Exhaust Help

[PaulLeyton]

Having recently finished my build and started using it the original exhaust was unbearable. So swapped it out for a Dansk twin centre outlet back box, it’s better but still 87db inside the car.

Which considering the amount of sound proofing fitted is still loud on a long journey, so started wearing ear plugs to dull it down.

What back boxes are people using? It’s a 2.0 with triple carbs.
Thanks Paul


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[hot66]

stock back box is usually fine. Was your original knackered ( could you shake it and hear the baffles loose inside) ? Its not induction noise your hearing is it

[PaulLeyton]

Hi James,

The original box had been modified to twin outlet and I’m not sure it had any internals at all. The Dansk one is better, some noise will be induction as it’s got K&N filters but ….

[Bootsy]

Can;t help as mine is an noisy as hell but lovely looking car - would be great to see more of it on a thread

[PaulLeyton]

Thanks Bootsy,
Might just have to live with it. An hour to Flat6 at the weekend was ok with ear plugs. Will sort through the photos and try and make some time to put something together.
Just had a photo shoot for Classic Porsche so need to get the info together.

[911hillclimber]

Not sure you have many options!
I have a 1986 works 2 in 3 out silencer, been welded for the MoT several times.
Surprisingly quiet on a long run, fab when all uncapped, but will tire on a long run. 3 open outlets is almost straight through i think.
I always thought the Dansk twin pipe too much for long runs, and I have a Dansk stock configuration silencer which I fitted and found killed all the '911 engine sound' but was quiet, so the old 2 in 3 out went back on a few years ago.

I think Dansk make a large outlet pipe stock silencer that might give a better sound but not tire.

Not sure that helps, but a final thought is a Turbo Thomas silencer that he can customise for noise levels if you ask.
Just a thought to get the best that suits you.

[RobFrost]

Do you have kilmat in the rear seats, floor etc. and the matting over the parcel shelf?

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[PaulLeyton]

Yes soundproofing under headliner, carpets, all round the rear tub and sound deadening/heat proofing in the engine bay. Just built a 2.4 on carbs to go in it so will be interesting to see the noise levels with that. Might have to get it cut open and rebaffled.


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