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soot on my bumper...

6K views 19 replies 6 participants last post by  ColoWRXer 
#1 ·
i have an 05 wrx with a few mods. i first bought a k&n typhoon short ram intake and then the catless dp from turboxs as well as their midpipe with a high flowing cat. i gutted the cat out of my stock up pipe. about a year ago i got a turboxs ti tip muffler. then finally a couple months ago i got a cobb ap and flashed to stage 2 (no protune yet:( ).

my question is that i have just noticed in the last month or so that there is soot on my bumper above the exhaust tip. i've read about this a little bit but i'm wondering why its happening just now. i have a white car and i hand wash it so i would've noticed if it was there before.

i read that catless will do this, but i still have one cat (high flow). and i also know that the accessport leans out the a/f ratio. i would think this would lead to less soot??

anyone have any input or having the same problem (if it is one)?
 
#3 ·
Yeah from what I've read catless as we know allows higher airflow thus reducing the filtering process of the exhaust. Theres your black soot. You can either find some lower hangers like 3EVEN said (if thats the case) or put an exhaust guard on the bumper. A black one would look good with black rims.
 
#4 ·
thanks for the replies guys...

i figured it was probably just because of reduced filtration due to having only one cat. maybe i'm only seeing it now because the cat has finally been saturated by soot or residue or whatever and now its letting the soot through. does that sound plausible or am i just making things up?

do the aftermarket hangers just make the muffler hang lower? i can't see how they would make it extend out beyong the bumper??? if they lower it that's a no go for me...i like my stock ground clearance. i like to abuse my car up on the dirt roads (poor baby) and i like not smashing down on every speed bump like my buddy's 330ci hahahahhaa.

that's a good idea longshot. maybe when i have a few more bucks i'll get a black bumper guard. i do have the black and white thing going afterall....black rims, black sti scoop, black spoiler....black bumper guard?....i think so.

for now it's not a huge deal, it seems to wash off without staining the paint.
 
#5 ·
The longer hangars just allow the exhaust to hang down farther from your bumper. If you look around most dont hang much lower than stock, but the bumper guard is a good idea. I like them regarldess of the color of car. They are kind of pricey though for what they are. I plan on making my own when I get back to my car.
 
#6 ·
.... and i also know that the accessport leans out the a/f ratio. i would think this would lead to less soot??

anyone have any input or having the same problem (if it is one)?

Incorrect. the OTS AP stage 2 map is pig rich. You have the right idea just backwards. Also instead of getting something to lessens the effect of the issue, fix the problem. Get a protune that will help it out more than a bumper guard or exhaust hangers
 
#7 ·
i know they make the OTS maps pretty general and safe, but i still remember hearing they thin out the mixture, atleast compared to stock. i agree, and if i had the $300 right now i would go get a tune and fix the problem as well as gain some power.

is it unsafe to be running stage 2 without a tune, or just not ideal?

thanks.
 
#8 ·
The black soot is from your AP running rich not lean. Cobb does this becuase a lean motor will destroy itself before a rich motor. Both are bad but one is not as bad. There are some instances where the cyclinder walls is washed down with fuel, read extremely rich, and causes premature failure of your rings. I ran my OTS stage 2 setup for 2 years and magically lost compression on 2 cylinders, the rings were bad. I think the OTS map is just there to get you by until you get it tuned, 300 for a tune is a lot cheaper than the money I spent to get it on the road.
 
#9 ·
jave, thanks for the replys man...i was wondering how much it was hurting to use the OTS map, and now i definitely feel a little more hurried to get that tune. i know the soot comes from a rich ratio, so what i was saying was that i found it strange that i'd get soot when the stage 2 (as far as i thought) leaned out the ratio.

also, i seem to get about the same gas mileage i had before the AP...maybe even better, and i think i've been stepping on the gas a little more since i got that extra power. I'm not saying your wrong, you seem to be a lot more knowledgable about this subject than me. would a lean or rich mixture be significant enough that you'd notice it in your gas mileage?

thanks
 
#10 ·
I too noticed that the mileage was better after flash but, BUT you are also allowing your motor to flow freer than before thus you get better mielage than before. The same trip as I lost my motor I got almost 30 MPG, then filled up and and lost my rings on 2 cylinders 4 blocks later. Again this was after 2 years of running on OTS stage 2. you should be ok for a few months but def get it protuned.
 
#11 ·
yeah i will definitely heed your advice. i was going to wait to get a vf34 before i got a tune so i didn't have to do it twice, but now i realize that a tune is definitely my next mod. hopefully just that will even get me a little more power. i'm assuming you got your tune eventually...did you notice power gains or overall performance gains?

also, though i hope to god it wouldn't happen, what kind of labor did they charge you to change your rings? (if you didn't do it yourself of course) and were rings the only things that had to be replaced?

its nice to have a forum so i can avoid making mistakes that others have learned from...i guess that's probably kinda the point. thanks for all the help jave.

peace
 
#12 ·
I actually took the opertunity to do a 2.5 hybrid so I am currently breaking it in and in the process of logging it for Tim Bailey so he can remote tune it. I did the install myself with a help of a buddy because I live in a small town and did not want to pay someone to learn to work on my car.
 
#13 ·
oh ok, right on. so you definitely did get some extra power:) . how exactly are you logging data? are you using the street tuner software or do you have some testing equipment or something? i don't know too much about tuning but would love to learn how to do some of that myself.
 
#15 ·
oh right on....so you're telling me there is free software out there that i can put on my laptop and just go datalog on my own??? wow, the things you learn. i think i may just have to go check that out right now and see what i can learn about it. how exactly are you going to get a remote tune?? you just send in your logged numbers and he writes you a map and sends it back or something? sorry for all the probably dumb questions.

-peace.
 
#16 ·
hey i was just searching around and couldn't find the software...i'm finding plenty of forums talking about it, with links that no longer exist...and a couple sites selling something like that for $250. did you really just find a site and download it?

thanks.
 
#18 ·
thanks for the link man, i'll be checking that out. my laptop is full of viruses so i think i may just erase everything on it and reinstall windows and all that crap first. i'd hate to think what that piece of machinery might be sending to my ECU:eek: .

i'll have to see what is going on with that program, and maybe in the future i'll have a few questions for you...hope you don't mind. thanks for all the help man.

-wrxer.
 
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