there is no performance difference between stainless and ceramic coated headers right?

 

no, just appearance

 

will the 4-1 make a big dif. in highend power on a b16

 

Ceramic headers lose less heat from the exhaust gasses. That's helpful if you're feeding a turbo, or to help the cat light off quicker. Less under-hood heat means the intake air stays cooler.

 

The way I've always read it is:

4-2-1 makes good low and mid-range hp and torque... some small gains up top.

4-1 *reduces* low and mid-rpm power/torque, but makes huge gains up top. It's a trade-off... if it's daily driven, I would recommend 4-2-1.

 

Well... yes and no. Ceramic coated headers are more heat resistant, and therefore should keep your underhood temps lower.

In addition, high temperatures are good for exhaust gas velocity, which is one of the reasons people are so fond of header wraps, sprays, etc.

BUT most ceramic coated headers are mild steel, which can be prone to cracking, rusting, and other annoyances.

So let me break it down:

Ceramic coating :thumbup:

Mild steel :thumbdown

Stainless steel :thumbup:

Ceramic coated stainless steel :thumbup: :thumbup:

First of all, a street designed 4-1 header should never lose low end power over stock. They may not provide gains anywhere near the magnitude of a 4-2-1 setup on the low end and midrange, but in general the OEM units flow pretty miserably (with the exception of R models) and to lose power an aftermarket header would either have to be A) too large for your setup or B) poorly designed.

Second, where the greatest power gains given by a header are located in the power band depends more on when and how the primaries merge than the basic layout.

For example, on many more expensive headers (such as the Spoon header shown below), you may see a 4-2-1 design, but the two merges are done in close succession just before the catalytic converter, in the style of a 4-1.



This tri-Y design creates a middle ground between 4-1 and 4-2-1 headers, and with modification of the distances between the merges you can create almost any desired result.


What you were saying was basically correct, but it is a lot more complicated than you may have thought.

 

so which will make the vtec crossover more dramatic or smooth

 

It *is* more complicated! ... that's interesting, and thanks for the info. I'm looking for headers now, actually, and this gives me more meat to chew on. Sweet! :thumbup:

 

how are you feeding a turbo with a header? that's one hell of a return pipe

 

That will have a lot more to do with tuning and than anything else. If your crossover is "dramatic" you should consider moving your VTEC engagement point. That usually means that you either aren't using the full power of your primary and secondary lobes (and should move the point up), or you are running those lobes to too high of an RPM, and running out of power (and should move the point down). Typically, modified Hondas like a slightly higher engagement point.

Well, tri-Y headers tend to be pretty pricey ($600+, but they do the job well), so depending on what equipment and price range you are looking at, you might not get to that sort of stuff. What you stated does hold true for inexpensive headers where the company is generally more concerned about selling a product than making horsepower.