The VG30DETT is known to fail the rod bearings. Since the oil pump seems to have decent capacity and the rod bearings have a sufficient surface area, we believe a lot of this has to do with the failings of the stock oil system. The first issue is the stock pan only holds about 3.5 quarts. In fact, the whole oil system holds only about 4.3 quarts including the oil in the filter and cooler. This is ridiculous for a performance turbo engine. This means that there is little margin of error in the oil system, you burn a little oil which is normal for track use and you are in danger of sucking air. The turbos get the oil and heat it up and whip it into a froth and dump it back into the pan, then you have normal windage whipping of the oil by the rods and crank, the engine is known to have poor head oil drain-back and the PCV system is prone to suck up oil under cornering forces. All of these means that the pan has little oil in it while operating hard and what little that is in there is super hot and airiated. We are going to work to prevent these issues to protect our rod bearings. Previously we had overfilled the pan by a quart when the engine was not running to try to compensate for the oil pooling in the heads but this tactic can lead to even more windage heating and foaming under some conditions. We are going to help out our oil system with parts from BDE Engineering and Engineered Performance.
The first thing to address is the low-capacity stock oil pan. This is solved with BDE Engineerings’ awesome oil pan. If you know the Z chassis, there isn’t much room for anything but BDE has managed to squeeze a deep sump pan into those tight spaces. The BDE pan holds 7.25 quarts of oil. This is more than twice the capacity of the stock pan. This alone is a great starting point but it doesn’t end there.
At the bottom of the pan is a baffled sump. The sump has trap doors that allow the oil to flow to the pickup but not away from it. This greatly helps maintain oil pressure under cornering and acceleration. There is also a horizontal baffle to prevent oil from sloshing out of the sump. We have seen the oil pressure logs from a time attack Z32 and can say that oil pressure loss when cornering is a big issue even with an accusump. This oil pan is going to go a long way towards fixing starvation issues.
Inside the pan, there is a louvered full-length baffle that also acts like a windage tray. This helps strip the oil cloud in the crankcase that the crank and rods have to cut through. This not only speeds up oil return to the sump greatly but increases power by reducing windage drag on the crank and rods. The windage tray also reduces the amount of entrapped air in the oil.