Exhaust Back Pressure and its too loud!

[saxos_rock]

hey i have a 1.0i saxo mischeif with a 4.5" exhaust. I have left the cat alone so it is just the exhaust but it is extremely loud at 60+mph. I love the rumbling sound it gives but want to eliminate the scream at 60. Does anyone know how i might be able to do this? I want to increase my back pressure as well because apparently im losing performance. thank yu

[Karl]

ditch the 4.5 inch exhaust for a smaller can

++ backpressure
++ less noise at 60+ mph probably

[Simpson_Sax]

mate i had the excact same thing when i owned my 1.1. i got a backbox then it was good, lovely sound. but then i added a straight through exhaust with a sports cat. Now i thought this was good but when i reached 60/70mph the noise was insane. I blame it on my sports cat but since u haven't got one its a confusing one. i'd say change the backbox for something else possibly if u still want the roar

[saxos_rock]

cheers guys! ill prob get a new exhaust then. any ideas what might be best? thanks

[KamRacing]

to reduce the noise you'd have to place another silencer into the system or change the backbox to a less boomy one.

[Karl]

Magnex are a bit more of a subtle sounding exhaust.

[Simpson_Sax]

Just depends really what your after. i'd say go to a proper car store and ask. i just had a cheap 'rage' backbox on my 1.1. its what i was after. not much point spending loads, like £300 on a fully fitted one cause its just a small engine. Good luck tho :D

[saxos_rock]

to reduce the noise you'd have to place another silencer into the system or change the backbox to a less boomy one.


Would thi silencer go somewhere before my backbox then? either that or yeah a magnex is the way forward!

[Ryan]

or you could just not waste time with performance parts on a hamster engine.

save up and wait till you have a better engine to make breathe

[VTS_16v_Boy]

Basically back pressure as I understand it is pressure created by exhaust gases which affect torque more than bhp.

With a narrow bore system and a centre box and back box back pressure is created becuase gases are entering the system slightly faster than they are exiting the system.

A larger bore system with just a back box with a larger straight through design will lose back pressure as the gases are exiting the system quicker than they are entering - With a Turbo setup this isnt a problem (to a point) but with a NA engine it is.

Getting a balance between the two is the key and some (Not all) sports exhausts brands spend alot of money gettin this rite.

Like mentioned no mod whether it be exhaust, decat, airfilter etc will transform a small cc engine but a better back box will reduce the noise.

[KamRacing]

Would thi silencer go somewhere before my backbox then? either that or yeah a magnex is the way forward!

yes it would.

If you want a full system that will include a big backbox you could consider the supersprint one. Comes with a 100mm backbox. They are well designed and would maximise performance. I'll check later that it would fit the 1.1 but off the top of my head there is a suitable center section.

If you installed an extra silencer it would be before the backbox. Could go to a custom exhaust place for them to knock up something that'll go in the standard system.