Front wing - WOW

DCMoney

Goblin Guru
Even a static gopro mount could probably show ride height if aimed over the hood and at a wheel or something like that.
Not accurate enough for me, but too much of what I do on a daily basis is measured out to 4 decimal places and I get stuck in an accuracy mindset.
 

jcdman

Active Member
The raing held off after work yesterday and was able to get some footage on the airflow around the wing. I was mainly interested on my 2nd element spacing and placement in relation to the main element. I was happy to see what looks like attached airflow to the underside of the 2nd element.

I'll need to attach a tuft to the underside of the main element to see what's going on there.
That and change my X-brace orientation to reduce vibration to the wing.
Hard to tell but it looks like the flow is detaching underneath on your second wing. When flow is attached, that piece of string will be stuck to the surface and no gap should be visible, more like the string on the top side of your second wing. Might be mounted with a little too much angle, the lower surface is the bigger concern for producing downforce. If you're interested in gathering physical data, check out XFLR5. Free program that'll let you import an airfoil and output theoretical performance based on different AOAs or velocity.
 

Attachments

Waterdriver

Goblin Guru
Hard to tell but it looks like the flow is detaching underneath on your second wing. When flow is attached, that piece of string will be stuck to the surface and no gap should be visible, more like the string on the top side of your second wing. Might be mounted with a little too much angle, the lower surface is the bigger concern for producing downforce. If you're interested in gathering physical data, check out XFLR5. Free program that'll let you import an airfoil and output theoretical performance based on different AOAs or velocity.
The second element I set it at my highest angle to see if the air would stay attached. It's right at the limit.
In reviewing the video, I think the yarn tufts on the right side element are too long. They're getting up into the airflow coming off the top of the wing and distorting the yarn. I'll maybe add a couple more that are shorter in view of the longer ones, to see if there's any difference. Then maybe drop the 2nd element down to the next lower setting.
Somehow I forgot to add some yarn tufts for under the main element. I guess I got excited to test it. Will be adding those for the next test.
 

Gtstorey

Goblin Guru
That and change my X-brace orientation to reduce vibration to the wing.
You may have trouble getting that vibration out. As slender and long as they are, you probably would have to brace them 1/2 way between the current mount and the end to get rid of it. Not that improvements can't be made by making the center more rigid. It might help some to connect the two wings at the 1/2 point. Maybe replace the aluminum plates at the end with abs to make them lighter?
 
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Waterdriver

Goblin Guru
You may have trouble getting that vibration out. As slender and long as they are, you probably would have to brace them 1/2 way between the current mount and the end to get rid of it. Not that improvements can't be made by making the center more rigid. It might help some to connect the two wings at the 1/2 pint. Maybe replace the aluminum plates at the end with abs to make them lighter?
I agree, I definitely wont get all the vibration out. But if I can reduce it by say half would be nice. When you watch black mounting arms, when hitting a bump, you can see them move a little and independently from each other. That little movement translated at the wingtips is large.
I think moving and/or adding a cross brace from the horizontal to vertical position might take some of that vibration/movement out.
Having 600lb front springs doesn't anything in this regard either at low speed.
CF endplates are in the future plans, which will help reduce the weight out at the ends. Looking to first play with the aluminum endplate shape and maybe addons to try and direct air out around the front of the tires.
I don't know, it's just fun researching, build and mess around with this stuff, then test it out and see what it does. Always been nerdy that way.
 

Waterdriver

Goblin Guru
Hard to tell but it looks like the flow is detaching underneath on your second wing. When flow is attached, that piece of string will be stuck to the surface and no gap should be visible, more like the string on the top side of your second wing. Might be mounted with a little too much angle, the lower surface is the bigger concern for producing downforce. If you're interested in gathering physical data, check out XFLR5. Free program that'll let you import an airfoil and output theoretical performance based on different AOAs or velocity.
Thanks, I'll look in to that program on airfoils. The pic you posted is pretty close to the main elements wing profile.
At one time I was looking into using SimScale for the whole car and was trying to learn it using some preexisting models. But I didn't have the time at that point to invest learning how to set it up and use it.

The main element I currently have set to 0 degrees angle of attack with the 2nd element set to an aggressive 25 degrees. Might be a little too much.
 

Waterdriver

Goblin Guru
Another option is put something wearable slider (some kind of plastic, UHMW, HDPE etc) on the front of the car that would drag against the road and wear down. You'd know the initial height of the slider, drive around with same parameters above, measure the difference in the plastics height no wing and wing.

If you have a data logger. I made a string potentiometer for my XT Racing GPX Pro back in day for one of my race bikes out of a badge lanyard and a rotary pot to measure front fork travel while on the track. Similar to this one. https://www.instructables.com/Low-cost-string-pot-displacement-transducer/
The zip tie shock travel indicator I've tried but its difficult to find an area smooth enough that's long enough. Otherwise its indicating the bumps you've hit as the farthest travel.

I really like your idea on the slider suggestion and it got me thinking. Using the camera to record using something like this.
Most likely will need to draw it up and 3D print it for the QA1 shock. I think I might start there. Maybe make one for the rear as well.

The potentiometer idea is an awesome idea as well, with exact readings. Keeping this one in mind.
 

TheNuker

Goblin Guru
Just got my front wing in and kinda disappointed, the mounts are way too wide to fit from the radiator mounts by 4 inches. Why would the mounts not be set to come straight off the radiator mounts with aluminum 90deg channel?
Nuker-
 

Waterdriver

Goblin Guru
Just got my front wing in and kinda disappointed, the mounts are way too wide to fit from the radiator mounts by 4 inches. Why would the mounts not be set to come straight off the radiator mounts with aluminum 90deg channel?
Nuker-
Did you get your front wing/mount issue figured out?
 

TheNuker

Goblin Guru
Did you get your front wing/mount issue figured out?
Well basically its going to take 3" 90deg angle to be able to mount to the radiator bottom support bars and line up with the spoiler mounts. Found out at the goblin meet in arkansas that the aluminum was not going to work. Under cough cough normal speeds the spoiler would start to bend due to downforce and scrap the side wings on the ground. So I'm going to design and weld up some custom steel brackets to mount the wing that won't flex at all!

I'll post pics as soon as I get the 3d printed versions done and test fit.

Nuker-
 

Gtstorey

Goblin Guru
Joined the front wing crowd this weekend. Didn’t get a chance to drive it, but probably will be more for looks than any real downforce. Still need to trim a little more on the hood and the wing is just rattle can paint for now. The pictures are with the car on dollies.
 

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Gtstorey

Goblin Guru
It’s probably more functional than you think. You’ll be amazed how a little downforce will make a big difference.
I'm not sure how good the wing "shape" is. It has a rounded front edge then top and bottom are flat and parallel followed by a kicked up tail. If nothing else it adds some weight in front of the front wheels.
 

Gtstorey

Goblin Guru
I am trying to figure out a way to install a Gurney flap but I'm not sure how I can fasten anything to the trailing edge.
 
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