What the lowest on track oil pressure you are comfortable with?

[J_D]

What is the lowest oil pressure are you guys comfortable running on track, once the car is a bit warm? My FL5 is bone stock, 0W20, race brake pads and high temp fluid. I run 20 minute sessions.

I’ve seen the LogR oil temp spike at 135C  = 275 °F, and the oil pressure hover around 60 PSI. Towards the end of a session, on PS4S tires.

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[Higgs Boson]

I don't generally worry about oil pressure unless it is 0......or if it is abnormal, meaning if I normally idle at 20 and suddenly I am idling at 4, I would look into that.

All the many years before variable or computer controlled oil pumps, you would look for 10psi per 1000 RPM, which I know is not the case any more but still....10 psi at 1000 RPM near idle, we were always fine with it.

What are you looking to understand? Remember that pressure is not a measurement of flow, pressure is resistance to flow, just like boost.

 

[J_D]

I don't generally worry about oil pressure unless it is 0......or if it is abnormal, meaning if I normally idle at 20 and suddenly I am idling at 4, I would look into that.

All the many years before variable or computer controlled oil pumps, you would look for 10psi per 1000 RPM, which I know is not the case any more but still....10 psi at 1000 RPM near idle, we were always fine with it.

What are you looking to understand? Remember that pressure is not a measurement of flow, pressure is resistance to flow, just like boost.

I guess I am reading too much into the doom and gloom of tracking a stock car, without any additional coolers. Thanks or the reply.

 

[ackermann_angle]

The wedging effect on the crank multiplies the oil pressure by an extreme magnitude. I cannot recall the exact amount, but I believe it is x1000 over the pump pressure. This diagram explains it well.

This is why the min spec before the oil light coming on is 14 psi for the k20c1. As long as the flow rate is not interrupted, you are fine (e.g. pump starvation).

 

[Junsupersti]

Get oil pan baffle

 

[AZCWTypeR]

I saw somewhere the FL5 has a 2 stage oil pressure relief valve. I see 2 completely different oil pressures (30's or 60's psi) driving around town at 2-3K pm. I assume the relief valve is ECU controlled to optimize fuel economy, but haven't seen much about it.

 

[Junsupersti]

 

[cryptolime]

I saw somewhere the FL5 has a 2 stage oil pressure relief valve. I see 2 completely different oil pressures (30's or 60's psi) driving around town at 2-3K pm. I assume the relief valve is ECU controlled to optimize fuel economy, but haven't seen much about it.

i've pretty much read the entire service manual and I haven't seen anything about that. I'll look again though. I'll let you know if I find anything different.

EDIT: only thing with an electric oil pump I could find is the cars with CVTs

 

[Ohlins8990]

This is from the SAE paper for the J35, but I assume its the same pump style.

Next, the 2-stage relief structure of the oil pump is described. This structure is intended to reduce the oil pump drive torque by optimizing the hydraulic pressure characteristics at slow and mid-engine speed. The conventional relief structure (1-stage relief) has a structure where the relief valve strokes and oil is discharged from a relief hole in the housing when hydraulic pressure of the set valve pressure or more is applied [Fig. 17(a)]. In contrast, the 2-stage relief structure enables 2-stage relief by adding a lubrication groove in the upper part of the relief valve and the housing upstream from the relief hole. Two-stage relief operates as follows. First, the relief valve begins its stroke when hydraulic pressure of the set valve pressure or more is applied. Oil passes through the lubrication groove formed by the valve and housing upstream from the relief hole, and is discharged from the relief hole. As the hydraulic pressure rises and the valve stroke progresses, the lubrication groove is blocked and the 1st-stage relief stops. When the hydraulic pressure rises further to the 2nd-stage valve pressure or more, oil is discharged from the 2nd-stage relief hole [Fig. 17(b)]. Figure 18 shows the hydraulic pressure characteristics at slow and mid-engine speed and the effect due to adoption of the 2-stage relief oil pump relief structure. As a result of optimizing the hydraulic pressure characteristics, hydraulic pressure reduction effects of 25% and oil pump drive torque reduction effects of 35% could be obtained. Other friction reduction technology included thorough measures to reduce mechanical friction such as application of a molybdenum pattern coat to the piston skirts, reduction of piston ring tension, use of low-torque oil seals and low- viscosity engine oil, and reduction of auxiliary belt tension. These measures achieved BSFC enhancement effects of 4% at 1500 rpm.

 

[J_D]

Get oil pan baffle

In my case that wouldn't help. I am not having oil pressure drops due to starvation, it's just oil pressure naturally drops when the oil is heated.

 

[ackermann_angle]

In my case that wouldn't help. I am not having oil pressure drops due to starvation, it's just oil pressure naturally drops when the oil is heated.

I agree. As long as oil is being delivered, you are fine, if you were starving the pump, you would know. Modern oils are usually temperature stable (~ 280 deg F max), if you want to ease your worry on seeing if your oiling system is working to spec, I would highly recommend doing oil analysis on your used oil. Otherwise, you are trusting the Honda engineers that they know what they are doing.

 

[J_D]

I guess what concerned me the most is the bearings. Online fear mongering worried me about high temps and the bearings

I will post an oil analysis with TBN shortly

 

[ackermann_angle]

I can post my oil analysis for comparison if you would like. My car has never been tracked, and only used as a daily driver, so it is a good baseline.

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