2.5" Exhaust Silencers

[JTaylor2005]

Morning All,

I am looking at quietening down my car a bit. At the moment apart from one tiny straight through style silencer at the back my car has a totally straight pipe. It's 2.5" and is a good laugh when driving aggressively. However I am now often doing over time at work on Saturdays where I am leaving around 5:30-6:30 in the morning and I think its about time I tried to reduce the noise level a bit!

I don't want anything toooooo restrictive. This car has been dynoed twice now in two different places at 135 and 137hp. I don't want to loose too much.

Has anyone had experience of fitting silencers into already straight piped exhausts? Is there a certain type I should look for? I need to reduce the rumble haha.

Any advice would be much appreciated.

Cheers,
Jack

[MY95]

Just go for a standard midbox Jack - will quieten it a little but you wont lose much power as they are generally pretty straight through anyway!
There's a guide for the midbox backbox mod on here too

Edit: the standard midbox will be 2.25"

[JTaylor2005]

I'd have to buy a whole new exhaust to do that though and it'd drop the size from 2.5 down to about 1.5" I am trying to stick with what I have and do a cheap quick modification to it :/

[MY95]

However you do it you will lose performance. Could always just buy a hoffman centre pipe and standard midbox as the backbox? both pretty much straight through anyway. Have you got no catalytic converter currently? If you aren't going any further tuning wise I would just go for a quieter exhaust as above. Bought a midbox for £20 for carparts4less and it is still doing great 40k miles later with no issues!

[Poodle]

You can get stainless silencers from most exhaust part suppliers in 2.5", just specify one with a straight-through design. If you get one with sleeves on the end you can simply cut a section from your exhaust and insert the silencer, no welding required and you can do it on the drive.

[madmadmax]

i was looking at at a bullet style straight through 30" long to put in middle, the ones that come on the 2.5" s/s systems are 26" long and straight through . so all you can do is add length.

the thing that hase the biggest efect is the back box with a large volume of sound deadening material and then with a mid box will give the most sound reduction. unless you want to get in to resenators and complicated maths but thay mostley deal with drone.

somthing to note is that the sound deadening material dose settle and get broken up by the sounde waves and vibration

[JTaylor2005]

Cheers guys. I don't mind having one that isn't straight through. I just don't want to go back down to a very small diameter exhaust like the standard one

I will have to do some measuring up under the rear of the car to see what can be fit in there

---

Is there much difference volume wise between a straight through exhaust and an exhaust with a couple of big straight through style mufflers on do you think?

[Poodle]

There's a significant difference in noise with a silencer in the system, clue is in the name. A compartmented reflection type silencer would be just a restrictive as a standard exhaust (which isn't really that restrictive at your power level anyway).

[welshpug]

quite unlikely you will lose performance, 2" is enough for 200+.

my 240 bhp engine is on a 2.25"

[bashbarnard]

Im sure every time someone talk about DIESEL exhaust size you pop your head up. Your 240bhp car is a petrol remeber. They dont shift the same amount of air and dont require unresrtive stuff to aid spool.

Sent from my Gemini using Tapatalk

[madmadmax]

the stock exhaust kill 8 hp approx, so i will say go for a straight through.

[Piggy]

Im sure every time someone talk about DIESEL exhaust size you pop your head up. Your 240bhp car is a petrol remeber. They dont shift the same amount of air and dont  require unresrtive stuff to aid spool.

Sent from my Gemini using Tapatalk

Yup. 

When the Racetractor downpipe fell off... Had instant power gains... And that was 2.5" straight through.