Hi,
Im new to Hondas and dont quite know allthe facts yet about the B16A. I noticed the stock exhaustmanifold was a 4-2-1 set up. i noticed a nice looking 4-2-1 shiny and longer after market manifold on ebay designed for the DOHC B engines, will bolting this onto my car improve the performance, bearing in mind im running my engine standard. Im working on the intake and exhaust efficiency at the moment. I will play with cams and pistons later. Will this new manifold boost my performance?

ps. i plan on also changing the cat and back box soon as well, so the stock/new manifold would be working with this exhaust set up. I also dont plan on turbo/super charging the engine at any point either

So is this new shiny ebay 4-2-1 DOHC manifold better than my stock B16A 4-2-1 manifold, and if so by how much?

thank you for your time

 

Well it's not the fact that it's a 4-2-1 design; it's the design of the tubes. The exhaust ports on the stock manifold are really small and rough; the exhaust ports on most aftermarket headers are fairly large and perfectly smooth. And for the record, Bisimoto headers gain you around 15hp for $500... is that worth it? I'd say so.

 

thank you, so what performance increase would i see with a performance header on a stock engine setup. i also plan on getting a decat pipe and maybe a performance backbox. i already have a cold air intake fitted too

this:
http://cgi.ebay.co.uk/ws/eBayISAPI.d...ayphotohosting
(4-1, came off of a B18, looks man enough)

or this:
http://cgi.ebay.co.uk/HONDA-CIVIC-DE...QQcmdZViewItem
(stainless steel 4-2-1)

 

deffinently ge tthe first ones megan reacing headers are amazing for their price, that what i have on my car, try to get the drift spec cat back from them too, sounds amazing and relativelly cheap

 

what difference would a new header make on a stock engine set up?

 

it frees up the exhaust a little bit so its add like 10 hp, that why you should also get the cat back from tehm if you can afford it, which will add like another 15 hp

 

^ pretty high estimates if you ask me. the general rule of thumb is 3-4hp for an intake, 5-7 for a header, and 5-7 for a cat-back exhaust. Also, if you're serious about letting your car exhale, high-flow cats usually gain around 3hp (assuming you're using a street-legal unit... please, no test pipes!).

Of course, all cars, and for that matter, all engines are different. Nobody can say exactly how your car will respond to the new addition. We can only give our opinions on what we think they'll do. For the most part, though, you can probably expect a little more power using the butt-dyno (my car seemed to be a little quicker after installing my 4-2-1), especiallysince you have an aftermarket intake already.

 

basbal123's estimates are fairly close to that of a k series with bolton's, not quite that of a b/d series, lol

 

my intake is an ebay non-descript CAI (bad ? ? ?). I would most likely buy an aftermarket stainless steel header and a maybe a decat pipe from ebay. This would be supported by a high flow back box. Im not going with a full cat back as i need the ability to put the cat back on when the MOT needs doing, otherwise it would fail on emissions.

 

throw an AEM or K&N filter on your intake and you'll have about the same performance as most name-brand full intakes. And full cat-backs don't remove the catalytic converter; they replace everything after the cat, so you wouldn't fail emissions for having a cat-back as long as you still have your cat.