True duals size question.....
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From: Little Rock
True duals size question..... Now that I have ordered the Sweet Thunders, I want to know if it's best to go 2.5" all the way back, or if I should mix and match the sizing? I noticed that a lot of people start with 3" then go into 2.5" tubing. I am pretty sure I've settled on the H-pipe. I know the X supposedly makes more power, but I want the sound. I'm already going to pick up the power with the headers, and I'm sure I'll gain some with the duals. A few ponies is not a big deal to me to get the sound I want. So what are the pros and cons around tubing size? What is affected and how...........sound, power. Clearance really isn't much of an issue. This should be interesting, so shoot away! Thanks a lot.
I personally went 3" into the x-pipe, and then 2.5" over the axle and out the back. I don't think it makes a huge difference, but I do remember Lane or someone else saying that keeping it 3" until at least the X will give you the best performance if you have to shrink it down to 2.5" like I did to get over the axle.
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From: Little Rock
I'll be dumping them before the axle, so the size doesn't really matter. I was leaning towards 2.5" all the way, but I don't want to choke the car. If they'll make good power, I'll just go that route.
Staging Lane
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Fwiw, Somewhere back on another site, somebody did a pressure check on a mandrel bent system, 2.5" running 600 hp ( nitrous, 200 shot) and it only logged 1.2 psi backpressure, they say you start losing power at 2 psi, so I think 2.5 is safe...
Well, it is really up to what kind of ground clearance you are looking for (you don't want to be dragging a 3" system on a lowered car), and your ultimate power goals. My car sits pretty damn low, so my system fit me well.
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From: Little Rock
Brandon, after numerous seaches on this site, I came to the conclusion that the H-pipe sounds better. That is what most people said. I have never heard one. Is there really a difference between the two? If two equal car were sitting next to each other, one with an X, the other with an H, would there be a noticeable difference?
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i went 2.5 all the way and dumped before the rear. i also have the sweet thunders. u wont regret it. it sounded sick 
the 2.5 will give u awesome torque as well as great ground clearance. and its still debatable how much the 2.5 will hurt u horsepower wise in the higher rpms.
the 2.5 will give u awesome torque as well as great ground clearance. and its still debatable how much the 2.5 will hurt u horsepower wise in the higher rpms. 
TECH Fanatic
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From: Tuscaloosa, AL.
I have heard both the x-pipe, and the H-pipe. I couldn't tell the difference, so i got the x. Speaking from an engineering perspective, or from what i have understood from the 3 or so years of formal education I have had so far in college, the sound amplitude, or loudness, is affected by not only the air velocity(speed), but also by the turbulance of the air. IMO, in other words this is my theory not proven fact, the x-pipe would increase the turbulance of the air more so than would the H-pipe (simply do vector anaylsis for the forces of the two moving streams of air), therefore possibly increasing the volume, although probably not enough to be detectable. In all honesty, the most likely outcome from swapping the two would be a different pitch. However, again i could not tell any difference. Oh, and about the size, go with th 3". If you ever dicide to go big(+ci, turbo, nitrous, blower, or big block) then you wont have to redo that part. Of course big block or turbo would require new headers, but you get the point. Go bigger at first, so if the plan changes you didn't under buy.
Dont mean to beat the horse dead, but I am running Mac's w/ ory to B&B Tri Flow and want to replace it with a true dual sytem w/ Hi Flo Cats and Sweet Thunders over the axle, since I plan on adding AFR heads and TR 224 cam would I be restricting my air flow by going 2.5" all the way back or should I do 3" system, I know about the panhard relocation for 3"
Dont mean to Jack 99Hawk262, just going through a similar situation as you and trying to get some info so that I can also do it right the first time
and we can all learn from each other
BTW, I plan on keeping my Mac's since I have the Pro Kit
Dont mean to Jack 99Hawk262, just going through a similar situation as you and trying to get some info so that I can also do it right the first time
and we can all learn from each other
BTW, I plan on keeping my Mac's since I have the Pro Kit
I've had both X & H center sections in my setup, I too could not tell much if any difference in the sound. Currently running the H style. I have a Spohn TA which requires the exhaust to snake around the pass side of the car. With the X style my fabricator couldn't get enough cross section at the smallest point. I elected to switch to H & don't regret it at all. Here's a pic. Sweet Thunder mufflers of course.
Like one person said, 2.5 inch is good to 600hp (I heard 550) I'm 2.5in all the way.
Like one person said, 2.5 inch is good to 600hp (I heard 550) I'm 2.5in all the way.
I went with 3" all the way with my setup, and didn't lose a wit of low end, even if lug away from a near stop in 2nd below 1000 rpm. If anything, I gained torque across the board. They say an H pipe will give a slightly deeper tone than an X, but it will be minimal if any. The tone difference will matter more with muffler choice and pipe size (bigger pipes will be slightly deeper). Go with an X, preferably the Dr. Gas.
Jason
Jason
