Why should I buy a Walton Motorsport Exhaust Manifold?
It's time we put pen to paper (finger to keyboard) and came up with some reasons to use a Walton Motorsport exhaust manifold.
Specifically, we are talking about our core range of manifolds. We have been doing this for a good few years now and have continually developed and improved our designs, along with our manufacturing processes to produce what we believe to be the best production turbo exhaust manifolds on the planet.
The primary job of an exhaust manifold is to get the exhaust gasses out of the cylinder head, and in the case of the turbo engine, past the turbine exhaust wheel, whilst spinning it as quickly as possible. This is the easy bit of the process, but we are going to talk more specifically about the strength and durability of the manifold, and also touch on turbo health.
Material Selection
Our standard material is 304 Stainless steel, We use 304 grade over 316 as it is a little less brittle. This allows the manifolds to resist cracks from vibrations or impacts, and deal with thermal expansion better. 304 Stainless steel is suitable for EGTs up to 900deg Celcius, above this temperature you need to start looking towards the Super Alloy Inconel 625.
Manifold Construction
We will start at the cylinder head end of the manifold, as that is where the exhaust gasses first enter the manifold. We design all of our head flanges in-house and have them Fiber Laser cut from 10mm thick 304 Stainless steel. As the head flanges are welded they have a tendency to "shrink" during construction due to the heat from welding. We take this into account in our design so that it still fits well. Importantly aligning with the ports correctly. The common shortcut to this is to use dramatically oversized mounting holes to account for the shrinkage. The issue here is that the flange will move around during mounting and not align with the exhaust ports correctly sapping precious power.
The Primary pipes are the tubes that go between the head flange and the turbo flange, Common practice is to weld the primary tube to the face of the manifold as virtually all our competitors do. Our method is to use a stub. This stub is a short piece of tube, which is pushed through the flange and welded front and back to create a super-strong base to support the turbo. The stub is how we tackle the problem of transitioning an oval exhaust port to a round tube. Its common to use a CNC Billet flange to help with the transition, but the use of the stub allows a longer smoother transition than is practically possible with a billet flange. The below picture shows before and after welding. We of course port and flatten the flange after this process to ensure the best possible gas flow, along with a flat mounting face. This is a process that to the untrained eye is difficult to spot, you will generally know if a brand does this or not, because they will shout about it.
The primary pipes are then back purged and TIG welded, Back purging is the process of flowing Argon Gas (in the case of Stainless Steel) through the inside of the pipe, The argon creates a shield over the back of the weld preventing the molten metal from reacting with air in the atmosphere and creating a rough weld on the inside of the primary pipe helping to promote the best possible flow, we also like to keep the manifolds compact in the primary pipe routing but allow fitting to be as easy as possible and utilize stock studs and bolts where possible.
Introduced in 2024 is investment cast collector. We have always been evolving the collector, aiming to maximize power, whilst retaining precision wastegate control. The goal of our in-house designed cast collector was to exceed the performance of our previous scooped port fabricated collector. We achieve this by widening the wastegate opening across more of the collector. This allows more gas to flow to the wastegate, whilst retaining a super-fast spool. We were also able to increase material in areas to ensure high durability in extreme conditions.
In our previously fabricated collectors, we welded the internals of the collector and ported it back to a smooth finish, With our investment cast collector, we were able to utilize the initial machining process to ensure the strength and smooth flow of that area. The image below shows the internals of a failed collector, this particular manifold was one that we removed from our own R34 Skyline (fitted before we purchased the car) that had led to subsequent turbo failure when the particles passed through the propeller wheel.
We can also produce a manifold for any application, as well as using the super alloy Inconel 625, which is predominately used for F1 and Rally applications, As shown in this WRX Ford setup complete with fresh air antilag.
Lifetime Warranty
Most aftermarket manifolds offer this, offering the warranty is easy but the more tricky bit is eliminating the need to use it, if your manifold happens to break its great that its covered but its even better if it never failed in the first place, the extra steps that we have spoken about, help to significantly reduce the risk of a failure. The benefit of this is that you spend less time with the car in bits and a track day or drift day isn't cut short.
We hope that this write up gives an insight into our manifolds that will help show the differences in the Walton Motorsport products.
For more information, don't hesitate to pick up the phone, or arrange to come and see us and the products
01494 715206 - sales@waltonmotorsport.com