“Mad Dog Racer”

[Twister]

looks great looking forward to see it on the racetrack

[Hcp22]

looks great looking forward to see it on the racetrack

Thank you Mr Twister

[Dadio]

That's looking very interesting , I like the front suspension !

[Hcp22]

The Thorp Dirt Burners #4940 dog bones have arrived, and my calculations was correct. I even think that they might fit with the original upper arms to when I fit those later on when I figure out the best way to reinforce them in a good way. I also got rid of the bump steer, at least the most. A bit left when the shocks are fully compressed, so I will leave it like that for now.

Have made some mockup for the layout of servo, ESC and Li-Po. As you see I have to go with the “super shorty”, I had hoped to go with the shorty. So, if I had gone for the SE chassis style, I probably would have had more space for a short. I might have to make a new chassis for the SE-style after the race.

I got some saddle pack arrangement from eBay that will do perfect for the super shorty. Just need to attach a piece of CF as stopper on the outside using double sided tape as precaution.

I made my own body post up front. I used a 20mm long M4 set screw and the top of body post.

Yokomo Racer 168b.jpg (10.82 KiB) Viewed 3152 times

Yokomo Racer 168b.jpg (10.82 KiB) Viewed 3152 times

Both threads in the gearbox for the upper deck was ruined, so I needed to fix that. I think tis is the result of mixing M4 and 6-40 screws by the previous owners. I got a Helicoil repair kit for M4 at hardware store. I never used Helicoil on plastic, and I don’t know if it will work in the long run, time will tell.

The low profile Savöx servo is in place.

Haven’t decided what winding I wane run… have this nice new (to me) 17.5 Trinity motor. A 17.5 will probably be a wise decision, sins I newer practice more than maybe ones before a race. Have a 13.5 Turnigy TrackStar Outlaw motor some ware, also 13.5 Trinity D4. But I will start out with the 17.5 Trinity motor.

[Dadio]

The helicoils should be fine, with the CF or a fibreglass chassis its so much more rigid that the top deck is really only serving as a chain/belt guide , unlike the stock Kydex chassis that really needed the extra stiffness , the flex in the Kydex chassis is probably why those threads fail anyway , its quite common from my experience .

[Hcp22]

The old Pro-Line bumper is mounted together with a reinforcement for the front shock tower that my brother folded for me. I also did some threading, M3 for the shock tower and M4 for the bumper. I think this will improve the sturdiness of the bulkhead in case of a crash.

I also mounted a belt tensioner.

I had time to rattle paint the body and wing, and after a few sticker it’s look fairly good for racing. And now you can see why I call this project “Mad Dog”. The body is cut down about 10mm, and that was a bit too much, so I had to cut a small hole for the motor.

I designed my own T-shirt for the upcoming race at Limburg Arena the upcoming weekend. Can't go race without proper T-shirt

[Dadio]

The weakness in the front bulkhead is shearing off the lower suspension mount points , that's what I've seen on a genuine and 3d printed examples , I've been planning on a modern style brace for the bottom arm pivot pins on my cars , you have to replace the stock pins with something a little longer but I'm thinking its probably worth it , might be worth a stab on this one , those bulkheads are getting harder to find .
Yours car looks better every time I see it !

[Hcp22]

The weakness in the front bulkhead is shearing off the lower suspension mount points , that's what I've seen on a genuine and 3d printed examples , I've been planning on a modern style brace for the bottom arm pivot pins on my cars , you have to replace the stock pins with something a little longer but I'm thinking its probably worth it , might be worth a stab on this one , those bulkheads are getting harder to find .
Yours car looks better every time I see it !

I was planing to do just that, but my brother misunderstood me (or I wasn't clear enough ) regarding the length of angle he folded. Hopefully the bumper will protect the bulkhead until I hav time to fix it. I will make a few updates after the race, I want to replace the Kyosho stuff with original Yokomo parts even if most are period correct.

I'm glad you like it

[Hcp22]

The race debut is done, and it lasted less then a lap on the open practice on Friday… The right rear arm snapped after a dodgy landing after a low speed jump.

I had a spare one, so replaced it. In the mean time I was practicing with my vintage Optima/Scorpion based 2WD. When I was ready replacing the arm, I decided not to run my 4WD “Mad Dog”. But when Sunday 4WD day come, the urge to run it got the best of me… So, I decided to race and only to wheel it over all the jumps. It felt the right ting to do sins I had traveled 750 miles (1200km) to the race. Actually, I didn’t qualify last, I had one guy behind me.

Losing 2-3 seconds every lap won’t take you to the A-main, but it allowed you to participate in the sponsor prices lottery.

I have to talk with “Dadio” about reinforced 3D printed rear arms, I want to race this car

[Dadio]

RE the broken rear arm , the plastic they are made of responds really well to CA , I broke a front knuckle and temporarily glued it and I swear it feels as strong as before ! I do have a design for reinforced rear arms as I had exactly that same brake , they look different in the conical section ,PM me if you want to try them .
Mine all nose dive on jumps and they tend to dig the nose into the track on landing , I've found that I'm cleaner if I keep the power on and nose up when jumping , doesn't look good but it works for me .

[Hcp22]

CA might work fine as the last way out. Yes, it’s nose heavy, so you have to give gas just before the front wheels leaving the jump as you say. Sins I have mixed 32p and 0.8 module gears in the gearbox it’s rely loud. And I lost the retainer for the Delta slipper, some one found it… But I was never able to find out who that was. I have another Delta slipper, so my friend will reproduce a new retainer. Other than that it was a good experience to drive.

[Marshky]

How long does the super shorty battery hold out compared to normal shorty batteries?

[Hcp22]

How long does the super shorty battery hold out compared to normal shorty batteries?

Well, those super shorty’s I run is 2600mAh and a shorty has capacity at 4200mAh and higher. I run a brush less 17.5 motor in the “Mad Dog”, and that is no problem to run 5 minutes heats. And it’s no problem if you want to go with a 13.5 motor as I run in my vintage Lazer RR.

[Marshky]

Oke, thanks. I always doubted about the capacity of these batteries.

[Dadio]

I get 10 min with my racy 834b with a 10.5 t brushless and a 2600mah lipo , plenty for 2 or 3 practice laps and a race .