exhaust problem...help!

[harras88]

i recently changed my car's exhaust and it works just fine until i noticed something a couple of weeks ago.

i noticed that when i drive fast say 160~180 km/h and then i let go of the gas pedal there is this loud popping noise coming out of the exhaust as my speed decreases and i can sorta feel like the exhaust is shaking furiously right under my seat.

so my question is could you guys please post your experience or opinions on what the crap is the malfunction here? thanks

oh yeah i drive a satria neo 1.6 (non-cps) and the exhaust is a 4-2-1 with a cat-back system

would really appreciate any insights on this thanks

 

[^pomen_GTR^]

engine backfire maybe???

 

[mines998]

The cat. converter already remove rite? If yes I think is quite normal. Infact is very cool to me rather install those fire dragon yet no speed at all.

 

[bera]

shaking furiously...?? please check whether the exhaust pipe is mounted correctly...make sure they dont touch the car under side...

 

[harras88]

The exhaust has a cat convertor its not one of those noisy cap ayam exhaust....

What I meant abt the shaking furiously part is like there is suddenly the air flow of the exhaust is sorta blocked or something not like its not mounted properly....hurmm dunno lah how to really describe it but something like that lah

 

[kumar22mostwanted]

the popping sound could be normal maybe even a bit of vibration under the seats but if you feel the piping is vibrating furiously definitely needs to be checked

 

[papagoines]

afr is rich perhaps?

 

[mines998]

I think check mounting. Maybe add few more support if can.

 

[harras88]

afr is rich perhaps?

whats afr?

the popping sound could be normal maybe even a bit of vibration under the seats but if you feel the piping is vibrating furiously definitely needs to be checked

really? normal is it?....theres still a warranty o the exhaust so i guess i'l just bring it back there lah see what can they do abt the mounts

 

[kumar22mostwanted]

whats afr?



really? normal is it?....theres still a warranty o the exhaust so i guess i'l just bring it back there lah see what can they do abt the mounts

afr is air fuel ratio normally the popping happens especially if you have an atmospheric bov which is a bov that vents the air out the atmosphere instead of recirculating it back into the system like what the oem bov's do
the reason why this cause the popping sound is that your maf would incorrectly calculate the amount of fuel needed to provide the right air fuel ratio because the amount of air it would have assumed in the calculations would be inaccurate due to the bov venting out some air hence the fueling would be too rich and this would cause the popping sound actuall i personally think its quite cool
but sometimes i also had this problem where i simply rev to get the bov sounding then suddenly i can feel something moving hard under the car and a huge backfire but all this is in a standstill
but since you have a warranty you should take it back and see what they can do about the piping vibrating vigorously and about the popping i dont think they can do anything about it

 

[harras88]

owhh kay....i think i kinda get it thanks dude!

 

[papagoines]

The popping sound (if caused by a rich a/f ratio) can be alleviate if you tune the engine back properly... maybe because your exhaust is too free flowing for the ECU to calculate itself

...err bro kumar... de popping sound is more prominent in NA cars IMHO... especially in carbie

 

[kumar22mostwanted]

The popping sound (if caused by a rich a/f ratio) can be alleviate if you tune the engine back properly... maybe because your exhaust is too free flowing for the ECU to calculate itself

...err bro kumar... de popping sound is more prominent in NA cars IMHO... especially in carbie

oh yea ke my bad
coz ive never driven an na car that pops thats probably because all the NA cars i drive are in factory condition :rolleyes:
always see turbo cars farting away though

 

[papagoines]

oh yea ke my bad
coz ive never driven an na car that pops thats probably because all the NA cars i drive are in factory condition :rolleyes:
always see turbo cars farting away though

popping exhaust sound during overrun in a carbie pops 1 blob at a time like a low pitch gurgling... in malay ppl say "seketul - seketul meletop" hehe

in a turbo car is mellower but higher pitch then carbie.... or should I say "sebu" or like bees buzzing in a glass jar...

but I like exhaust popping sound a big engine car ... i.e 2.5liter and above... be it turbo or NA

 

[DanzEterna]

just wondering, y ppl plant a spark plug in the end muffler? can create fire ah?

 

[^pomen_GTR^]

danz....thats what all autoshow car with fire dragon does



exhaust popping in n/a not really normal...but i kind of like it especially on my race bike..

maybe u need a better flow of air from intake...lean a/f ratio also can make exhaust popped (along with bluish flame)

*if reddish orange flame it was a sign of rich a/f

 

[DanzEterna]

but i tot fire dragon is a flame throwing system?
if i just plant the spark plug there will it create fire?

 

[kumar22mostwanted]

but i tot fire dragon is a flame throwing system?
if i just plant the spark plug there will it create fire?

yeah i think thats the trick some of these autoshow guys use to impress people

 

[DanzEterna]

kumar...tq bro...sorry...but i meant will my exhaust create fire if i just plant a spark plug there without fire dragon?

just wanna understand the concept..:)

 

[kumar22mostwanted]

kumar...tq bro...sorry...but i meant will my exhaust create fire if i just plant a spark plug there without fire dragon?

just wanna understand the concept..:)

hmm that part i cant say
but i guess you could always test the theory