View Poll Results: What X-pipe / H-pipe setup are you running?
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H-pipe vs X-pipe - great article to clear up some of the confusion...
#1
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H-pipe vs X-pipe - great article to clear up some of the confusion...
Doing some research on the whole X-pipe vs H-pipe setup on our cars and found a great article that compared both setups by Magnaflow...
if you want the cliff notes:
X-pipe made more power than open headers
H-pipe increased back pressure which also richened up the air/fuel mixture by about two carburetor jet sizes
Read more: http://www.carcraft.com/techarticles...#ixzz1pDjCKvP2
and here's a hottie on a Mercedes for your pain in reading...
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!
Read more: http://www.carcraft.com/techarticles...#ixzz1pDhpLVCE
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!
Read more: http://www.carcraft.com/techarticles...#ixzz1pDhpLVCE
X-pipe made more power than open headers
H-pipe increased back pressure which also richened up the air/fuel mixture by about two carburetor jet sizes
Read more: http://www.carcraft.com/techarticles...#ixzz1pDjCKvP2
and here's a hottie on a Mercedes for your pain in reading...
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#8
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yes, I've seen your vids definitely mean sounding and from what I've seen/heard- the H-pipe will sound gnarly - headers help with that too!
#9
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I dont have an H pipe on the e55 unfortunately, it is an x pipe. If it was an H, it would have WAY more drone. What you hear is open headers in my vids homey.
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03 E55 AMG, 06 Harley Road King Custom 06 Ram 2500 Cummins, 97 Firebird Race Car, 88 Cutlass Supreme
I didn't care much for the girl on the car either.
I will agree X pipes make more power and have a more fancy tuned type of sound, and an H pipe makes a lil less power but has the deeper muscle car type sound typically.
An X pipe on the right old ford 5.0 sounded downright amazing in my opinion, whereas an old school or LT1 small block chevy sounded better with an H pipe.
My race car just has longtubes to a short extension pipe with Borla XR1's and sounds pretty good and performs very well though. If i had more room I'd do a nice X pipe.
With a car like the E55 I personally think the X pipe sound would be more fitting.
I will agree X pipes make more power and have a more fancy tuned type of sound, and an H pipe makes a lil less power but has the deeper muscle car type sound typically.
An X pipe on the right old ford 5.0 sounded downright amazing in my opinion, whereas an old school or LT1 small block chevy sounded better with an H pipe.
My race car just has longtubes to a short extension pipe with Borla XR1's and sounds pretty good and performs very well though. If i had more room I'd do a nice X pipe.
With a car like the E55 I personally think the X pipe sound would be more fitting.
#14
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Not to throw a wrench in the works, but the Mustang is presumably NA, or did I miss something while enjoying the additional hotties? doesn't the whole equation change with blown engines?
#15
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they're just air pumps - right?
Would like to see before/after for the e55
Last edited by Toadster; 03-16-2012 at 08:47 PM.
#16
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Meaning Superchargers and turbos vs engines that are normally aspirated like the Mustang in question. It seems the normally aspirated (NA) engines like a little back pressure, but not necessarily the supercharged (blown) engines. It does seem to be controversial though.
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#18
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Hey, toadster, it looks like I misunderstood your response. Yeah, SCs are big air pumps. I think the difference has to do with the pressure they create over NA, but don't really know.
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2014 E63s amg 4matic, 2009 C63, 2006 E55 AMG , 2001.5 AUDI S4 stg 3+ w/meth
n/a engines work better with a little more back pressure than F/I engines due to the fact that f/i engines create more of their own back pressure...
turbos create the most backpressure since they are relying on the exiting exhaust pressure while s/c creates a little less than turbos since s/c is mechanically driven and will still create boost right away, but at the cost of effiency since the mechanical operation of the s/c is basically fighting the backpressure.... the turbo at the same time will take longer to spool up with to much backpressure..
this is why turbos gain the most power from catback/ downpipe systems and s/c less and n/a motors even less.
Last edited by gaspam; 03-17-2012 at 02:50 PM.