Engine Drivetrain 2nd Gen S Helix Intercooler Datalogging Results

As many of you know, we at Helix have been working on our latest revision of our Stepped Core Intercooler for a loooong time. Well finally, we are ready to release it. We've been installing prototypes on select cars, and yesterday we put it, and other coolers, through a battery of tests. The tests included dyno evaluation on our MD-250 chassis dyno, and street datalogs. Here's what we did:

The test car was a 2013 GP2 with stock DME tuning. The only modification on the car was a high-flow air filter. All of the tests were done same-day, same-car, same dyno calibrations. The one exception was that over the period of the day, the ambient temperature rose more than 12 degrees, which make some of the scaling in our street testing variable. The dynamometer has a weather station which automatically adjusts the weather correction factor in real time. The weather correction factor changed the output numbers less than 1/10th of a percent, because although it got hotter, the humidity dropped about 20% during the day. This worked toward cancelling a big correction factor change over the test period.

We did both street and Dyno logs, because each can show a different aspect of the performance of an intercooler. Like any dyno cell without a wind tunnel, it's very hard to create the air volume and speed needed to truly replicate road conditions. Road logging will give you great information on intake temperature and boost pressure vs. RPM but won't give you torque and power readings.

Because we were running both street and dyno tests for three different intercoolers, we decided to remove the front bumper cover for all tests, making it easier to swap coolers. All of the data runs, both dyno and street, were done in the same fasion. The street runs were done in the same gear (3rd) on the same closed not-publicly-used course:wink:, and consisted of multiple runs from 2500 to red line. The Dyno runs were also done multiple times for engine temperature stability and consistency of results.

We started in the morning testing the stock cooler, we then tested another brand of aftermarket cooler, and finally we tested the Helix cooler. I'm really going to focus most on Helix vs. Stock. Here's a typical data set from the street logs of the Helix vs. stock. In this graph, we've logged Intake Air Temperature after the intercooler, Boost Pressure after the intercooler vs. engine RPM. Notice that the ambient temperature was some 12 degrees higher in the Helix test runs than it was in the stock runs. This makes for a slightly messy graph, but the important data is temperature rise during the run.



The bottom two plots are the IATs: the dark blue is the stock cooler, the purple is the Helix cooler. Notice the temperature rise in the stock vs. the Helix intercooler. The top two plots are boost pressure, Helix red, stock green. Notice that the boost pressure is lower with the Helix intercooler. That's because the boost mapping on these cars is done through torque targets. The DME calculates torque via speed change over time, and limits boost once the car has achieved maximum allowable torque. With the Helix intercooler the car is making more power with less boost (as you'll see on the dyno plots). This means there's less demand on the turbo. Custom tunes on these cars manipulate torque targets, among other things, meaning that a Helix intercooler will allow for greater boost before the targets are met. This means more power and torque.

On the dyno the deltas were narrower, partially because of our limited ability to supply wind-tunnel-like air volume and speed, and partially because of the way the cars are tuned as stated above. Narrower but significant. We would typically do several 'warm up' runs to stabilize engine coolant and oil temperature, and then do a series of test runs concurrently. We allowed at least 60 seconds between runs so the evacuation fans could remove inert gasses from our dyno cell. Here's a cluster of runs done on the stock intercooler:



This shows three runs on the same graph. The red line is engine power, the dark blue line is engine torque, and the light blue line is fuel/air mixture. On all test, we calculate a 12% drivetrain loss. The average peak power was 222.6.

Here's the same test with the Helix intercooler:



The torque and power numbers were stable and consistent, with the average peak power at 228.6. Again, if we had a half million dollars in fans, I think the result deltas would be greater.

I'm not going to dwell a lot on other coolers on the market, but we did have another popular brand of cooler in stock and ran it through the same tests. Here's a dyno plot of that cooler:



The average peak power was 224.

I have to admit that we were all a little nervous before the tests: all of the work, from Solidworks designs, to CFD flow testing, to 3d printed models, to failed prototypes, everything was on the line. We've got a ton invested in these things and thankfully they did not disappoint.

We have begun production and will start a special offer thread next week when we get a clearer idea of when the first production run will be finished.