1994 Civic World Time Attack Challenge

[longerpay2]

Aim: Build from the ground up a World Time Attack Challenge (WTAC) Racecar from the a 1994 EG Civic Hatchback.

Goal: Place in the top 10 open class at WTAC Open Class 2019

So welcome to what will undoubtably be an adventure and quest largely into the unknown. My background is Mechanical engineering and have spent the last 5 years building and racing cars but never something on this scale.

The Car: Well after much deliberation about which car would be best suited for such an application, and studying the WTAC open class rules, the decision of a hatchback was made and with a 1994 Honda Civic showing up for a tiny $400 with no signs of rust and slightly leaky engine, the purchase of a small yet incredibly slow and smelly car was made.









The Plan:
- Create or Find a CAD template of the car.
- Begin the design of basic aerodynamic features
- Strip the car of anything that will not be required and can sell on
- Finalise the final body shape so production can begin on the 'wide body'
- Create accurate CAD model of the engine bay
- Select an engine, Make a CAD model and design mounts
- Mount the new engine into car and start plumbing it in
- Wire the new engine with the use of a MoTec ECU (Have past experience and a tuner)
- Fit rollcage and seat along with any other internal safety devices
- Finalise Design of Aerodynamics package
- Manufacture the aerodynamics package
- Fit and upgrade the suspension
- Paint the car
- Turn the key and hope it doesn't go boom!

I am sure there will be a lot of smaller, time consuming steps to be completed but they are the major steps from what I can see but plenty to be done.

--- Step One:
Step one was to start to develop a complete CAD model of the car. I spent days searching the Internet looking for a CAD model but none existed, so it was time to make a measuring jig and mark over 300 points on the car to create an accurate CAD model that aerodynamics could start to be modelled upon. If anybody is interested in this CAD model, more than happy to share it around as it took so long to make.



--- Step Two:
The basic design of the aerodynamic package is largely governed by the rules so using the cad model, the extremities of the rules were marked out and using some intuition and past experience, the beginning point of the package was created. It will consist of a front splitter and wing combo, sideskirts, rear wing and a rear diffuser. The main concern was trying to keep the centre of balance in the centre of the car, as a rear biased car would create understeer through the high speed corners and that is not ideal.

The use of NACA and several other types of wings were tested using CFD with the front wing and splitter being tested using quarter car simulations and the rear wing and diffuser being tested using half car simulations. Future iterations will be constantly occurring during the build and the design will forever evolve until manufacturing of the wings and diffuser.

--- Step Three:
Stripping the car and discovering its past. This was fun as I intend to use nothing from the interior other than the dashboard, door cards and steering column so everything was out in a hurry. Still have quite a few parts hovering around the joint so if anyone is looking for that missing part, I might have it. Anyway, the car was stripped and then put up onto jackstands, ready for the exterior to also be stripped and most parts will be custom throughout this build.





The main pieces to keep were the front fenders, the lower hatch and the bonnet. All of these will be modified and recreated using Carbon fibre to limit the weight and also allow the body to 150mm wider to allow for wider tyres and additional shaping for aero. I intend to do a full how to guide on the creation of composite panels so anyone can do it at home.

This is currently where I am at with the build. The front left fender has been shaped and is going through the final stages of sanding. Once I can get access to my computer, I will be looking to upload photos on the progress to date and also elaborate on anything interesting.

This is a long term project and will take considerable time. I am always open to comments and feedback and also giving out any advice if someone my ask.

Updates coming shortly
David

[beeza]

Subscribed.

This will good to follow.Very cool stuff David!

[longerpay2]

Been working through the front fender wide body over the weekend and the last few days. Below is a quick run through of the steps so far;

1. Clean the panel with prepsol ensuring a nice clean surface

2. Tap up any holes and indentations (Although will not affect the final product, keeps everything clean)

3. With the designed front fender in mind, create a cardboard surround. In this instance, the widebody will be 100mm wider at the wheel centreline and will seamlessly join back to the original panel near the bonnet line. The cardboard surround will be held onto the panel using hot melt glue as it is cheap, easy to apply and quick drying. If the panel needs to be kept for resale or any other purpose, I would have put some masking tape along where I was going to glue, this ensuring the panel is not damaged.

4. Using some expanding polyurethane foam in a can, start spraying the foam onto the panel and into the cardboard enclosure. Build up several layers and remember the foam will expand quite dramatically, and put aside to let cure and completely expand before moving it or touching the foam. The cans of foam cost about $10 each and 2 cans was more than enough to complete the front fender.

5. After the foam has cured for atleast 24 hours, I removed the cardboard backing and placed the foam covered panel back onto the car ready for shaping. For the larger portions to be removed, I use an old plaster saw. Once the rough shape has been achieved, a mixture of an orbital sander with 120 grit disc and 80 grit hand sanding will get the foam back to its desired shape.

6. To obtain a nice hard workable finish on the foam, body filler is applied and the shaping and sanding continues. All holes that are in the foam need to be filled and the panel is smoothed out to a paint-prep finish. All low points and filled and all high points are blocked back to obtain the shape required. It takes a lot of body filler and a lot of time but the more time spent on this step, the better quality of product will be produced.

This is currently where the car is at, for the next few weeks, more sanding and shaping along with the purchase of coilovers, fibreglass consumables and hopefully the first mold for body work can be produced by Christmas.

I will be uploading pictures later to go with the update.

[beeza]

People WILL read your long posts but if U ignore their posts,they will ignore U.

It's a simple rule of life,no one likes to be ignored.Remember,I too could have chose to ignore your post out of fear of being ignored like everyone else mate.

[Super-DA9]

People WILL read your long posts but if U ignore their posts,they will ignore U.

It's a simple rule of life,no one likes to be ignored.Remember,I too could have chose to ignore your post out of fear of being ignored like everyone else mate.

Chill dude.. I don't think anyone is intentionally ignoring you. If you asked a question then that would be different but saying "subscribed" doesn't usually warrant a reply.

Speaking of which, subscribed. lel

[Super-DA9]

David, have you decided what sort of powertrain you intend to run?

[longerpay2]

People WILL read your long posts but if U ignore their posts,they will ignore U.

It's a simple rule of life,no one likes to be ignored.Remember,I too could have chose to ignore your post out of fear of being ignored like everyone else mate.

Not intentionally ignoring anyone. You left a comment, I smiled and continued working on the car. Glad to have you subscribed

[longerpay2]

David, have you decided what sort of powertrain you intend to run?

Not as of yet, I have thrown around several ideas but yet to come up with a solution that I am 100% set on. So far I have looked at:

Honda B20A6 out of a 3rd gen Prelude
Mitsubishi 4G54 out of a 1st gen Magna
Honda K24A1 with AWD from a CRV
Holden 186 RWD from An LJ Torana

The usual suspects such a B16 of B18 or even a K20 have been looked at but cannot find one at the right price currently. All a bit too costly considering they will need a full internal rebuild regardless of which motor I go with.

[Super-DA9]

Not as of yet, I have thrown around several ideas but yet to come up with a solution that I am 100% set on. So far I have looked at:

Honda B20A6 out of a 3rd gen Prelude
Mitsubishi 4G54 out of a 1st gen Magna
Honda K24A1 with AWD from a CRV
Holden 186 RWD from An LJ Torana

The usual suspects such a B16 of B18 or even a K20 have been looked at but cannot find one at the right price currently. All a bit too costly considering they will need a full internal rebuild regardless of which motor I go with.

That is a very unusual line up of options for an EG.

I think most other open class Hondas are running K series engines. Look into K24A3s out of accord euros, they can come cheap enough. From what I've been told I'm fairly sure the K24 that comes in the CRV is basically junk.

[beeza]

Sorry David...been having a hard time.Sorry mate.

[longerpay2]

Sorry David...been having a hard time.Sorry mate.

No stress mate. ��

[longerpay2]

That is a very unusual line up of options for an EG.

I think most other open class Hondas are running K series engines. Look into K24A3s out of accord euros, they can come cheap enough. From what I've been told I'm fairly sure the K24 that comes in the CRV is basically junk.

In order to beat the competition, either need to out develop know systems that are currently in use or think a little outside the box. I have several spare B20A6 engines lying around. The magna engine is a bit unusual, SOHC, 2.6 litres but capable of holding boost from factory (Same engine used in a Mitsubishi Starion)

I might have a quick look into the accord engines while I am on break today.