Track Test of our Grassroots Performance 19-Row Oil Cooler [PROVEN]

In  2021, we asked BSquared to test and evaluate the performance of our Grassroots Performance 19-Row Oil Cooler. Here's what happened.

REPORT SUMMARY

Our 19-Row Oil Cooler was installed on a Toyota 86/Subaru BRZ platform. A comparison case was developed by comparing the oil temperature variations on two NA 86’s. Car A is the 86 with the Grassroots Oil Cooler installed while Car B is the baseline vehicle, a stock 86. Both vehicles completed a Time-Attack style stint of one warm-up lap, three hot laps, and one cooldown lap under the same driving pattern.

OIL COOLER TEST SETUP

Track conditions: The tests were carried out at Shannonville Motorsport Park (ON, Canada) which has a long layout. The track is ideal for the purpose of the validation as it offers a mixture of tight technical corners and long straights where both successive RPM variations and sustained high RPM can be achieved. The decision on the location is to make the test broad spectrum so that the results presented in this document is generally representative for other types of tracks as well. On the test day, it was mostly sunny with some overcast. The air and ground temperatures were approximately 10 °C and 12 °C, respectively. 

Test vehicles: Two NA 86’s were used as test objects. The Grassroots Oil Cooler was installed in Car A. Car B is the baseline vehicle, a stock 86. Both vehicles received identical Castrol 5W-40 synthetic oils, identical OEM oil filters, and were pumped at the same fuel stations prior to the test day. Each car was tested in direct succession after the other and were driven by the same driver, maintaining the same track conditions, and mitigating human factor.

STRATEGY & CONSIDERATIONS

Driving patterns. Driver completed a Time-Attack style stint of one warm-up lap, three hot laps, and one cooldown lap on both cars. This is to replicate the driving patterns of both time-attack and casual lapping that most potential customers would achieve in their 86’s.

Modifications. The modifications (i.e., header, engine tune, springs, tires) do not play a significant role in affecting the cooling capability of the heat exchanger.

Driver’s efforts. Repeated laps were executed by the same driver on warm-up, hot, and cool-down laps, following a similar path and RPM ramp-up pattern. Time and driving behavior variations were mitigated, and negligible influence was observed on oil temperature ramping and cool-down. The Time-Attack style was maintained by the driver driving to the fullest potential, obtaining the fastest lap time for both vehicles.

ANALYSIS RESULTS

"the Grassroots 19-Row Oil Cooler experienced a significant cooling effect on engine oil of nearly 68 °F in peak conditions"

1. Cooling performance in peak heat conditions

Figure 1 demonstrates the difference in engine oil temperature and engine RPM between Car A and Car B in a single hot lap. In Car A, a mean temperature of 95 °C was observed and was considerably lower than that in Car B by 20 °C, in peak heat conditions. The plot of engine RPM vs. Time shows a consistent driving behavior of the same driver. Thus, the oil cooler is shown to be capable of sustained temperature cooling in peak engine heat soak.

Figure 1. Single hot lap: comparison of Car A and Car B: (1) Temperature (C° ) vs. Time(min); (2) Engine RPM vs. Time(min)

2. Consistent cooling at high RPM

Figure 2 shows the temperature spread over the RPM range (0 – 7500 rpm). A clear gap in temperature between Car A (with the Grassroots 19-Row Oil Cooler) and Car B (without oil cooling) was observed, indicating a consistent cooling at any RPM. At any RPM in peak heat soak, the Grassroots 19-Row Oil Cooler consistently kept the temperature down below 100 °C while the oil temperature in Car B reached 120 °C the highest. With hotter ambient temperatures in summer months, the 86 platform commonly sees 135 °C or higher oil temperatures. It should be noted that many oils are rated to a maximum temperature of 145 °C sustained before the lubricative properties fail. Given that, the Grassroots Performance 19-Row Oil Cooler successfully maintained a sub-100 °C temperature in peak heat soak. This is direct evidence that the Grassroots Performance oil cooler at work keeps the engine oil properly lubricating the system without any risk of chemical breakdown.

Figure 2. Engine RPM vs. Temperature in Car A and Car B

3.Cooling performance on warm-up lap

Figure 3 shows the difference in temperature and engine RPM between Car A and Car B on a warm-up lap where temperature ramp-up was considered. On the same lap, Car A and Car B had a ramp-up rate of approximately 5.25 °C/min and 12.37 °C/min, respectively. The oil cooler could potentially slow down the heat-up in oil temperature during warm-up laps, as the results showed that it took significantly longer to heat up in Car A. Thus, it is recommended that care should be taken by the driver to allow the cars to heat up to operating temperature before driving at full pace.

Figure 3. Full lap: comparison of Car A and Car B: (1) Temperature (C° ) vs. Time(min); (2) Engine RPM vs. Time(min)

4. Cooling performance on cool-down lap

Figure 4 shows the difference in temperature and engine RPM between Car A and Car B on a cool-down lap. Car A was observed to have a cooling rate of 4 °C/min, and Car B had a cooling rate of 3.66 °C/min. Both vehicles presented a similar cooling rate. This is possibly the result of the driver still applying throttle throughout the cool-down lap, thus re-heating the oil (see the plot of engine RPM vs. time shown at the bottom).

Figure 4. Cool down lap: comparison of Car A and Car B: (1) Temperature (C° ) vs. Time(min); (2) Engine RPM vs. Time(min)

CONCLUSION

The Grassroots 19-Row Oil Cooler for Toyota 86/Subaru BRZ was shown to have effective performance in keeping engine oil temperature below the upper limits of performance oil temperature threshold. Compared to baseline 86’s, vehicles equipped with Grassroots 19-Row Oil Cooler experienced a significant cooling effect on engine oil of nearly 20 °C in peak conditions. This is critical to any safety and performance factors in racing applications. The oil cooler exhibits considerable cooling control at temperature ramp-up, but did not provide a significantly faster cool-down rate. This indicates that the drivers should drive at faster pace on their warm-up laps in order to get the engine oil to operating temperatures as the cooler could slow down the onset of temperature increase.

FULL REPORT PDF "Track Evaluation of the Grassroots Performance 19-Row Oil Cooler on Toyota 86/Subaru BRZ, by BSquared"

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