AxeHealey said:In reply to sleepyhead the buffalo :
See, now, that's why you're head aerodynamicist of this illustrious race team!
stafford's commented in here too... and reckon he'll be on-site at challenge; so a more fitting title is "co-head aerodynamicst" 
sleepyhead the buffalo said:AxeHealey said:In reply to sleepyhead the buffalo :
See, now, that's why you're head aerodynamicist of this illustrious race team!
stafford's commented in here too... and reckon he'll be on-site at challenge; so a more fitting title is "co-head aerodynamicst"
Oh man you and I have the same Aero team! They should really get a logo so we can put it on our cars.
nocones said:sleepyhead the buffalo said:AxeHealey said:In reply to sleepyhead the buffalo :
See, now, that's why you're head aerodynamicist of this illustrious race team!
stafford's commented in here too... and reckon he'll be on-site at challenge; so a more fitting title is "co-head aerodynamicst"
Oh man you and I have the same Aero team! They should really get a logo so we can put it on our cars.
Deal. Co-head Aerodynamicist, it is! Didn't mean to excude a valuable member of the team!
Nocones, will I hear in my headset that I should let you go by on the dragstrip in the best interest of the team?
The two-piece splitter is now glued and weighed down to dry.
I couldn't really find any NHRA rules on how far the splitter can extend beyond the body work. Some SCCA classes seem to be 3 inches, others are 5. I cut the profile to be about 6 inches forward of the body.
It's dry and mounted. I also put a screw in each corner, just for extra stability. It's about 4.75" above the ground at ride height. How important is it to get it down to the 3" target? I assume quite. I was much more focused on using the splitter to support the rad/broken core support when making the mounts than I was concerned about how close it was to the ground.
Other than how high above the ground it is, I'm happy with how it's looking so far.
AxeHealey said:I couldn't really find any NHRA rules on how far the splitter can extend beyond the body work.
Learned from the Nelson's about shallow staging. I though about making some way about making a movable light tripper so that when I took off it would raise and not trip the light giving me a head start.
Could you just remove the splitter between the autocross and drag so you don't have to worry about staging lights or the extra aero drag? Plus you probably have to remove it anyway to put it back on the trailer.
In reply to maschinenbau :
splitters (especially like above) are pretty commonly known for reducing drag, not increasing
In reply to AxeHealey :
it'll try to dig up the difference in downforce based on height, but I wouldn't be surprised if 4.75 to 3in was a doubling.
first thing, though, is to stand on the very front (even better if you can stand heel to heel, with your toes out towards the sides "ballerina style"), bounce a little, and make sure the mounts are strong enough
I'm not sure where you are heading and I'm sure the real aero folks will be along soon. But I would think this would make your spliter effectiveness increase.
Have the green parts be "fences" that stick out and trap some air and force the to go up over the Blue part. I do not believe there are any aero rules at the challenge. Overhang as much as you feel like.
In reply to sleepyhead the buffalo :
Not standing on it yet. I've still got to get the forward mounts in. Don't want to do that until I figure out whether or not I'm going to drop it down.
In reply to nocones :
Yes, that's where I'm headed. Picture a common Miata valance lots of endurance cars run. The valance will be aluminum. I have yet to decide whether or not I'm going to do steel flares like your MG or if I'll fashion something else out of aluminum. EDIT: I also want to wait to finalize flares until I have the size tire I'll actually be running.
Getting the splitter lower will increase down force but it will be front biased. That may not be the balance you want. Start with it in the current location. If the tires you wind up running are smaller diameter then you will reduce splitter gap by half the difference. Lowering the splitter from 4.75 to 3.0 will nearly double the front downforce.
After driving it, if you feel you need more front balance you can add a sacrificial bottom face near the leading edge. It only needs to be the front 6-8 inches and shaped to taper to the plywood surfaceat the back with the radius at the front. Some rigid foam would work well. Or another chunk of off cut plywood.
In reply to stafford1500 :
Thanks! All of that is extremely helpful. Proceeding as is and adding a sacrificial face if needed is definitely the route I'm going to take.
The tires on the car are 23.0, SM tires are 22.8. Not a huge difference but with doubling the effect over 1.75", every little bit helps. I do think with the weight balance of this car, however, I'm going to be more in need of rear down force than front.
Or a big front bar to move some of that grip rearward
In reply to jfryjfry :
Totally a possibility too. I have to admit that I have no idea whether or not it's a stock bar up front. I'll need to research that. The problem with all of this is that I really don't think there will be much opportunity to test it before the Challenge so any adjustments will be made in the paddock between runs or by the next owner once I've shaken it down for them.
Last night I got the forward mounts in. I just took square tube and chopped it into little brackets. Two screws hold each bracket to the splitter. I'd really like to make slits in the splitter and make mounts that stick up through. I could spread the load out much further and it would look much cleaner.
I did stand on it. The limiting factor is the 3/8 ply. The mounts are, without question, strong enough. The forward mounts will be even more solid if I make them from the underside.
Revised mounts are done and I dig them. I did almost no measuring so each one is bespoke (different), so that makes it extra fancy, right?
looking good. Time to break out the router and work the lower leading edge.
In reply to stafford1500 :
It's nice of you to assume I've got the proper tool. It'll be shaped by a grinder, flap disk and my artistic eye.
In the meantime, I made a prototype valance out of a single piece of super duper thin aluminum. It's clearly do able in one piece but if I want to use a more appropriate thickness of aluminum scrap I have sitting around, I'll be making it out of three pieces. Progress shot.
In reply to AxeHealey :
That looks nice.
nice job planning ahead, and making the overlap so that it supports the bottom of the aluminum "air dam". when you make the hole for the radiator... don't make it more that 1/3 the size of the exposed radiator behind it.
part of me wants to suggest you do something stupid like make it trapezoidal to match the opening made by the middle two support wires. but, I think, instead you make a slot the same width as the radiator about halfway up, that way it's easy to seal the air dam back to the radiator, and then it's a simple vertical expansion above and below to get to the radiator face.
In reply to sleepyhead the buffalo :
That was my plan. Somehow I didn't execute on it though. The only thing I can imagine is I used the plum bomb (nut on a string) when the front end was up in the air like an idiot. Best laid plans.
This is turning into me posting a highly similar picture every day but here we are.
It's cold in the garage and the cold and I don't get along whatsoever so things are moving more slowly. That said, Guac can now breathe a little better.
As I get older I hate the cold too!!!
In reply to TurboFource :
I always have and, for me at least, the hatred grows every year.
I got the first side piece done via multiple little breaks throughout the day. There is a mounting flange on the under side. This evening I took the first crack at the template for the filler piece.
This design makes it a pretty steep angle. Should I bring the bottom of the filler piece further forward so that it can be more gradual? I think I can visually deal with it starting 1.5-2 inches closer to the leading edge before it starts to look silly to me.
Either way, my plan is to add a few tabs to the template that will bend and allow the filler piece to be riveted to the side piece and air dam. I also trimmed the splitter width-wise to better match where the SM tires will be.
can you give us a shot from the side?
any plans to go up and over the tire?
Yes.
And yes. I intend to make a rudimentary flare attached to the hood that will continue this surface up and over the wheel.
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