Tag Archives: Steam STX 71 Testing

Steam STX 71 Flow Testing [part 1]

Steam STX 71 turbo mounted to gas bench
A Steam STX 71 Turbo mounted to the gas bench test rig.

Did you ever want to know how it’s possible for our Steam STX 71 turbocharger to make over 425+ WHP on your STI?  It’s all about flow dynamics.   We are not content with just having high-quality high-performance products so we decided to take the engineering to the next level.

Learn more about the Steam STX 71 for USDM STI, or JDM twinscroll STI.

Here is a dyno plot of our Steam STX 71 turbo in action.  There is a whopping 140 WHP gain over the stock VF39 turbo with very little left on the table.

The STX 71 vs VF39
The STX 71 vs VF39

Other manufacturers, like Blouch and ForcedPerformance, can simply make claims to how much their products flow.  But, how do they arrive at that number?  Without compressor maps to demonstrate thorough testing, one can assume they are just guesstimating.  Why make a guess?  Because real engineering is expensive.  Turbo testing is also very expensive, but that is what the big boys do to actually improve their products.  You can’t get, what you don’t measure.

Garrett also makes claims to how much their turbos flow, but they actually provide detailed compressor maps.  This is the result of rigorous engineering efforts.

Compressor Maps Explained

When Garrett improved their ball bearing turbo line, they actually provided empirical data showing how their product has improved.

gt4202R vs gtx4202r compressor map
gt4202R vs gtx4202r compressor map

Although we have had great results with our STX 71 model, and lots of happy customers, we never stop thinking our products can be better.  How do you make a great design better?

Steam STX 71 Performance Testing

First step, measure the performance of the current design.  The way Garrett and other serious turbo companies make compressor maps is by testing it on a gas bench, so that is exactly what we are doing.  The gas bench provides a super controlled environment to reliably test the turbocharger.

We measure a number of things on the gas bench: compressor wheel speed, pressures and temperatures before and after both housings, etc.  With this data, we will be able to generate compressor maps similar to those of Garrett.

Checkout our current production STX 71 on a gas bench as we map out the performance and efficiency of the current design.

Here is a production turbo with the turbine housing all mounted up to the hot side of the gas bench.  The yellow thing sticking out of the compressor housing is a speed sensor.  It measure how fast the compressor wheel is spinning.  The compressor wheel can spin in excesses of 150k RPM.

Steam STX 71 turbo mounted to gas bench
A Steam STX 71 Turbo mounted to the gas bench test rig.

Oil anyone?

Steam STX 71 turbo mounted to gas bench
Here the center housing’s oil ports are hooked up to ensure proper lubrication and cooling.

Here is the cold side being hooked up.

Steam STX 71 turbo mounted to gas bench
Here is the cold side getting hooked up.