DEVELOPMENT: The GT4 is a masterfully built machine from Porsche. The 3.8L emits a distinct wail that is so incredible that it is begging to be amplified. Our Valved Exhaust System is designed to help you extract the most potential from your GT4 while still being streetable. While in quiet mode with the valves closed you will have a refined and sporty sound with no drone (with factory headers and high flow catted headers) at highway speeds and retain the ability to quietly enter and exit your neighborhood without annoying those around you thanks to the high quality mufflers. We know that a lot of owners plan on running catless headers on the street and minimizing drone was a goal of ours. Unlock the valves and you’ll be ready to turn off the radio, roll down the windows and hit your favorite back roads or go hard at the track. Every blip downshift will emit an incredible bark that will make the hairs on the back of your neck stand up.
CONSTRUCTION: Each system is made from mandrel bent T304L stainless steel tubing (featuring 2.5″ OD over axle pipes) and features mufflers with fortified casings in the interest of durability. With valves closed the exhaust gasses are routed into the SOUL muffler, which is packed with high quality sound deadening material designed to withstand abuse and not blow out over time. The mufflers are incredibly effective at minimizing drone. Exhaust gasses make their way through the muffler and out through perforations into the outer piping. With valves open, exhaust gasses are now free to exit out through large 2.5″ piping while perforations allow exhaust gasses to “talk” with the muffler, encouraging a fuller, more robust tone. Choose from a variety of 321 stainless exhaust tips in different styles and finishes – or contact us to customize your own set! Titanium single wall tips are also available and save nearly a pound of weight over stainless steel tips!
BOLT ON AND GO: Each exhaust is tested in a fixture to guarantee fitment and then foam packed to ensure it arrives in perfect condition. Thorough installation instructions are included in the box for a straightforward install that can be performed by most DIY enthusiasts. Valves are controlled by the existing valve button, our valve controller fobs, and are compatible with HomeLink!
LIFETIME WARRANTY: Enjoy your SOUL exhaust components with confidence on both the street and track as they are covered by our Lifetime Warranty! Our team will quickly work with you to resolve any issues or answer any questions that you may have.
Estimated install time: 2-5 HRS
Vehicle fitment
- 2016 Porsche Boxster Spyder
- 2016 Porsche Cayman GT4
All products are shipped out from one of the Signature Autohaus shipping locations. Signature Autohaus drop ships some products and ships direct others. All products are shipped via FedEx, UPS, DHL or another qualified shipping carrier.
Special arrangements may need to be made for international orders and oversize packages.
In the event a product arrives damaged to your location, please follow the steps listed below. All damaged items must be reported to the shipping carrier immediately and you must notify Signature Autohaus within 5 days of receiving your order. If these steps are not followed, your shipment may not be able to be a candidate for a claim.
Complete the Shipping DAMAGE Claim Form by contacting the carrier that delivered your package.
1) Keep the product and its original packaging and box
Make a list of the damaged or lost item(s)
2) Signature Autohaus will contact the shipper once we receive the email info above to schedule a pickup, DO NOT send it back to us
3) Once the product is picked up and inspected by Signature Autohaus and or Supplier, a replacement or credit will be issued.
4) The Shipping Rates shown at time of checkout our dimensional rate only. If your shipment weight is to much then contact us for a shipping quote. If there is an error in the shipping rate quoted we will contact you and let you know of the changes. International orders(Outside the USA) are not automatically processed as we may require additional information from you.
If a product is ordered and not wanted, the UNUSED item can be returned for a 35% restocking fee. Shipping is not refundable in either direction. All items wanting to be return MUST be reported within 30 days of the original invoice date. No items will be returnable after 30 days. All products shipped from the Signature Autohaus warehouse are shipped via FedEx or Freight and require a signature when delivered. Some packages shipped from the manufacturer may or may not require signatures for package release. Fedex, UPS, and DHL have package pick up locations if you are unable to sign for the package. If the package is returned to Signature Autohaus or manufacturer, you will be responsible for the return shipping costs and pay a 35% restocking fee. These fees will be charged to your account on file.
SIGNATURE AUTOHAUS DOES NOT REFUND SHIPPING CHARGES. If you modify, install, or alter the item in any form, we cannot accept it as a return, will not cover any expenses related to the product or installation, and you maybe be required to purchase a replacement.
In the event that the product you ordered is sent either incorrectly or processed wrong by Signature Autohaus, we will arrange for the package to come back to us and ship out a replacement. We will evaluate the situation before we determine the shipment was incorrect.
To return a item back to us, please do the following:
1. Contact our Customer Service Department to receive a RMA number. All packages returned without a Returned Merchandise Authorization number will be refused.
2. Package the item up in original packaging unless deemed unuseable
3. Include the UNUSED parts and any additional information that was included
4. Include a copy of your receipt
5. Write a brief description of the problem with the product
6. If you have a receipt for the return shipping include as well
7. We DO NOT accept any freight collect packages
8. Once we have received the above information we will notify you via email or phone and let you know the status.
