Ok so the other night im coming home from the movies and according to my brother and his wife, when i shift my exhaust shoots about a foot long flame. to give some insight my mods are Fujitsubo EX Manifold, Legalis Super R, cusco dp and hks ssqv. No before some of you go on your rants about BOV's i know that its most likely the cause of it. What i dont know is what kind of realistic damage, if any could this cause? Am i going to melt something or is a infrequent ex flame not that big a deal?

 

its not too big a deal. as long as your exhaust temp doesnt go over 1600

 

It's all good, after I had my bike tuned it would shoot flames on decel and between shifts too. I'd say the bov and lack of cats probably has alot to do with it.

 

i figured the BOV and catless would be the cause....as long as somekind of mechanical part doesnt shoot out with it then i really dont care....i think its acutally kinda bad a$$.

 

Looks like your running way to rich? Do you have a lot of black soot around exhaust? Just guessing.

 

actually no i dont have any soot around my exhaust or rear bumper. THeres a little bit at the very tip of the exhaust but i figure thats normal since i dont run any cats.

 

The reason its shooting flames between shifts is in fact the BOV. Consider this, between shifts, when you vent 100% atmospheric, for that instance you are running very rich... although just for a moment... once that rich mixture is sparked, it shoots a flame

Makes sense given common sense. But I'm guessing that the lack of cats is also contributing to the action. I know of many Subies with BOVs 100% atmos. that DO NOT Shoot flames... So it's most likely the BOV causing the flame and cats usually supress these "flames"... since you have no cats, let there be light!

Enjoy!

 

Yeah, the BOV = bad news. The DP isn't helping if it's catless either.

 

i wish i shot flames im guessing you have 93 octane which also dont help non

edgar,

 

Im running no cats and dyno tuned. I'll bet I am a tad richer now then i was when I tuned since I tuned in the fall with cooler weather. But My BOV is stock recirculated. once the exhaust heats it will shoot a flame whenever it backfires. Sometimes during a slow 1-2 shift in higer revs or a 3-2 downshift in higher revs will make a loud pop (backfire). And if I"m really on it. I will hear it popping everytime I get off the gas in 4th. Since there are NO cats that raw fuel just ignites itself on the way out if the exhaust is hot enough. If you are catless and your car backfires it probably shoots flames, or at best the tips will look like a round fireball for a second. no flames like "that movie" though unless you have an anti lag kit.

 

Just curious, I'm running catless right now and I pulled off my axle back exhaust a week or so ago on my 03 WRX wagon so now my exhaust dumps right in front of my rear axle. I don't mind the black soot it protrudes onto my rear differential, but should I be worried about 'shooting flames' onto my axle, or worse yet, my boot? Opinions anyone? I've never known anyone to drive around like this so I don't know if what I'm doing is not good?

Smitty

 

im not sure that its bad or good. I mean the flames you might shoot are only going to be quick little bursts and thats not to say it will happen often. but come to think of it, Im not sure what people running cars with straigh dump tubes right off the turbo do either (rally cars or other race cars). I imagine that there isnt anything that is going to cook down there but I cant be certain either. Just out of curiousity, why dont you have the entire exhaust on the car? and are you catless and shooting fire?

 

Thanks for the reply. Yes I am running catless and to tell you the truth, I really don't know if I'm shooting flames, it's too far under the car. I guess maybe I'm not really worried about the bursts of fire as much as I am the hot exhaust gases that are constantly being dumped there. I know there are companies that sell racepipes that dump in the same basic area, that's why I thought it would be safe to do so, but I figured I'd get some outside info just to be on the safe side of things. The reason I'm running without a muffler? Coolness factor...haha. It sounds lame but that's it. I love the sound of straight pipes and I know if I get pulled over I'm screwed...ahh the price we pay to gather attention, right? I need to invest in a custom exhaust pretty soon...

 

well dude, I figure yeah its going to be hot down thre but at least the car is always moving ya know. a friend of mine had a nissan NX with an SR20det swap in it and had the rear section on the hangers but it was just s dump pipe off the motor (sleeper style) and he never cooked anything. if you like the sound. you should look into an ATR. There isnt another WRX that I have heard that sounds like mine.there really is no muffler on it. its pretty much the piping and then splits into dual tips. it sounds pretty much the same if I run the car off the DP.

 

You might want to check and see how close the exhaust is exiting near the gas tank. I'm sure you wouldn't want those afterfires lighting up your gas tank!!! IMO it is a bad idea to run w/o a muffler b/c you are going to end up damaging something or getting hassled by the police.