Anyway, we are back in Maui Hawaii from vacation and while doing some yard work (digging up cane-grass) I came across an old concrete patch in the yard. As Rally fan you are probably thinking the same that I was thinking – BRILLIANT now I can have my track be a mixed surface environment -just how it is supposed to be for Rallycross and Rally cars.

The real problem is to get the soil leading to the concrete patch to become hard enough to drive on it. The original track took about 2-3 month to harden and compact. I don’t have any tools or tractor that could help. I thought about driving the family car over the track, but it won’t work due to my wifes potato patch close by. And trust me you don’t mess with a wifes garden -ever!

The extension will add an additional 90 feet / 30 meters to the track. This will bring the track to a total of 220 feet / 67 meter

Looking at it in a 1/10 scale:  I am still short by almost 130 feet / 40 meters to have a “true” 1/10 Rallycross track which are usually 0.932 Miles  //  1.500 km long.

Here is a picture of the new section under construction.

I also had the chance to do some track maintenance, the old Papaya died which now allows for complete view of the track from my driving position. The chicane has been reworked too, which means lap times should go up by a second because the banks on the S turn can no longer be drivin over in such an aggressive manner as before.

I do have a Macbook Pro that can run Windows (I need to run Windows for the Laptimer software), but it’s a bit too risky to use it in the “dirt”. If you have taken a look at Apple’s price list lately you know what I am talking about.

In addition I am going to be traveling to the Wordpress Conference in San Francisco and the track needs some work.

Other than that I just bought a Arduino (Duemilanove) Microcontroller – I will use it to simulate a ride around the “old” pre 2001 Hockenheim Ring located in Germany with my Touring Car. More on that in a different post soon.

I did a Front Wheel drive test a while back, impressions and lap timing results are available here. Now I finally had the time and most importantly consistent track conditions to run the Tamiya Subaru in AWD and RWD on the same day back to back.

In order to change the rc car to rear wheel drive only I simply removed the front drive shafts as shown in the picture below.

Granted that this does not produce the optimum performance compared to removing the main drive shaft and therefore eliminating the friction drag considerably, however it is quick and easy and allows for the rc car to be converted back to All Wheel Drive in a matter of minutes.

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The Results:

Driving a Tamiya Subaru DF03-RA in rear wheel drive is a lot of fun -but challenging at the same time! Laptimes where 3 seconds slower compared to the All Wheel Drive configuration. Interestingly, the Front Wheel Drive configuration was only 2 seconds slower then the All Wheel Drive lap times.

All Wheel Drive

Fastest Lap | Avg Lap | Total

12.908 | 15.410 | 1.16
12.217 | 19.552 | 1.38
13.580 | 17.362 | 1.27
11.626 | 13.429 | 1.08
11.746 | 18.612 | 1.33
11.997 | 15.550 | 1.16
13.409 | 14.969 | 1.15
12.848 | 18.150 | 1.31
12.107 | 14.879 | 1.15
12.377 | 13.833 | 1.10
12.608 | 23.858 | 2.00
11.907 | 15.954 | 1.20
12.778 | 16.936 | 1.25
11.656 | 14.857 | 1.14

12.411 | 16.667 | 1:26 | Session Averages

Rear Wheel Drive

14.330 | 22.446 | 1.55
15.462 | 23.668 | 1.59
16.423 | 20.761 | 1.44
15.392 | 23.970 | 1.56
15.732 | 19.484 | 1.38
16.734 | 23.230 | 1.56
15.622 | 22.382 | 1.53
15.772 | 19.758 | 1.40
14.390 | 24.997 | 2.06
15.612 | 17.665 | 1.29

15.569 | 21.836 | 1:53 | Session Averages

Who drives better – man or machine?

At what Voltage does the computer beats the human driver and vice versa?

How much does the slot car speed increase starting at 7 Volt  in 0.5 Volt increments?

All data was taken using a Slotcar track based on our outdoor RC Rally track.

Results:
Computer can’t drive slot car over 11 Volt – Car becomes to fast in corners
Ideal Voltage for Human Driver appears to be 17 Volt – At 17V the slot car has the best acceleration, breaking and top speed balance.

A designed the track based on my measurements using the Carrera Slotcar Track Planner. Unfortunately we only have the “cheap” Carrera Go track – which actually has lot of potential when you replace the stock power supply with an adjustable lab power supply, replace the throttle controller with some old-school Carrera Servo 140 controllers and hook the whole thing up to your computer for some accurate lap timing.

Here is my modified Carrera Slotcar Power-Control-Timing Setup:

Here is the Carrera Slotcar Track-Planner Render:

And here is the ready to drive slotcar rally track:

And here is the timing setup using the EasyLapCounter – the Electronics Setup above shows the hoslotstimer using a phototransistor:

Simply download Torcs, install it, unpack the backyard3.zip file and move the folder into your torcs dirt track folder.

Watch the Video of my Torcs RC Car Track here or read the blog post here.

Here are some Torcs RC car track screenshots:

It seemed like a fun idea to build a drive-able computer car racing game based on our R/C backyard track and our Subaru Tamiya Rally car. Needless to say that it does not come even close to any of today’s Xbox360 or PS3 games, but that wasn’t the point in the first place. Driving my own track on the computer while looking at the “real thing” out of the window still makes me happy :-)
With the initial experience and all the measurements taken I am really tempted to build the whole thing on XNA Express to make it playable on the 360. I am afraid they will have released 3 new models of the 360 until I figure it all out though…