These modular headers are the perfect solution for any street driven 4.0 liter Cayman or Boxster. Our modular design features a quick release V-band connector that allows the owner to easily swap between our German made HJS 200 cell cats and a cat bypass “straight pipes” for track use. Rennkraft, translated from German is “race power”. These unique headers offer true street and racetrack functionality in an innovative precision engineered package.
Many have complained about the lack of sound with the new 718 4.0 Liter cars, these high flowing headers completely solve that issue. Equipped with our 200 cell cats, you will get a louder exhaust note with a much more raw sound. Higher frequency tones are more defined, and deceleration burbles are more robust and transparent. With the cat bypass pipes installed, you’re in store for a sound much more akin to a 911 CUP car than a Porsche street car. The volume isn’t overbearing, but the sound is very aggressive and race bred. It totally changes the character of the car. With the stock muffler in place, there is no drone what-so-ever, even with our Over Axle GPF Delete Pipes also installed.
After extensive dyno development we found that mid length headers made the most power across the entire power band. With no tune, compared to a stock car we gained 31 whp and 19 ft/lbs of TQ at 7400 RPM with Sport Cats and 33 whp and 24 ft/lbs of TQ at 7200 RPM with Cat Bypass Pipes installed. That’s a gain of 33 HP and 36 HP, respectively, at the crank! Peak horsepower also increased from our baseline of 383 whp to 405 whp with our HJS Sport Cats and 409 whp with Cat Bypass Pipes. See our dyno graph above for more details.
Fits all Porsche 4.0L Cayman/Boxster GT4/GTS/Spyder vehicles 2020+
Impressive dyno proven power gains of 31 whp and 19 ft/lbs of TQ with the Sport Cats and 33 whp and 24 ft/lbs of TQ with Cat Bypass installed
Why We Choose HJS Catalytic Converters:
HJS German imported catalytic converters are made from some of the highest grade materials you can find in a catalytic converter. This yields high performance gains and longevity so it wont deteriorate over time like lower grade catalytic converters. These catalytic converters flow up to 93-95% of a straight pipe in most applications. The benefit is that you get the "straight pipe sound" while still being able to provide enough emissions scrubbing to prevent a check engine light. If you'd like to learn more, watch our video about HJS catalytic converters.
DISCLAIMER: This product removes the OEM catalytic converters from the vehicle, and as such, is strictly intended for closed track events and off-road use only. This product contains a High-Flow Sport Catalytic Converter solely intended for track and race cars as it is NOT California Air Resources Board Certified (CARB) and not EPA certified. You are hereby informed and warned to check your local, state, and federal laws before buying and installing these or any aftermarket parts to be sure whether usage is in violation. All installation-risk and use-risk is borne by the end-user and installer of these parts.
DISCLAIMER: This product removes the OEM catalytic converters from the vehicle, and as such, is strictly intended for closed track events and off-road use only, never to be driven on public roads. This product is or contains a Racing Cat Bypass Pipe, which will give you check engine lights on OBD2 cars. We suggest pairing this product with racing software to prevent fault codes and check engine lights. Racing Cat Bypass Pipes are solely intended for track and race cars as they are NOT California Air Resources Board Certified (CARB) and not EPA certified. You are hereby informed and warned to check your local, state, and federal laws before buying and installing these or any aftermarket parts to be sure whether usage is in violation. All installation-risk and use-risk is borne by the end-user and installer of these parts.
You may return most new, unopened items within 30 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).
You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).
If you need to return an item, simply login to your account, view the order using the "Complete Orders" link under the My Account menu and click the Return Item(s) button. We'll notify you via e-mail of your refund once we've received and processed the returned item.
We can ship to virtually any address in the world. Note that there are restrictions on some products, and some products cannot be shipped to international destinations.
When you place an order, we will estimate shipping and delivery dates for you based on the availability of your items and the shipping options you choose. Depending on the shipping provider you choose, shipping date estimates may appear on the shipping quotes page.
Please also note that the shipping rates for many items we sell are weight-based. The weight of any such item can be found on its detail page. To reflect the policies of the shipping companies we use, all weights will be rounded up to the next full pound.
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