Denny
Canned Monster
That looks like a really bad copy of a transformer.
Diamonite Electrathon America Racer
- Thread starter Functional Artist
- Start date
Master Hack
Well-known member
Travis is such a great guy, always friendly with the kids. Travis and grand brat #2 at the Oregon Trail rally in '22
Functional Artist
Well-known member
Hey Denny,
Yup, that's kinda the idea/concept
&
This guy (was an aerodynamicist for a Mercedees F1 team) seems to explain "why" pretty well
Whitetrashrocker
Inmate #952016
Ive been a fan of pastrana since his early MX days.
Im not sure thats an accurate photo. There no way he got his big cajones in those pants.
Im not sure thats an accurate photo. There no way he got his big cajones in those pants.
Functional Artist
Well-known member
Winter
We gots a bunch of snow recently
...with some snow drifts ~2' (24") deep
Also, It got so cold (~-15*) that I found some ice ferns on a couple of the North facing windows of my house
Natures art
Can't do much outside
...so, lots of time for more research & contemplation
This video discusses reasons for automotive undertrays & diffusers pretty well
...& illustrates much of the info with computer simulated air flow
...& pressure difference visuals
We gots a bunch of snow recently
...with some snow drifts ~2' (24") deep
Also, It got so cold (~-15*) that I found some ice ferns on a couple of the North facing windows of my house
Natures art
Can't do much outside
...so, lots of time for more research & contemplation
This video discusses reasons for automotive undertrays & diffusers pretty well
...& illustrates much of the info with computer simulated air flow
...& pressure difference visuals
Functional Artist
Well-known member
TMI?? (thats Too Much Info...for the OG"s)
...& (thats Old Goats for the...um...never mind)
Just tryin' ta give you'all an insight
...as to "where I'ma commin' from"
OK...back to the CAD model
Let's take a closer look at "what I'ma thinkin' for" the bottom side
So, I'ma thinkin the front air intake will "go" from the front "edge"
...to just behind the front wheel well
...about here
Then there will be a ""flat" or horizontal area (just under the centrally located battery box)
Some specs
The "nose" intake ~16" wide x ~2" tall
...narrows down to ~12" in between the wheel wheels x ~1" tall
...then, the air flow "splits"
...& gets "channeled" into (2) narrower ~5" wide passageways
...while getting sped up & more energized
...as it (air flow) "rushes" toward the throat of the diffuser tunnels
Then, the air starts to expand
...while flowing into the 6"wide throat of the tunnel
...& then, flows out from under the car
...thru the (2) 6" wide x 18" tunnels
...that can "raise" up to as much as ~12" tall at the rear of the body
The body would extend down on the sides
...& the wheel well area would be "sealed" off, from the air flow, a bit
...like this
Could also have some kinda "air guides"
...maybe like this
Another view
...& (thats Old Goats for the...um...never mind)
Just tryin' ta give you'all an insight
...as to "where I'ma commin' from"
OK...back to the CAD model
Let's take a closer look at "what I'ma thinkin' for" the bottom side
So, I'ma thinkin the front air intake will "go" from the front "edge"
...to just behind the front wheel well
...about here
Then there will be a ""flat" or horizontal area (just under the centrally located battery box)
Some specs
The "nose" intake ~16" wide x ~2" tall
...narrows down to ~12" in between the wheel wheels x ~1" tall
...then, the air flow "splits"
...& gets "channeled" into (2) narrower ~5" wide passageways
...while getting sped up & more energized
...as it (air flow) "rushes" toward the throat of the diffuser tunnels
Then, the air starts to expand
...while flowing into the 6"wide throat of the tunnel
...& then, flows out from under the car
...thru the (2) 6" wide x 18" tunnels
...that can "raise" up to as much as ~12" tall at the rear of the body
The body would extend down on the sides
...& the wheel well area would be "sealed" off, from the air flow, a bit
...like this
Could also have some kinda "air guides"
...maybe like this
Another view
Whitetrashrocker
Inmate #952016
How fast are you planning on going?
Denny
Canned Monster
20 mph.
Functional Artist
Well-known member
Hey WTR,How fast are you planning on going?
Well, my Polaris & Sequoia EA race cars both "top out" ~25MPH with a 12S or 13S battery pack
...or nearly 30MPH when "running" with a 14S or a 15S battery pack
&
Both of those racers have heavy steel space frame chassis
...& don't hardly have any aero or "streamlining" by body panels
This monocoque chassis should be a lighter (hopefully)
...with some (trying for lots of) thought into aero &/or streamlining
&/so
Maybe up into the mid 30's
...or nearly 40MPH
Here is an excerpt from the EA rule book
AERODYNAMICS
Aerodynamic drag increases rapidly the faster you go, enough to be a deciding factor over the duration of the race. Wind resistance has a noticeable effect above 15 mph, and grows exponentially as the speed increases. Aerodynamic drag is the result of speed, frontal area and length of the vehicle and the shape of the body shell.
Whitetrashrocker
Inmate #952016
Sarcasm doesn't translate well.
Just busting your balls dude.
I admire your creative brain. Your thought process far exceeds most.
Just busting your balls dude.
I admire your creative brain. Your thought process far exceeds most.
Functional Artist
Well-known member
Hey Denny,20 mph.
1.) 20 MPH is probably the most speed, most folks could "handle" on an average EA track (parking lot or road course)
Q: how fast could an EA racer attain with a 1.2HP engine?
Q2: Could it even move, a kart/racer with a driver aboard??
Functional Artist
Well-known member
Hey WTR,Sarcasm doesn't translate well.
Just busting your balls dude.
I admire your creative brain. Your thought process far exceeds most.
Ohhh the sarcasm...
Thanks...my friend
Sometimes it's a (+) & sometimes it's a (-)
More thoughts
I heard/read somewhere "As speed doubles, the effects of aero quadruples" (sound correct??)
...& if so/as such
I was thinking/for example/hypothetically/for discussion purposes, let's say:
...~1lb. of down force could be created when going ~10MPH
...&/or when going ~20MPH, ~4lbs. of DF, could/should be created
...& then, if going ~40MPH (if we ever get going that fast) maybe ~8lbs. of DF, could be created
&
On a ~300lbs. racer an extra lb. of down force, @ ~10MPH, could/would be helpful
...& potentially ~4lbs. of DF @ ~20MPH...even more so
...&/or/even/maybe ~8lbs. of DF when cruisin' along at ~40MPH
Functional Artist
Well-known member
Another view
Let's look at "it" another way
More drawin's
...& some more expanded explain-ation(s)
Havin' the front of the racer "blocked off"
...or not
...isn't a big deal, while just sittin' still
When driving along
...& having the front of the racer blocked off
...a lot less air would flow under the racer
...but, IIUC (if I understand correctly) a high(er) pressure area (drag) would be created in front of the racer
...& the faster the racer "goes' the higher that pressure (drag) would get
&/also
As a "Free Bonus" a low(er) pressure area (another form of drag) forms behind the racer
& (remember)
The faster the racer "goes" the higher the pressure (more drag) that is exerted, on the front of the racer
...& /also, (in turn) an even lower pressure forms behind the racer (even more drag)
But, think of this...
...even "if" the "fancy" shaped floorboard, doesn't actually create any noticeable down force
...the undercar air flow, along with the Venturi effect, should still "inject" some high(er) pressure air
...into the "known to be created" low pressure, area behind the racer
* So, to re-interate
...it seems like having air flowing under the racer
...& thru some venturi tunnels, would help reduce the drag, on the racer, in (2) different ways
1.) From the front, of the racer
...by allowing the higher pressure air (that has built up)
...to "vent" under the body
&
2.) By injecting that "manipulated/conditioned" higher pressure air
...into the lower pressure area, behind the racer
...should help reduce drag too
Let's look at "it" another way
More drawin's
...& some more expanded explain-ation(s)
Havin' the front of the racer "blocked off"
...or not
...isn't a big deal, while just sittin' still
When driving along
...& having the front of the racer blocked off
...a lot less air would flow under the racer
...but, IIUC (if I understand correctly) a high(er) pressure area (drag) would be created in front of the racer
...& the faster the racer "goes' the higher that pressure (drag) would get
&/also
As a "Free Bonus" a low(er) pressure area (another form of drag) forms behind the racer
& (remember)
The faster the racer "goes" the higher the pressure (more drag) that is exerted, on the front of the racer
...& /also, (in turn) an even lower pressure forms behind the racer (even more drag)
But, think of this...
...even "if" the "fancy" shaped floorboard, doesn't actually create any noticeable down force
...the undercar air flow, along with the Venturi effect, should still "inject" some high(er) pressure air
...into the "known to be created" low pressure, area behind the racer
* So, to re-interate
...it seems like having air flowing under the racer
...& thru some venturi tunnels, would help reduce the drag, on the racer, in (2) different ways
1.) From the front, of the racer
...by allowing the higher pressure air (that has built up)
...to "vent" under the body
&
2.) By injecting that "manipulated/conditioned" higher pressure air
...into the lower pressure area, behind the racer
...should help reduce drag too
Denny
Canned Monster
But chasing downforce also induces drag. There’s even an old law about this. Energy can not be created or destroyed. It can only be transformed. So by building in the front you’re gettin screwed in the back so to speak.
Functional Artist
Well-known member
Hey Denny,
OK Let's look at this at even another way
We are all pretty well familiar with regular 'ol go karts...right?
&
If your drivin' a kart, that understeers a bit, at 10MPH
...it would/should understeer even more (worser) at 20MPH
...& even "way more worser" at 30MPH...right??
&
Not just understeer
...even trying to control many karts on straights
...can get "squirrely" or twitchy, the faster ya go
Now, let's say we mount a 5 lb. weight, over top of each of the front tires
...which would increase the "down force" on each wheel by 5lbs.
...& "give 'er a go"
I think we all should be able to "see" (vision/understand) how
...the kart should/would now steer better
...& maybe/hopefully help reduce any squirrely/twitchy-ness too
But/now, we added 10lbs.
...that the kart "now" has to "drag" (technical term) around (all of the time)
...ta "gain" that steering benefit
...&/or "run" stable-er
Whereas, if any "down force" created was (basically) speed controlled
...it would only be created &/or "appear" when needed...most
Denny
Canned Monster
Now your added aero down force introduces 20lbs of drag. When you could have had only 10 lbs with the weights.
Functional Artist
Well-known member
OK/well...movin' on...
For my "next trick"
...let's make a full-size wooden mock-up
Rounded up some scrap plywood
...& commenced ta measurin', markin' & drawin'
* Winter may slow me down (~30* this afternoon)
...but, it cannot/will not stop me
Got 'er assembled
...but, it wasa frickin' HUGE
* The side "sponces" (12"T x 12"W) looked/were "way" too big
So, a "trip" back "out in nature"
...& a bit of trimmin' on the sponces (down to 10"T x 8"W)
That looks a bit better
...now, its 8" (sponce) x 20" (cockpit) x 8" (sponce) - ~36" W (total)
Side view
* Playin' with some different length & dimension "nose" configurations
For my "next trick"
...let's make a full-size wooden mock-up
Rounded up some scrap plywood
...& commenced ta measurin', markin' & drawin'
* Winter may slow me down (~30* this afternoon)
...but, it cannot/will not stop me
Got 'er assembled
...but, it wasa frickin' HUGE
* The side "sponces" (12"T x 12"W) looked/were "way" too big
So, a "trip" back "out in nature"
...& a bit of trimmin' on the sponces (down to 10"T x 8"W)
That looks a bit better
...now, its 8" (sponce) x 20" (cockpit) x 8" (sponce) - ~36" W (total)
Side view
* Playin' with some different length & dimension "nose" configurations
Functional Artist
Well-known member
Hey Denny,
This doesn't seem to "jive" (technical term) with what I've been learning
...please explain??
AFAIU
DF (downforce) produced by "force" (air "hitting" a surface) is supposed to be ~3X "draggier" (technical term)
...than any DF that's created by "pressure differences" (by creating a lower-pressure area) under the car
Functional Artist
Well-known member
Please don't take "my questioning" personal...my friends
I truly want to learn & understand more about "how things work"
...so, I can then (hopefully) apply some of that knowledge, to my mini-racers
My new Life Ethos is to question...everything
...&/then, try-n-make my own conclusions/decisions
* I used to "think" others knew...everything
...&/or "what's best", for most any given situation
But,
Have NOW come to realize
...that "this" is NOT always true
Theres almost always
...continual "real world" testing
...more research
...&/or new info
&
As time "goes on" folks get a better understanding
...of how "things" work
...&/or how "things" interact together
&/or
Again, NOT referring to you, Denny (just rantin')
...but, many times, the person (teacher, journalist, business competitor, guy in a video, an online commenter etc.)
...doesn't know all of the details, for a specific situation
...or has a mis-understanding about "how" a concept actually "works"
...or is misapplying differing affects, from different situations (like aircraft aero vs. automotive aero)
&
Sometimes
...opinions can interfere with facts
...or "slanting" of info "happens" for personal reasons (political, financial, vindictive etc.)
...&/or/even, "if" the "poster" is pessimistic or optimistic, about a situation, can HUGELY (technical term) influence the situation
So,
I now "question"...everything
...& try-n-research & evaluate, things that I'm interested in...myself
I truly want to learn & understand more about "how things work"
...so, I can then (hopefully) apply some of that knowledge, to my mini-racers
My new Life Ethos is to question...everything
...&/then, try-n-make my own conclusions/decisions
* I used to "think" others knew...everything
...&/or "what's best", for most any given situation
But,
Have NOW come to realize
...that "this" is NOT always true
Theres almost always
...continual "real world" testing
...more research
...&/or new info
&
As time "goes on" folks get a better understanding
...of how "things" work
...&/or how "things" interact together
&/or
Again, NOT referring to you, Denny (just rantin')
...but, many times, the person (teacher, journalist, business competitor, guy in a video, an online commenter etc.)
...doesn't know all of the details, for a specific situation
...or has a mis-understanding about "how" a concept actually "works"
...or is misapplying differing affects, from different situations (like aircraft aero vs. automotive aero)
&
Sometimes
...opinions can interfere with facts
...or "slanting" of info "happens" for personal reasons (political, financial, vindictive etc.)
...&/or/even, "if" the "poster" is pessimistic or optimistic, about a situation, can HUGELY (technical term) influence the situation
So,
I now "question"...everything
...& try-n-research & evaluate, things that I'm interested in...myself
Denny
Canned Monster
I agree drag is bad and lift is worse first of all. Second for the speeds we’re running aero is just not as important as mechanical efficiency. And thirdly without a wind tunnel you may as well be peeing into the wind. Everything is just a guess. Break out the yarn and masking tape and go out and experiment.