ace car back to street?

[crashmy911]

I've got race headers into straight pipes and this thing will cause hearing loss without a helmet on. What kind of a muffler or endings for race headers will make it except able for street without killing hp?

[Schulisco]

Dansk mufflers with german TÜV approval are street legal in Germany with a measured noise of approx. 100dbA on that early noise regulation standards and measurement methods of the 70ies up to early 80ies..that sound level has also been emitted by stock exhaust. They emit 80dbA by cruising with 30mls in town. Don't know if they keep this level with your headers and straight pipes.

Thomas

[stownsen914]

It depends a lot on the engine, and in the headers. A full tilt race engine will need a free flowing mufffler, or it won’t run well. A milder build might be fine with even a stock muffler.
And which headers you have may dictate muffler options. E.g. European Racing Headers have off the shelf adapters to use standard 911 mufflers. Many other headers can use custom adapters as well to keep your options open to use an off the shelf muffler.

[crashmy911]

this motor is a mild race motor. 240hp at wheels from a 3 liter

[REVerend]

I ran a straight pipe (cat bypass and little slightly angled pipe to exit bumper cutout) on my 1983 SC for a couple weeks. It was definitely not hearing safe but did sound incredible.

Switched out the little angled piece coming off the cat bypass pipe for a FabSpeed Supercup and it was a lot more livable, though still pretty loud. The Supercup is basically just short section that makes a U turn behind the muffler but it otherwise completely free flowing.

[crashmy911]

my motor is a 240 hp beast so it makes a lot more noise then stock