 Poster: A snowHead
|
|
since diesel engines are very energy effective, generates not much heat thus takes 10+ km drive to reach working temperature, they have electric heaters and starts heating car interior after ~1 minute since you turn it on.
|
|
|
|
|
|
Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
|
|
|
|
Well, the person's real but it's just a made up name, see?
Well, the person's real but it's just a made up name, see?
|
Engine braking compresses air in the cylinders. Very effective though creates a lot of heat.
Diesel engines are more efficient than petrol engines but still very inefficient.
|
|
|
|
|
|
You need to Login to know who's really who.
You need to Login to know who's really who.
|
| cameronphillips2000 wrote: |
Engine braking compresses air in the cylinders. Very effective though creates a lot of heat.
|
completely wrong, creates heat, compared to doing nothing, but in general, engine temp drops compared to running idle or driving. Tried it many times, diagnostics shows coolant and oil temp, at the bottom of 600 meter long downhill coolant and oil temps are 3-5 degrees lower.
|
|
|
|
|
|
Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
|
| kosmoz wrote: |
| cameronphillips2000 wrote: |
Engine braking compresses air in the cylinders. Very effective though creates a lot of heat.
|
completely wrong, creates heat, compared to doing nothing, but in general, engine temp drops compared to running idle or driving. Tried it many times, diagnostics shows coolant and oil temp, at the bottom of 600 meter long downhill coolant and oil temps are 3-5 degrees lower. |
Isn't it just the relative difference? The heat generated going down is completely outstripped by the capacity of the cooling system to dissipate it to air.
If you flip it, going up does the opposite. Under power the capacity of the cooling system is far more used and the residual temperatures rise accordingly.
It's only energy transfer in different pathways. Brakes are kinetic, friction, builds store of heat in rotor, radiate to air. Engine / transmission unit, friction, builds heat in assembly, oil / coolant, transmitted to cooler matrix, transfer to air.
The difference between brake friction material causing friction and oiled mechanical components causing friction is obvious. The brakes can enact that friction much quicker than the oiled system, which is why we have them. 
|
|
|
|
|
|
You'll need to Register first of course.
You'll need to Register first of course.
|
Carry on, now where is my popcorn? 
|
|
|
|
|
|
|
|
|
When you take your foot off the accelerator with the car in gear the car stops using fuel and you slow down. If you brake you stop quicker so you have had your foot on the accelerator for longer so you will use more fuel but cover distance slightly more quickly. It's why racing drivers lift and coast to save fuel when needed.
|
|
|
|
|
|
|
|
| kosmoz wrote: |
| cameronphillips2000 wrote: |
Engine braking compresses air in the cylinders. Very effective though creates a lot of heat.
|
completely wrong, creates heat, compared to doing nothing, but in general, engine temp drops compared to running idle or driving. Tried it many times, diagnostics shows coolant and oil temp, at the bottom of 600 meter long downhill coolant and oil temps are 3-5 degrees lower. |
Engine braking compresses air in the cylinders. fact. Doesn't create as much heat as the combustion diesel but it's where most of the energy goes. Hence you're engine doesn't completely cool down but drops a fair bit.
Regenerative braking is cool. I have it on mine and it recharges the battery. It doesn't have an electric motor so not the greatest of savings but looks great on the little video image on the computer screen on the board showing energy flowing from the brakes in to the battery.
It's these little things in life that keeps us Physics teachers happy.
Regenerative braking has actually been about on trains since the 30s. The Swiss liked those big resistors on the tops of trains to dissipate all of the energy from regenerative braking. I guess they go down a lot of hills.
520d Efficient Dynamics if anyone's interested. The next best thing to a Tesla.
|
|
|
|
|
|
You'll get to see more forums and be part of the best ski club on the net.
You'll get to see more forums and be part of the best ski club on the net.
|
|
I often thought ski resort would be a lot more efficient if they put snow on teh lifts at the top stations, creating less work for the electric motor to do, and improving the snow quality lower down when you spread it out a bit.
|
|
|
|
|
|
|
|
FAQ
