Performance in hot weather

[outahere]

I think you're confusing the failsafe in the filter with the oil bypass valve.

 

I'm not confused. I know the difference between the bypass valve in the filter and the relief valve in the oil pump.

 

Never heard of a filter "failsafe".

[meier motor sports]

ever hear of a "vimy"?

[Vimy101]

I'm not confused. I know the difference between the bypass valve in the filter and the relief valve in the oil pump.

 

Never heard of a filter "failsafe".

 

"Failsafe" is just a descriptive term.

 

Here's a decent description of the bypass valve in a boxer engine no less:

 

http://www.hillmanimages.com/912/manual9.html

[fizxman]

Gee, from the FWIW physics department...

Inertia is how hard it is to change the motion on something, while torque is a twisting force that starts, or stops something from spinning/rotating.

 

If you want a lot of torque, you have two solutions re: flywheels. 1) Get a big, heavy mother spinning fast (you can do this gradually without a great deal of effort) then when you want torque, try to stop it from spinning. This is what a "flywheel" does. Solution #2) Use a very powerful motor on a system without a lot of inertia. Large engine on lightweight car with small flywheel. Here, the motor supplies the torque instead of the momentum of the flywheel.

 

If you want lots of WHP, a big turbo and smaller, lightweight flywheel is in order. You put lots of power to the wheels without wasting it spinning up mech. components in-between engine and wheels.

 

If you want a tiny POS engine to enable an underpowered car to continue at speed, use a larger flywheel and use the engine to spin it up gradually. Then when you need more torque than the little engine can supply, you can steal it back, so to speak, by turning big flywheel momentum into torque applied to the drive train. Some electric/hybrid systems do this.

 

The A/C does indeed spin and store some rotational inertia, but hardly enough to provide substantial torque to the drive system - it's far too tiny and light weight. The reason it sucks power is the relatively immense amount of work it takes to move heat out of the passenger compartment into an already warm environment. High pressure differentials between hot side and cold side require a substantial amount of HP to create and maintain -- and this comes from the engine.

 

Bottom line, Vimy is a lot more on the beam than some of you give him credit for. Maybe he doesn't make a living preaching the Gospel of Newton to the infidels like I do , but he's on the right track.

[meier motor sports]

i will give him that. he has the right idea but completely wrong application's.

[jagcars26]

i will give him that. he has the right idea but completely wrong application's.

 

Like this?

[Vimy101]

i will give him that. he has the right idea but completely wrong application's.

 

I understand that parking a car with a light weight flywheel is a PITA.

[PhilT]

I understand that parking a car with a light weight flywheel is a PITA.

 

No it isn't at all, your understanding is based on your own experience or what you have read on the internet ?

 

Do you actually have an oil pressure gauge on your Spec B Vimy ? because if you did, you would see that the oil pressure varies with engine speed and oil temperature. When the oil is cold, it is over 100 psi, but once the oil is warm it is pretty constant between 3,000 rpm and redline. So if you go WOT in 5th at 3,000 rpm, the oil pressure is the same as if you were partial throttle at 3,000 rpm in neutral.

[Vimy101]

^ A light weight flywheel makes stalling easier at low RPMs.

 

I believe there is a pressure regulator valve to help maintain oil pressure as well. Normally, there should be 10psi of additional pressure per 1000 rpm beyond idle.

[PhilT]

^ A light weight flywheel makes stalling easier at low RPMs.

 

I believe there is a pressure regulator valve to help maintain oil pressure as well. Normally, there should be 10psi of additional pressure per 1000 rpm beyond idle.

 

And how would this oil pressure regulator know what the engine speed is, never mind the throttle position as you originally claimed ?

 

The oil pressure comes to around 80 psi at around 3,000 rpm and stays solid until redline, no matter whether the throttle is part open or WOT.

 

Try it and see, I have.

[rao]

I bet the Spec B has an electronic oil pressure control system

[Vimy101]

I bet the Spec B has an electronic oil pressure control system

 

You go, girl!

[Vimy101]

And how would this oil pressure regulator know what the engine speed is, never mind the throttle position as you originally claimed ?

 

The oil pressure comes to around 80 psi at around 3,000 rpm and stays solid until redline, no matter whether the throttle is part open or WOT.

 

Try it and see, I have.

 

"The by-pass flow circuit insures oil

flow to the engine when there is a significant restriction

across the filter due to loading or cold start conditions."

 

http://www.fram.com/pdf/CollapsedCenterTubes.pdf

[tommypenguin]

I understand that parking a car with a light weight flywheel is a PITA.

 

Indeed on my prelude I had a 13.5lbs act flywheel with an streetlite clutch. I hated driving the car with the ac on, parking was also a nuisance.

[PhilT]

"The by-pass flow circuit insures oil

flow to the engine when there is a significant restriction

across the filter due to loading or cold start conditions."

 

http://www.fram.com/pdf/CollapsedCenterTubes.pdf

 

Duh !

 

That's so you don't starve your engine of oil if the filter blocks up, and no one is contending that.

 

Now find me proof to back up your original claim, that the oil pressure increases with throttle position.

 

Oil pressure is nominally somewhere between 40-60 psi depending on the OEM. This pressure is normally exceeded on cold starts (because of viscosity) and at WOT.

[meier motor sports]

again hes got the right idea but wrong application of thoughts. higher rpm will allow for a higher pressure. higher rpm comes from opening the throttle more. (usually). you could floor the pedal and have the engine bog at say 700rpm and oil pressure would stay at the same psi as if you where ideling at 700 rpm.

[Vimy101]

^ I've been correct all along.

[fizxman]

Wow! 59 degrees and a little foggy this morning, nothing like dropping 50 points off the thermometer to improve your mood and your performance... in almost everything!

 

Seriously felt like a new vehicle this morning. Mid range throttle response was soooo much better! I could accelerate at highway speeds, passing was a delight again. Feels like 20-30 WHP difference on the butt dyno; no more having to drop two gears and really put my foot in it to get it to respond! I know it's all about the air temperature-volume-density relationship, Charles' Law, stoichiometry, blah, blah. For me the bottom line is, I just fell in love with my car.... again!

[PhilT]

^ I've been correct all along.

 

Still in your little dream world I see

 

Here's some facts for you, readings I took on the way into work:

 

* Start up car, oil pressure immediately rises to 100psi, stays there at idle.

* Stays at 100 psi for first 10 minutes of drive in.

* Oil starts to warm up, pressure starts to drop, after 15 minutes oil is hot, pressure steadies out at 80 psi.

* Crusing along at 70 mph in 5th, 80 psi.

* Drop into 4th, accelerate at WOT to 90mph, pressure stays at 80 psi

* Through varying throttle positions and speeds, pressure stays at 80 psi

* Arrive at work, as revs drop below 3,000, oil pressure drops off quickly and settles at 30 psi at idle.

 

Now where do you see the oil pressure varying with throttle position ?

[rao]

Let's not forget this gem from the first page of this thread.

 

All cars will be affected by high temps and humidity. Forced induction cars slightly less so.

 

I mean, everybody KNOWS that high temps have no effect whatsoever on cars with forced induction.

 

Vimi - you go girl!

[Vimy101]

Still in your little dream world I see

 

Here's some facts for you, readings I took on the way into work:

 

* Start up car, oil pressure immediately rises to 100psi, stays there at idle.

* Stays at 100 psi for first 10 minutes of drive in.

* Oil starts to warm up, pressure starts to drop, after 15 minutes oil is hot, pressure steadies out at 80 psi.

* Crusing along at 70 mph in 5th, 80 psi.

* Drop into 4th, accelerate at WOT to 90mph, pressure stays at 80 psi

* Through varying throttle positions and speeds, pressure stays at 80 psi

* Arrive at work, as revs drop below 3,000, oil pressure drops off quickly and settles at 30 psi at idle.

 

Now where do you see the oil pressure varying with throttle position ?

 

Congrats. It appears that your oil pressure bypass valve and oil pressure regulator are functioning nominally.

[PhilT]

Congrats. It appears that your oil pressure bypass valve and oil pressure regulator are functioning nominally.

 

 

Is that your best attempt ? At least have the balls to admit when you are wrong.

[Vimy101]

^ Take your own advice, hoser.

[PhilT]

^ Take your own advice, hoser.

 

Prove to me I'm wrong, and I will

[jagcars26]

I just put the meter on Vimys' theorys,,

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