Lexus iS200 Supercharger – Katana Exhaust Manifold

The standard exhaust manifold is very restrictive and is detrimental to performance, fuel economy and engine reliability.

The standard manifold has exceptionally small primary pipe diameters (probably to assist a fast warm up of the pre-catalytic converters), and the primary pipe lengths are too short (probably due to packaging concerns) for optimum torque. The manifold also includes pre-catalytic converters which are restrictive and known to fail internally.

The first stage of our development process was to accurately measure the camshaft timing so that we could run some calculations through our modelling programme to determine the ideal theoretical primary lengths and diameters, the secondary lengths and diameters, and the collector lengths and divergence angles.

Because of the packaging issues and design of the downpipe/main cat pipe, we could not implement the ideal secondary collector length so we chose to introduce pulse tuning loops in the desired location of a secondary collector. This proved to be an acceptable solution because it provided easy interchangeability with the standard manifold and gave us a good performance increase.

Dyno testing was carried out with various combinations of pipe lengths and pulse tuning loop locations, and the final design was signed off.

The improvements in power and torque makes it ideal for all fast road applications, and for any intended race use where uprated engine internals are deployed.

Benchmark testing was carried out competitive products, and we were pleased to note that the Katana exhaust manifold outperformed the other manifolds by a very significant degree.

We were not surprised by this as the Katana manifold was (and still is) the only high performance exhaust manifold for the Lexus iS200 which has had some science applied to it’s development.

Other concerns were raised about the other manifold such as incorrect pipe dimensions, quality of manufacture, slip joints instead of being a one piece construction, the collector pipes being squashed together instead of having the correct divergence angle.

The Katana exhaust manifold can be purchased at www.tdi-plc.com/catalog/index.php?cPath=107_197_214_384_385

Here is the Katana manifold for the Lexus iS200 showing the pule tuning loop pipe

Here you can see the difference between the standard manifold and the Katana exhaust manifold for Lexus iS200.

Here you can see the difference in collector design between the Katana manifold and that of a competitor. Note the poor design of the competitor.

Here you can see the difference between the Katana and the competitors manifold. Note the sharp change in in primary pipe direction which slows gas speed.