Proximacentauri ExoCar

[Karlo]

proximacentuari Quote Posted: Fri Dec 21, 2007 12:46 locostusa.com


"This is my build log -

I'm building an Atom-style semi-locost mid engined car. I started at the beginning of the summer of 2007. So far:

June-August 2007:
Summer job to raise money
Reverse engineering of pictures
Learning of Cad
Building of Cad Model
Learning to Weld
Reading books on suspension
etc.
August-September 2007: working with a friend doing FEA analysis on the frame to determine the results of a crash.
September 2007: front and rear box built, beginning to learn how to effectively tack weld and use a tubing notcher
October: College Applications
November:
Four main tubes bent
Frame progress
December: frame nearing completion. Hopefully I'll be done by Christmas.

The Project Plan:
January-Feb: Acquire and disassemble donor car
Feb-March: a-arms/suspension and mount motor
March: get motor working
April: Begin composites and get pedals/brakes/radiator/gas tank/steering working
May: troubleshoot
June: troubleshoot/finish composites

Things I've Decided:
Frame: mostly ERW tubing, roll bar components DOM
A-Arms: 1" DOM tubing
Shocks: Koni drag shocks
Donor Car: 2002-2004 Civic SI (160 HP, cable shift, rear-facing exhaust)
Knuckles: stock with fabricated steering arm
Brakes: stock
Pedals: Tilton pedals/ MCs/ with balance bar
Accelerator: stock
Clutch: stock
Seats: F1Spec type 2 seats - great for the price, two fiberglass seats, mounts/sliders for 400$
Steering Wheel: Momo Race
Steering Rack: Sweet or Woodward manual rack (whichever comes up on ebay)
Gas Tank: 10X30 10 gallon tank from Dansperformance parts, with sender/sump/fuel return/larger holes/remote fill
Exhaust: custom with stock muffler

Many thanks to JonW and the rest of LocostUSA for ideas!
For those interested in what I've done so far, check out my flickr acct at"

http://www.flickr.com/photos/25435483@N00/

:popcorn:

[Karlo]

proximacentuari Quote Posted: Fri Dec 21, 2007 2:26 pm locostusa.com

"I'll probably end up buying some shocks off ebay. I didn't know that drag shocks were a different valving...I just thought it was the manufacturer's way of saying that they weren't for any specific car.

Yeah, the tubing is 2.5" .065. The smaller stuff is 2" .083. The roll points, front and rear, and the back's support, is 2.5" .120 wall DOM. Heavy, but i'm not taking any chances. Plus, the extra metal in the back means that the engine won't get to ride shotgun in a front-end collision."

[Karlo]

proximacentuari Quote Thu Jan 03, 2008 2:54 pm locostusa.com

The fuel cell will go in the same place it is on the Atom, directly underneath the rear roll point, behind the passengers. I considered the front, but I don't have enough money to buy a full-on crash-safe fuel tank.


Also: I will be using the stock knuckles from the RSX/Civic SI. The front knuckles are macpherson struts. Therefore, the force of holding the car up will be placed on the bottom ball joint. Since there is little up-down load on the ball joint in the RSX, do you guys think that the stock bottom joint can handle the pushrod as well as the normal a-arm?
Picture of the knuckle:

[Karlo]

proximacentuari Quote Posted: Sat Jan 19, 2008 locostusa.com

Update:

Things completed since last:
Many more frame parts in. All frame pieces officially required are tack welded. Welding is slow, but i'm learning quickly. Tomorrow, I'll buy some square tubing to form an additional step in the tub. As it is now, it's impossible to get in and out of the car without stepping on the seat, which I don't want. By placing a bar about 6 inches in front of the seats, it gives the driver/passenger a place to step when getting in and out of the car.

In related news, I cut and fit one piece, the first time. Too bad that I finish the frame just when I start to get good at fitting tube.

Also, solidworks is in the mail, alibre just doesn't cut it for modeling suspension stuff.

The next step is finding a donor car. I need a crashed RSX/CIVIC SI...preferable a rollover.

Updated hi-res pictures are on my flickr account, see earlier post.

I asked several questions about suspension and fuel over at k20aforums, the url is http://www.k20a.org/forum/showthread.php?t=38559

[Karlo]

proximacentuari quote Posted: Tue Jan 22, 2008 11:02 pm locostusa.com

1/22/08 - Playing around with Solidworks, I'm absolutely regretting not buying it in the beginning. The extrusion function has the ability to essentially do tubing joints automatically - I usually had to guess, degree by degree, to get two tubes to match up for a junction.

1/20/08 I deviated from the atom design here - I added an additional rectangular bar about 6" in front of the front of the seat. This allows for people to get in/out without stepping on the seat or the fiberglass pan, which will likely be non-structural (at my skill level with fiberglass - none). This way I can avoid an additional Aluminium floor.

1/15/08 - I followed an ad on craigslist to a pile of military surplus bolts - I picked up around 50 3/8 solid stainless steel bolts which will work wonderfully for the inboard suspension mounts and engine mounts. These bolts really are a thing of beauty, polished stainless and all. Also, I grabbed a box of rubber grommets, a bunch of bolts with holes in the top for wiring (anti-vibration for aircraft), several rod ends made out of some strange alloy that rings like a tuning fork, and all sorts of other stainless stuff. Not bad for craigslist. Probably saved me 50$ in fastener parts.

I am now planning to use front spindles all around. In the front, my addition will attach to the steering rack. In the rear, that addition will attach to part of the a-arm. In the rear, the top ball joint and toe-in angle joint just need to be at the same level in order to prevent twisting on bump.

Attached is how I plan to modify the front spindle. I would go with the weld-on bolt approach, but I don't know the material of the spindle (probably Aluminium) and I like the additional adjustment that I get from choosing the length and angle of the steering arm.

[Karlo]

proximacentuari Quote Posted: Wed Jan 23, 2008 11:42 pm locostusa.com

1/23/08 - I bought the two front struts off a 2002 civic si. This will give me something to do while I work out the donor car, and will give me the four front spindles I'll need for my car. Also I identified a possible issue: the track of the Civic SI 2002 is 57.9", whereas the atom's is 63. This means that the atom is using custom half-shafts. Five inches is a lot when it comes to suspension, so I can no longer trust the values from the real car.

[B-T]

Wow, cool project Karlo! That car looks pretty large in the photos, how does it compare dimensionally to an Atom?
Any further progress?
BT

[xperimental]

Updated pictures. Pretty interesting.

http://www.flickr.com/photos/25435483@N00/

[cheapracer]

Thats the "Kid" who built it sitting in it, he's about 19years old! Great job!