This is part 2 of my Dirt Burners! Avante XL build. Make sure to check out part 1 as well.
Before we begin, here’s a little more of the history of the Avante and it’s siblings. When former Tamiya Chief designer Fumito Taki was asked about his all time favorite RC car, here’s what he answered: “My design of course! I have to choose the Avante. It wasn’t perfect, but was designed on the concept of being for one race only. I ended up compromising as an expensive throw away car was not an real option. Every car breaks, but it was such an iconic design, I really loved that car.” I’m a little unsure what he really means by “designed for one race only” and “expensive throw away car”. Does it mean that it was designed with a special event in mind? A Japanese Championship? A World Championship? Or does he really mean that he originally intended the car to just last one race and then be thrown away? I’m really puzzled by these statements, so please chime in further down in the comments section if you have a view on this.
Here’s a list of the cars that’s based on the base chassis concept of the Avante. I have not listed a few of Tamiyas newer cars that carries the Avante name, as they’re just that, carriers of the name, and based on different chassis’ than the original Avante. I have omitted the Vajra as well, as that’s a completely different kind of buggy.
58072 – Avante – March 1988
58076 – Vanquish – December 1988
58079 – Egress – June 1989
58085 – Avante 2001 – June 1990
58489 – Avante (2011) – January 2011 (re-release of 58072)
58583 – Egress (2013) – November 2013 (re-release of the 58079)
84270 – Avante (2011) Black Special – January 2012
The Vanquish and the Avante 2001 have not been re-released, although the Avante 2001 body set was re-released as an option for the re-released Egress. If you’re restoring old cars, be aware that parts specific for the Vanquish and the Avante 2001 are a bit harder to find than the parts for the Avante and Egress. A few parts for the original Egress, that were omitted from the re-release, could also be a challenge to come by. I’m in particular thinking about the dreaded BF-8 and BF-9 lower front shock mounts. I bought a second complete Egress wreck to get those small parts….
Since part 1 I have assembled most of the car, with just a few more things to do until it’s finished. The differentials are from the Tamiya #53034 “Dual Ball Diff & Torque Splitter Set”, and are the same that could be found on the Egress. Instead of the center diff of the original Avante, that is integrated in the spur gear, this set includes a spur gear that is either locked or equipped with a one way bearing. I decided on using the one-way bearing option. Like the gear diffs of the original Avante, these ball diffs are also of a kind of unusual design.
While the original gear diffs are of a planetary design, as opposed to the more commonly used crown/bevel gear type, these ball diffs work in the same way as all other ball diffs, but what is different is the way they are adjusted. Most other ball diff designs incorporates a tightening screw that is accessible through one of the out-drive cups, but these differentials can only be adjusted by totally dismantling them, to add or remove shims on each side to tighten or loosen them.
Luckily the diffs are easily removable, compared to most other buggies of that era. If I should have raced this car, I would probably have pre-built several sets of the diffs (loose, medium, tight etc), so I could just change the diffs instead of tearing them down and adjusting them in the pit. On the re-release of the Egress, Tamiya changed the design of the ball diffs to the more common and adjustable type.
When it comes to the universal drive shafts, I have used a new set of the standard universal shafts at the front and a lightly used set of the #53032 posi-joint (double jointed) universals at the rear. I would have used the #53031 front posi-joints if I had a set, but unfortunately I don’t. There is (at the moment) a rear set, like the one I have, on ebay for the price of EUR 225 (=280 USD) plus 35 Euros in shipping. That’s utterly ridiculous. There are even some standard universals (like the ones I have mounted at the front) listed for 120 Euros (+35 Euros for shipping) and another set for $175 (+$34 for shipping). May these greedy sellers never get them sold!
UPDATE: I got a set of the front posi joints from my Finnish friend Jerry Hellström, so now I have those both at the front and the rear.
In part 1 I briefly mentioned a little concern if the Pro-line wheels I was planning to use would fit at the front. My suspicions were right, as they do conflict with the front suspension while turning. I really want to use these wheels, so I pulled out the Dremel and cut off the inner flange. So instead of the wide Schumacher T650 tires that I have on the rear wheels, I have used a set of the matching T652 narrow tires on the cut front wheels. This gives enough clearance for the steering to work properly.
Cutting the wheels were quite straight forward, and I used some medium hard adhesive sponge tape around the center, inside the wheels, to make an “artifical” groove for the inside edge of the tire to slot in to.
The shocks are giving me a bit of a headache as well. The You-G/Racing House shocks that I’m using are a little too long for the front, and a little too short for the rear. Remember I have 4 short shocks, instead of 2 long and 2 short, but I have only 1 set of short springs, while the other set of springs are for long shocks. The long springs are way too long for the short shocks, and I really don’t want to cut them in case I find a set of long shocks later. The springs have a light pink anodizing, so it’s not easy to find other springs that will match. Up front I fixed the problem with the short shocks being too long by putting 6mm spacers on the shaft, inside the shocks. The shocks still have just enough travel for the suspension. By design, the Avante has a limited suspension travel, something that was a big drawback compared to it’s competitors, as the suspension “bottomed” quite easily, especially at the front.
Using the short shocks at the rear creates a different problem, as the shocks seem to have enough travel, but are too short for the tall shock tower. I can make them fit, lengthwise, by using extensions on the piston shafts. Even if I had the long rear shocks there would have been problems, as the rear shocks from this You-G/Racing House kit are too long for the Avante, so to make them fit they would have been partly pushed in, again limiting the suspension travel like on the fronts, but even more. The easy solution would then have been (like I did on my Avante LWB build back in the day) to lift the rear shock tower(s) with some spacers underneath. The preliminary solution I chose was to extend the shafts with brass spacers, and using the long springs (they’re still a bit too long). I have sourced another set of short springs from Scoot Mike in Ohio, so I’ll try those when I get them. Remember that the shocks look shorter than they really are, as they have a wider outer diameter than eg. the Kyosho gold shocks.
With the help of my Japanese friend Shin-San, I had the instruction sheet for the Dirt Burners! Avante XL kit translated. The instructions are pretty straight forward, and the drawings shows how the body must be adapted to fit the extended chassis. But one important thing that the translation revealed was that the longer propeller shaft is actually of titanium. This makes it even more annoying that I haven’t found a titanium screw kit for this build. I will keep looking for such a kit….
Here’s a rough summary of what the instructions say:
#2201 Long Chassis XL
With the Schumacher Cat XL, with the extended wheel base, winning the World Championship, and also special long versions on the Optima Mid being released, here’s the long wheel base kit for the Avante. The kit is a combination of FRP chassis plates and a titanium propeller shaft. All parts are machine cut. Please change the hole position (on the body) according to the illustration. The hexagon mount for fixing the under body should be mounted by drilling a new hole for it, where it will line up with the under body.
I think I have come to a decision regarding the body…. I will use a standard Avante body, painted in my own racing colours from back in the day, red with a black stripe, like you could see on my old bodies in part 1 of this build. So there will not be a Y. Shimotori theme this time, as I would like to save that for a Hotshot build that’s coming up.
In part 1 I also mentioned the motor I’m using for this build. It’s built from parts around a Kyosho LeMans armature. I wrongly said it was a 240SB armature, when it really was the armature from the 240S motor. I still haven’t received the Phoenix end bell, so for the time being I’m using a Parma Turbo Intercooler end bell.
I think the motor looks stunning.
I have also found the rest of the electronics I’m going to use on this build. Many places around the world Tamiya and Acoms shared importers and distributors, so for this Tamiya build I dug out a very nice set of Acoms radio gear. The electronic speed controller is an Acoms AT-6 FET unit rated at 184A, with a peak rating of a whopping 740A. The ESC is a couple of years too new (around 1995) to be completely period correct, but it’s close enough and I really wanted to match that green colour with the green fiberglass chassis. The Acoms AR-211 receiver and Acoms AS-12 servos are closer to the Avante when it comes to releases, even if I don’t know the exact dates for those.
I’m still waiting for some parts like the racing steering kit and the body, but I don’t think I’ll make part 3 until the build is complete. It could take a while as I’ll have to wait for warmer weather to paint the body, and it’s in the middle of the winter here, with freezing temperatures outside. Maybe I’ll do a small update when the chassis is complete and the radio gear are mounted. We’ll see….