Ok, to set up the scenario and reduce questions, here is the exact situation the flames occur under.....(car is an 05 evo RS)

When I'm driving regularly, I have never had one problem. I HAD cat-back exhaust with a downpipe, but stock cat. I NOW HAVE turbo-back completely 3 inch. No other mods at all. Now Since I installed the cat-delete w/02 fix, I have experienced (3-4 times now) a backfire at high rpm, wot. Note, I can be almost full-throttle and not experience this, and it only happens in 3rd or 4th gear. I can stomp it in 5th and not have any firing. Now when it backfires, I guess it could be described as a falling on it's *** for a second performance wise, then shooting a flame, a very large one at that. It only occurs at the 5500-7000 rpm range. It seems like a timing issue to me, where the exhaust valves would be opening too early and allowing ignited fuel to blow out the exhaust, also explaining the drop in power for a second. Would a dyno-flash help this? Any help is greatly appreciated, thanks guys. by the way, I''ve run multiple tanks of gas, so i don't think it's occuring because of a bad-batch or anything.

 

Almost sounds like fuel cut if it falls on its ***. But moreover it is probably likely due to the evo running rich, and you not having a cat on the car, without a flash. Should be fixed by a flash as it will lean out the car a bit.

 

That's not fuel cut, that's just your car running RICH. The stock ECU runs pig rich from the factory for added safety. Nothing to worry about. I ran 3" TBE for about 2 weeks (fireballs everyday) before getting my flash and now all is well. Fire ***** are cool, but performance is better. Get a flash and you'll be good to go.

 

I had the same issue and came to realize that doing a flash fixes that.

My scenario after install:
DCsports SS exh man, turbo dump pipe, full 3" TBE w/cat delete, Profec B II set at 22psi.....first time out I saw flames too. In the same gears, at one point, it felt as though I had a fuel shut off at around 5500 and then the fuel kept dumping and then BOOOOM! I thought my car blew up. So it was back to my shop to check things out. The cool part was a guy in a new C6 Vette next to me on the hwy and saw the flames, and his jaw dropped and then 2 thumbs up with a big grin

 

If it is running that rich, it is costing you HP, get flashed and lean it out a bit!

 

what if you had a flash with tbe with hi flow cat,cams, fule pump, k&n drop in, mbc... and plan to go test pipe? would I see shooting flames?(hope not) after installing test pipe?
or do i need a retune?

 

http://media.putfile.com/Darth_OnFire61

 

With the best tune you could have, no. Flames = Rich. A quality tune should keep you right on the money with ANY mods. I'm not saying i would do this, but a buddy of mine (wrx with stand alone) will add more fuel on friday nights just for show. AHAHA... So rice

 

For the record.....the tune I run when road racing is very FAT (but safe) and that is why I shoot flames.....and yes I am catless.

 

so you are saying since i already have the tune(custom tune by Turbotrix), I wouldnt get flames even after i install Test pipe? which is good..

 

Thanks a million to all of you who responded so fast I'm not so worried now. Thanks

 

I had some flames shooting out the exhuast as well, though not much. Now I have the proper fueling tuning and parts to match, so it's all good.

 

Your tune would be off a little, but not enough to cause you to shoot flames. With a TBE and no tune, an evo will run richer than 10:1 at the top end. Your car is probably running around 11:1 with your tune, and it might change to 10.9:1 or 11.1:1 with the test pipe. I'm not sure which way it will go, probably leaner, but it won't change much.

-Paul

 

The fact that it falls on it's face leads me to belive it is the ECU cutting spark or retarding timing and then blowing flames out the exhaust because of the unburnt fuel. If it was just running that rich and making flames when the fuel vapor got some oxygen at the end of the pipe why whould it fall on it's face?

The video shows flames coming out at off throttle that's normal for a catless setup running rich and that's not what this guy was talking about.

 

If the car falls on it's face during a wide open throttle pull you have a problem which needs addressed immediately. This is not a case of a car running a bit rich. Get it to a shop.