Warm Ram Air Intake?

[Caddylackn]

don't know why my photo did not show in my reply post above, but here it is again

[oil pan 4]

Someone on here pit a heater core inside their air cleaner box for consistent temperatures.

[Logic]

Originally Posted by aerohead

The lowest pressure will occur along the sides of the vehicle, not the rear.
Exhausting to the rear requires that zero leakage occur at the trunklid (boot) seal, and seal between trunk and rear seat/cabin.
It's the reason NASCAR demands side pipes to dilute tailpipe gases which could be inhaled during 'drafting.'

(Apologies for hijacking your thread Talos, but the pics below do show the high pressure areas in front of the car too)

I'm aware of the venturi effect aerohead and that fast moving air generally means lower pressure.

But aerodynamics is a counterintuitive business and i'm confused.

Here's the intuitive idea:


And here's flow which goes with what you said:


And here's a pressure view from underneath a car where one can see a hint of orange high pressure behind the car:

(Is the high pressure just low down..?)

Here's the exhaust next to the number plate on an early Lotus Europa:
(my project car if I ever get the damn Anglia sold)


But it was moved to the more conventional spot in later models.

At a guess I'd say the rear number plate area is likely to be the most consistent low pressure area on a car at various speeds if you don't care about CO poisoning..?

Link to article where the pics come from:
(properly placed bonnet vent seems like a good idea)
https://robrobinette.com/S2000Aerodynamics.htm

Other links showing the low pressure area behind a car, where people like to put boat tails to 'fill that vacuum' (your canopy included! ):

https://www.researchgate.net/figure/...fig2_322640200

Car Aerodynamics Basics, How-To & Design Tips ~ FREE!

[Logic]

Originally Posted by Caddylackn

I am trying this out, making my exhaust exit at a low pressure area. Air velocity should be high here and pressure low. I should get a bump up in engine efficiency.



Seems to work well. Someday I will put on a slip on tail pipe and extend it past the bumper and do a A B A comparison in gas mileage.

Sounds interesting Caddylackn. Do give me a heads up when you post!

[Vman455]

Originally Posted by Logic

(Apologies for hijacking your thread Talos, but the pics below do show the high pressure areas in front of the car too)

I'm aware of the venturi effect aerohead and that fast moving air generally means lower pressure.

But aerodynamics is a counterintuitive business and i'm confused.

Here's the intuitive idea:


And here's flow which goes with what you said:
https://robrobinette.com/images/S200...ion_NASCAR.jpg

And here's a pressure view from underneath a car where one can see a hint of orange high pressure behind the car:

(Is the high pressure just low down..?)

Here's the exhaust next to the number plate on an early Lotus Europa:
(my project car if I ever get the damn Anglia sold)


But it was moved to the more conventional spot in later models.

At a guess I'd say the rear number plate area is likely to be the most consistent low pressure area on a car at various speeds if you don't care about CO poisoning..?

Link to article where the pics come from:
(properly placed bonnet vent seems like a good idea)
https://robrobinette.com/S2000Aerodynamics.htm

Other links showing the low pressure area behind a car, where people like to put boat tails to 'fill that vacuum' (your canopy included! ):

https://www.researchgate.net/figure/...fig2_322640200

Car Aerodynamics Basics, How-To & Design Tips ~ FREE!

Gee, if only there were a way to measure aerodynamic pressures on your own car instead of all this guessing and speculation.

[aerohead]

Originally Posted by Logic

(Apologies for hijacking your thread Talos, but the pics below do show the high pressure areas in front of the car too)

I'm aware of the venturi effect aerohead and that fast moving air generally means lower pressure.

But aerodynamics is a counterintuitive business and i'm confused.

Here's the intuitive idea:


And here's flow which goes with what you said:
https://robrobinette.com/images/S200...ion_NASCAR.jpg

And here's a pressure view from underneath a car where one can see a hint of orange high pressure behind the car:

(Is the high pressure just low down..?)

Here's the exhaust next to the number plate on an early Lotus Europa:
(my project car if I ever get the damn Anglia sold)


But it was moved to the more conventional spot in later models.

At a guess I'd say the rear number plate area is likely to be the most consistent low pressure area on a car at various speeds if you don't care about CO poisoning..?

Link to article where the pics come from:
(properly placed bonnet vent seems like a good idea)
https://robrobinette.com/S2000Aerodynamics.htm

Other links showing the low pressure area behind a car, where people like to put boat tails to 'fill that vacuum' (your canopy included! ):

https://www.researchgate.net/figure/...fig2_322640200

Car Aerodynamics Basics, How-To & Design Tips ~ FREE!

1) the highest possible pressure will be the forward stagnation point ( Cp + 0.8 on Tesla 3 ( Edgar )
2) the lowest ( but not exhaust-related region ) pressure will be just ahead of the windshield header ( Cp - 0.69 on Model 3).
3) the next lowest area will be under the car at the diffuser ( Cp- 0.37 ).
4) The base pressure of the wake will be at a higher pressure ( Cp -0.16 ).
5) The 'template' has positive pressure at its rear, all around.
------------------------------------------------------------------------------------
The rear spoiler probably allowed re-attached flow to the boot, killed separated flow upstream at a much lower pressure, allowing the attached flow to decelerate before separating at the 'new' rear of the spoiler, increasing base pressure, lowering pressure drag, and total drag.
Yes, there's 'low pressure' in the wake, but it's at a higher relative pressure than elsewhere.
It's why the aft-body is the most crucial part as far as drag goes.

[Logic]

Originally Posted by Vman455

Gee, if only there were a way to measure aerodynamic pressures on your own car instead of all this guessing and speculation.

Gee thx for the links.
BUT:
One does want somewhere to start your investigations before you go as far as designing and building an exhaust system.
You haven't dashed out with and angle grinder, welder, bender, some pipe and a pressure meter have you..?

[aerohead]

This will be an interesting project when you get to it.
It's one car that put the 'body' where most place a rear spoiler. Wolf Heinrich Hucho had mentioned in his 2nd-Edition book that, adding a rear spoiler affected drag and lift almost as good as just designing the aft-body to the same 'height.'
If it was Frank Costin who did the design, I applaud him.
At Cd 0.29, the Europa was probably a benchmark for low drag in 1968, when it debuted. It just so happens to intersect the span of the 'slow,' 2.5:1 streamline body of revolution-derived half-body contour I used for the 2007 AST-I.
I got to drive a spyder version at a party in 1969. It remains my favorite sports car. A real slot-car! Elegant. Visceral. No girly-man creature comforts. Just legs-straight-out, buns-on-the-floor, unadulterated performance!
And driven 'conservatively', no doubt, very efficient, naked, off the boat from England.

[Logic]

Originally Posted by aerohead

This will be an interesting project when you get to it.
It's one car that put the 'body' where most place a rear spoiler. Wolf Heinrich Hucho had mentioned in his 2nd-Edition book that, adding a rear spoiler affected drag and lift almost as good as just designing the aft-body to the same 'height.'
If it was Frank Costin who did the design, I applaud him.
At Cd 0.29, the Europa was probably a benchmark for low drag in 1968, when it debuted. It just so happens to intersect the span of the 'slow,' 2.5:1 streamline body of revolution-derived half-body contour I used for the 2007 AST-I.
I got to drive a spyder version at a party in 1969. It remains my favorite sports car. A real slot-car! Elegant. Visceral. No girly-man creature comforts. Just legs-straight-out, buns-on-the-floor, unadulterated performance!
And driven 'conservatively', no doubt, very efficient, naked, off the boat from England.

Thx; yes it's a nice car to start with.
Aero and 649kg.
But some room for improvement left.

The challenge is making changes that are easily reversible so that reverting back to original is easy.
Then I want to keep the "legs-straight-out, buns-on-the-floor, unadulterated performance!" too!

I think perhaps a new thread as I/we're hijacking poor Talos' thread way off course.

[Talos Woten]

Originally Posted by Logic

I think perhaps a new thread as I/we're hijacking poor Talos' thread way off course.

No worries. I've already decided not to mess with my air intake, given than my initial tests at changing things all resulting in worse fuel economy. Whatever Toyota is doing in the Prius, it's probably already been optimized.

So feel free to hijack away!