I know, what you think! What the hell did this guy again?! Right? Right! After my Yokomo 870C Masami Hirosaka replica, I wanted to use the same Neo Vintage chassis to make a more modern version. Something what I can use for racing! And one of my all-time RC heroes is Brian Kinwald! So a Kinwald themed Yokomo Works `91 could be a cool project. His attention to the details is legendary! Brian was one of the worlds best buggy drivers ever! I only had a little contact to him. And all I can say is, he was one of the nicest persons I ever met. Brian passed away April 3. 2019.
Brian, where ever you sit on a cloud, I hope you have Internet and enjoy my build!
Let´s start with some body-on pictures! Yeah, you are right! This is not the original Kinwald Yokomo paint. Some will say, it is not even the right body shell! Brian used the Yokomo Protech body and much later the Works body on his ´95 Yokomo Works. And there he used another paint. You are right, but I like this RC10 Worlds ´93 paint much more.
Brian´s Yokomo with a Protech body
Brian´s Yokomo with a Works body and a little different paint, than usual.
Left side. Did you spot the Reedy 10.5T motor?
The Team Associated 5 1/2 inch rear wing. I have cutted hundreds of them over the years.
Rear view. The beautiful Yokomo Works body. Low and wide! This is an iconic design!
All the decals comes from MCI Racing. Since you can layout your own stickers on their website, I simply love them! The quality of the print and material is amazing!
Front view. The long arms of the Works made this car perfect for rough and bumpy tracks!
Let´s look under the hood! We see the same chassis, what I used for my Masami Hirosaka 870C project.
The chassis is made for a low shorty Lipo battery type.
And I use a Reedy 10.5T motor setup for modern vintage racing.
The chassis is very narrow. The electronic layout is pretty perfect to make a clean installation.
The steering. Bellcranks, gear covers and some other parts comes in black. Other parts in blue colour - just like Brian had build his cars. Maybe.
I designed the lower chassis plate to fit the Highest RC Yokomo BD7 servo. This was made as floating servo with direct mount on the right side of the servo case. The left side of this servo has no mounting tabs - and fits perfectly!
If you look hard, you can see the 3D printed front bulkhead from the 3DRC Shapeways store. To make it stronger, there is added material and there is a captured M3 nut for the shock tower screws against stripping the hole. Clever!
Since I use the shock oil memory stickers, life is much better in any ways! I have put the Transponder with some Velcro tape on the top of the servo. So I can put it quick and easy into another car when racing.
Wheels off! Endless legs for endless travel for the post apocalyptic tracks we had in Germany these days!
Clean wiring is so easy! Don´r ruin your vintage build with bad wiring!
Talking about suspension geometry. Yokomo did a good job with anti dive and front kick up ange. But why no toe-in at the rear? WHY?
The Yokomo rear shock are only 1.18 inch long. Problem: most springs are made for 1.32 shocks and simply too long. This is a problem. The solution are Team Associated Element shock springs (yes - the springs for their crawlers!). They have the correct lenght and you get many different rates.
The blue Aluminium c-hub and Kyosho Optima front knuckles. I use them, because they are much stronger, than the original plastic parts. But you need to use some shims to make it fit.
Because the race ready car is much too light, I made a laser cutted 3mm stainless steel plate under the battery. This gains 100g. But this is not enough. I have put 80g more weights everywhere into the chassis to make it easier to drive on high grip tracks.
This is a belt tensioner from a Hot Bodies touring car. It is not neccessary, but it helps to get some space above the belt for the wires to the battery.
Electronic setup for Vintage racing!
Top view front.
Top view rear.
Back in the days, I never drove a Yokomo. It was simply too expensive for me, when I was very young. But I always remember the awesome and forgiving handling of their cars. The Kyosho cars were always on the edge, but the Yokomos ran super easy to drive around the tracks. Not spectacular, but fast! I remember Chritian Keil, Martin Fließbach and some other of the great guys und racers in Germany. The Keil guys were always fun and a pleasure to meet! Sascha Falter was mostly the fastes driver with his Yokomo and won countless races and national titles. So all in one only good memories to Yokomo and the guys behind the team! Now I am looking forward to race this beast. My last race is 3 years ago. Crazy.
UPDATE 2023
OK - here we go! Time for a little update to tell you, what happend to my Works 91!
Last year I finally was able to move that thing at the Oldschool RC Euro Masters Race 2022 in Germany (check out my race report in the article-section!). It was indeed the very first time, that I drove this car - and I was pretty nervous, because there was no chance to test this car. COVID 19 restrictions were hard and no tracks were open at that time before this race really.
The race track in Geilenkirchen/Germany. They installed some jumps for the Off Road category later.
There was no reason to be nervous. The Works 91 was on rails at the track! The car was very light and the 10.5T Reedy motor has so much power for this relatively small track, that I reduced full throttle down to 90% for better car control. The setup was great on the jumps and the only issue was the front one-way. Braking on high grip tracks with a front one way is no fun. If your car is not absolutely straight when braking, the car tends to oversteer alot! I tried not to break, or only a little bit at the corners. This worked pretty well and I was with the fast guys at this race. Another problem was the 3d printed bulkheads. I broke all of them! But I had enough spares until the end of the race, what I finished 5th. I came back home, the war at the Ukraine started this weekend and from one day to another there was the strange feeling, if you hear the word nuclear threat.
Back home with my impressions about the car, I was sure, I need to make some areas better. So I ordered the cnc machined bulkheads and motor mount from my friend Bora from Custom RC Parts / Serbia. He had some black anodized parts and I was happy to have some indestructible parts to improve my Works 91! I also ordered cnc machined bell crank arms from Manobet to make the car even stronger. Then I found a original Yokomo mid drive with lockable one way to get a permanent 4WD action and save braking.
The black cnc machined motor mount. Beautiful and strong! And there is a fan now!
Rear bulkhead
Xray T4 aluminium front hub. Not very vintage, but strong!
Some fine tuning at the rear shock tower. the new one is 4mm higher.
Left side
Right side
I made a taller front shock tower to allow Team Associated 1.02 shocks size.
Another thing, are the Team Associated B6 ball ends. Because the original Yokomo ball ends are very fragile over the last 30 years and it was each time a lottery when driving, if they break, I decided to use some modern ball ends. The B6 ball end set is great! You get some different lenghts, precise ball studs and the good feeling, they will hold the hardest crash.
The rear view is nice.
The side view is nice.
The body is also pretty nice - no need to change something here.
The longer front shocks looking good - and they deliver a little bit more up and down travel.
After installing all the new parts I an pretty confident this car is ready for racing more than ever! 2023 has just started. We have 19 degree Celsius outside at January and next month I will travel to the UK for the Oldschool RC Euro Masters 2023 in Leeds! Hope, we see us, friends!
NOT OUR BOYS!
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