Huzaifa

iTrader: (1)

Is it possible to get the carbon buildup in the exhaust system cleared? I’m currently running a full 3” Tomei system from turbo back and it doesn’t quite sound the same as it did when it was crisp and brand new…

jaygsi

iTrader: (46)

Normally in my findings performance exhausts start out quite quiet when new. And get louder as they build up with carbon I'm guessing. After a month the sound has changed loads.

Huzaifa

iTrader: (1)

Its lost its tone and sounds like a motorbike now at least it looks cool

jaygsi

iTrader: (46)

How long did it take for that too happen?

Gambit

iTrader: (6)

your findings are back to front. Carbon buildup acts as a sound absorber

1509joe

iTrader: (2)

As above and if you have a carbon build up its probably running far too rich.

jaygsi

iTrader: (46)

Never found that at all. surely all the carbon will help block up the baffles? Therefore increase sound. All my exhausts start of quieter when fitted, then get louder. Fitted a brand new Jap style exhaust once, and was shocked how quiet it was. Month later and was insanely loud.

Huzaifa

iTrader: (1)

I’ve got pops and bangs mapped in and it’s my daily so that probably doesn’t help. A/F ratio is fine as it’s mapped by SC and no soot on bumper or exhaust tip. So is there a way to get the carbon buildup inside all cleared out?

1509joe

iTrader: (2)

Pops and bangs is fuel being dumped in on the over run. That is the cause of your carbon.
Get rid of them and your exhaust will clean up and your fuel consumption will improve.

jaygsi

iTrader: (46)

Really don't understand the pops and bangs, yeap that will fill your exhaust with carbon for sure. Also a dump valve will do the same. My Impreza came fitted with one, use to pop now and again, removed it and runs alot better.

The Joshua Tree

I presume having no Cat and a straight through exhaust wouldn't help with carbon build up.

jaygsi

iTrader: (46)

Anything that changes the fuelling and making engine run rich would cause carbon build up. Unless its been mapped for a decat.

marcomurabia

if you have a carbon build up its probably running far too rich.

fpan

iTrader: (11)

If anything an exhaust should quieten (sound less tiny) with carbon build up as carbon acts like an "insulator".

jaygsi

iTrader: (46)

Never found this in my life. And I've fitted an insane amount of exhausts.

My only explanation is the carbon builds up and blocks up the baffles in the exhaust, causing sound to increase due to baffles being blocked so less effective.

Just my theory.

Gambit

iTrader: (6)

It's a wrong theory

johno01

All tail pipes I've ever seen are black inside when there not cleaned...is that carbon build up?

jaygsi

iTrader: (46)

That's correct. That and unburnt fuel, over fuelling.

jaygsi

iTrader: (46)

Can you explain then why every exhaust I've ever had went louder with time?

After about a month when the inside of the exhaust is no longer shiny but all blacked up with carbon etc is then louder.

Had it with brand new exhausts and used. From scorpion, Prodrive, magnex, powerflow, jap sytle, JDM exhausts, and many more. Had over 50 + exhausts.

marcomurabia

get louder as they build up with carbon I'm guessing. After a month the sound has changed loads.