The very first product produced by Walton Motorsport was the top mount Nissan SR20 Manifold. Huge numbers of the SR20 Exhaust Manifold has sold since the original to people all over the world. Throughout the years Walton Motorsport has worked to refine the design. As a result, this manifold is what is regarded to be the best SR20 manifold on the market today.
There’s no shortage of Nissan SR20 exhaust manifolds available. The construction methods we use set our product apart from the rivals. 
 
 
NISSAN SR20 EXHAUST MANIFOLD FEATURES
Carefully selected 304 Stainless steel tube. Working to eliminate the risk of material failure.
Fully Purged welded. Subsequently improving gas flow leading to increases in power and lowered response times.
Ported Merge Collector Welded Internally and Externally. Resulting in high strength, durability and turbo lifespan.
Curved wastegate port design developed with leading engine tuners to allow high control and remove boost creep.
Fully Smoothed Head Ports designed to optimize gas flow. As a result, providing an increase in power and lowered response times.
Optimized for use with Turbosmart Gen-V Compgate 40 Wastegates. On large turbo setups, a Turbosmart Hyper Gate 45 is recommended.
 
 
Material Selection
First and foremost not all 304 Stainless steel is created equal. We carefully select the exact specification of the tube that we use. The use of poor quality tube can compromise the whole design. For Instance, exhaust manifolds experience repeated high-temperature cycles. In these situations, we have seen poor tubing split along the seam.
We design the head flanges inhouse. However, we outsource the precision waterjet cutting. We use waterjet cutting as it results in a more accurate cut over traditional laser cutting
 
 
Processes
Where the manifold meets the exhaust ports, Walton Motorsports process is to push the tubing through the head flange and TIG weld each side. This process is followed by a selection of finishing tools. We do this to create a smooth port for the gasses to freely flow through. Consequently, this process greatly increases the durability of the manifold. Rather than using the traditional method of welding the tube to the face of the flange. Moreover, our method is where we also face the problem of an oval port needing to transition smoothly to a round tube. The stubs process, in short, helps increase power through the improved flow.
The collector we use is a custom-designed merge collector. We proudly design and build in house. This results, in allowing us to add some features to set it apart from the competition. The first step is to TIG weld the seams inside the collector. Our fabricators then turn their attention to the outside of the collector. They TIG Weld the seams from this direction. The next step is to port the inside of the collector back to a smooth point. Subsequently, this improves gas flow and adds a large amount of strength. Without welding the inside of the collector there is a danger of small fragments breaking off at the high temperatures. These fragments will then make their way through your expensive turbo. We don’t need to tell you how bad that can be.