Well, you beat us. Our best run was our first- 1.13g
Like I said, I tip my hat.
I'm pretty sure we got the setup right later, but not until the track got puked on. We pulled a 1.11g on the slick track, so I think we had a big improvement, but no track to run it on.
Great effort, Jim! Good to see you!
yeah, I kinda wish I had gotten a run in before the track got dumped on but it was really weight distribution that was killing me. I should have grabbed my towing wheels from back at the RV and strapped them to the front :)
In reply to SVreX:
1.139 thank you very much. 
JThw8 wrote: yeah, I kinda wish I had gotten a run in before the track got dumped on but it was really weight distribution that was killing me. I should have grabbed my towing wheels from back at the RV and strapped them to the front :)
Don't need weight up front.. just add and learn how to use the steering brakes..
ronholm wrote:JThw8 wrote: yeah, I kinda wish I had gotten a run in before the track got dumped on but it was really weight distribution that was killing me. I should have grabbed my towing wheels from back at the RV and strapped them to the front :)Don't need weight up front.. just add and learn how to use the steering brakes..
Bingo!
ronholm wrote:JThw8 wrote: yeah, I kinda wish I had gotten a run in before the track got dumped on but it was really weight distribution that was killing me. I should have grabbed my towing wheels from back at the RV and strapped them to the front :)Don't need weight up front.. just add and learn how to use the steering brakes..
yeah, a set of turning brakes would have been sweet
More weight needed up front, something like this gradually filled with lead shot until it behaves?
In reply to Kenny_McCormic:
Or a wing that does not cost weight.
Yeah, that's what I essentially have in mind but I'll use plates from my weight bench...they might as well do something useful ;)
Actually I had hoped to make 2 different mounts one on each side so I could move the weight around for the skidpad but just didn't have time to execute.
A side note, I was very worried about taking an "oil dripper" out on the pad. As the old joke goes if an aircooled VW isn't dripping oil it's run out. But putting new seals throughout paid off and it was dry all weekend.
Ok smart people...step into my office...lets talk wings.
Here's what I "know" for low speed use wings are a mixed bag, they must be designed, tested and of a proper size to be of any effect.
I have neither the funding nor facilites for any of that so is there really anything to be gained by slapping a 24x36 sprint car nose wing on the front of this thing....like so
Or is it really just a waste of time and all our talk of wings has been in fun? I can get the above wing at a price which is, lets say, affordable, and I'd be willing to give it a shot for autocross but I don't want to be slapping a wing on the nose of the car for the hell of it, it would need to actually do something.
Ok, serious question, did it understeer thanks to the rear balance of the car?
If it did, I think the front wing will help- probably at a pretty steep angle- much like a sprint car. Maybe steeper, since you are going slower.
Well on the skidpad it didnt understeer terribly but the front was very light. Whereas the rear tires actually looked like they were doing something the fronts weren't even scuffed. The front end is definitely too light and when pushed in an autox it will definitely understeer like a pig.
If you can get a wing cheap, seems like it would work. Heck- so many autocrossers use just a basic lip spoiler quite effectively. And they have real bodies on the car.
alfadriver wrote: If you can get a wing cheap, seems like it would work. Heck- so many autocrossers use just a basic lip spoiler quite effectively. And they have real bodies on the car.
Yeah, I dont want to spend thousands, or even hundreds but I can get that one above for $50 and fab up some adjustable mounts to play with the angle a bit. Its light so it won't give me any weight in the front end unfortunately but if it makes any downforce it might be worth it.
I keep thinking if I keep this thing and keep developing it then I may have to skin the underside to make it smooth...sigh...scope creep.
mount it forward of the wheels ... well forward. mount a steel plate under.
voila, weight well forward of the front, but not as much weight had you put it between the wheels...
any idea of the curb weight?
Mad_Ratel wrote: mount it forward of the wheels ... well forward. mount a steel plate under. voila, weight well forward of the front, but not as much weight had you put it between the wheels... any idea of the curb weight?
Haven't weighed it. Thought about it when I passed some truck scales on the way home but didnt feel like pulling it off the tow dolly.
I can always add weight too, still mulling over the wing...
As an old Amod guy I know said. If its shaped like a banana it will make down force. On the FSAE car we put some 18" deep single element wings and saw an improvement from 1.6-1.8G on a smaller diameter skidpad. I would think some home depot pink/blue 2" foam a homebrew wirecutter and a very thin layer of Sglass prior to monocoating to reinforce the leading edge would work great. Somewhere on the internet is a airfoil simulator (aerofoil I believe) that will simulate single and multi element wing profiles. You can find a wing profile and print it from the equations provided.
nocones wrote: As an old Amod guy I know said. If its shaped like a banana it will make down force. On the FSAE car we put some 18" deep single element wings and saw an improvement from 1.6-1.8G on a smaller diameter skidpad. I would think some home depot pink/blue 2" foam a homebrew wirecutter and a very thin layer of Sglass prior to monocoating to reinforce the leading edge would work great. Somewhere on the internet is a airfoil simulator (aerofoil I believe) that will simulate single and multi element wing profiles. You can find a wing profile and print it from the equations provided.
yeah, the more I looked at the cheap one I found I didn't like that it was a flat wing, I definitely want an airfoil shape. Although I have loads of glassing supplies here I don't need another fabrication project right now, that could change I suppose but if I can find a suitable wing in the $100 range (which does seem possible with some hunting) then its the easy route.
You say an airfoil wing-is that like the wings they used to use on tow rigs to smooth air over an enclosed trailer? How much are those wings some tow rigs used to smooth airflow over an enclosed trailer?
Could you hang the battery off the front of the beam?
Junkyard_Dog wrote: You say an airfoil wing-is that like the wings they used to use on tow rigs to smooth air over an enclosed trailer? How much are those wings some tow rigs used to smooth airflow over an enclosed trailer?
Yes but I priced those and holy E36 M3 they are expensive. I did find a sprint car nose with with a better shape for an acceptable price so I guess we'll give it a try :)
Actually I should say sprint car nose wings are really damn cheap. The truck wings are priced where I expected something of that nature to be but well above what my cheap ass would spend.
Kenny_McCormic wrote: Could you hang the battery off the front of the beam?
I thought about it, it's how we always had them in the Formula Vees but to be honest I never really felt safe having it be the first thing to hit something. I have it mounted forward just not that far forward.
We'll see what the wing does and if needed I'll make a "weight basket" out front of the beam to put weight into.
In reply to JThw8:instead of adding weight and complexity to the car, why not try some factory fresh slicks on the front? Did the tires get a chance to warm up properly? Those tires looked humongous on that thing, is it possible that smaller tires might suit the chassis better. (Those giant slicks do look bad**s though
)
What kind of speed were you averaging on the skid pad? I'm guessing that it would be slower than typical AX speeds, so any aero devices would need to be really aggressive to do anything. Is there anyway to add negative camber? (would that even be useful on a car that light in the front end?)
This is a fantastic build Jim, I too am jealous of your ability to complete projects.
Speeds were slooow. Guessing 35-40mph.
At autocross speeds any wing is better than no wing. If it has some banana shape (Camber in airfoil terminology) it will work better. Also wider is better, so make it as wide as the front track. If you have questions on airfoil shape for the application, drop me a line if you decide to build one.
As far as putting a pan on the bottom, don't bother with that until you get the chassis much closer to the ground, and then you have to deal with the wing interaction.
Steve Stafford
Why add more weight? Steal a page out of the VW family and just borrow the control forward bits from a Microbus. Look where the driver and his weight is located.
I think sitting on or in front of the axle would be way cool as you carved up a field of cones.
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