i have a 2.5 inch y pipe and a 2.5 inch custom catback on. it sounds like i have a sorta backfire from 1st to 2nd and sometimes from 2nd to third. is this becuz of loss of backpressure? am i hurtting the engine? how do i fix or will the ecu adjust? sorry, just wanna know if anyone else had this, what causes backfires, by backfire i mean i get maybe a not too loud crackkle pop sound in between gears, my dad thinks my engine will blow i think it just cuz a v 6 has an odd firing pattern, help me out will ya? it only happens between those two shifts, never while actually accelerating....

 

I think lots of the videos of sx7r, and roadbeast and big modded maximas backfired some.

I may be wrong

 

Ever since I put my y-pipe on my car does the same thing. I still have my stock catback so it is only noticable when I stand outside the car and have my friend rev it for me. I think it sounds good, but that may just be me. I wouldn't be worried about it.


Adam

 

wont this damage headers, or exhast???

 

my car backfires all the time with me nex exhaust setup.
i have no problems with the car.

 

I don't think what you're describing is technically a "backfire."

Rather, it is a noise generated in a "free-er flowing" exhaust when there is a sudden change in both the velocity and backpressure of the gasses travelling through that exhaust system (as when you shift, or let off the accellerator suddenly from high RPM's)

These sudden changes in velocity and backpressure create "turbulence" in the exhaust flow; the result to your ears is the crackling, popping or in milder cases, burbling sounds you hear.

This is NOT harmful to your engine. (Just upsetting to more "conservative types.")

Think about it from this standpoint: almost ANY racecar will exhibit this behavior, including say. . . the cars that race the 24-hour Le Mans race. 24-hours is a LOOOOONG time to push equipment at race-limits & I doubt any racecar designer would put a component on their car that would knowingly contribute to a premature engine failure (Sponsors pay lotsa $$$$$ to see that any car they back has a good chance of staying on the track for the whole race).


Let the free flow, flow freely. . .Don't be stressing it, mon.

 

thanks a lot man, what u said makes perfect sense and thats is what i was thinking on the lines of.... my dad just likes to get involved...

 

thanks a lot man, what u said makes perfect sense and thats is what i was thinking on the lines of.... my dad just likes to get involved...cuz i like the crackling sound specially when im downshifting to a stop, i just hope my muffler doesnt sound to ricey i need to hear it from the outside, cuz inside it sounds nice as hell

 

A backfire sounds like a gun shot.