Das Beast, 3.0T Conversion Update. Dawn of Darkness Draws Near; Something Wicked This Way Comes...
10-10-2007, 05:20 PM
#142
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Isn't the heat created by the gears meshing, and doesn't the coolant keep the gears cool?
So doesn't keeping the gears cool commensurately keep loss down, by keeping temps down?
Where is the heat coming from?
Also, it's the rapidity of the 'cycles' of gear mesh/friction that creates the heat, right? So if the coolant keeps the temps down, then the loss stays down too, no?
Otherwise, why use coolant?
I understand that 'time' is part of this, and that HP rises as the 'heat inducing' cycle (gear teeth mashing, friction from pinions spinning, etc), so at some point the coolant doesn't keep up well enough, as the cooling system overall is engineered for normal street use, not triple the power racetrack use, but I have to wonder how much heat really builds as you create a better gearbox?
I.E., how much difference does it make then - the cryo-treated REM coated gears, better fluid, and auxiliary cooling?
Bottom line, I'm just wondering what an accurate appraisal of CHP really is from a WHP reading, given the changes made to my gearbox?
It can't be the same loss as what you see in a stock transmission, can it?
Really, I'm looking for a way to 'talk down' whatever WHP number I get on my car - it's not as if I'm looking to inflate whatever my car ultimately produces. Quite the opposite, actually. Ultimately, I just want to know what the best estimation might be, and how to best make that estimation...
Where is the heat coming from?
Also, it's the rapidity of the 'cycles' of gear mesh/friction that creates the heat, right? So if the coolant keeps the temps down, then the loss stays down too, no?
Otherwise, why use coolant?
I understand that 'time' is part of this, and that HP rises as the 'heat inducing' cycle (gear teeth mashing, friction from pinions spinning, etc), so at some point the coolant doesn't keep up well enough, as the cooling system overall is engineered for normal street use, not triple the power racetrack use, but I have to wonder how much heat really builds as you create a better gearbox?
I.E., how much difference does it make then - the cryo-treated REM coated gears, better fluid, and auxiliary cooling?
Bottom line, I'm just wondering what an accurate appraisal of CHP really is from a WHP reading, given the changes made to my gearbox?
It can't be the same loss as what you see in a stock transmission, can it?
Really, I'm looking for a way to 'talk down' whatever WHP number I get on my car - it's not as if I'm looking to inflate whatever my car ultimately produces. Quite the opposite, actually. Ultimately, I just want to know what the best estimation might be, and how to best make that estimation...
10-10-2007, 08:21 PM
#146
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So what's the equation for calculating loss, and how do you account for all the variables?
I.E., if you knew what amount of loss was attributable to the gearbox in my allroad in stock form, how much less loss might there be with:
1. REM-coated, cryo-treated gears
2. auxiliary cooling
3. higher-quality (Motul, IIRC) fluid?
IOW, I'd expect the above to result in lower friction and between lower friction, harder, slicker gears (how long that REM coating lasts I don't know) and consistently lower coolant temps.
What equation should be used to estimate driveline loss, and what variables does it account for?
It just seems people quote 85-90% efficiency and leave it at that. But I assume a real engineer has a better answer than joe-six-pack-enthusiast?
1. REM-coated, cryo-treated gears
2. auxiliary cooling
3. higher-quality (Motul, IIRC) fluid?
IOW, I'd expect the above to result in lower friction and between lower friction, harder, slicker gears (how long that REM coating lasts I don't know) and consistently lower coolant temps.
What equation should be used to estimate driveline loss, and what variables does it account for?
It just seems people quote 85-90% efficiency and leave it at that. But I assume a real engineer has a better answer than joe-six-pack-enthusiast?
10-11-2007, 09:31 AM
#147
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Thanks! My co-workers and I went out and shot it during lunch.
We work for a company that makes acquisition and post-production video software, so we get to play with cool cameras and such and call it "work" 
10-11-2007, 09:37 AM
#148
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The best estimation is to throw it on a dyno :)
Why have coolant? To keep things from breaking! Radiators and other cooling hardware exist to keep the heat-generating components operating in the temperature range that they're designed to operate in. If things get too hot, unpredictable things can happen... and things break.
The exception is the air going into your motor, but we all know why colder air there helps!
The exception is the air going into your motor, but we all know why colder air there helps!
10-11-2007, 06:32 PM
#150
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No idea. I'm putting the trip off until later next week now due to business obligations...
It will give Mark a chance to get his dyno running and pull some numbers too, which is good. I may not know 'when' until I'm there, as the whole sched is up in the air right now!