LocostUSA.com

My goals are relatively modest. I want to build a locast, I want it to look like a locast, and I want to milk what i can from a relatively modest motor. I want it to be open wheel.

I would like it to be able to lap at something like Formula Ford times.

I am willing to do some work to become more aerodynamic. In the mid-eighties he aero FF's showed up and obsoleted everyone overnight. I think there's a few things you can do to clean them up a bit. I also think it will be fun to experiment.

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Marcus Barrow - Car9 an open design community supported sports car for home builders!
SketchUp collection for LocostUSA: "Dream it, Build it, Drive it!"
Car9 Roadster information - models, drawings, resources etc.

Better aerodynamics would improve fuel efficiency. With the typically tiny fuel cells, that might make touring a bit more fun.
I just wish the 11 was a little prettier ...

White Pointer in Australia makes an Eleven-based body without the headrest streamlining and with cutout fenders for larger wheels. Any Eleven body shell could be altered similarly. It reminds me of the XKE:



http://www.whitepointer.com.au/bella.html

Mine uses the same numbers, they're just arranged a little differently, 105 MPH

I've posted an article on my website describing how you can easily measure how much WHp (wheel Hp) it takes to drive your car at a continuous speed.

The link on the site is named; "How much power does it take to drive a car?"

It also helps to explain why a Locost has so much performance with not all that much Hp. You have to read the article and think it out a little but the info is there.

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"My junk is organized. At least is was when I put it wherever it is." -olrowdy
Completed building GSXR1000 CMC7, "Locouki"
Website: http://projekt.com/locouki/

I have an 8 gallon tank. with about 7 usable, it'll cruise about 150-170 miles.

That's about as long as I can sit in my car without needing to get out and stretch.

First off, it's nice to see the many replies .

I started the topic with more than just the current locost that I'm building in mind, as some of the stuff I'm talking about cannot be applied to it.
Because you took a really wild guess?


This is right along the lines of what I was thinking, with a few variations that are mainly related to class rules.
I'm trying to avoid going to NASA's SU.

Fenders - yes sir!
I'm thinking of front fenders that are some hybrid of the CSR shape and the Donkervoort nurburgring special deep cut in the front, possibly vented in the rear.

Oval / teardrop tubes - I'd love to but the price is cost prohibitive at this point, unless someone has a good source to recommend.

Inboard shocks - that was the plan from day one, as I mentioned in the first post of my build log .

Agreed, I need to check class rules to see if I can cut mine.
It also improves the cooling by a good bit, which is never a bad thing for a racecar.

Why bothering making a locost aerodynamic?
Because I like it.
I like it better than a lotus 11 or 23 which are nice but not my style.

The Donkervoort D8 GT is a great example of the potential that I see it, probably not as radical in its design but the concept is there.

Funny, but as I progress more into my build I can definitely see how I build anther one for pure street use and completely different style.

Moti

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Moti

My R1 powered Locost build log

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A brick is a brick. You will never get good aero numbers from a 7 shape. Having said that, there are fun things you can try that might make a difference. Make it narrow. A couple inches less frontal area will at least make it a smaller brick. Use narrower tires, and smooth wheels. The really bad drag comes from the wheel/tires, and for some reason, taller, narrower tires have a better Cd that fat meats. Try a small ducktale on the cycle fenders, if you use them, to separate the air before it starts around the back of the wheel. Use a bellypan. Use a Brooklands size windshield, and a hard tonneau over the passenger seat. Teardrop tubing is too expensive, but what about teardrop A arms? with really thin steel, the weight would be minimal, and probably strengthen the arm. The teardrop shape is the best, but if you can't do a gradual taper, less than 10 degrees, you're better off cutting it off sharply. Mostly, dont confuse downforce with aero. Most modern racecars are serious bricks. They are made for downforce, which causes drag. F1 cars probably have a Cd over 1, and LMP etc. aren't that far behind.
Check out "New Dimensions in Race Car Aerodynamics" by Jos. Katz. It's mostly about downforce, but there's a lot of basic info that helps a lot.

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It's my leg, Jack. The string's gone out of my leg.

Couldnt you make your own teardrop tubes. Use normal tube to build the suspension and then form some sheet metal into the teardrop shape and tack/bond w/ glue that to the tube?

Thinking about it I wonder if you could make some fiberglass covers that taper the entire control arm. Instead of focusing on the tubes themselves, do the whole arm as a unit. Hmmm.... It's sure look unquie if its anything like whats popping into my head.

Carrol Smith, in one of his books, showed a product that did just that. It was a plastic extrusion that wrapped around round tubing, snapped together, creating a nice aero-shaped cross-section. Don't know if the product still exists.

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Midlana book: Build this mid-engine Locost!, http://midlana.com/stuff/book/
Kimini book: Designing mid-engine cars using FWD drivetrains
Both available from https://www.lulu.com/

For wishbone tubing, you could try flattening it yourself. Any hydraulic press should do, and I think you could find other ways because the individual lengths you need to work with are pretty small.

The wishbones on a Swift FF car look like they are just tubes squashed almost completely flat. The wall appeared to buckle a bit in the middle. I wold be uncomfortable going that far...

These folks will run whatever you ask them to thru a set of rollers, minimum order 1 full tube.

http://www.aedmotorsports.com/4130/Streamline.htm

I think taking the radiator out of the nose might be a good idea. It could go on the inside back face of the car's rear or other places in the back. In a Swift and other FF's it sort of goes just behind the driver and roll bar.

I think opening up the space between the chassis and rear wheels would help. That would allow you to taper a bit towards the back and let you run a bit wider track.

Run a full belly pan and raise it towards the back a bit. It looks like the frame can be adjusted a bit to help here.

What do the rules say about what motors you can use? Find a short motor like an xflow which would give you a big reduction in frontal area. It's a least 4" shorter then most of these DOHC units and can be tipped a good amount ( I think ), towards the passenger side. Then build your frame to original height or even an inch less ( 2" under book ). Then build your hood and scuttle shorter too. Shrink the nose in height, and make the lower surface parallel to the ground.

Get yourself a Hewland. It will help with packaging, you will shift way faster without needing the clutch, and you will be able to have proper track gearing.

_________________
Marcus Barrow - Car9 an open design community supported sports car for home builders!
SketchUp collection for LocostUSA: "Dream it, Build it, Drive it!"
Car9 Roadster information - models, drawings, resources etc.

This looks to be the EVO article referenced:

http://www.evo.co.uk/carreviews/cargrou ... r_260.html

Downforce and drag both include aerodynamic forces.

The hardest part of DIY aero is collecting good data. Yarn tufts and manometers can tell you something about the flow in specific areas, but not much about the overall effect.

Here's one approach to measuring aero drag without a wind tunnel: 1950 Plymouth Drag

A means of measuring lift would be useful. Some fancy cars monitor ride height, but not many Locost donors. Maybe rig sliding scales to suspension components, put a camera where it can record the motion?

The problem is measuring perhaps 1/10" movement masked by inches of noise from road irregularities.

_________________
Midlana book: Build this mid-engine Locost!, http://midlana.com/stuff/book/
Kimini book: Designing mid-engine cars using FWD drivetrains
Both available from https://www.lulu.com/

Areo seven has been discussed....

Windshield (should be rounded, slopped and angeled back at the
sides...their are many cubic feet there for improvement)

Head lights Should be built into the nose ala Doonkervort 8

Nosecone Why not something less like an air ram and more like a "circle track nose" or modern car air intake where air seeps in everywhere

Inboard suspension Natch....

ROOF Yes I said that loathsome word to most seveners, but not just a roof a total enclosed cockpit

Areo front fenders I have the idea but they would almost have to hard mounted to avoid a sail effect at speeds (maybe that would be good but you get into unsprung wheel weights)

Belly pan Defusser Well ....yeah, better airflow top and bottom

There was a red posted picture of some high dollar carbon fiber ugliness that could be accomplished using locost building methods and a custom body(fiberglass)....truly modern race-like car for the street more than most Houses if I remember right.

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I'll keep an eye out for you!

To err is human...
I am more human than most.

The underside of the car already has a partial "belly pan" (the floor). The bottom of the tunnel itself would need to be sealed up and the boot needs to have a pan put on the bottom.

Some people have mentioned exiting the radiator hot air upwards through the nose cone behind the radiator. It looks like that would be a high pressure area since it is exposed to the direct air stream. Reversed NASA tunnel notwithstanding.

In reality the underside of the engine compartment should also be enclosed and the radiator hot air diverted to a low pressure area (if one exists) through a large reversed scoop or louvers along the sides of the car behind the front tires.

The picture below is how a Jaguar race car was fitted with a fan to cool the rear end. On a Locost maybe this idea could also be used to pull hot from the engine compartment through the tunnel with a smaller diameter fan.

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"My junk is organized. At least is was when I put it wherever it is." -olrowdy
Completed building GSXR1000 CMC7, "Locouki"
Website: http://projekt.com/locouki/