Front air dam / valance questions

[gran racing]

Well it is good thing I never go off being too aggressive.

I also need to figure out how much lower I could go with my "trailer" and not destroy it then. I can just picture spending hours on the thing then taking it right off as I load the car for the first time.

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Dave Gran
NER ITB #13
'87 Honda Prelude si

[67ITB]

Dave,
You can make it easily detachable and you don’t have to worry about trailer clearance.
As long as you have room in the tow vehicle? Or if it can some how fit in the car itself?

And that is you can make it “detach easily”, NOT you can “easily make it detach”
As that part of the design took a little more thought process than I realized going into it, but we were still able to get it done

Matt

[Diane]

Dave,

Mine is detachable. Let me know when you are in this area and I can show you. Or I'll drive it to work some day and you can get some new bike gear for next MTB season.

Diane

[gran racing]

Detachable? That means I'd have to attach it too. So I'm a bit lazy. I'll have to check out what you did with your car.

Mt biking...just picture 4 racers getting together for a "leisurely" ride. I'm so glad none of us are at all competitive.

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Dave Gran
NER ITB #13
'87 Honda Prelude si

[Greg Amy]

This is great information, but it pisses me off; now you've taken away my excuses for lack of motivation of building one...

Dave et al: detachable is easy. Six to ten quarter-turn "Dzus" fasteners in key locations ought to do it...

[Diane]

Originally posted by gran racing:
Detachable? That means I'd have to attach it too. So I'm a bit lazy. I'll have to check out what you did with your car.

Mt biking...just picture 4 racers getting together for a "leisurely" ride. I'm so glad none of us are at all competitive.

Yes, it does mean you have to attach and detach. I could however go over speed bumps with it *slowly* but rarely used it on the street. Never in the winter of course, but I'd install it to show you (even though I know it won't clear the driveway to the shop ). I want to say it's maybe 10 fasteners? It's flexible enough to stow in the car for the trip to the track.

As for non-competitive mountain biking, what's that? My bruises say otherwise. You forget to mention 4 *IT* racers.

[slackerjay]

here are a few great ideas from another site on making a splitter.

happy holidays

http://honda-tech.com/zerothread?id=930543

~jay

[Boswoj]

Couple of things to throw on the pile:

When Mario won his World Championship it was at least in part due to the radical approach to "ground effect" aeodynamics. He was at the forefront of a spectacular wave of development intended to increase grip through aerodynamic downforce, without the huge penalties in drag imposed by wings. I was reading an engineering brief comparing current F1 cars to their counterparts of the late 70's and early 80's and I was shocked. If you think that todays F1 cars are the absolute pinnacle of technology, you would be wrong when it comes to aerodynamics. If you look at the downforce/drag ratio of current wings it's about 1.2 to 1.4, meaning for every pound of drag you get something like 1,4 pounds of downforce. With a smooth, clean, well designed underside with tunnels and diffuser like in 1978, you get SEVEN POUNDS FOR EACH POUND OF DRAG! Experts postulate that a modern F1 car with full ground effects would be in excess of seven seconds faster a lap with the addition of this "old school" technology. Even on a low HP car, you are pushing a "whoopie cushion" of turbulent high pressure air through the convoluted and aerodynamically "dirty" undercarriage of your car creating drag and causing lift. Does anyone remember Smokey Yunick putting 600 pounds of bondo on the underside of one of his his famous Nascar "rule-stretchers" to clean up the airflow and gain advantage on his less inventive competitors?

Happy Holidays - Boswoj

PS - As a sidenote, that same Smokey is the reason NASCAR has templates today. He showed up to race with a hand-made 7/8ths size replica of a production stock car because it saved him 12.5 percent of the frontal area of a real car! Took a while before someone noticed - but there wa a lot of hollering afterward!

[This message has been edited by Boswoj (edited December 24, 2004).]

[Knestis]

I've been playing with the analysis software that came with my DL1 and it has a clever utility that uses two sets of coast-down data (high- and low-speed, easy to collect, now!) and vehicle mass to compute the sum of aero and rolling resistance drag - in negative horsepower.

This just get cooler by the minute...

Then, once those figures have been established, the system can do the math the other way to determine positive (engine) power, based on on-track performance - even correcting for ambient temperature, pressure, and relative humidity.

K

[Racerlinn]

OK, get ready, here it comes.......
I got a wild hair (plus it was a balmy 40 degrees here over the weekend - perfect time to work on the car) so I took a stroll thru my favorite speed shop (aka Lowes Home Improvement). In the HVAC aisle, the always-a-fan-favorite 3" flexible aluminum ducting was procured. After a wander thru the hardware, paint, and flower arranging sections, I made my way down to Siding and Guttering. A pair of plastic 3"x2" gutter spouts later, I was in the checkout line spending the balance of my X-Mas gift card - about $12.00.
Here's the results of $12 and an hour and half of free time in the garage.
Ducting the drivers side was pretty darn easy. Lot's of room next to the tranny, lot's of clearance from the wheel, and the wheel well splash shield makes a nice mounting "bracket" for many zip ties. The passenger side is a different story. Just like traveling the the roads in Pennsylvania, you just "can't get there from here". I finally decided that a decent trim of the splash shield would allow as high of routing of the duct as possible along the edge of the oil pan. The duct on this side is now the lowest hanging part of the car and is sure to take a beating. Plus, when at full left-hand steering lock, it made the nice 3" diameter tube into a 2"x4" rectangle. Hopefully the differential of air flow from the added restriction does not cause to much of a balance issue for the brakes (hmm, will Steve by consistently locking the drivers side wheel this year?) But, for $12, what the heck. The results:
Air dam (installed in my vinyl siding air dam):

Drivers side duct:

Passenger side duct:

Let the pointing and smirking begin!

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Steve Linn
'92 ITA Sentra SE-R
www.indyscca.org


[This message has been edited by Racerlinn (edited January 31, 2005).]