Supercharged Lexus iS200 Uprated Katana Intercooler

As part of our Stage 2 upgrade for the Supercharged Lexus iS200, we incorporate a larger intercooler than the standard TTE item.

When air is compressed (such as by a supercharger or turbocharger) it’s temperature increases (see BoylesLaw) and loses density thereby reducing the amount of oxygen available to produce power, so we can see that reducing the air temperature at the back of the intake valve is crucial for increasing engine performance.

This is why intercoolers are used in an attempt to reduce and control intake temperatures. Unfortunately the presence of an intercooler also creates a restriction to airflow which in turn reduces power so we therefore have a bit of a paradox which is generally dealt with by compromising the airflow efficiency in an effort to keep the temperatures down.

The two critical design features of an an intercooler are it’s thermal efficiency (how good it is at reducing temperatures) and it’s air flow efficiency (how good it is at transferring air with minimal internal losses).

Having very good airflow testing facilities in-house, we were able to test all of the branded intercoolers on the market and found that they varied dramatically in terms of air flow efficiency so we decided to think about how we could improve this without reducing the size of the intercooler core.

Traditionally, a larger core gives a cooler charge but more resistance to flow, so we designed an aerodynamic and plate for the core which significantly increases the air flow through the core.

We also wanted to increase the volume of intercooler core to maximise the cooling capacity so we designed a intercooler which is around 250% larger than standard. We paid particular attention to the quality so we ensured that the end tanks were properly cast and aerodynamic shaped too. We increased the size of connector spigots from 50mm to 60mm so that the Katana intercooler can be used on very high power applications. We also considered the packaging to ensure that the intercooler could be installed without cutting the body work and with minimal fuss.

The end result was an increase from the standard TTE intercooler of 123CFM to the uprated Katana intercooler of 161CFM which is an increase of 30% !!!

On the chassis dyno we found that with no other modifications, changes or tuning, we saw an increase of 0.1 bar of boost pressure (due to the aerodynamic end plates) and a substantial increase in torque throughout the power band (see graph below).

We are very pleased with the results of an additional 20 lb-ft at the hubs, and the Katana high performance uprated intercooler for the supercharged Lexus iS200 can now be bought at www.tdi-plc.com/catalog/product_info.php?cPath=107_197_214_384_392&products_id=4117

Here’s a picture of the intercooler in place

Here is the performance certificate without any tuning or adjustments being made. Very impressive!

because of the science and technology deployed in the Katana intercooler, we are confident that it is currently the best in terms of effectiveness and quality.