We’ve discussed the Accusump before, but this is one of the most practically sound tests we’ve ever seen, showing the worth of an Accusump system. The Subaru BRZ/Toyota 86 platform and its FA20 engine have been documented to have oil pressure loss in high-G right-hand turns. The issue is so severe, that there are cases documented where extended lateral-G has resulted in oil starvation to the point of engine failure.
In order to solve this Ansix Auto decided to undertake significant oil pressure testing, choosing to use a Canton Accusump to provide supplemental oil pressure during periods of low oil pressure. In order to provide accurate A-B testing, laps with the Accusump deactivated and activated were made not just at the same track, but within minutes of one another. On-board data acquisition, combined with GPS track mapping and synchronous video recording made for extremely thorough information gathering.
The first laps at Area 27 Motorsports Park showed that pressure loss was indeed occurring during high-lateral-G cornering, with the oil pressure dipping as low as 18 psi, while the engine is turning anywhere from 5,000 to 7,200 rpm during those pressure dips. Those are quite concerning numbers, if you care about engine longevity. Especially when you consider those dips appear to be happening with as little as 0.4g of lateral acceleration, which is less than 25-percent of the test vehicle’s cornering ability.
The simple and clean installation of the Accusump into the BRZ/86 engine bay provided significant benefit to oil pressure while on track.
Once the system was activated in the hot pits and the car was sent back out on track, the data was again recorded, this time, with no dips in oil pressure below 30 psi in left or right-hand turns. Looking at the data, the car was pushed even harder in the corners with the Accusump activated, so there was no “taking it easy” in order to make the Accusump look good.
While ultimately, the answer appears to be a properly baffled oil pan for the FA20 engine, until that product is developed, the Accusump makes for an effective solution to maintain oil pressure in situations where lateral G loads are a regular occurrence. Additionally, as we’ve showcased in the past, it’s a simple installation and won’t break the bank — especially for the gains you get from it. This once again proves that in performance applications where oil starvation is even a remote concern, an Accusump can be a cheap insurance policy to keep your engine alive.
As you can see in this scatter plot of oil pressure versus lateral-G, it isn’t even really extreme loads that are causing the worst oil pressure drops, with the dips under 20 psi occurring at only 0.4g. However, with the Accusump (blue dots), the oil pressure is always above 30 psi.
