For those of you who are thinking this is a photo shop or some other kind of fact, I know for a fact this is real. They just haven't got it lifted up into position yet.

 

I know its real. Its all stainless steel and only cost me $10899. I needed to upgrade the rear coils to 1000k springs but it rides real good and sounds mean as fawk.

 

35mm, now that I think about it, is closer to 1.5" - but it's still going to be closer to what they need than the 4" I've seen! Probably less restrictive (since there won't be much internal turbulence from uneven pulse cooling.)

However, I was just pulling out a number - I wasn't even crunching numbers. Call it hyperbole, it's probably less of an exaggeration than some of the really pointless stuff I've seen ricebois do...

(If I mean to give a definitive answer to something, don't worry - I'll show my work... )

 

Got my gear installed today. The magnaflow is noticably louder but has a nice mean rumble. I stripped the threads removing the downstream o2 so that needs replaced. I did nothing with the stock downpipe and just kept it. Added a flex pipe right before the cat. For the o2 i just disconnected it until i get a new one and plugged the new cat's port for now. Did not throw a CEL which I thought was surprising. Hopefully mpgs improve!

 

He's blown it on cool factor. You want cool? Look up the guy out here at Stanford engineering who put a jet engine in a late-model Bug!

 

I read this entire thread and still have no idea what the consensus is. I'd like to know, because I'm in the market for upgrades.

 

1. Bigger isn't always better.
2. Exhaust systems are about science, not size.
3. Ideal is probably in between 2.25 and 2.5, ergo,
4. You won't hurt anything by going 2.5, and,
5. You probably won't see any magical gains, either.
6. Unless you are going to install a complete performance system (headers to tailpipe), engineered for this particular application by people who actual know what they are doing, you probably aren't going to see much difference.