I have a 98 civic with a gsr swap, I have a usdm itr oem header which is better oem itr or aftermarket?

 

Wow guys thanks for the opinions 74 people viewed and not 1opinion

 

dude.... aftermarket only if its done right though. when it comes to headers believe it or not there is a lot that comes into play. first of all there's the whole equal length discussion. but it goes much deeper than that. With every bend in your exhaust, there's an equation of back pressure. to get it "equal" the headers aren't just the same length. each degree bend (ex. 90 degrees) must be calculated for what kind of back pressure it will create. and that is the kind of equal you want. On top of that everything should be mandrel bent but everybody knows that. But to get a header such as this... pay big bucks. for eye candy and minor horsepower increases, id go with ebay, or for a little more - DC sports. there pretty decent from what i've heard and perfectly fine for street use. If your going to spend a crap load of money on a header. make it later down the road. go with cams with a mild to medium grind and a good tuner. To answer your initial question. dyno run your current set up. then switch it out to a cheap header and run it again. Experiment, your personal experience will beat any online response any day of the week. if you do your dyno runs. keep them and post the charts.

 

Thanks dude

 

no prob

 

Contrary to popular belief, on an N/A Civic, IT DOES NOT MATTER

 

I'd argue it does to a small degree. Something like a Bisimoto V2 will gain more (I've heard 10-15whp) than something like a DC Sports piece (something like 3whp). But as far as the unequal length headers, no, it doesn't matter. Not many people are willing to shell out $500+ for something like an equal-length header.

 

I'd be hard pressed to believe a 10-15hp increase on an otherwise un-modded honda motor being based on anything other than a change in temp/humidity.

 

without internal upgrades aftermarket headers don't do a whole lot. Yes it matters in my opinion the design of the headers. Id say both of you are right. but ive seen custom made equal length headers go for over 1000 and thats for a four cylinder. N/A they do make a difference but there typically race only headers. also race engines don't use stock valve trains lol. Its the same never ending argument that a cold air or short ram will make lots of hp. you want lots of hp with the n/a route. ITB's with standoff fuel injection. and for that you'll need the basics of a bigger displacement, higher compression, camshaft grinds to accommodate the size of throttle bodies your running and the amount of air flow you want. bigger injectors. and for the stand off fuel injectors even bigger injectors, plus a stand alone EMS. I've seen a b16 with 240 hp N/A with just regular itb's i've seen a k20 stroked with standoff injectors pushing approx. 330-340 hp... N/A but its super pricey. and a lot of diy machining. thats a race setup only by the way.

 

Don't forget the desired powerband factoring into the cam grind; you don't want too little overlap if you're going to be making peak power at 9k and whatnot.

But yeah, N/A builds are expensive... that's why nobody really does them. Actually, it kind of makes me want to get an EG, drop an H2B in it, and do an N/A build.