Need help? Refer to our frequently asked questions below:
Q: Do your 991 Headers Drone/do your systems maintain the exhaust valves?
A: Our headers don’t drone as the stock functionality of the exhaust valves remains, and we use the stock or our Lifetime muffler to control the drone.
Q: What is Drone?
A: Drone is a frequency of sound that causes the interior volume of air to resonate or amplify that frequency (like a speaker box). The way you combat drone is to change the frequency in the offensive rpm ranges so that the cabin doesn’t resonate. The stock muffler and the Dundon Lifetime Muffler both have an upper path that is a different diameter and length than the lower path ensuring the frequency is out of the “drone” range.
Street Headers 101:
Weight Savings on a 991.2 GT3RS with Street Headers while keeping the stock muffler is about 50lbs.
Weight savings with our Loud muffler is about 38lbs as our Muffler is heavier than the stock Ti muffler on the RS.
Power with the Loud Muffler is about 4-5whp more than the Stock Muffler on the dyno, but you’d really only see it on a track during 30minute session as the exhaust gasses backing up a bit make the cylinders hotter and the car has to pull timing to compensate for it.
As far as NVH and Drone. Both system keep valves and the valves in combination with a muffler are what keep Drone minimized. Not understanding what drone is is part of the disbelief that a system can be drone free. Drone is result of the cabin resonating due to a frequency of sound that excites it. The way you get around drone is to ensure that frequency is avoided. You do this by using a smaller tube that is a different length in the muffler, (think a trombone). By using the valves to direct the exhaust into the smaller longer tube at those RPMS (frequencies) that would cause the cabin to resonate, you eliminate drone. You can disconnect your valves and make the stock system drone as well. Or leave the factory headers with catalysts and delete the side mufflers without valves and make drone.
As far as vibrations and the like, it’s an RS, not a Cadillac, you’ll need to set your expectations appropriately in that regard…. ;). Because of the power gains, you may notice different sounds, but none of them are eBay trash can civic...
The Titanium mufflers both Akra and Stock can crack depending on the type of headers used. Race headers that do not have catalysts will crack them in 2 sessions on track. The Street Headers that we have do not crack them in part due to the catalyst “chopping” up the pressure waves before they get to the muffler.
We haven’t seen any issues with the mufflers with Street Headers, Race Headers is a different story.
Street Headers do not smell any more than the stock car, there are catalysts and they work wonderfully.
No Tune is necessary or required and no check engine lights if the system is installed properly and competently (meaning someone doesn’t leave a wire too close to the system and melt it, for example…)