Im not sure if my car is back firing, or there's just a lot of built up back pressure in the exhaust. But when my car is completely warmed up and the exhaust is hot, sometimes when down shifting, it will pop really loud like gun fire and occasionally throw flames. I think thats normal for a full 3in turbo back exhaust, because I've seen it on many other cars i know were running fine. What i am a little concerned for, is when im slowing down to a light/stop sign ect when in gear (usually 2nd), my car will make a really loud "pop" like a gun shot at exactly 1500 RPM's almost every time. Im not sure if that's built up back pressure exiting the exhaust, or a back fire. My tune is a tad bit rich but it runs fine. Is it an issue or is it normal like i think?

 

My sr with 3" turbo-back did that for years. It dont do it anymore some time it does its very quiet and no fire now that I have 550 injectors z maf n tuned ecu

 

I figured it was normal. Hell my stock KA did it when it was running a little rich to. Just wanted to make everything was good since this is my first SR and im still figuring it out.

 

Mine did that when I had a cracked turbo mani. Good for scaring middle schoolers walking home

 

My car is awesome and does this, therefore your car must be awesome as well.

 

Preferably. Maybe it's cause it's Kouki

 

it is generally accepted as "normal"

personally, I don't see how shooting a fire ball out of the tail pipe is "normal" but if you're cool with it, then rock it.

 

Factory cars backfire, the only difference is the catalytic converter, resonated sections of the exhaust, and muffler dampen the sound and resulting flame. Combine a car running a little rich with a straight through 3 inch exhaust with a canister style muffler and you'll get flames.

My old ka-t car ran a little rich and used to shoot huge flames out of my hks hi power with a megan racing straight test pipe.

I switched to a resonated test pipe and my rsr exhaust (conventional style muffler), low popping no flames.

I put a stock catalytic converter on the car with the rsr exhaust and what do you know... no flames and barely audible popping.

My STOCK ka used to pop a flame out of the tail pipe with a straight through test pipe, hotshot header and my old Apexi N1 exhaust.

On a turbocharged car you're making the car go rich - lean - rich - lean by modulating the throttle open/ closed. Recirculation of the bov on maf equipped cars also have a lot to do with it. On ANY sr or ka car running a rom tuned ecu if you drive in a high gear at low throttle basically on the threshold of boost and release the throttle the car should pop because you're loading it with fuel and purging it by releasing the air through the bov.

 

My stock kouki blasts fire from under the car on decel (open downpipe, auto ecu).

Basically what you are hearing at 1500 rpms is the DFCO stopping (deceleration fuel cut off) so it starts fueling again below 1500 so the engine doesnt stall.

My Eclipse does that alot too...its kinda funny cause when I flash it while driving down the road it will shut the motor off, then when it finishes flashing the ECU it will kick back on and POP!. lol

 

That makes alot of sense. Never thought it was too big of a deal, but figured i'd ask for my cars safety lol. Thanks dude