WEEZEL

I think about things like this when I'm bored. It seems that people are getting 25-35 hp with the addition of an intake and long tube headers on the LS2. My question is this: Why can't Chevy (or any performance car manufacturer) put things like intakes and long tube headers on these cars from the factory instead of clunky semi-restrictive air boxes and exhaust manifolds? It seems like the Vette, for instance, would pump out 425-430 hp with probably the same efficiency/ gas mileage. The answer most likely has to do with emmisions. This has perplexed me ever since I bought my new 1985 Mustang GT. Ford goes a step further and puts real honest to goodness tubular headers on this car and then screws it up by having a 2 into 1 into 2 exhaust system from the headers back. They fixed it in 1986 but why couldn't they have seen the obvious problem in 1985? I mean, true dual exhaust has been a muscle car staple since the 1960's. Not new technology. I think that if cars like the Vette came stock with LT headers that people would pay for any extra cost. There's no reason why this car, and cars like it, can't make full power potential from the factory. The aftermarket parts distributors and tuners are probably gonna send a hit man after me for this thread. Any thoughts on the above?

dashotgun

emmisions and noise and cost control ae some of the reasons i would guess

OttoNP

dashotgun nailed it...GM has to conform to emission of course and a stupid noise passby test. That test is why most stock exhaust suck. That's one thing I love about the Z06, it has flaps in the exhaust that open at higher RPM, my complete speculation is that they are there to get the vehicle to pass the noise test, but still have a pretty good exhaust. Aftermarket ones will probably still be better, but I like it that GM tried to "beat the man"

VET4LES

The bean counter's alway's control these issues. Header's and the best intake system's cost more than what they usually use. When marketing can convince the bean counter's header's will pay off then they use them. From what I have read on the forum it sound like GM has done a good job on the air intake. I have not seen any real gain's with the after market and I plan keeping the original.

WEEZEL

The headers do work though. The exhaust from the pipes back( i.e. mufflers etc..) also seems to flow well so it seems that they could put headers/ decent x-pipe on and probably not get into too many "noise" problems with the current mufflers. Probably a cost issue though like you said. The exhaust manifold may be the same one that is used on the Suburban/ Tahoe or something like that.

catpat8000

As far as headers go, I can imagine two reasons for GM
not supplying these from the factory.

First, it's far from clear steel tube headers will last
100K miles. Corrosion, warping, loosening, etc.

Second, and more importantly, the headers showing true
power gains are long tube headers which relocate the
catalytic converters. Cats need to heat up to function
properly which is why they appear close to the engine.
Long tubes move them further away and may not
fully meet 50 state emissions during warm-up.

Pat

mforman42

Bingo! We have a winner. All manufacturers must meet a 100K/10 year durability standard for emissions control/warranty for CA certification. Even if the long tube headers meet standards when new, it is not clear that they would pass for 100K miles with the relocated cats. But aftermarket suppliers don't need to do the durability test for a CARB number.

Lee6

...so that the C6 hp will come in just under the C5 Z06?

rosemaryburm

Maybe, just maybe, 400 hp is plenty for most of us. If it isn't enough for the rest of the folks, there is after-market, just like there is aftermarket for 2000 watt stereos and 22 inch wheels and flames and premium seats and whatever.