3" system, how loud?

[williams]

im getting a 3" turbo back exhaust made up, inc elbow.

for the people that already have a 3" how many boxes have you got? i was planning on just getting 1 large box in the centre, like the mongoose systems.

the car needs to be able to pass trackday noise tests.

 

[red reading]

I have 2 x 18" powerflow boxes boxes in the middle of my car (3" built by me) and it is as quiet as a stock car.

 

[williams]

thats what i wanted to here.

 

[red reading]

If you wanted you could put another at the rear in the stock position with mine to make it even quieter but then with the size of the pipe work and silencer i would have trouble fitting my rear diffuser. but i decided that it was quiet enough as it is.

 

[splmum]

im getting a 3" turbo back exhaust made up, inc elbow.

for the people that already have a 3" how many boxes have you got? i was planning on just getting 1 large box in the centre, like the mongoose systems.

the car needs to be able to pass trackday noise tests.

Now down in oz we like noise so the louder the better, or so it appears with most of the modified exhaust systems you hear.

In reality, I fitted 9 years ago a 3" mandrel bend mild steel system that has a 3"x10" flex joint, a High-Flow Cat and nothing until it hits an east-west Stainless steel muffler (as big as a standard muffler), then coming out in a 4" chrome extension tip.

This was tested at 89dB at 4000rpm so I would say it would pass most tests.

Not noisy (until you really wind it up) and gives excellent flow with adequate back pressure.

just an option.

 

[stevepudney]

I have 2 x 18" powerflow boxes boxes in the middle of my car (3" built by me) and it is as quiet as a stock car.

Sounds perfect, did you make up the boxes from scratch or were they made up from those universal silencer kits you can get, got any pictures..........

 

[red reading]

I got the boxes of ebay (from powerflow) 1 is 6"x 18"round (which i had to modify) and the other is oval 9"x 18" and fit's where the cat used to be, it wasn't a kit i just built the exhaust on the car, i'm taking the loop over the axel out soon and having the exhaust exit in front of the rear wheel, i'm dropping the gearbox soon so i will get a picture then.

 

[vss irvine]

you could also use jetex as they do 3" boxes

 

[vpulsar]

I had a custom 3" system made that was very quiet at normal driving speeds and track day friendly, And even with the big box at the back the car still made over 500 bhp so loads of noise doesn't mean loads of power.

John

 

[williams]

is that the cusco 4 point brace? was worried i wouldnt have enough room for the 3" system and the cusco brace.

 

[skiddusmarkus]

I have a Janspeed 3" downpipe and it fits with my cusco 4 point brace fine.

 

[red reading]

I have a Janspeed 3" downpipe and it fits with my cusco 4 point brace fine.

same down pipe as you and i have a whiteline brace and i don't have any problems

 

[vpulsar]

is that the cusco 4 point brace? was worried i wouldnt have enough room for the 3" system and the cusco brace.

Yes it is and it fitted no problem.


John