73-87chevytrucks.com
73-87 Chevy _ GMC Trucks => Performance => Topic started by: mats1985gmc on February 28, 2011, 04:46:59 PM
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I am in need of new exhaust in a month or two does anyone know what is better or do you even need one of these? What is everyone running.
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Im running true duals with glasspacks. I like them because I have a cam with a lot of lope and rythym and its cool hearing each bank on each side of the truck idling at 500. If I had an x or h pipe it would have all 8 cylinder sounds through both sides.
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I sell X pipes for these (headers back) in the catalog, stainless Steel and mandrel bent.
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where be the catalogue? gotta link? am i blind? Zeke
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Click the banner at the top of this page for the catalog.
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Thanks.... it looks a little odd on an ipad..... I guess i just missed it
zd
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Here is a interesting link... http://www.carcraft.com/techarticles/exhaust_system_installation/index.html
And here is the article...
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!
Note: Another thing I read somewhere else is the H pipe has a "muscle" car sound, while the X pipe has more of a "exotic" car sound.
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good info thanks Beastie. sounds like an xpipe is the way to go. I had a set of left over pipe from another car with Cherry bomb Vortex muffers on them. This is what is no my truck right now. These blister my ears with the sound. My neighbors HATE my truck and the cops love it! I was think to tone things down and get a flowmaster 50 series or 40 series. Any one running these? Any suggestions?
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ive run flowmaster 40 series they sound great. they are loud but sound good.not to sure how much you want to tone down but magnaflow sound awesome also. no drone when on the highway.
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i run thess on my truck Patriot Smithy Mufflers, they sound great. mine are 3 feet long so they stay about the same tone the hole time and dont get to loud, i work on my truck at night and never had a person call the cops.
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If you're not looking for loud, but crisp and beefy, the 50 would be the way to go, great tone on a H or X pipe system. Also since its an 85, I'd run magnaflow's high flow cats. Most speed shops have them for about 100 a piece.
I'm planning on getting one of Capt's X pipe systems and run those with some 44 series flowmasters, I like it loud.
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Captkaos... will the tailpipes with your x pipe kit clear the axle if it's been flipped?
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Beastie, you the man. I have been wondering this for awhile, thanks for the info.
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Yes the first kit I sold was on a lowered truck.
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not to spoil it, but it can depend on the engine setup too. I was watching an episode of Gearz and Stacey was at a manufacturers site and he asked why their new Camaro kits were H pipe instead of X. The guy said the H made more power on that particular car. Go figure.