wtcc5s Tamiya MadCap overk*ll build

[wtcc5 5933]

 

The picture maybe says it all already. I am at it again. New year, new madness build.

The MadCap is a legendary buggy. A manifestation of Tamiyas genius. Full tub plastic buggy meets iconic body design. And with some Hop-Ups it becomes a decent racer.

As you can see above I am about to make friends and foes with this build by mixing original parts with modern design and my own ideas to create a unique tracktool.

I chose the new Super Astute rerelease and the XB2‘2025 as donors. Base parts are a MadCap tub plus arms and hubs. The rest is yet to decide. The black MadCap is not planned as donor, but will serve as example and object for measurement.

 I hope you enjoy what will follow this post in the coming weeks.

 

 

[Pylon80 4226]

🍿

[bsy2010 347]

Can’t wait

[ThunderDragonCy 8970]

Yes

[Andreas W 2999]

Looking forward to read about this. Now I assume the rules and requirements for the TOC is read as thoroughly as can be . 

[ruebiracer 1325]

This will be so good! Thanks Kevin in advance! Madcap was my first "modern" 2WD Buggy after Dad´s Sand Scorcher and my Subaru Brat b.i.t.d.. Wish I had some things left of it now. Keep it in the spirit of TOC, so that we can enjoy it on the track.

[Sgt.Speirs 1585]

Great project and a very interesting model. Because of the shared gearbox with the King Cab and the (Super) Astute, the Madcap would also be my choice for a second class in the TOC.

@wtcc5: I am really excited to see what you will make of the three dispensers. And I hope you don't overdo it with the modification, so that the waves at the TOC are smoothed out and don't rise even higher😉

[matisse 1723]

Can

Not

Wait

[BuggyDad 6501]

Ooooooh. Awaits eagerly....

[wtcc5 5933]

Great to see you guys being on board for this project!

I started recently with the shocks. For a buggy one of the most important functional pieces. These come from the XB2 kit. Quality is nice and they come with numerous parts for length adjustment.

Because I love Hop-Ups, I invested in outrages expensive aluminum shock caps… I don’t think these will improve the performance…

 

After the experiences of last year at Kinzigtal,  I will use shock socks to prevent the fine dust to reduce their efficiency:

The socks will get a branding soon 

[wtcc5 5933]

Next on my list was the gearbox build. I try to complete most of the chassis with existing parts before going into the prototype phase.

The geardiff is generously filled with Anti-Wear-Grease.

 

Then the one-piece-gearbox gets all its internals before the slipper is build:

 

Next on is the attachment of the rear arms and arm mounts. Here I use a combination of Super Astute mounts with MadCap arms to have the cool ball bearing system. I think that especially at dusty dirt tracks these will make a difference. For that I use double sealed bearings, that will get another grease layer before the clay-track-race at Kinzigtal.

The large E-clips in the Super Astute rere bag surprised me. They may be good for the front O-ring assembly, but make my special tool obsolete. No, I don't want that! For the rear the small E-clips will jump in.

 

If you go for that build, watch out for the screws. The Super Astute uses flathead screws, while the MadCap is all button heads at the rear:

 

Gearbox meets chassis:

 

For the last step here, I had to make an important task. The sticker for the gearbox cover:

So important 

[ThunderDragonCy 8970]

1 hour ago, wtcc5 said:

So important 

Truth

[wtcc5 5933]

Waited some weeks for these parts from my favorite chinese tuning company:

 

Super Astute and MadCap are the same family, but use different part designs. Sometimes these are only a bit different, but still enough to not fit. One of this parts is the front bulkhead. Because of the support brace design of the MadCap two posts block the „plug and play“ installation.

To make it work, two 6.5mm holes need to be drilled 7.5mm in front of the larger holes. A bit more material needs to be removed to prevent collisions with the strengthening braces. Ét voilá:

[jonboy1 3748]

Oh this is just perfection happening here!!!

[ruebiracer 1325]

Very clever Kevin, so you increase the wheelbase, too.

What do you plan for bracing the chassis similar to Madcap? Guess otherwise the Madcap chassis get´s the weak point on a hard front collision?

Loving the built so far, you haven´t promised too much.

[wtcc5 5933]

@ruebiracer: Glad you like it. I hope to keep the quality of this thread high.

As far as I can see, the wheelbase stays pretty much the same.

At the moment I have two major challenges:

1. Steering assembly: I want a proper ball bearings aluminum rack, but the design of the original limits my choice. This time I will try everything to not hack the chassis, but find efficient workarounds.

2. As you said, the chassis is stiff as a wet towel. My plan is to design a long, thick, wide brace to connect the rear horizontal plate with the front shock tower.

Still not sure how this will look later, but it should be possible.

 

[wtcc5 5933]

I continued with the build today. After the work on the front bulkhead, the next steps were mostly "plug and play".

 

Attaching the front shock tower:

 

Then the front arms:

 

And while I was at adding so much aluminum, I replaced the rear arm mounts with aluminium ones, too:

Nobody will ever understand why these were anodized black, while everything else is silver... (ok except for the steering)...

 

The gear support bulkhead was replaced, too:

Shiny 

 

Back at the front, I attached the Super Astute bumper:

 

 

[ruebiracer 1325]

Lookin really good, as if it was meant this way. 

[wtcc5 5933]

Over to the rear. These are all Super Astute parts:

 

Tamiya really checked for clearance here. Every screw head finds his space in the holes of the tub chassis:

 

Then I switched to the Xray XB2'25 kit and build this buggy like the manual suggested. The quality is overall very nice. But you see, that Tamiya is a plastic injection mould specialist. So why this build change? I need to know the distances and positions of the dampers and compare with what I have on my Super Astute-MadCap mix.

In the rear having the shock tower in the lowest position fits like a glove:

 

In front I had a collision on the lower end. Xray delivers several lower end parts for their shocks to adapt the length. I used the longer lower spring retainer to prevent it touching the arm:

Additionally, I had to take some material of the lower ball to make it fit in between the arm.

 

 

 

[wtcc5 5933]

The rear hubs from Xtra Speed were next. These break easily especially on astroturf and harder driving:

The kit bones have to take the pace for the coming CVDs for the moment.

 

Back to the front. Also all Xtra Speed aluminum hubs:

 

Getting somewhere nice:

 

Then I was at the drawing board, decided the components and electronics. Implementing a proper steering rack is a real problem. Something is always in the way. After two days searching for the right one, I decided to go for custom installation mounts as fitting bridges or steering arms were nowhere to be found. I will also put the servo vertical into the chassis.

A big problem is the battery. I hoped to drop a smaller shorty LiPo into the battery compartment, but it doesn't fit. So right now it seems, that I cannot prevent hacking the chassis there if I want to use that battery ... Well, nothing bad happened to the chassis up to now and I hope to find a cooler solution or maybe just use a round LiPo...

So this is the concept for the moment with the carbon plate stiffening the chassis and offering the mounting points for steering, battery and servo:

 

[ThunderDragonCy 8970]

@wtcc5 lovely work. Are you allowed to used a steering with a 90deg crank in it? If you could then maybe put the vertical servo in the middle of the original battery tray, long turnbuckle like in an m05. Then maybe the shorty lipo can fit all the way forward?

[Sgt.Speirs 1585]

Complete 3D model of the model🥰

[ruebiracer 1325]

Nice work Kevin. Liking @ThunderDragonCy´s idea. Or you can try to fit an LCG Shorty. Maybe it would still slide in from side with the smaller height?

Hacking the pristine chassis is really a hard decision as rare as they are. Maybe a HV Stick Lipo is sufficient for the Torque Tuned, and you can play with ballast weights instead.

Regarding the Xtra speed rear hubs: do they offer the toe in as the originals? Or are they just rectangular copies of the design? Could need a set, too, but don´t want to loose the toe in of the originals.

 

[Thommo 1418]

Quality and class for sure.  Interesting choice of upper links with the very flexible Madcap rear suspension arms.  Twist the rear hub and see, I would expect a lot of torque twisting on power with this set up.  Sometimes that’s desirable for a very low grip surface.

[wtcc5 5933]

12 hours ago, ruebiracer said:

Nice work Kevin. Liking @ThunderDragonCy´s idea. Or you can try to fit an LCG Shorty. Maybe it would still slide in from side with the smaller height?

Hacking the pristine chassis is really a hard decision as rare as they are. Maybe a HV Stick Lipo is sufficient for the Torque Tuned, and you can play with ballast weights instead.

Regarding the Xtra speed rear hubs: do they offer the toe in as the originals? Or are they just rectangular copies of the design? Could need a set, too, but don´t want to loose the toe in of the originals.

 

I used a LCG shorty already… That is why I am so sad…

The good news: Yes, the Xtra Speed huns offer toe-in 

@ThunderDragonCy: That is a good idea. I will try to work on something.

@Thommo: I don’t see how any single camber link can prevent the arm from flexing. What solution do you suggest?