2.5i running a track pipe/hfc

[kevinblahh]

Hey i had a question for any one that might be running these things. Right now i have stromung mid pipe 2.25" and hks hiflow axe bacl 2.25" I was wondering if any one here is running a stromung hfc or stromung straight pipe on there daily drivers and what they think about it, thanks.

[williaty]

Hey i had a question for any one that might be running these things. Right now i have stromung mid pipe 2.25" and hks hiflow axe bacl 2.25" I was wondering if any one here is running a stromung hfc or stromung straight pipe on there daily drivers and what they think about it, thanks.
You're either a wee bit confused or you mistyped your question.

A straight pipe is a single pipe extending all the way from the header to the back of the car with nothing in it. No cats, no resonator, no muffler.

The pipe that replaces the cats with a hollow tube is a track pipe.

The track pipe may be difficult to run on your car. The 05+ NA ECUs monitor both the front and rear O2 sensors in Closed Loop to control fueling. People who log their car regularly have noticed that when the rear O2 sensor is not in a situation it expects to be in, the car runs very rich to protect the cats. Most people have found this out by removing the rear O2 from the main flow of the exhaust. However, to my knowledge, no one has yet proven that a track pipe won't affect fueling on an 05+ NA.

[kevinblahh]

yea, i was looking at a lot of different things when i typed the question, i meant track pipe lol. So pretty much it would just be better to run a hfc? Also, what does running rich mean? Thanks.

[williaty]

Yes, the new cars are going to respond better to a HFC than a track pipe. I would recommend the double-bubble Random Tech cat as people seem to have very good results with it.

Running rich means the ECU is adding too much fuel to the engine.

[kevinblahh]

hopefuly make the car sound a little ruder too?:p

also, i was at the stpr this past weekend, what is it that makes rally cars sound the way they do?

[westy2005]

hopefuly make the car sound a little ruder too?:p

also, i was at the stpr this past weekend, what is it that makes rally cars sound the way they do?


That, my friend, is Anti-Lag. Not for you, as you have nothing that is lagging..lol

Had it on my red WRX for awhile...its fun, but gets you pulled over...ALOT. so its not really for street use...

[me_jimmy]

pulled over? did you get a ticket? and what was it for? making a racket?

[kevinblahh]

That, my friend, is Anti-Lag. Not for you, as you have nothing that is lagging..lol

Had it on my red WRX for awhile...its fun, but gets you pulled over...ALOT. so its not really for street use...

haha yea no turbo :-( oh well, do you think i should still get the hfc, or wait and put my money into something else

[westy2005]

pulled over? did you get a ticket? and what was it for? making a racket?
No ticket..cop was "Uhh sir, I don't think that your car is running properly, it would be in your best interest to have it towed..." I replied with "It should make it home, then I can fix it!" he responded "well with the car backfiring and shooting flames out the exhaust can't be good! I will escort you home" Me "ok!" all while thinking "Dammit, I wanted to do some on ramp pulls!!1 FCUK!!"

lol they were decent about it..just stopped running it b/c of all the noise.


haha yea no turbo :-( oh well, do you think i should still get the hfc, or wait and put my money into something else

Yes, I think that you should get it! I wish that I had the $$ for a set of headers and HFC...as of right now though, I can't afford it :-( stock stuff sucks!

[me_jimmy]

rip off the headers end run naked! http://hem.bredband.net/jimwoo/smilies-filer/image020.gif

N/A needs back pressure to work right in normal conditionshttp://hem.bredband.net/jimwoo/smilies-filer/znaika.gif (sorry for being a party pooper) cam-times and stuffs.....

[RS-ti_Andy]

No ticket..cop was "Uhh sir, I don't think that your car is running properly, it would be in your best interest to have it towed..." I replied with "It should make it home, then I can fix it!" he responded "well with the car backfiring and shooting flames out the exhaust can't be good! I will escort you home" Me "ok!" all while thinking "Dammit, I wanted to do some on ramp pulls!!1 FCUK!!"

lol they were decent about it..just stopped running it b/c of all the noise.




Yes, I think that you should get it! I wish that I had the $$ for a set of headers and HFC...as of right now though, I can't afford it :-( stock stuff sucks!


i am too jealous! haha

what system did u use? or was it mechanical?!

[westy2005]

Hydra...

[RS-ti_Andy]

nice

[MConte05]

So far I have been very pleased with my results with Borla UEL's and a Stromong HFC. I got them both together for $250 off of a 2000 Forester.

KChUmrblxdk

So far no problems, except for I have been throwing a CEL for a P0171 "system too lean" even though I haven't touched the intake (yet).

Williaty, would it make sense if the rear O2 sensor wasn't reading at all, for it to throw a system too lean? i.e. because of a melted/burnt wire cutting off the circut?

[williaty]

So far no problems, except for I have been throwing a CEL for a P0171 "system too lean" even though I haven't touched the intake (yet).

Williaty, would it make sense if the rear O2 sensor wasn't reading at all, for it to throw a system too lean? i.e. because of a melted/burnt wire cutting off the circut?
No, P0171 is almost always a leak. Either a vacuum leak or an exhaust leak before the front O2 sensor. If the rear O2 sensor is absent or not in the exhaust flow, it should be throwing a "Hey, the rear O2 sensor isn't fraking there" code plus running the car at 11:1 or so instead of stoich.

[kevinblahh]

http://img.photobucket.com/albums/v333/kevinblahh/vacation/th_MOV08696.jpg (http://smg.photobucket.com/albums/v333/kevinblahh/vacation/?action=view&current=MOV08696.flv)

this is my car just with the axle back

[RS-ti_Andy]

^^^ civic sounding.. this stinks.. i dont want a subaru with a boxer engine to sound like a normal 4 banger when i get the rs... grrr

would uneven headers help with the boxer rumble on the N/A motors?

[westy2005]

^^^ civic sounding.. this stinks.. i dont want a subaru with a boxer engine to sound like a normal 4 banger when i get the rs... grrr

would uneven headers help with the boxer rumble on the N/A motors?

Andy, I believe, that was taken before he put the Borla's on.....the 06-07 models have an equal length header, the rest of the years, 93-05, will have a boxer rumble to it...

[RS-ti_Andy]

Andy, I believe, that was taken before he put the Borla's on.....the 06-07 models have an equal length header, the rest of the years, 93-05, will have a boxer rumble to it...


oh thank god!

that clip of kevins is a axle back fart can.. thats what i was getting at.. did u watch the video of his?

[kevinblahh]

oh thank god!

that clip of kevins is a axle back fart can.. thats what i was getting at.. did u watch the video of his?

it sounds better in person, ive found that a lot of videos make some exhausts sound ricey, to tell you the truth it sounds almost exactly like when i had my stromung, and they make great exhausts for n/a's, the can also has 2.25" piping so its not oversized, although the can is a little bigger than what i thought it would have been, but im satisfied with it compared to stock exhaust, and im getting the stromung midpipe next week.

[MConte05]

Williaty, you nailed it. I checked under the car and found black soot near the exhaust manifold and could feel a ton of exhaust exiting the gasket right before the front O2. Spent most of the day removing the header, cleaning the gaskets, scraping off anything that was caked on there so it was a smooth surface, and making sure to evenly and slowly put everything back on so it would be a tight fit. Now it sounds even better, and here is to hoping the p0171 goes away!

Thanks!

[williaty]

Williaty, you nailed it. I checked under the car and found black soot near the exhaust manifold and could feel a ton of exhaust exiting the gasket right before the front O2. Spent most of the day removing the header, cleaning the gaskets, scraping off anything that was caked on there so it was a smooth surface, and making sure to evenly and slowly put everything back on so it would be a tight fit. Now it sounds even better, and here is to hoping the p0171 goes away!

Thanks!
No problem. However, I would be pretty surprised if you manage to re-use gaskets and ever get them to seal right. They're really meant to be disposable.

The reason the exhaust leak caused a lean code is that, at low throttle openings, the pressure in the pipe drops below ambient pressure in the partial vacuum between exhaust pulses. This sucks outside air, which reads as fully lean to the O2 sensor, into the exhaust pipe. To compensate, the ECU adds a ****-ton more fuel. This is why it was making such black soot. Your gas mileage and power were also likely down. If the fuel trims are pegged for 2 drive cycles in a row, you get the CEL.

[RS-ti_Andy]

it sounds better in person, ive found that a lot of videos make some exhausts sound ricey, to tell you the truth it sounds almost exactly like when i had my stromung, and they make great exhausts for n/a's, the can also has 2.25" piping so its not oversized, although the can is a little bigger than what i thought it would have been, but im satisfied with it compared to stock exhaust, and im getting the stromung midpipe next week.


oh ok.. yeah ui suppose the exhaust note will only be as good as the camera.

you have to get the video/sound clip of it with the mid pipe!

[kevinblahh]

oh ok.. yeah ui suppose the exhaust note will only be as good as the camera.

you have to get the video/sound clip of it with the mid pipe!

haha yea i cant wait, all i can do is sit and watch the tracking for ups:lol2:

[MConte05]

No problem. However, I would be pretty surprised if you manage to re-use gaskets and ever get them to seal right. They're really meant to be disposable.

The reason the exhaust leak caused a lean code is that, at low throttle openings, the pressure in the pipe drops below ambient pressure in the partial vacuum between exhaust pulses. This sucks outside air, which reads as fully lean to the O2 sensor, into the exhaust pipe. To compensate, the ECU adds a ****-ton more fuel. This is why it was making such black soot. Your gas mileage and power were also likely down. If the fuel trims are pegged for 2 drive cycles in a row, you get the CEL.

The two gaskets for the exhaust manifold seemed okay, the one connecting the cat and the headers is pretty much toast. I used some gasket goo stuff to help temporarily seal it up untill I can get a new gasket. I think I am going to replace the manifold one as well just for the hell of it, and to be safe.

I am just glad to finally solve the problem. I was driving myself mad thinking it was intake problem, o2 sensor problem, cat problem, vacuum problem, etc. etc.