No, I have a friend with a GT500 running 778 at the tires with 2.5" all the way through to the mufflers. He has no plans for any 3" system.On a 505hp engine, would that small 2.5" bottleneck make a big difference in both sound and performance?
That is called a merge collector and if designed properly can make a lot of power. The problem is that 90% of the companies that offer “Merge Collectors” don’t have ones that work as advertised. If you are looking into a merge collector or a header with a merge collector I recommend extensive research.I heard of headers design where they actually create a bottle neck right at the collector to induce some kind of a venturi effect.
No, nothing like it.Would that 2.5" section on my setup make the same effect
or would it be better to remove that 2.5" section and run a 3" straight though down pipe? I mean what's the point of having 3" pipes if you have that little connecting section that is 2.5" anyway?
I know Kooks has a catted x-pipe with 3" inlet and outlet (6023-CX-3R). But even with that, I still have to cut off the 2.5" section on the Magnaflow 3" Magnapacks.
Thanks in advance for your reply.[/quote]
The best designed exhaust systems have “stepped” tubing. It can start at the headers and run to the outlets or just work in a section of the exhaust.
The bottom line is that a well designed exhaust system will:
- Have headers that the tubing diameter gets slightly larger before it gets to the collector.
- Have an efficient properly designed merge collector
- It would have 180deg headers but that is for full blown race cars with lots of room so forget about that.
- The tubing after the collector would continue to grow in diameter as it leaves the collector.
- An X crossover would be located in the proper location (lots of testing we can’t do is involved in finding this spot). H crossovers are not as efficient as X crossovers period.
- Straight through mufflers of some sort. The larger their volume the quieter they will be.
- The tubing diameter “growth” as it works its way back is not dramatic. At a maximum it would want to grow about .5” from the headers to the mufflers. There is not much if anything like this available off the shelf because the manufacturing process takes some very specialized machines or the entire system needs to be sectioned and welded using slightly different diameter tubing (clearly not ideal). Either way it’s expensive. I have had “stepped” headers that were made with a seamless no sectioned process on a few of my racebikes, there are a few companies that have them available off the shelf. They worked incredibly, they also cost a fortune.
- And of course all tubing should be mandrel bent and make as few turns as possible.