A locost style track car, Car9

[962porsche]

down at the fab shop i have print outs of a mid engine rear drive car i designed hanging on the wall in my office .
but we were talk (the guys in the shop and i ) about building that car . we would use a porsche motor and trans that i have if you turn the trans around and flip it up side down now it will work for a mid engine car . they tend to use the porsche trans in many kit type cars for many reasons so they do offer many adapter plates if you did want to run some like a LS motor . and they will hold up to alot of HP and tork .
another thing we were talking about was installing the trans in the rear . you could use the trans from the 944 and have the motor in the front of the car . this way too you could still use a LS type motor they make adapter plates for the LS and SBC motors to do motor swaps into the 944 . i have done many of them to date there cheap and a very ez swap to do .
what we were talking about was that there are some many other 7 type cars offered now so would one more really sell all that better ?
yes they are great cars and a blast to drive but does the market really need one more ?
then what would set your apart from the others ? to make it sell and stand out ?
when i was thinking about building a car i checked out prices to have some one build the fiberglass body they were not all that much about 600 dollars a unit for a complete body if i had they build 200 at one time . the less they build at one time the more the price want up .
again i'm not trying to slap your dick in the dirt we were just sitting around talking .

[horizenjob]

that there are so many other 7 type cars offered now so would one more really sell all that better ?

You had a few questions but I'll focus on this now. There are a couple of areas of difference.

First, this is an "open design". That means that everything about this car - it's design process, specs, blueprints, computer models etc. is freely available to anyone that wants it. It will be great if other people decide to manufacture it, that's more marketing. I was happy when you suggested a better arrangement for some tubes, I put that in and gave you credit for it. If this was a computer program, you could share the copyright.

I would love to get this to the point of having files to drive a laser tube cutter. Someone could download the file, mail it to a steel shop and get back a complete set of notched tubes that could have tabs and slots to be self jigging. I think I saw this was priced $6 a cut for small orders.
http://www.youtube.com/watch?v=FYLhQ2XW ... re=related

Secondly this is a track oriented car first and foremost. It has an integral roll cage that meets SCCA and NASA specs ( well that's the goal ). Since it's an integral cage designed up front with the car frame, it is stronger, stiffer and lighter. It is about 6-8 times stiffer then a normal Locost. It does that while putting less stress in it's tubes, so it is very strong. The suspension has adjustable roll centers and anti-dive / anti-squat. It's designed to be able to crush in the front and back without injuring it's passengers.

Lastly it's being designed to work with different parts so people can make choices. If people make different choices, they can contribute their work so other people can follow in their footsteps.

[962porsche]

i see ! we were thinking you were going to build and sell the chassis and body panels more like a kit car .
i think it's great what your doing !
so what is the plan for the body panels ?

[horizenjob]

Researching suspension tradeoffs all night and I find this commnet:

The bigger picture is that you can spend thousands of hours doing design & analysis work & in the end you must shoot the designer & then build & develope the car.

I am just going to start off by shooting non-critical parts though...


David, I'll write you some stuff about body work soon.

[horizenjob]

An interesting body for a Locost with half the drag ( twice the power is a good way to look at it ).

Here is a great video of some of the design research and development that went into this. Jack McCornack is the developer and was recently included in the Experimental Aviation Hall of Fame. He designed the strap on gliders parachuters use in a James Bond movie a few years ago.

http://www.youtube.com/watch?v=RU0R_r1yC-g

[horizenjob]

I didn't have much time to write a post above. The picture is to give an idea of what that body work would look like. It started with body work for a Lola Mark I, what you see there is the work in progress to fit it to a Locost. Jack eventually plans to make molds from this and have the bodies available this fall. He has a traditional looking fairing behind the driver now and it looks more finished.

He also sells a lot of Locost parts. This Locost is powered by a 35 HP Turbo diesel and gets 100 MPG, he has entered it in several competitions. He can run it on olive oil for the price of your average car's gas...

http://kineticvehicles.com/

His aerospace company is here and you can see his gliders for paratroopers on the front page:
http://www.kineticaerospace.com/

[962porsche]

i had in my mind your were doing an open wheel design on the body kindof like the lotus 7 .

[horizenjob]

Yes, I'm thinking open wheel or Seven style, just thought I'd put up those pictures as an option. A Locost style chassis is so generic, you could fit all kinds of bodies on top. You just got me thinking about that a bit when you made those comments about the cost of fiberglass bodies.

So the easiest thing is a Seven / Locost style body. There are several noses available for that and the rest is just simple aluminum sheet. I keep wondering though about some older style roadster bodies, both oval track cars and street cars. The Massachusetts laws recently enacted for kits and home builts seem complicated but maybe are easier for pre 1948 cars? I don't know.

The fellow with the above Lola style bodywork sells several Locost noses including ones that come in pieces that you can fiberglass together to accommodate different height and width noses.He also sells the scuttles the same way.

[962porsche]

lotus 11 body would be cool i think ? or a XKE i think the wheel base would be to short for that ?

[horizenjob]

I need some help / advice on wheels. I am having trouble getting info on offsets. So far I have found Enkei, Compomotive and Minilite to list their available offsets. Sites like TireRack.com don't let you browse by things like offset, which is making it difficult. Do you folks know anywhere I can search by parameters like diameter and offset?

This is where things are at the moment. In rough numbers it would be nice if the car could have a set of wheels with 25" tires for the street and 22" for the track. Then you could have a 2.5" ground clearance for track and 4" for street with just a wheel change. For cost and performance reasons I would like to be able to use 13" rims for the track and considering 17" rims for the street.

The front spindles are Mustang II with a 2" drop. These spindles originally would be installed with a very high scrub radius, which I would like to reduce to roughly 1". This requires wheels with something like a 50 mm offset. Using Miata spindles would reduce the required wheel offset, but probably cause other tradeoffs. I'd like to include all these parts and more but want to provide tables of parts that go together.

On the V8 car I think rim widths like 8" front and 10" rear would be right. This car with a 4 cylinder might want the same or perhaps could use 8" rear also.

The sticking point at the moment seems to be getting wide 13" wheels with a fairly high offset for the rear.

Clear as mud? Any advice appreciated...





Ford
front 4x4.25" rear: 5x4.25" 5x4.5"

Subaru
5x100 (5x4" ?)

[zchris]

A problem with a car running both 13" and 17" wheels will be brake sizing. I believe about a 10.5" rotor is all you will get in a 13" wheel. Thats fine for stopping a 13" wheel/tire combo. It will be way undersized for the 17" setup. Marginal for street use. Better hope you don't have to do to many panic stops. Street tuner guys never take into account the inertia of a 30 pound 20" rim. You need lots of brake just to stop the wheel spinning, let alone slow the mass of the car. Even the 17's will weigh in over 20 pounds. Run the #'s on MOI of a 13' vs 17" wheel tire setup. You'll be surprised.
Chris

[horizenjob]

Hi Chris, thanks for the note, I owe you an email and thanks for the pictures you sent me. Nice work on your car!

So interesting point on the brake size. My thought had been that the track use would be much more severe then any street use. Simply scaling the wheel and tire from 13 to 17 would more then double the inertia. Both would be heavier components too, so it's not hard to imagine 4 or more times as much inertia.

I'm not sure where I stand on this. With the 17" rims and rubber I think it would be safe at speeds resembling common highway usage with hardware suitable for track use on 13" rims and slicks. The 17" rims would allow very large brakes to be fitted and they are easily ($$) available for these spindles. So it's the combination use that would be an issue, like you suggest.

It's possible the V8 version, which is probably 300 lbs. heavier, will not do so well with the smaller rims. I'm hoping that version comes in a bit under 1500 lbs.

Since I want less scrub radius then a Pinto that is probably compounding the space issues since the upright is further into the rim by a couple of inches. I'm fixing up my model in that area now, I made a steering arm for the spindle, working on an inner profile of the rim and will draw up a rotor and I have a Wilwood caliper in the model already I'll use.

[horizenjob]

Still pugging away. trying to tie up a bunch of details and get closer to playing with metal. I have a question about driveshaft u-joints that I'll post below. Here's the what the car looks like now. This has the improved engine bay and dash bracing. It removes the cross tubes on a Locost that are often modified to fit various engines/transmissions. Instead the dash is made stronger and the bracing forward from there is well tied together. The dash is now a "Terry Hoop".

I haev placed the front suspension parts and coilover. There is both an outboard and the start of the inboard version. I think the best option for inboard suspension is the bodywork from Jack McCornack shown above. He has removed the mock up from his car and is currently building a set of production molds. He sold the first three bodies for $2500 and the production versions will be a bit more. Half the drag means twice the power, that's a pretty good deal.

I have put in a floor to help tie down some details. Will make a Kirkey seat later today. Moved the rear hoops back a bit to allow a vertical shape 5 gallon fuel cell.

Made up a set of Wilwood hanging pedals and a set of floor mounted Tilton pedals. The Wilwood ones have the proper support drawn, the Tilton ones are just pedals for now. I think the floor mount pedals seem more right for a very low seating position, perhaps the hanging pedals are better for street use.

I made drawings of a Woodward steering rack and also an aftermarket Mustang style rack and also a collapsable oval track steering column.

Working on checking the cockpit sizing etc.

[zchris]

I forgot to ad that you can also use 4x100 front hubs from speedway on your pinto spindles that will give you a huge wheel selection. They do not list that hub on there website, but it cost no more and takes no longer to get. It also makes brake rotors choices easier as they have several size aluminum adapter plates.
Chris

[horizenjob]

Thanks for the pointer Chris. I'll do some more wheel huntings and keep that in mind. What I would really like is a hub with the wheel mounting surface closer to the spindle. I'll have to do some more looking.

A couple more Locosty pictures. Here's LocostUSA member Heikki winning the "Chase the Dragon" hillclimb last weekend. He took first place overall! By a couple of seconds.

7433236174_624e44ab46_k.jpg (188.99 KiB) Viewed 7463 times

Also another picture of the Lalo bodywork for a Locost. I see from his notes that this bodywork changed the top speed of his Locost from 72 MPH to 90 MPH with a 32 HP motor. He figures that with 250 HP the car should do about 180 MPH. Heikki is also buying a beta version of this bodywork.