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The main reason I am going to run a 2.25" is that is what most of the people on this forum agreed to be the best for this car. Why do you think a 2.5" is better?
Its not really better or worse. My plan is to add a supercharger around the 1st of the year so I'll need larger piping. 2.25 is large enough if you stay @ the stock HP. Adding 40hp from a supercharger will require larger piping. IMO---The smaller the pipe the louder/higher pitched the sound will be with more drone. This is based from past history with some of my old cars.IMO The main thing is not the size but placement of the x-pipe and mufflers. The x-pipe should be placed where the exhaust starts to cool and mufflers with in 12"s of the x-pipe. If you run larger pipe then the x-pipe will be closer to the motor. Smaller will be closer to the middle. Placement is everything when I comes to the x-pipe!!
Its not really better or worse. My plan is to add a supercharger around the 1st of the year so I'll need larger piping. 2.25 is large enough if you stay @ the stock HP. Adding 40hp from a supercharger will require larger piping. IMO---The smaller the pipe the louder/higher pitched the sound will be with more drone. This is based from past history with some of my old cars.IMO The main thing is not the size but placement of the x-pipe and mufflers. The x-pipe should be placed where the exhaust starts to cool and mufflers with in 12"s of the x-pipe. If you run larger pipe then the x-pipe will be closer to the motor. Smaller will be closer to the middle. Placement is everything when I comes to the x-pipe!!
I don't have much experience with exhaust design, so I can't really disagree with you. However, I am curious where you have acquired this knowledge. Much of what you are saying seems counter intuitive regarding the placement of the X-pipe. If the purpose of the X-pipe is to improve scavenging and equalize flow between the 2 pipes, then I don't see why it wouldn't ALWAYS be best to have the X-pipe as close to the exhaust manifold / header as possible. It also seems backwards about the smaller piping causing the exhaust to be louder with more drone.
From what I have seen and heard to increase the scavenging effect of the headers, the crossover should be located close to the collectors. 18-24 inches or just look at where Borla has it place.
Come to think of it, the only place to put the x-pipe is right where the secondary cats are placed. The oil pan, chassis brace and tranny are in the way to put the x-pipe any closer to the headers and you wouldn't want the crossover to be any further back in the exhaust system.
Last edited by caymandive; Nov 14, 2007 at 08:00 AM.
From what I have seen and heard to increase the scavenging effect of the headers, the crossover should be located close to the collectors. 18-24 inches or just look at where Borla has it place.
Come to think of it, the only place to put the x-pipe is right where the secondary cats are placed. The oil pan, chassis brace and tranny are in the way to put the x-pipe any closer to the headers and you wouldn't want the crossover to be any further back in the exhaust system.
If I remember correctly in the other exhaust thread, a guy kept his secondaries and put the x-pipe right after it then into the magnaflows. He said he liked it, but I wonder how it would do on a dyno?
Gernby-- The idea is that when exhaust gases are hot they flow. When the cooling takes effect (somewhere mid pipe) is where the crossover should be placed. This is where the vacume effect from the crossover is needed to help maintain flow from the cooling. As for where and how i learned exhaust...From the age of 13-19 I worked for a local Nascar team. I pretty much cleaned for years and didn`t do anything with the cars. But once I turned 18 they allowed me to work on the modifed late model cars for the local tracks. In exhaust fab/sheetmetal dept.I was able to work with alot of smart people. These cars ran crossovers depending on the track they were on that weekend. I learned alot about cars and fabing exhausts/sheetmetal etc... Most likly not enough justication for you but hands on is enough for me. Caymandive-- You right about the tranmission etc..in the way but its usually around that area when this(^) takes effect. If I had to guess the cooling of the exhaust would be about where the secondary cats are. This is most likely one of the reasons they are placed so far away from the primarys.
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