What gives an non approved exhaust away

[1fast1]

An LTA-legal aftermarket exhaust will just look bigger and sound a little louder than stock.

 

A catless system (one operated to remove the catalytic converter, of course LTA-illegal) is obvious to an experienced modder. Sound: damn loud, and there may be afterfires, especially if there's an aftermarket atmospheric BOV (blow-off valve) installed in a turbo car. Smell: damn bad, and there may be a strong fuel smell if the engine is tuned to run rich. Sight: extra "burn-like" brown stains around the exhaust, especially obvious in a light-coloured car.

Edited June 21, 2012 by Turboflat4

[Holdenutessv]

Unusually loud, lots of black smoke?

If already had illegal exhaust, why not go straight pipe?

[Calvinus]

I spoke to one of the shops doing exhaust modifications. The owner advised that modification of mufflers to a sport mufflers means that the sport mufflers will over time suffer some kind of wear and tear and degradation of quality and needs to be 'repaired' or 'fixed' every 2-3 years... Anyone know anything about this?

 

Unusually loud, lots of black smoke?

If already had illegal exhaust, why not go straight pipe?

 

[Mits_jc]

Scared dun mod, mod dun scared.

[Weichien]

What's the different between a "operated" exhaust and catless straigh thru isn't it almost the same or it's the same

[GTR78]

That is usually true, but not always.

 

Mugen used to make aftermarket exhausts for road use which actually enhanced low end torque (Twin Loop). The exhaust probably didn't look so powerful on the dynochart but it offered better driveability in real life situations, it also sounds much bassier compared to stock and didn't sound like a "fart" can.

 

Cheers

 

Actually an aftermarket exhausts will give out less low end torque,means not so good pick up.

 

[Elmo]

I spoke to one of the shops doing exhaust modifications. The owner advised that modification of mufflers to a sport mufflers means that the sport mufflers will over time suffer some kind of wear and tear and degradation of quality and needs to be 'repaired' or 'fixed' every 2-3 years... Anyone know anything about this?

 

Modifications to an exhaust can mean a few things:

 

Within muffler: can be a joining of a piping from midpipe and straight-thru to tip instead of the stock piping that lets the exhaust gas flows thru a few chambers surrounded by sound absorbing material (sam). Thus the operation will require cutting open the muffler, remove the sam, join the piping from inlet straight to outlet, which may involve cutting thru or removing the chambers, and repacking back the sam.

 

Midpipe: Usually change the whole piece to a larger diameter one, but if just want to mod on existing, then usually it is to punch thru the silencer or for some a CAT.

 

CAT PIPE usually placed right after the extractor. It is a honey-comb structure covered by a hexagonal shell which is supposed to filter out toxic stuff before the exhaust gas gets to the rest of the exhaust. Modding it will require opening up and removing the honeycomb and packing in some sam and resealing the shell.

 

Extractor: usually from a 4-2-1 to a 4-1 for faster flow or for Subaru from equal length to unequal length for the boxer note. For performance, it is usually from unequal to equal for good low end.

 

People mod to allow the exhaust system to pass visual inspection but only if well done. Lousy jobs will have tell-tale welding marks or rusty joins.

Thus the 'repair' or 'fixed' every few years is to cover up the tell tale signs just before inspection.

 

The sound from a good (well-packed sam and appropriate size for the car) aftermarket muffler can be very good without the need to mod other parts of the exhaust. For performance, then the whole system should be modded.

[GTR78]

 

"Operated" = usually means knocking out the catalyst honeycomb inside the catalyst convertor, making it just a hollow box, it still looks stock from the outside.

 

Catless straight thru = usually refers to test pipes (straight tube) installed in place of the catalyst convertor. Easily spotted from the outside (cat is obviously missing).

 

Cheers

 

What's the different between a "operated" exhaust and catless straigh thru isn't it almost the same or it's the same

 

[Elmo]

What's the different between a "operated" exhaust and catless straigh thru isn't it almost the same or it's the same

 

Operated means taking an existing exo, usually stock, to open up and mod it.

A catless straight thru is a customised pipe made to look and fit like the stock one but without the cat.

[GTR78]

He could be referring to degradation of the sound deadening material inside the muffler (usually glass fiber & metal wool) so it needs to be repacked with new fluffy glass fiber material to keep it quiet.

 

Personal experience with my LTA approved exhaust is that it really does happen even with the reputable Japanese "in-house brands" (etc Nismo, Mugen, TRD). The exhaust sounds much louder now compared to new.

 

Cheers

 

I spoke to one of the shops doing exhaust modifications. The owner advised that modification of mufflers to a sport mufflers means that the sport mufflers will over time suffer some kind of wear and tear and degradation of quality and needs to be 'repaired' or 'fixed' every 2-3 years... Anyone know anything about this?

 

[KaKiLang]

NA car can forget about modding, driving on the road got to siam here siam there, inspection time damm lechey, kpkb but car not any faster.

[Mockngbrd]

neighbours

[Wrathchild156]

NA car can forget about modding, driving on the road got to siam here siam there, inspection time damm lechey, kpkb but car not any faster.

[Frozentrace]

Unusually loud, lots of black smoke?

If already had illegal exhaust, why not go straight pipe?

 

not everyone burns oil :)

 

[Edms]

change bigger tip and install open pod filter =)

[Cephas]

BIG SOUND + SLOW SPEED...lol

[Qr25vet]

BIG SOUND + SLOW SPEED...lol

[thumbsup] [thumbsup]

[Hotfavourite]

Bugatti Veyron?

singapore got bugatti veyron..?

 

haha...i hear big sound...but damn slow.....many years.....got use my brain..so no change....its engine roar..not butt fire...wat else..turbo charging means pressure air force in.....wad else.....its like raping engine with more air ...eh..not oxygen..oxy ...gen.....leh....hehehe...

 

i think this post..kanna monitored..cya bye!

Edited August 27, 2012 by Hotfavourite