Exhaust Noise Reduction
Discussion
Dave
I have an exhaust extension, which I believe reduces noise levels by about 5dbs. It was made precisely to fit the “normal” exhaust but I have to say it’s far from ascetically pleasing. To be honest, I’d rather use the tracks with a higher noise allowance than go out with this on the back of the car. The extension was made by Gardner Douglas. Hope this is a little help.
Andy
I have an exhaust extension, which I believe reduces noise levels by about 5dbs. It was made precisely to fit the “normal” exhaust but I have to say it’s far from ascetically pleasing. To be honest, I’d rather use the tracks with a higher noise allowance than go out with this on the back of the car. The extension was made by Gardner Douglas. Hope this is a little help.
Andy
I bought a exhaust piece from Summit Racing that looks like a ice cream cone full of holes. It goes into the exhaust at the colector, pointy end towards the motor. its not hard to Put it in place temporarly so that you only run it when you need it. How much horse power? I don't know, and anyone who thinks he can feel 10 0r 15 horse power in a car this light when you already have 565 is either named Hamilton or he's fooling himself. It did make the car a bit less noisey. If anyone tries this idea and gets some before and after dyno readings I would love to hear them. Lee
Steve_D said:
There was an old thread on this subject which basically revolved around an owner who fitted these devices for a track day. They caused back pressure in the system which in turn raised the temperature which all but melted the rear clip.
Steve
That problem was caused by those Supertrap things was it not? They have a variable number of plates on the end, but as you say sound quite restrictive and cause a lot of heat in the silencers.Steve
Those cone shaped hole things I thing are made by a US company Dyno something. I contacted them and they were not very positive on how much they could lower the noise level (1 to 3dB I think was the typical value, not great when you are starting at 105+).
Jetex do some long type inserts which I am yet to find much info one (Demon Tweeks sell them).
You could always go for the Factory aftermarket option.
But, from what I have learnt is that the more packing material you can have the better. I liked seeing the pics posted recently at: http://www.pistonheads.com/gassing/topic.asp?h=0&a...
To make sure I didn't get turned away at the Ring last year, I made up some additional mufflers to replace the final tailpipe sections. this brought the noise down from 100dB to approx 96dB. The pipes, the 4 90deg bends and tube were from Merlin and cost under £100 plus a couple of hours to weld. They only protrude about 10cm further than the s/steel ultima pipes and are easily added/removed. Only thing you might struggle with is if you have the mesh over the rear aperture, but it's alot easier to remove the rear clip if it hasn't been fitted, allowing much better access to the engine/g'box/suspension etc. Just my 2pworth.
Thevet said:
To make sure I didn't get turned away at the Ring last year, I made up some additional mufflers to replace the final tailpipe sections. this brought the noise down from 100dB to approx 96dB. The pipes, the 4 90deg bends and tube were from Merlin and cost under £100 plus a couple of hours to weld. They only protrude about 10cm further than the s/steel ultima pipes and are easily added/removed. Only thing you might struggle with is if you have the mesh over the rear aperture, but it's alot easier to remove the rear clip if it hasn't been fitted, allowing much better access to the engine/g'box/suspension etc. Just my 2pworth.
Do you have any pics, would be great to see what you did?extra length is the way to do it! I lost over 9db from back to back testing with the std system, 3 db was from change to different silencers and over 6 db was down to adding an extra 3ft in length and a balance chamber.... all this using freeflow silencers rather than z trap like the std ones... so less heat, less noise and prob more power!
gtr-gaz said:
Hi Dave, How about concentrating on getting the damn thing on the road first, before you start thinking about track days? 
How long's it been??
btw, there will only be 2 reasons for me to go to this years FOD. One, to see your car and the other to see Ditto's paint job
How dare you sir, such cheek!!! How long's it been??
btw, there will only be 2 reasons for me to go to this years FOD. One, to see your car and the other to see Ditto's paint job
are you suggesting 4 1/2 years is a long build?
Just hope youre not dissapointed with my smoke billowing petrol guzzling attempt, its not very fashionable nowadays you know
Pb3 said:
Jetex do some long type inserts which I am yet to find much info one (Demon Tweeks sell them).
I tried these and barely noticed the difference. You need quite a long straight tailpipe for these to go all the way in. I don't, so I had to mod them slightly which may also have had a minor effect. Liam
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