Without a dyno sheet, I cant say how much if any low end is lost. I will on our engine trade some low end for more mid and top for what I am looking for. And considering I got the car 13.9 new, I got a little leeway until my pocketbook meets up with an SRT.caveman said:Common NickZak, you can't say 2.5" is best for any 4cyl. I've personly seen low end loss from larger exhaust. My brother n law installed a larger exhaust on a escort GT. I drove it afterwards and it bogged for a bit before it started to pick up. I got a little bit of low end loss on my turbo car with a full 2.5". The loss is so short and the overall gain is much more, that it doesn't matter, but the loss is so short because the turbo spools. It would be longer if it were NA.
I'm not saying that a larger exhaust is never the right choice, because it can be. I wasn't suggesting that you don't get a larger exhaust or telling you how to tune your car. However, like you said yourself, you gotta be working on a real build up. Not every spec V owner on this list is going to be doing major build ups. Most of them will probably be doing bolt on mods. They are worth doing too. They free up some HP and raise the MPG. I was just suggesting that the cost to HP ratio would probably be better to get a K&N drop in, header with no cat, high flow main cat, and muffler for a bolt on build up only. If you arn't going to touch the engine, then what's the point on going with a larger exhaust size? I would personly spend the rest of the money on other things cause for bolt ons only, the extra few possible HP is gonna cost hundreds. You could save it for new tires cause everyone is bitching about the stockers. That and the stereo. Or hell, buy your date something.
Last but not least, if your build up and car cost get close to the cost of a srt-4, then um, you must really love Nissan.
To answer the original question, I really like magnaflow for a 4cyl car. They look and sound great and they last.