X-pipe vs H-pipe vs Straight pipe

[E55 RUSS]

Which combination is better for E55 Kompressor motors that is the question and WHY ??? Many people when removed their middle resonators have said the Straight (by pass pipes) or H pipes are better for S/C cars...as they hold togues better... Other have said that X pipe provides bettter and equal follow in the exhaust system which makes better sound and more power... Looking at Supersprint system its seems that they are using 70 mm X pipe design on SL55 cars...and 60 mm which I think is X pipe with muffler on E55 as well... So does that mean that X- pipe will works better on E55 Kompressor engine as well... cuase Supersprint does lots of R&D and know what they are doing... Look at the pics guys and comment please... May be someone "Experinced" people from Evosport and Kleemann or elsewhere can comment as well...

To remove this ad, register today or login if you already are registered!

[AMG-fanatic]

This should be an interesting debate.. I'm no expert but here's my reply:

My local custom tuner said that the best sound/power would be achieved by removing the bottleneck at the front caused by the 4 catalytic converters (2 each side) and replacing them with straight flow pipes.. He said that the centre resonator is not the biggest problem, the restriction occurs at the start from the manifold to the centre resonator)

Personally I wouldn't recommend this because

(i) The car would be street-illegal and when you come to renew your registration you'll need to pass the test (at least in my country) and they WILL find out that you have removed your cats so the car would legally be banned form being registered until you re-fit the cats!

(ii) This would also trigger the "check engine" indicator on your dashboard since there are sensors hooked up to your cats and removing them triggers this error.

(iii) The exhaust sound might resonate and start getting a bit on the "getto" side for my taste..

Having said that, I know a few friends who are quite happy with this configuration. If you find the exhaust sound too loud for you but the OEM being too tame, you can always install an exhaust insert (typically Cone style) to the straight flow pipes. This gets rid off the resonating sound.

Here's a link on how to install it (although it's not a benz, the idea is basically the same). In the link they actually remove the muffler not the cats but you get the idea:

http://www.cadillacfaq.com/faq/answe...nes/index.html

This is my two-cents worth, hope it helps you

[benzmodz]

Originally Posted by AMG-fanatic

This should be an interesting debate.. I'm no expert but here's my reply:

My local custom tuner said that the best sound/power would be achieved by removing the bottleneck at the front caused by the 4 catalytic converters (2 each side) and replacing them with straight flow pipes.. He said that the centre resonator is not the biggest problem, the restriction occurs at the start from the manifold to the centre resonator)

Personally I wouldn't recommend this because

(i) The car would be street-illegal and when you come to renew your registration you'll need to pass the test (at least in my country) and they WILL find out that you have removed your cats so the car would legally be banned form being registered until you re-fit the cats!

(ii) This would also trigger the "check engine" indicator on your dashboard since there are sensors hooked up to your cats and removing them triggers this error.

(iii) The exhaust sound might resonate and start getting a bit on the "getto" side for my taste..

Having said that, I know a few friends who are quite happy with this configuration. If you find the exhaust sound too loud for you but the OEM being too tame, you can always install an exhaust insert (typically Cone style) to the straight flow pipes. This gets rid off the resonating sound.

Here's a link on how to install it (although it's not a benz, the idea is basically the same). In the link they actually remove the muffler not the cats but you get the idea:

http://www.cadillacfaq.com/faq/answe...nes/index.html

This is my two-cents worth, hope it helps you

The error message can be switched off with the right coding of the engine module.

[E55 RUSS]

The main question is ...What is better to USE to replace Resonators X-pipe or Straight Pipes ???

You dont want to loose too much pressure with custom made exhaust on E55K...The reason for this, it will cause the drop in S/C boost...

Kleemann Germany told ME (they actually design Kleemann system for SL55 and E55)...That with their Free flowing 70mm exhaust system the pressure drops from 0.9 to 0.7...and they use ECU and pullies to bring this boost back...and this combo makes more power...

Also been told that by Kleemann DK that fully freeflowing Kleemann exhausts without any CATs doesnt make more power and actually looses Togues, then Kleemann exhaust with CATS...

SO... if we make fully custom exhaust and dont have ECU for it, the S/C pressure will drop and there POWER (especially TOGUES) is most likely to fall...


The Q remains X or Straight for E55 ???

[AMG-fanatic]

Originally Posted by benzmodz
The error message can be switched off with the right coding of the engine module.

You are right it could be switched off but as far as I know they simply de-activate it for good..This means that in the case of a real disaster in the engine you wouldn't have a clue until you literally see the smoke coming out of the hood!!

I don't think it's possible to avoid the "missing" cats from triggering the error message.. You can simply switch it off completely for your own convenience, nothing more, nothing less..

and going back to M5-RUS's point:

I think that X pipes are a little louder overall, but the H pipe is much deeper and lower pitched.

Here's a quote from an article which might best answer your question:

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...

Hope this answers your question

[Akara1]

I'll add my .02 to the pressure side of it. Heres what i've learned:

With a free flowing exhaust, a drop in S/C pressure is not a bad thing. Pressure is only created by the engines inability to flow a given volume of air through it. You'r boost psi may be lower with a free flow exhaust, but thats not important, because the volume of flow through the engine has increased. Also dont forget that pressure causes heat. On my Evo, stock boost was set at 19 psi. With an itnake, exhaust, intercooler, boost colntroller and tuning, the car was making 50-60 more awhp on only 17 psi of boost. Lower boost means the engine is operating more efficiently, not that its making less power.

[BlownV8]

With a free flowing exhaust, a drop in S/C pressure is not a bad thing. Pressure is only created by the engines inability to flow a given volume of air through it. You'r boost psi may be lower with a free flow exhaust, but thats not important, because the volume of flow through the engine has increased. Also dont forget that pressure causes heat. On my Evo, stock boost was set at 19 psi. With an itnake, exhaust, intercooler, boost colntroller and tuning, the car was making 50-60 more awhp on only 17 psi of boost. Lower boost means the engine is operating more efficiently, not that its making less power.

You beat me to the punch! Yes, boost is a measure of backpressure in the intake. If the boost drops from modifying the exhaust in a supercharged engine, that means the exhaust was a source of excess backpressure. The resulting decrease in measured boost pressure will actually equate to greater performance gains.

Remember, an engine is an air pump. The more air in and the more air out the greater the power. You just have to keep in mind that the exhaust velocity must be kept as high as possible witout experiencing too much resistance in flow. Pipes that are too big will slow the velocity and pipes that are too small will restrict the flow.

An x pipe is usually better for normally aspirated engines while an H pipe is better for supercharged engines. The supersprint looks to me more of a semi-X pipe design than most I've seen. Kind of a 2 into 1 back into two. You want equilization of exhaust pressure between cylinder banks but, IMHO, you don't need the air to collide like that in a forced induction motor to have the best results. I like the sound of an X-pipe more than the sound of an H pipe system. I guess it comes down to personal preference of the sound because the power difference will not be that great in a forced induction engine.

[E55 RUSS]

If H pipe is better then X pipe forom S/C cars like E55 then why does SS using X-pipe ???

I want to find out the truth...

Here is 2 options that I am considering:

1. Remove from CATS which I heard most resistant ones and make same diameter pipes to Secondary CATS or make an X pipe instead of straight pipe...

2. Replace resonators with X-pipe or Straight pipe instaed and remove Secondary CATS...

Should I make same diamter Straight pipes or X-pipe as stock ot bigger like 3 inch (70mm)...dont what to loose togues...

[CA_E55]

These kinds of debate are always stimulating, albeit, anybody thinking that with a floor jack and a set of wrenches he can outsmart the tuners is just kidding himself big time if he expects to increase his engines output beyond SOTP measures - but it does help to increase the GDP, although even that is debatable as a muffler wasted sitting in a garage corner cant be that good for the real economy, either.

[BlownV8]

If H pipe is better then X pipe forom S/C cars like E55 then why does SS using X-pipe ???

X-pipe tends to help eliminate drone and sounds better on acceleration.

[Luna.]

We had a similar discussion related to this on the Caddy boards...

I don't believe that there is a significant difference between an X-pipe or an H-pipe. A dyno comparison between the two was posted on the Caddy boards and both had certain advantages at certain RPMs, resulting in negligible performance gains overall for either system.

And I don't necessarily agree that an H-pipe increases drone---my exhaust has an H-pipe and it has no significant drone at any RPM, while some other V-owners have X-pipes and they drone like mad. That doesn't necessarily mean much, but it does suggest that there is much more to drone than just an X or H pipe.

[BlownV8]

Hot Rod magazine tested the X-pipe vs the H-pipe on an Lt-1 engine. Here is the result:

[E55 RUSS]

So H pipe (straight pipe) makes more HP or Torgues at wider ranges then X pipe...X-pipe make more on Top...but SC cars are diff or not...

[GTA23109a]

Those numbers (X vs H) will vary for every different motor. Hell, they can even vary on the SAME motor depending on whether it's using an exhaust manifold or header, collector length of the header, etc. I even had a guy I race with tell me thay they dyno'd their motor with and without an exhaust crossover (I think they were using an h-pipe ) and even though the motor made more power on the dyno with the h-pipe, the car consistently ran 2-3mph faster at the end of the main straight at their home track and was .3-.4 of a second faster with NO crossover of any kind!! I have no idea how or why this would be the case, but it just shows that dynos don't always simulate real life and there's a lot more to the physics of exhaust flow than we can figure out here.

[E55 RUSS]

Still no explanation... X pipe or H pipe on E55 ...which s best solution ??? why does SS makes X pipe and other tuner tend to use H (straight pipe)..

[BMWEATR]

Originally Posted by M5 RUS

Still no explanation... X pipe or H pipe on E55 ...which s best solution ??? why does SS makes X pipe and other tuner tend to use H (straight pipe)..

call them and ask.

[GTA23109a]

Originally Posted by M5 RUS

Still no explanation... X pipe or H pipe on E55 ...which s best solution ???

I hate to say it, but unless you try both and dyno / track-test both, I don't think you're going to ever know for sure. Even if you DO try both, it's entirely possible that there will be no substantial difference between the two. Sorry.

[rrrruBENZ///E55]

Originally Posted by M5 RUS

Still no explanation... X pipe or H pipe on E55 ...which s best solution ??? why does SS makes X pipe and other tuner tend to use H (straight pipe)..

To flat out answer your question, the answer is neither. The differences in exhaust output (power and flow) are miniscule. However, to the trained ear, the difference in exhaust note is significant . Having owned four high performance Mustangs in the past, this debate between X or H is by no means news to me. The final verdict at the Mustang forum(s) is X for the exotic note, and H for the muscular note. Where H provides few more ponies, X provides a better flow, and less drone. Thus, my bottomline here is that it is a matter of personal choice determined by sound not power. Personally, I would choose X for any high performance Mercedes-Benz. Simply because Mercerdes-Benz is an exotic. And finally, being new to this forum, I am allowed an occasional dumb question or two. What, or who, is SS?

[Grumpy666]

Originally Posted by rrrruBENZ///E55

Where H provides few more ponies, X provides a better flow, and less drone.

Actually, the drone is still there - it just gets moved to a different RPM range that is less evident.

Originally Posted by rrrruBENZ///E55

What, or who, is SS?

http://www.supersprintna.com/

[rrrruBENZ///E55]

Originally Posted by Grumpy666

Actually, the drone is still there - it just gets moved to a different RPM range that is less evident...

As long as it's not at 2,000 RPM @ 70 mph; I'd be a happy camper.

Originally Posted by Grumpy666

http://www.supersprintna.com/

Thank you for the enlightenment.

[E55 RUSS]

OK..thanks everybody...I think I will go for straight pipe...

[Bernanke]

Here are other comparisons I have found. X-pipe is actually supposed to reduce droning b/c it helps the engine cancel out the pulses created and is also better for high end HP than H-pipes. H-pipes do not alot for smooth gas flow between the two banks.

http://www.magnaflow.com/05news/magazine/vette.asp

http://www.carcraft.com/techarticles..._installation/

those two give a good idea (and pictures) of how the system should look and work. X-pipe is the best out of all three for overall performance and has been dyno tested many times on V8 to give great performance (especially on cars where there is no connection between the two exhaust tracts at all (aka E55 cars). hope that helps.

[jangy]

Originally Posted by OmeyHomey

Here are other comparisons I have found. X-pipe is actually supposed to reduce droning b/c it helps the engine cancel out the pulses created and is also better for high end HP than H-pipes. H-pipes do not alot for smooth gas flow between the two banks.

http://www.magnaflow.com/05news/magazine/vette.asp

http://www.carcraft.com/techarticles..._installation/

those two give a good idea (and pictures) of how the system should look and work. X-pipe is the best out of all three for overall performance and has been dyno tested many times on V8 to give great performance (especially on cars where there is no connection between the two exhaust tracts at all (aka E55 cars). hope that helps.

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??

[amgdriven]

The 2.5" x-pipe woke up my w210 E55. It causes some back pressure, due to cross flow......in which regulates/matches both left and right bank exhaust pulses. I don't get ANY drone with my set up; secondary cats removed, x-pipe and factory muffler.

My x-pipe is a true x-pipe....it looks like some just combine and almost share a tube....then split. I don't know if that really matters, though

Get the x-pipe. Keep a little backpressure for the bottom end and enjoy the deep....not raspy.....tone.

[haister]

Do you have any pictures of your setup?

thanks