Drag vs Pressure in Race conditions

[avu3]

I have a mazda race car which uses hydraulic lifters. Me and a friend are discussing the merits of a heavier weight oil keeping the lifters pumped up during road racing VS the drag of a heavier weight oil.

Over the course of a 10 lap race, we see about a 10psi loss in OP, and a corresponding loss in performance of the car as measured by lap time, segement time and trap speed.

We typically run 5w30 in the motor. We've run a similar car/engine with 15w50 but never in sprint racing (enduro) and never with data.

Any thoughts to the weight vs drag debate, ie, will the thicker oil be a bigger loss than its benefits?

Scott

 

[MGregoir]

Try something like Red Line 10W-30, or Shell Helix (Q HorsePower) 5W-40 first and see what happens.

If you lose oil pressure due to thinning, and it gets to the point you are losing valve lift due to it, thicker is about the only thing you can do.