Vents

[aerohead]

Originally Posted by Taylor95

Can you elaborate on what an ideal cooling system is?

I'm thinking about putting vents in the wheel wells too. This would improve airflow through the engine bay in addition to keeping my brakes cooler at lower speeds.
I think that venting the wheel wells might improve mpg slightly at highway speeds because my wheel wells are a high pressure area.

At the time Hucho wrote the second edition of his aerodynamic textbook in the late-1980s,the typical passenger car's cooling systems drag contribution was around 12% of the car's overall drag.
With a cooling system,like freebeard has shared,the drag portion is reduced to 2% of the overall drag.
And as freebeard also shared,on a land speed record streamliner at Bonneville,at transonic speed,you could take advantage of that Merideth effect,where the heat flux coming off the engine expands the air against compressed-ram-air,actually providing net thrust.
The trick with the extractor side of the equation,is expelling the air in such a way that it merges with the external body flow field at an identical velocity,and parallel to the body.A look at the 1978 Pininfarina CNR,'banana' car will illustrate such a setup.It took about $100,000 in wind tunnel time to 'tune' these vents for the lowest drag.

[Taylor95]

Wow, that is a huge reduction in drag from heat extractors. I will take a look at this vehicle you mentioned.

[freebeard]

https://driventowrite.com/2015/09/18...mics-analysis/

I believe the discussion is about the vents at the front axle line.

ecomodder.com: The body shape of minimum drag

[euromodder]

Originally Posted by Taylor95

I think a lot of gains are available to me in the front wheel wells, since my jeep is lifted

Aerodynamic fringe mods on a lifted Jeep are pretty futile

Sorry to burst that airbubble

[euromodder]

Originally Posted by Vman455

I'll be curious to see what results you get; to my knowledge, no one on this forum has tried hood vents yet. I probably won't get around to them until later this summer if I do them at all.

Vekke did , Hucho style, on his Seat Cordoba

[slowmover]

Originally Posted by euromodder

Aerodynamic fringe mods on a lifted Jeep are pretty futile

Sorry to burst that airbubble

Yup.

The baseline is usage. Not just miles, but cold starts. Getting down into this level of analysis is where the money is located. On-road mpg can be separated by highway or street. Percentage.

As a daily commute is likely, it will be the other uses where the money can be reduced (combining ALL errands into one trip, for example). Designing a trip loop for those places one nearly always goes.

Farthest point first (via highway preferably to hasten warmup) and then back to home without any left turns, etc.

Parking so as to ease exit with dead-minimal steering inputs.

Leaving early enough to avoid high traffic volume

Etc

For me this was also ZERO vehicle use on Sunday. Forgot something? Tough. Do a better job of planning. (It worked).

.

[gumby79]

Originally Posted by euromodder

Aerodynamic fringe mods on a lifted Jeep are pretty futile

Sorry to burst that airbubble

Function must lead form... else form has no purpose for existence