| Just presenting info here for what its worth. I'm pretty excited about Greg / Ash / Labree / B+B / etc producing 3 inch exhaust components. The general Z community seems to be on board with 3 inch exhaust systems adding benefits to the high rwhp Z's - finally ! So the next logical question to me is, how big is too big. I came across this article - figures I would share. To put it into perspective, take the rwhp figures thrown around and multiply by 2 since we have two 1.5 liter engines ( I am assuming that this article is based on a single exhaust car ).
Pipe Sizing
" We've seen quiet a few "experienced" racers tell people that a bigger exhaust is a better exhaust. Hahaha… NOT. As discussed earlier, exhaust gas is hot. And we'd like to keep it hot throughout the exhaust system. Why? The answer is simple. Cold air is dense air, and dense air is heavy air. We don't want our engine to be pushing a heavy mass of exhaust gas out of the tailpipe. An extremely large exhaust pipe will cause a slow exhaust flow, which will in turn give the gas plenty of time to cool off en route. Overlarge piping will also allow our exhaust pulses to achieve a higher level of entropy, which will take all of our header tuning and throw it out the window, as pulses will not have the same tendency to line up as they would in a smaller pipe. Coating the entire exhaust system with an insulative material, such as header wrap or a ceramic thermal barrier coating reduces this effect somewhat, but unless you have lots of cash burning a hole in your pocket, is probably not worth the expense on a street driven car. Unfortunately, we know of no accurate way to calculate optimal exhaust pipe diameter. This is mainly due to the random nature of an exhaust system -- things like bends or kinks in the piping, temperature fluctuations, differences in muffler design, and the lot, make selecting a pipe diameter little more than a guessing game. For engines making 250 to 350 horsepower, the generally accepted pipe diameter is 3 to 3 ½ inches. Over that amount, you'd be best off going to 4 inches. If you have an engine making over 400 to 500 horsepower, you'd better be happy capping off the fun with a 4 inch exhaust. Ah, the drawbacks of horsepower. The best alternative here would probably be to just run open
exhaust! " full article
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"....Thanks captain obvious, would you recommend air to resolve a low tire pressure situation? coolant to keep temps down? perhaps a battery for electrical devices? " ... LJZTT on June 10, 2006 at 6:36 PM
"How the hell would you have gotten on the track had you not *somehow* purchased a ticket? He's so overzealous about making other people look bad, that he sticks both feet down his throat. It's fun to watch though :) " ....ZEngineer on June 07, 2006 at 6:22 PM
"as useless as an EGT Gauge..." *shakes head* Its comments
like this that hold the Z32 community back. " ....Z-Jay (Edmonton, AB) on April 21, 2006 at 11:46 AM "Somebody give this man a medal. Arguing with kenny is like being in the special olympics" ....ENVYMYZ on November 01, 2005 at 11:59 PM " .. going back and forth with you on a stupid point is like watching a retarded kid double dribble in basketball, you get tired of calling foul all day" ... Slowninja(GT28RS Inconel Z) on October 03, 2005 at 8:43 AM "the only chips you know about are Doritos. =)" ...ZEngineer on June 11, 2005 at 4:23 PM "....These posts only serve to make you look even worse, its gotten so bad it even makes me look bad to reply to you...." maglito on January 22, 2005 at 3:11 AM "What, are you afraid that only a couple of good ones have rolled off the production lines and the rest are crap?? ... Its mechanics not the stockmarket." ... ZisLuv on May 03, 2004 at 6:12 PM 
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