I have a 2.2 legacy motor in my 87 GL wagon, will headers help a stock motor or will they hinder. Has any one got any answers to help me out?

If you modify one part of the exhaust train do all of it..

 

Thats my 2 cents. I put headers on my 2.2 but i also got a high flow muffler and....ahem...opened up the flow on my catalytic converters..

 

Its not that helpful to an exhaust to modify one part....its why coffee can mufflers are not a performance enhancement

 

Good luck

I have a 94 Legacy that's had a single port 2.2 put into it. In the beginning It had a stock header and cats from a 96 impreza and the rest of the system was the stock legacy system. I couple of years ago I replaced the stock header with a borla header and yes I did notice a difference through the power band, mostly above 4Krpm. A year later I added a custom 2" catback and a highflow muffler. This made a much bigger difference in the power output and the decibel output. A few days after WCSS10 I did a couple of baseline pulls on Pacific Import Auto's dyno. At the wheels my legacy is putting out 118 Ft-Lbs at 4300rpm and 113hp at 5800rpm. The only other engine mod I have is a K&N panel filter.

 

So now back to you question. Yes a header will help but in my opinion you should start with good catback first and go from there.

i asked a related question about EJ exhaust roughly a year ago. wasn't much response, but there were a few replies. might want to search for that thread.

Thank you all for the replies,yes I will put the header on and all new exhaust all the way out Thank you.

post back how it does, i'd like to get an exhaust for my EJ. have you seen any statistics or anyone mention anything about it on other sites? i'd like to see some power/gas mileage numbers. i've seen more info on that on older generation subaru's than any of the newer stuff (not counting turbo's of course!).

something to considder. By replacing the headers you are changing the exhaust scavanging. Headers and cams are mated parts. You may very well end up losing low end power. You will however see some gains at top end. This would follow suit with what was said earlier about gains over 4k. It all depends upon what you are looking for I guess.

I have had a gasoline engine described as an air pump. It pulls air in from the atmosphere (intake) and pumps the same air out the tail pipe (exhaust). The result is horse power. So, horsepower is increased when more air is pushed out the tail pipe faster. Super chargers, turbo chargers, and four valves per cylinder are all designed to increase air flow for more hp.

 

In addition to working on increasing exhaust air flow, suggest thought and work be put into the air intake system. There is a fresh post by someone working with the air intake box for hp increase. Suggest reading that post for some ideas.