning is absolutely true, except that I like to hear the two banks independently. As far as for performance, no way. Straight pipes give it WAAAY more gut. Keep in mind that I kept the stock exhaust system. If you put on a system that has too little back pressure, then an X pipe to make turbulence would help. But, if you have a truly tuned system no way that an X or H pipe will ADD. As I say, i have tried it in real life, but I don't even get the theory behind why the X or H could add power??

Originally Posted by Fast55

So, you also had a droning probelm with BOTH E's?? I *****ed to MB and was told it's "normal". Right at 2200 RPM which equals 72 MPH, it drives me nuts. The X pipe changed the drone to what RPM??

Originally Posted by Vadim @ MBLN

Sorry Gentlemen, but there is no debate.

Either X or H will make the same power and very similar sound effects.

With stock or even shorty headers, stock catalytic converters will dampen a significant amount of power and sound.

I do not want to make it sound like been there done that, but I have.

When one goes to full length headers with bigger cams, than X pipe will make a difference.

Untill then, please lets not compare AMG V8 with NASCAR V8s. The only similirality is the V8.

Originally Posted by jangy

I wouldn't call the drone a problem. I like it. But, I did notice it go away with the X setup. I did not notice it move. I only kept the car that way for about 500 miles and went on over to straight pipes that I kept. I started with an H, by the way.

Originally Posted by Fast55

I like the sound of the exhaust, especially compared with the very quiet 2002 E55, but the drone is right at my usual cruising speed and it sucks. MB will do nothing, so a low cost mod like this is perfect for me, thanks.

Originally Posted by jangy

Actually, the E55 has a connection pipe just after the cats.

I have tried all three setups on my cars ('05 and '06 E55). The x pipe helping droning is absolutely true, except that I like to hear the two banks independently. As far as for performance, no way. Straight pipes give it WAAAY more gut. Keep in mind that I kept the stock exhaust system. If you put on a system that has too little back pressure, then an X pipe to make turbulence would help. But, if you have a truly tuned system no way that an X or H pipe will ADD. As I say, i have tried it in real life, but I don't even get the theory behind why the X or H could add power??

Originally Posted by ProjectC55

Here's a good read on why I think the x-pipe is better:
http://www.carcraft.com/techarticles..._installation/

http://www.carcraft.com/techarticles.../photo_10.html

Good pics and HP #'s



H-Pipe, X-Pipe, 1, 2, 3...
An Exhaust System Based On A Universal X-Pipe Crossover And A Pair Of Stainless Steel Street Series Mufflers

By Matthew King
Photography: Matthew King



Do you really need an exhaust system on your car? That’s a good question. If you have neighbors, drive it on public streets anywhere there are cops, or race it on virtually any NHRA track in the country, the answer is probably yes. Will it cost you power compared to open headers? Although that answer is also frequently yes, it can be no with the right system.
We’ve been running open headers on our ’86 Mustang project car since day one because it was the easiest thing to do and it seemed cool. It was also brutally loud, but it did pass muster at our local track because Los Angeles County Raceway doesn’t enforce a 95-decibel rule or require mufflers like many “street-legal” drag programs do. However, we always wondered if the open headers were costing us a little low-end torque due to a lack of backpressure. To find the answer, we took the car to Magnaflow Performance Exhaust’s research and development center. After discussing our combination and the way the car is used (100 percent at the track), Magnaflow built a system based on its universal X-pipe crossover and a pair of its stainless steel street series mufflers.

For any performance exhaust system, some type of crossover connecting the two sides of a dual exhaust system is important because it acts to balance the two banks of the engine. The common H-style crossover is good at balancing sound pulses between the two halves, but does little to promote scavenging because the exhaust gases tend to follow the path of least resistance, which is straight through each pipe rather than taking the 90-degree turn through the H-pipe into the other half of the system. In an X-pipe system, however, where the two sides of the system intersect, the gasses have no choice but to intermingle as they pass through the junction. This promotes improved scavenging effects by smoothing out uneven exhaust pulses from the engine’s firing order. It also helps quiet down the exhaust, resulting in a mellower, less raspy tone. According to Magnaflow, the faster acceleration of the gasses through an X-pipe causes them to flow in a linear fashion parallel to the walls of the tubing rather than tumbling. This “laminar” flowing gas is much quieter than tumbling gas, resulting in an exhaust tone up to 8 decibels quieter than a traditional H-pipe.

We left the car at Magnaflow for about a week, and when we came back we found that after some preliminary testing, the guys had built a really trick system consisting of 2-½-inch tubing from the header collectors into the X-pipe, 3-inch out of the X flaring into 3½-inch tubing running for about 26 inches before necking back down into a pair of 3-inch mufflers with turn-downs. The theory behind this design is that it will keep the velocity of the exhaust gases moving quickly through the headers into the X-pipe to maximize the scavenging effect, while the larger-diameter tubing ahead of the mufflers prevents the gasses from stacking up as they pass through the mufflers to avoid excessive backpressure in the system.

Sounds good, but would it work? To find out, we tested three exhaust-system configurations on Magnaflow’s in-house Dynojet. For a baseline, we ran the car with open headers and saw 333 hp at 6,300 rpm and 304 lb-ft of torque at 5,200 at the rear wheels. Next, we ran a 2-½-inch bolt-together system consisting of a BBK short off-road H-pipe designed to fit the company’s full-length headers connected to a set of race-type 2-½-inch welded mufflers with turndowns. Our Mustang’s carbureted 302 didn’t like this combo, as power fell to 323 hp at 6,300 rpm and 295 lb-ft of torque at 5,200. The increased backpressure also richened up the air/fuel mixture by about two carburetor jet sizes.

Finally, we swapped on the stepped X-pipe setup and were impressed to see power levels equal to the open headers: 335 hp at 6,300 hp and 302 lb-ft at 5,200. That’s a gain of 12 rear-wheel horsepower, although it turns out we weren’t really giving anything up or gaining anything extra from the open headers. So the car’s happy, and our ears are even happier!

Originally Posted by mfissel

I realize this is an old thread, but I'm wondering if there as been a conclusion about exhaust drone reduction? I recently installed Supersprint mufflers which sound awesome and throaty but have increased drone at <2K RPM on partial load. Will replacing resonator with an x-pipe reduce this? Doesn't the design of the stok resonator which is 2 straight through perforated pipes act like an x-pipe anyway?

Mark

Originally Posted by OmeyHomey

it does not on a W210, only on W211s

Originally Posted by jangy

So, you reposted for your own clarification?

Originally Posted by Vic55

Since directly above this thread is another about the exact same topic I will merge them together ...

Originally Posted by E55 RUSS

So anyone actually installed X-pipe of E55 ???

Originally Posted by E55 RUSS

Hey...is that VRUS exhaust system ???

What is th diameter of those pipes ???

What where the gains and did you dyno the car before and after ???

and a Sound Clip would be nice

Originally Posted by mfissel

I realize this is an old thread, but I'm wondering if there as been a conclusion about exhaust drone reduction? I recently installed Supersprint mufflers which sound awesome and throaty but have increased drone at <2K RPM on partial load. Will replacing resonator with an x-pipe reduce this? Doesn't the design of the stok resonator which is 2 straight through perforated pipes act like an x-pipe anyway?

Mark

Originally Posted by Ajai Thomas

what's the best or most efficient placement for the "X" in an X-pipe to maximize power on a 2006 SL55 AMG? is it where the cats use to be? further back, or where?
ANyone?