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8. So the next thing to do was to mount the Dynatech 02H motor. Given the aim of this build was to produce a racing car hopped-up with period mods, I was looking for a suitable period hopped-up motor and the choice came down to either the Technigold or the Dynatech 02H. Given the latter was the quicker of the two, I decided to go for that. This motor was made by Tamiya in 1989 and has the following specs:
Usable voltage: 7,2V - 8,4V
Torque at best efficiency: 413g-cm (7,2V)
R.P.M. at best efficiency: 25.000rpm (7,2V)
Current drain at best efficiency: 19,3A (7,2V)
Best efficiency: 74% (7,2V)
Turns (6513W):13 double - 0,65mm
Turns (7010W):10 double - 0,7mm I used a 17 tooth pinion gear, which is reasonably high. However, given the torque and revolutions of the motor I think higher rather than lower (in terms of teeth) is more appropriate to start with.

9. Now on to the Parma adjustable rear sway bar. This required some drilling in the rear lower suspension arms so that the track rods could be fitted. Adjustablility is achieved by moving the track rod ends along the bar either towards the chassis (stiffer) or away from the chassis (lighter): After all this, I finally feel that the end is in sight and am getting excited at the thought of seeing the finished product - something I last saw when I was 11!! :

10. At this point I remembered that I had missed one additional hop-up. This was the JG front shock mount. Clearly, in the car's current state, this was not necessary - sufficient stiffening would already be achieved by the front sway bar. However, I have been looking to fit period mods where possible (even if at the sacrifice of outright performance - fine tuning could be carried out to achieve the best performance at a later stage if necessary): 11. Now to fit the Thorp/Dirt Burner aluminium wing to the body. The instructions were in Japanese so I had to guess but I think it was fairly straight forward. The body was cut out first and then the wing built and fitted. Amazing how the "fox" look starts to come to life with the body and wing. If anything, I think this wing adds to the "Fox" look over and above that of the original Tamiya wing: 12. And now to fit the wheels to the chassis to get to the rolling chassis stage. The tyres fitted on the rear are original Tamiya Fox tyres. The front Tyres are Tamiya hop-up tyres which have both a rib and spike combined grip to assist with turning in heavier track conditions: Was definitely excited at this point to see the finished product by fitting the body/wing to the rolling chassis......

That looks very nice, very cool hop-up´s! Can´t wait to see it done!

13. And so, finally, the end arrives and it is now time to fit the body/wing to the rolling chassis. I'll let the pics speak for themselves. I'm well chuffed with the end result though; a real piece of my childhood re-lived (seems like only yesterday!!). I hope you enjoy....:

Fascinating build and thank you for all the pics and info.

2 small suggestions:
- use the front shock mounts as a template for some home-made shorter ones (maybe in black?)
- use hornet shock mount parts to fix the front shocks to the mount.

Looking forward to see the paint job you're going for

I like everything except that front shock set up. How about a set up similar to the Hotshot HP front suspension?

that is a sharp car I love the wing, but I agree the front shock towers take away from a other wise great car.

Man that is really cool. I got to know though, how long did it take you to find all the parts for it?

Thanks for the comments, and I'm grateful for those who have provided their suggestions too. Any other comments most welcome. Just to come back on the points raised:

Mr. ED wrote:Fascinating build and thank you for all the pics and info.

2 small suggestions:
- use the front shock mounts as a template for some home-made shorter ones (maybe in black?)
- use hornet shock mount parts to fix the front shocks to the mount.

Looking forward to see the paint job you're going for

Good idea for the front shock mounts. I think maybe carbon fibre would be a suitable material. Not aware of the Hornet shock mount parts. Do you have a link you could provide so I could view them?

shodog wrote:I like everything except that front shock set up. How about a set up similar to the Hotshot HP front suspension?

I'm not aware of the Hotshot HP front suspension. Do you have a suitable link? I agree that the JG shock mounts are a bit cumbersome, which is why one probably does not see too many Foxes with them fitted. However, they are a true period hop-up for this car which was partly the aim of the build. I would be interested in seeing examples of the Hotshot HP setup though...

[email protected] wrote:Man that is really cool. I got to know though, how long did it take you to find all the parts for it?

It has taken me about 6 months of very involved Fleabay searching to get these parts. I am aware of others which I have missed out on but continue to remain always on the look-out....

shodog wrote:I like everything except that front shock set up. How about a set up similar to the Hotshot HP front suspension?

Are you sure those firberglass mounts don't go the other direction?

Nice build CNA!

I always wanted a set of those shocks for my frog BITD. How hard is to find You-G parts?

That is pretty different and cool, love the rims. Though not sure if I'm a fan of the upright front shocks, they take away from the sleekness of the Fox.

If you are going to run it, I would be looking at a way of bracing those front shock towers to the main tub part of the chassis. The front of the Fox chassis is pretty weak at the best of times, but those shock towers are going to put way more leverage on it if you land upside down while at speed... SNAP!

You should also look at mounting the wing onto the rear shock tower or you will crack the body around where it mounts.

We used to slice the upper chassis piece between the 2nd and 3rd lot of holes to enable easy electronics access when racing them BITD. We would mount the receiver where the stock mechanical speedy went and put an electronic ESC where the driver figure once mounted. Undo 4 screws (less than a minute) for full electronics access. Made life so much easier and didn't affect chassis strength.

JPAE07 wrote:
Are you sure those firberglass mounts don't go the other direction?

Nice build CNA!

I always wanted a set of those shocks for my frog BITD. How hard is to find You-G parts?

The fibreglass mounts are definitely fitted correctly. The screw holes are unevenly located so that they can only be fitted this way round. Plus this is correct with the instructions.

Generally, I have found it very difficult to locate You-G parts. I was fortunate in that the same seller (located in Indionesia) had 3 sets of these Fox shocks which I just bought all at the same time.

dangermouse wrote:Though not sure if I'm a fan of the upright front shocks, they take away from the sleekness of the Fox.

Aesthetically, I agree that they definitely look different. It is, indeed, a departure from the oem Fox look. However, functionally, there are definite benefits to obtaining independent shocks for the front suspension. One of the key problems, I understand, with the original fox front suspension/single shock set up was lack of suspension travel and, therefore, bottoming out too easily. I also note that the fibreglass mounts are more sturdy than they look - they are of good thickness and, with the additional other fibre glass bracing at the front end, there is a significant increase in rigidity/strength.

dangermouse wrote:You should also look at mounting the wing onto the rear shock tower or you will crack the body around where it mounts.

We used to slice the upper chassis piece between the 2nd and 3rd lot of holes to enable easy electronics access when racing them BITD. We would mount the receiver where the stock mechanical speedy went and put an electronic ESC where the driver figure once mounted. Undo 4 screws (less than a minute) for full electronics access. Made life so much easier and didn't affect chassis strength.

I agree that mounting the wing on to the rear shock tower bracing would be better. This is something I looked briefly at doing but concluded that it would require further drilling/adapting, so decided to put that on the back-burner.

As regards electronics access, I have seen in other examples what appears to be a hop-up for the top chassis which is largely open and allows easy access. It is indeed a pain to access the electronics using the oem chassis - the chassis should never have been designed in this way in the first instance.....

Can I also ask how you found the Fox compared to other cars when racing? What was good/bad about it (in terms of performance) in comparison to its peers?

Can I also ask how you found the Fox compared to other cars when racing? What was good/bad about it (in terms of performance) in comparison to its peers?

I didn't really race mine for long before getting a Cat XL, but I spannered for my brother when he raced my old Fox for a season in the budget stock class which pretty much limited them to out of the box (not allowed to run optional front swaybar). Running the same motors and tyres as the guys in 2wd stock with RC10's/Ultimas the top Budget Stock kids were nearly always within a lap of the top 2wd stock racers. Often their qualifying times would have put them in the A-B main of 2wd stock.

The biggest limitations of the Fox were the lack of swaybar to keep the inner rear tyre planted, limited steering lock (weird ackerman) and lack of suspension travel on rougher tracks or big jumps.

They were very fast in a straight line, had very little maintenance requirements, and were quite easy to drive. On a fairly smooth grippy track there was very little difference between them and an RC10/ultima.

The best thing you could do for the performance/handling of that car would be fit 2.2" rims and modern tyres all round with foam inserts. Tyres (and motors/batteries) seem to be the biggest improvement to rc buggies over time. Take it out to 250mm wide or whatever the legal width is these days.

CNA75 wrote:

JPAE07 wrote: Can I also ask how you found the Fox compared to other cars when racing? What was good/bad about it (in terms of performance) in comparison to its peers?

The Fox was much improved over the frogs and Wild Ones we were running but only a slight match to the RC10 which just smashed the the market when it came out.

As for the Hotshot HP suspension, it's basically what came on the supershot take a look at some TC members entries to see how it was fitted to the buggy http://www.tamiyaclub.com/userridescat.asp?id=54&cat=2

Thanks a lot for that info. Very interesting, especially to hear the comparison with the RC10/Ultima. I had thought about upgrading the wheels/tyres and will perhaps do so for the purposes of running the car (if/when it makes it off the shelf)...