Some of you are saying you have 2 1/4" exhaust piping. To me, that sounds way too big for a tiny 1.6L 4 banger. The stock piping is 1.75" so I figured 2.0" would be plenty when I did my exhaust.

Even my Regal which puts out nearly 400 Lb.Ft of torque and over 300 HP from a V6 only has 2.5" single exhaust (2.25" was stock).

So which is better on the 8V kicker, 2 1/4" or 2" exhaust? Has anybody done any comparisons?

Also, my limited understanding of how exhaust works is the more back-pressure you have (to a limit, of course) the lower your torque curve is. So going to a larger pipe diameter can increase top-end power but decrease low-end torque...

The only tuning I know much about is for my 3.8L S/C V6 though I've never really tried to get performance out of a N/A 4 cylinder.

Like I said in your last post, I wouldn't go above the 2 1/4 inch pipe as its loud and yes you have to seriously consider the back pressure. Lots of people that I have asked suggest 2". Just my 2 cents.

steveo

1.6L 8v are also really low compression engines (forget the exact numbers), so a 2" exhaust is really the max you should go

Also, my limited understanding of how exhaust works is the more back-pressure you have (to a limit, of course) the lower your torque curve is. So going to a larger pipe diameter can increase top-end power but decrease low-end torque...

The only tuning I know much about is for my 3.8L S/C V6 though I've never really tried to get performance out of a N/A 4 cylinder.

I think that's the way it works.  But I think the size of the exhaust manifold or header primaries is more important to backpressure than the rest of the exhaust system.  At some point, the size of the exhaust pipe will just be overkill, but I'm not sure if it would affect anything.  Maybe it would affect scavanging if the flow got too turbulent.  Like most of them, the exhaust can be a complicated system.  I guess and it'd be nice to have dyno numbers on some of the options to know which ones have what effect, but I haven't seen anything like that out there for these engines.

Compression on an 8V is 9.1:1
2" or 2-1/4" should work, the
prefabbed systems use 2" I think
they have done the testing so you
might as well take advantage of the
testing allready done.

As for me, I'm going to a 3" system,
Cat too no muffler, but don't try this
on a non-turbo motor, you would be
dissapointed

Wild