"pop" sound in the back after each hard shifts.. backfiring? why?

[91nissantwo40sx]

ok the car is running fine but it seems to backfire after each hard shift.? anyone know why its doing that? It only backfires when i drive it hard but when driving normally it doesnt backfire at all.

[rb25xtc]

Unburned fuel igniting in your exhaust.

[kainvamp]

its running rich at high throttle

[91nissantwo40sx]

how do i fix this problem?

[cheapscheisst]

if you're running w/o an safc or something similar to compensate for you're bov (if you're running a non-recirc) it causes a rich spike which will cause a backfire.

[91nissantwo40sx]

if you're running w/o an safc or something similar to compensate for you're bov (if you're running a non-recirc) it causes a rich spike which will cause a backfire.

what do i need to solve this problem? i would like to get this over and done with quick because i dont want the engine messing up on me

[adrianfromthecastle]

what do i need to solve this problem? i would like to get this over and done with quick because i dont want the engine messing up on me

recirculate your bov or get the hks eids or an afc

[91nissantwo40sx]

recirculate your bov or get the hks eids or an afc

sorry man im such a rookie at this but please be more specific

well i dont have an aftermarket BOV installed and wat is an hks eids? or afc?

i need like a step by step on what to do. I am trying to learn as much as i can because im really interested in this kinda stuff but its hard for me because i dont know much about them.

[adrianfromthecastle]

sorry man im such a rookie at this but please be more specific

well i dont have an aftermarket BOV installed and wat is an hks eids? or afc?

i need like a step by step on what to do. I am trying to learn as much as i can because im really interested in this kinda stuff but its hard for me because i dont know much about them.

Ooh... then that changes things... what modifications do you have, if any?

[otterman]

Adrian your sig makes it impossible to read any thread you post in

[91nissantwo40sx]

3" inch all the way back with a 4 inch glass pack muffler ( it has no catalitic converter on it). That exhaust is a strait pipe (no resonator)

SR20DET stock @ 7psiBlitz boost guageCone air filter

[Stripes]

3" inch all the way back with a 4 inch glass pack muffler ( it has no catalitic converter on it). That exhaust is a strait pipe (no resonator)

SR20DET stock @ 7psiBlitz boost guageCone air filter

Running a straight pipe has something to do with it. and from the way im understanding what you're saying, this isnt backfiring, you're actually experiencing an afterfire. its happening after you shift because when you take your foot off the gas pedal, the car has a moment of running rich, so the unburnt fuel left over doesnt have enough air mixed in with it to burn it off properly, so it explodes inside your exhaust.im not 100% sure, but i dont think that this will affect your engine at all. now if it was a backfire, then it would definently be a good idea to find a way to fix it.hope this helps : )
Modified by Touge' at 6:54 PM 10/15/2007

[New2SR20]

like the last person posting said..its an afterfire..my S4 had the same thing after i installed downpipes and ran open pipe exhaust to remus mufflers...nothing to be worried about

[91nissantwo40sx]

I actually hear the same thing when i put it on high throttle. After i let off my foot off the gas i get the "pop" sound in the back. what does that have to do with a straight pipe?

[Stripes]

I actually hear the same thing when i put it on high throttle. After i let off my foot off the gas i get the "pop" sound in the back. what does that have to do with a straight pipe?

because there is no catalytic converter to filter out the fuel from the air.

[fast_s13]

every turbo car i have ever owned has done that

[homeslicej2]

Interesting. Mine does this now, but I'm running open BOV and pig rich, so I assume it's backfire. But I have a test pipe so, is it afterfire or backfire? It didn't do it when I first got the car, that's why I thought it was backfire.

[New2SR20]

u pretty much answered ur own question.. uncirculated BOV and runing pig rich...take a wild guess.

[Jadesr20det]

SR's are known for backfiring. If you are runninc your BOV to the atmosphere (as stated) your gonna have that backfire. Im used to it already and people think the flames are cool especially the rotary guys lol

[homeslicej2]

Yeah, I want to re-circ it, but I have the older model SSQV. I'm thinking of some possibilities as to how to re-circ it, bc I don't want to buy a new BOV when I need an AFPR and gauge.