Visc Props To Consider Fr Top End Output

[Nederlander75]

Im liking the added benefit of the 40wts oils and the do qualify under my warrenty, but wondering if Id get more top end output past 110mph with lighter viscocity. Running 0w40s and 5w40s at present. Thoughts please.

Thank you

 

[jldcol]

What do you mean by top end output? OIL flow to top end or something else. rpms of engine more useful info than mph. If you mean top speed then anything that maxes hp will help out here. Oil pump hp used could not be very much perhaps 3hp? You may not notice this if even eliminated completely.

 

[Nederlander75]

Sorry, speeds above 110 and rpm above 5K. Obviously we are dealing with air drag here, but looking at the oil for the moment. Car hits 152, but its the 110 to 140 Im looking to address. Wondering if the oil has anything to do with this. Redline is 8K, natuarlly apirated (for once in my life).

 

[jldcol]

If i understand what your saying not satisified with pull from 110to 140 mph right? What gear is this in? What ratio trans, rear end? Is this rpm range above the engines torque peak? If so engine not turning as hard even as it speeds up. Is your ecm keeping up with fuel delivery here?

 

[Nederlander75]

You are above me now. This is in 4th gear heading into 5th of 6. ECU is set to lean out reversing Nissan's de-tune. Ratios as follows.

1st Gear Ratio: 3.153:1
2nd Gear Ratio: 1.944:1
3rd Gear Ratio: 1.392:1
4th Gear Ratio: 1.055:1
5th Gear Ratio: 0.809:1
6th Gear Ratio: 0.630:1
Reverse Ratio: 3.002 :1
Final Drive Ratio: 4.133:1

FWD platform.

However, this is going beyond oil so we may want this topic moved. My question is oil related only unless Im barking up the wrong tree.

 

[jldcol]

If this rpm range is above engine torque peak your engine is getting weaker even if it makes more hp.Your essentially in direct drive in 4th gear. Shift to 5th and now a net loss of torque to rear end of 10%. Maybe need to lower rpm to better torque range for your engine, hopefully on a climbing torque curve or at least a flat one.

 

[Nederlander75]

The torque curve pretty runs to about 6.5K.

 

[BuickGN]

You will never ever ever ever ever ever notice an acceleration difference at 110mph by going to a lighter weight.

 

[Nederlander75]

Originally Posted By: BuickGN
You will never ever ever ever ever ever notice an acceleration difference at 110mph by going to a lighter weight.


Can you explain why please?

 

[MGregoir]

When Dodge was running a Super Touring car, they tested oils for horsepower.

In a two-litre, 300 hp, 8200 rpm normally aspirated four cylinder engine...the oil made less difference than the percent error on the dyno. The difference between the best and worst oil in a highly tuned engine was 3 hp.

 

[Nederlander75]

Perfect, thank you and all.

 

[tdi-rick]

I've dyno tested oils in a Ford 1600 Kent (Formula Ford) engine fifteen years ago and there was 4HP difference between a 20W-50 and 0W-5 and we were only using 35psi oil pressure @ 6500RPM to minimise losses there.
Oil clearances needed to be tightened substantially to run the light weight oil without incurring cavitation erosion of the bearings and bore finish was critical with the light oil.
There was less than 2HP between a race 10W-30 and the 0w-5 from the same blender ad the gains were consistent right through the power/torque range. Both were di-ester oils.