wtcc5's TT-02 race development and race reports: Version 5.2 release

[wtcc5 5899]

This will be one of my favourite post if I should ever look back on this project in the future.

The car transformed into something beautiful. Chassis and custom parts just fit together nicely. Somehow both compliment each other and make their counterpart look more technical, more functional, more quality. At least in my eyes. The proportions of the tub match in harmony with the front and rear end. I am very happy:












The chassis looks quite complete already (except for the shocks of course), but there is still a lot of detail work to do.
I decided to minimize the orange colour and to invest in more blue gold. The screws and nuts will be exchanged soon.

(6. april 2019)

[wtcc5 5899]

The irony is that the blue metal you see on the pictures and the blue metal that comes next week costs more than all custom parts I have ever installed in this car 
I had to bite the lemon once more and ordered some more hardware. Some of it is to make the car bulletproof for a race weekend, but most of the money is to get rid of the heavy steel ballstuds and nuts I have everywhere in the chassis. I want a light and agile car for our south german asphalt tracks. This should also lower the c.o.g., because nearly all of the steel is located in the upper quarter of the chassis.

Today I focussed on details:
I aligned the anti-roll-bars and installed the set screws to take out excessive play.
The rear TT-02RR oil filled gear diff got a service and a lot of Green Slime. Unfortunately it still starts to leak after a day of running, but only out of the left outdrive...

In the front the Tamiya double joint cardans got longer axles (46mm), as the 44mm were a little too short. Luckily I had the 46mm axles at home from the KR-MF project.

Then the arms were upgraded with Awesomatix excenter ballheads and adjusted to the right height. While doing this, I had real trouble with the suspension ballcups (again). Two broke and every second had to be squeezed a lot to get rid of bending. There seems to be the need to learn how to work with this part. I thought it would be more easy...

I also installed the ULP shock absorbers. Early next week I will get RC missions short shock shafts. They recommend to use new plastic parts for their shafts, so I installed my SLP shafts to finally see the car in full:










(7 april 2019)

[wtcc5 5899]

 Thank you, Thank you, Thank you!

The shock shafts arrived from Canada. The FedEx guy hid the package on a lamp, around 1.8m high. A point where I didn‘t search and didn’t find it at first 
I finished the shocks, set ride height, camber, toe, droop and tweak. Everything worked on first try, like working with a normal car. Also the parts geometry is spot on. All shocks are within half a millimeter on their ride height setting nut (I don‘t know the word...). Very cool. It seems I am full of luck with this build.
With tires the chassis looks even lower.
Remember the discussion we had a few months ago? With version 2 I would say the KR loses its TT-02 character by a huge amount. On some pictures it looks like something individual. Well, I don’t mind.


First a look on the RC mission shock shafts:






On the Hudy tweak station:




Low, lower, TT-02 KR v2 



(8 april 2019)

[wtcc5 5899]

Meanwhile I continue with detail work. I added all the blue screws, nuts and ballstuds. Also the expensive servo mounts, an alumium servo arm and the new hard bumper of the T4‘19. The latter three parts added weight, while all the aluminium screws shaved off more than 20 grams.
The steering assembly was rearranged to put the whole unit 2.5mm lower in the chassis. A very easy modification if you have the blue drivetrain parts. The trick is to install the steering posts from above. That is all.







Today the dust caps arrived:



Unfortunately the weather will be cold this weekend. I hope to do the first shakedown indoors in two days.

 

I finished all small tasks and made new holes in the body, because of the changed body post locations.
I also used the time to measure the „fight“ weight of the RTR car:



My hope is to be 150 - 200 grams lighter than the competition to compensate for the shorty lipo use outdoors.
The straigths will be my weak point and the curves my strength, at least that is my hope...

(11. april 2019)

[wtcc5 5899]

Back from the track. The first run was a big relief  The car is working great! Already in the first laps I found a good rhythm. The car does its work in an unimpressed manner. Nothing failed, again not even a loose screw.



The track was hardly used in the past 3-4 weeks and I had to work the driving line all by myself today. With every run the line got faster. In the last run I ended up with 10.9s best laptime and an average of 11.2s the whole day. These numbers tell the story quite good (the driver was not up to his full potential, though). The car is more easy and predictable to drive than the v1. I really wouldn’t have thought, that the lower c.o.g. is as clear to feel as I experienced it today. In the first runs I had the droop set wrong (more than 3mm over ride height) and I didn‘t recognize it, because the chassis hardly rolled under load. After correcting this, I didn‘t improve much and couldn‘t see the car behaving different. Also the car is a blast over the curbs. It stays calm and allows the driver to keep pushing.
Also very recognizable are the Awesomatix camberlinks and my new carbon fiber arms. The car can take more speed into a fast corner than before. With less flex it also seems, that it doesn‘t scrub off speed in the corner middle like it did before.
The plastic parts hold up well. Well, I didn‘t crash the car even once, so they do their job.

If everything goes as planned, I will do an outdoor test on tuesday. Until then I have a load of work to do checking everything, rebuilding the differential, installing the dust covers, and so on (I finally came up with a good idea for the batterymount, too).

(13. april 2019)

[wtcc5 5899]

I was diligent again 

First I was excited to finally make a befitting lipo mount to get rid of the tape and and the lexan angles I used up to now. It is definitely an easy solution consisting of two L-shaped carbon fiber parts with two holes to mount them on the backbone of the chassis just underneath of the drive shaft; and one hole on the other side to mount a small post and the small carbon fiber plate (this part is doing its job since I bought it from Reflex Racing for my TC6.1) that holds down the battery:




And then I installed the dust covers. The fitting is nearly perfect, but I am sure dust will find a way. If it keeps out sand and stones, then I am happy.








Again the rear differential needed a full service. A mix of green slime and oil was pushed out and all over the left side of the car. I had enough of this and cleaned everything. I took an 8mm drill, widened and deepened the O-ring hole. Then I took Xray shock O-rings and slipped them over the outdrives. Lets see if this will solve the leaking from the outdrives.

 

I made video of the third run:

https://youtu.be/E6-oSBNKvlA

I think despite the lower grip level it is visible, that I can take more speed into and through the corner, and that the car stays flatter and/or is less rolling.

 

(14 april 2019)

[wtcc5 5899]

Gregor and I went to Dasing today. A beautiful weather greeted the whole day. The sun was strong, but the temperatures didn‘t went up to high. We had 17 degree Celsius air und 29 on the track surface.
I definitly had too much to test and learn today. I tried different bodies, tires, springs and camber adjustments, while relearning this track.



I rediscovered the picture wall of clubchampions and got reminded of the three championships I won here in the past.





The good rhythm came around lunchtime. The car was not as easy to drive as I hoped. My last serious outdoor season was in 2015 and I had to adapt to the low grip surface. Which I have successfully done now. The car was good in all corners, but needs more steering in the corner entry for my liking. I think I will try softer springs next time. Body roll wasn’t a problem event without a.r.b. in front... So much to try... I need to make a good plan.

The dust caps worked like charm. Fine dust found its way, but sand stayed out.

 

(16 april 2019)

[wtcc5 5899]

I had another outdoor day with a happy end. I was consistently three tenths faster than the last time. The track had a similar grip level. All my ideas worked in the beginning. Then I worked in the wrong direction for a few runs, but found the way back on the right track.



Today I could attack harder into the corner and had a little more rotation. For the last run I found something that brought more traction for the front end, made the car faster and nicer to drive. It felt really good to hear the time announcing voice to start with 16 every lap. My fastest laptime is now 16.495s With ten and more laps in the 16.6s and even after nearly 15 minutes I could stay below 17s. That was a solid step forward and made me very happy 

With that good feeling I will rebuild and check the car next week and hope to deliver a good performance next weekend in Erlangen.

 

My friend Gregor did a lot of filming on the first outdoor running last week. He now made an amazing video of my car. I am speechless of his skills and talent. He published it on Youtube:

https://youtu.be/A4I8K1uUUcQ

(22. april 2019)

[wtcc5 5899]

This weekend will show if my car concept can deliver the performance I expect it to do.
In preparation I disassembled the car, cleaned and checked everything, rebuild shocks and differential and serviced all ball bearings.



This took a whole day. Sometimes I wish to have a mechanic just to prepare my car 
Well the shocks and the diff are very smooth now, so I guess it was worth it.



Wish me luck 

(25. april 2019)

[wtcc5 5899]

And now the race report from Erlangen:



The weather forecast predicted a rainfilled weekend. Saturday I got up early to cover the 2.5 hours driving time to the track. Until half past twelve it stayed dry, but it was cloudy and cold. Chris and I sat together for this training day. We managed three runs until the rain stopped our quest for fast laptimes. On one run we changed cars. It showed, that Chris already had a very good setup. His car was benevolent and fast. Mine in comparison pointy and snappy. Later I discovered, that I set the rear ride height wrong and had a lose screw in the front suspension  While the rain continued and prevented the track from drying, I used the time to correct these mistakes and to change the oil to 350cst. The temperatures on sunday were forecasted with 6-10 *C. I arrived early in the hotel and spent the rest of the day watching 1:1 racedrivers doing their job (ADAC GT-Masters and F1 qualifying).





On sunday I arrived early at the track. The rain didn’t stop and a wet track welcomed us. Now it was time to protect the electronics with a lexan tub and lots of tape. At least the expensive rain tires weren’t bough in vain. After some chaos and discussions with the organizer about the procedure, the first qualifier started at 9:30. My car behaved great in the rain. I had a lot of fun, could dominate the other drivers and was fastest overall. Now that the rain has stopped, the wet got less. I also dominated the second qualifier and was happy with the performance of the car in the wet. For the last qualifier we already had dry spots on the line. This made it very difficult to drive. I had several spins and couldn’t improve my time. The second group of my class (GT-Sport) had a nearly complete dry track for their run and so I lost my pole position to Marc (club member), because of his faster run.
Somehow I start to despise this qualifying rule. If there are three qualifiers and you won two, then shouldn’t you get the pole position instead of for example one guy who just attends one qualifier and then is faster...
Whatever, the starting position were marked with chalk with different distances to each other. My position two was on the inside to the first corner, meaning that I need to accelerate for two meters, then brake to make the apex on to the straight, while the third position guy could stay on the throttle...



I had a good reaction at the start to the first final and could pressure the pole man in turn two already and pulled up to his side in turn four. I slipped through and the drivers in position two and three started to battle. They also rubbed and I could pull away fast in the first five laps. Then I concentrated on finding a secure rhythm. It showed after some minutes, that I couldn’t pull away more. Nothing more happened and I won with ease, but with knowing, that the other two were as fast as I.

Their speed showed in the second final. My times were a tenth slower and on the second lap already I started to slip and slide. I had my hands full with the third place driver (Sascha), while Marc pulled away in front. After some minutes I could open a gap to Sascha, but never got near Marc again. So on the second run my tires already lost grip. I ran with Sorex 28 on a 20*C track. Sascha ran the Sorex rain tire and seemed to have more than enough grip.

This wasn‘t an option for the last final. The sun finally came out. The track temperature climbed to 26*C. I prepared one new set of Volante hybrid. I made a good start again and was all over Marc in turn two already. As hometown hero he stayed cool and didn’t miss one apex. With the tire additive slowly fading, my car developed snap oversteer in the corner middle and exit. Suddenly I had my hands full with my car. I was still very close to Marc with Sascha also in close pursuit. Marc was slow in one corner entry, I went up his side and we touched and ended in the grass. We both weren’t sure who was at fault. After being marshalled, we both waited for each other. Sascha in the meantime gained 5-6 seconds. Marc and I started the chase. I could follow for several laps with my problem, but spun several more times until the raceend. Later I discovered that the rear rims rubbed on the upper ballcups under load  Volante rims are so much smaller than Sorex rims. I am very angry at myself for not having doublechecked this. This cost a possible win, as I did the fastest laptime with this set of tires (11.4s) and was faster than Marc, who in the end caught up with Sascha and even overtook him for his second final win.



In conclusion this was a difficult weekend. In the wet weather I didn’t want to drive my sunday racecar. So maybe I should build a wet race car to have fun on saturdays, too. My setup isn‘t good enough, yet. I still need more steering and a stable car on the exit. Over huge bumps and curbs, this car is great. The track in Erlangen is very very bumpy. With a little droop adjustment I never had to avoid these bumps, like other drivers needed to. Also, fast corners are dominant to drive and whenever I accelerate, it is visible that I have an advantage. Last I learned a lot about tires and temperatures.



For the upcoming weeks I want to work on the steering, turning and to get rid of the pointy behavior.

 

The new points standing:

(29. april 2019)

[wtcc5 5899]

Already before the race in Erlangen, I started to optimize the geometry of most of the parts. The car will lose some more weight. I reduced the thickness of the carbon plates and saved material through new forms. The wheelbase was 2mm longer than expected in the actual car and is now corrected to 257mm. The battery mount is new and the upper bumper brace got a new geometry. It will now direct the surplus of impact energy into the chassis, preventing a breakage of the droop plate.

My friends Michael and Eric are eagerly waiting for their V2 already 

Since the race in Erlangen the car was laying around as a 3d puzzle on my table. My wife celebrated her birthday and together we celebrated our 10th wedding anniversary last weekend, so I had to skip the last race in Bamberg. Chris won the race in front of Marc and my nearest points rival Sascha. This severely cut my points lead down...



Some days ago the new carbon fiber parts arrived. Tomorrow the 3d print parts will arrive. Then I need to assemble the car. I started today to put the electronics in a new tub.



The next weeks will be full of non-RC-work and I don‘t know when I will drive KR again. A very unsatisfying situation as I need to do setup work to make the car faster and better on asphalt... At least I have some clear ideas and a plan what to test.

(30 april 2019)

[wtcc5 5899]

The car together with the series I race it in becomes a kind of second job. A lot of hours went into the development and preparation already. On a raceday the car runs for 39 minutes (3 x 5 minute qualifyer and 3 x 8 minute finals). All the following maintenance and preparation for the next race/training takes around 7 hours. So for every minute of running, more than 10 minutes of work go into the chassis...



As my time is limited right now, I made an evening shift yesterday, not only adding the new parts, but cleaning everything. To my surprise the ball bearings survived the rain and days after, until I cleaned them pretty good. Just one old bearing couldn't be brought back to a smooth resistence free spinning. The new parts fit very good. Just some of the 3D printed ones needed correction. In the print process some dimensions get more material than planned. This is very good recognizeable with parts where I need precision, like the caps/spacer for the carbon plates that hold down the differential ball bearings. This time around 0.25-0.5mm needed to be removed to have no play.
On the pictures the new carbon fiber parts are shown. They are reduced in thickness and geometry to save money and weight. The droop plates are not the lowest part anymore. The tub chassis is 0.5mm lower. On asphalt I prefer the tub to be worn down as it is (nearly) the cheapest part on this car. I really like the new bumper brace, which will now lead the excessive crash energy into the tub and is therefore saving the front droop plate and lower bumper brace from damage. It might not show, but every part is a little different than the first v2.While the carbon fiber parts lost material, I added a little strategically to the plastic parts.

Unfortunately I have problem with not Tamiya differentials and my dust caps. Somehow the 3racing diff is larger in width and diameter (around 1mm). Now my caps are too small  This is a little unfortunate, because the next race is next week already. I guess I will have to drive with an open diff...

(24 may 2019)

[wtcc5 5899]

Maybe three weeks ago I played around in my CAD program to check for a possible rear diffuser. After several approaches I decided for a design that uses the maximum of available area and that would not lead to a stall of the flowing air by having a steep angle.
In between my work I let the old 3d printer build the now following prototype. It came out quite good and is stronger than I would have expected. I will now use it for a pre race test on saturday. My aim is to renounce the normal rear wing on larger fast outdoor tracks... This aspiration is maybe utopian, but I will try. Well I am not really overmotivated, but will give undertray downforce a last chance.

 

It looks much better fittet to the Venom body:

 

(29 may 2019)

[wtcc5 5899]

Time for a (loooooong) race report 

I got up early on saturday to travel the 200km to Bad Gögging (Bavaria). It is an old roman town with a lot of wellness baths, hotels and golf holes. At the side of it there is a beautifully placed racetrack for our onroad cars.




What then happened was all clumsy and mishaps. First I roasted my esc by getting the polarity wrong, then after installing a new loaned esc, I chose the wrong tires and drove the car into the wall, killing my servo. Again on the track with a loaned servo I lost a tire in the middle of my run  After a little more than one hour I was already in a mood to commit the japanese ritual suicide (seppuku). I regained my will to continue and have to say thank you to all the guys who helped me out. One guy even sacrificed his spare car to give me his esc. So three guys saved my weekend after I behaved so stupid in the beginning.

I was able to drive the next battery incident free. Looking at the times I was over one second slower than Chris. This was a mild shock. I changed to the Volante Hybrid tire and was suddenly on pace. Then I changed to harder springs and a different front suspension geometry and was blistering fast. The times were up to 4 tenth faster than Chris, but looked better than they were, because he drove very old tires and I a new set. So it was a strange day, but with a happy end on my side.

At this point I have to praise the track layout. Consisting of a fast part with full and nearly full throttle corners and s-curves and a slow section with u-turns and slow chicanes. One section of the fast layout needed a special driving line to carry the speed from the main straight through a 90 degree left corner, a chicane, two left corners and one right corner until you reached the first hairpin after another short straight. You could run through all these full throttle, if you lifted just a little before the first one of the two left corners. Hitting the line and all apexes really made the lap satisfying.

Then a real nice evening followed. Chris and his wife Diana offered me to stay at their home. They prepared an extraordinary barbeque with fine meat, salads and drinks. We had nice talks and a good time. Thanks again for the hospitality 

The raceday started early. I didn‘t change the setup and drove two runs to regain a good rhythm for the track. The first qualifier then was crazy. I was dominating, lapping the field twice except for Chris of course. Around this time the temperatures were maybe around 20-25*C. With new tires my car was awesome. Just the tight last sector was not nice. The car didn‘t build up the front grip under braking that I needed.
The second qualifier was very good, too. Not as commanding as before, but still nice. Chris changed back to the setup with what he drove his fastest laptimes the day before and reduced his times by two tenth that way. In the last qualifier I made a mistake, jumping the curb and losing 5.5 seconds laying on the roof.

Then a very long lunchbreak followed. I again used it to keep a good rhythm and drove for 10 minutes. In between the laps I stopped on the poleposition mark and practised the start and the first corners. No problem here, all went well.

The first final: Chris and I had a good start, while the rest of the pack seemed to be a little surprised by the starting signal. My car had understeer in every corner. Chris was at my tail and chased me through the tight section. I had to fight, but made every apex, preventing his overtake. Unfortunately in the last hairpin before the straight, he touched my rear end and pushed the body under the tire. Chris continued, the field got through and I lost around 10 seconds until the car was marshalled. I hunted the field and was lucky to see them chrash in front of me giving me the second place on a plate. I concentrated on reeling Chris in, but failed by just under 2 seconds after 8 minutes. Well I wasn‘t happy about our clash. The good thing is, that we openly discussed about it. The other side is, that we are not different from any other rivalling race car driver. We had two different opinions and no one saw a fault in what he did. We also sat next to each other in the paddock and started to speak about it several times.

I was in a bad mood before the second the final and chose another starting position. Even though the positions were marked on the track, at this race nobody cared if you had your car in the marked box or not. As the pole position was offside the driving line, we guessed that this caused my bad understeer in the first laps... (as stupid as the 1990 Suzuka pole position box). All went well. Just the tight section still didn‘t suit my front axle. This time I didn’t let Chris come close enough to make a move. After some laps I opened up a gap and brought it home safe.

In between the runs, the technical inspection was very interested in Chris and my car. We constantly lapped the whole field. Well they had to accept that our cars were legal. Us drivers later recognized, that the magnetic field of the motors was recognizeable differing in strength. My motor is one of the first hour and has the weakest field. Chris motor has a significantly stronger field and newer motors show an even stronger magnet. So my dominance was helped not just by my lightweight car and less rear toe, but through a higher rpm of the motor. I am honest: I am not sad about it and I don‘t care that this gives me an advantage. I just hope this motor doesn‘t die like the LRP X11 did years ago.



For the last final I increased the brake power from 70% to 75% to help with the turn in steering in the tight section. And voilá, it worked much better. Chris still was a little faster there, but much less than before. I pulled away slowly and was happy with a better performing car. Even though the track got slower through the hot temperatures (30*C air) I drove a second faster overall.



In conclusion this was a nice weekend with a perfect result and a lot of mixed emotions. My nearest points rival didn’t attend, so I gained back my points advantage. The winner trophy is huge and heavy, which always makes me happy. I again learned a lot about my car and asphalt tracks. Chris and I are always close in a race, with him being the better driver and me having the better car. Changing luck then decides who is in front of whom. And we return ever stronger and faster.

 

The current points standing:



Chris flies upwards through the ranks. I rebuild the gap to the second place driver. Overall the field got weaker in number of drivers with the higher temperatures...

(3 june 2019)

[wtcc5 5899]

I am currently working on a version three of my conversion. My bravest construction so far. I will take a lot of new ideas and implement them. If all these will function properly, I don't know, well in my my head they do.

...and I will give you a blurry sneak peak that shows nothing, but you can guess what comes.



(10 june 2019)

[wtcc5 5899]

I am sorry for letting you wait so long. I just came back from China and couldn't draw at all. Additionally I came up with new ideas that changed a lot of my old concept. Getting it all right and source the parts for making it work is a real challenge. So I will need much more time than intended...

One little update are the caps, that I designed, finally arrived. Somehow the first order was lost and they had to do it all again. I nearly cancelled, but now I am very happy with the result:



Big logo in front with two lines ("rubbing is racing" and "GT-Sport") on the sides and again "KR motorsport" embroidered on the backside. The cap is also very light with the rear half of the sphere being very thin fabric.

(25 june 2019)

[wtcc5 5899]

Lets start with the elements that will make the v3 special for me.

Lets begin with a new shock absorber system that is a key element and because of it several other "innovations" are possible. You guess it already, it will be a rotationdamper. I thought of traditional cylindric shape - 4 chamber system like that of Awesomatix first and also would have liked to use an already available shock body, but in the end I decided against it. I don't want to implement a Awesomatix suspension 1:1 and existing shock bodys would need a lot of very small internal parts with a small volume of oil as a result of it.
Instead I remembered the one chamber unit I drew some years ago for a spine car chassis that also included a kind of FRICS system. I never build one part of the car as at that time it was just impossible. In the research for rotation damper I discovered the small angle of movement that the Awesomatix rotationpiston has when the arm is moved. It looks like it only makes between 20-30 degrees. I always thought, that we want the piston move through more oil and/or fast, a long way. Obviously the A800 works perfectly with its suspension and wins race after race. I just recognized the small movement on some YT videos and started wondering (no critic here form my side). Maybe someone with experience can explain that to me.
Well, right now I plan my piston to move up to 60 degree on a full arm swing (downstop to running over a curb). Therefore I will separate damper and spring. Today I will show to you my damper unit. The pistonaxle pivotes between two ball bearings. Parts from other manufacturers are needed to seal the damper (Xray O-rings), I also use a Xray piston rod as well as the lower SLP damper O-ring-shim. To reduce the complexity of the housing, one ball bearing will be inside the damper swimming in the damper oil. The second bearing runs "dry" next to the small O-ring.
My rotation damper will be positioned along the tranverse axis (so 90° turned in comparison to the Awesomatix layout). That way I can connect the rod to the arm next to the c-hub to achieve more piston movement and a more direct reaction to smallest arm movements.

Here now the first pictures of the (unfinished) unit with one unit "assembled" and next to it a explosion view:





 

I have to admit, that the whole TT02 KR project developes in a way now, that I myself could/would have never predicted. Already with the v2 I thought, I made a progressive design. Right now, it took me more time to draw the rotationdamper than the whole v2. You may easily say that a rotation damper is a simple not very demanding thing, but fitting it in a very tight space, arranging it to the spring, assuring that it is easy to work with and sourcing the right parts makes the whole project very complex. Most of this is totally new for me. For some parts I made, I watched and rotated the view (CAD) more than half an hour until I made the first move for a design. More than one time I needed to step away from the project to get new energy, new ideas and motivation, before returning and trying to solve a problem.

The following pictures show a suspension, that will probably work already. I designd a new seal without the edges and redesigned the whole damper housing. You can also see the spring and its adjustability. The longer this project lasts, the more growes my respect for Olegs ingenuity. The principle to setup the spring is taken from his Awesomatix design. I will also implement some of his production parts to save some money. Initially I would have liked to use a torsion bar as spring, but this is beyond my abilities...






With this as base design for my other ideas, a lot parts will change and be added in the coming weeks.

 

(28 june 2019)

[wtcc5 5899]

Thanks for the suggestion! I will look into it.

Lets give CAD a break! In reality the v2 still has to do the „dirty“ job. After my horrible begin of the last race weekend (killing esc and servo) I decided to go for another R1wurks product. The Digital-3 found a home in my 6$ plastic tub chassis and is my entrance to the world of app programmed Wifi escs. The number of settings is crazy. Many of them will never be touched, but some are very useful. One of them is the motor wiring. I can change from ABC to CBA and with it comes a clean wiring. All the other cool stuff like the logging will be tested next week.





Right when I was travelling through China, The race in Hassfurt happened, with all my competitors attending. My lead is down to several points in the championship. Next week the race will take place in Marktoberdorf. A track with 16 slow to fast corners, and not very easy to learn as it seems...

(30 june 2019)

[wtcc5 5899]

I continued a little with CAD. I implemented the new suspension in the rear and started to think of a body post arrangement. Again I am being inspired by Awe (sorry). I just need to check if and how it could work on the present GT-bodies.

 

Explanation of my damper setup: There is a piston that looks like a flag on a pole. Well the "flag" is solid plastic and firmly attached to the "pole" that is the pistonrod. The "pole" itself can turn and is supported by two ball bearings on each end. Now I put this "flag" with the attached "pole" into an oilfilled chamber. One side of the "pole" sticks out of the chamber and got a ballstud attached. This ballstud is moved by the suspension arm when it travels up and down and causes the "pole" to turn. The dampening happens inside the oilfilled chamber with the "flag" moving through the oil.
On one side of the damper is a leaf spring. It is held down by the damperhousing and on the other side is attached to the arm. It fullfills the function of the normally used coil spring.

The assembled unit:






Exploded view:

(2 july 2019)

[wtcc5 5899]

Due to ZooRacings large success as body manufacturer in R/C with its rather extreme shapes, I have to try their new GT-body. Shapewise it promises a better handling and better times. The look clearly shows tc-body features which takes away scale appearance. To achieve a nice race livery and to make life easy, I got a Tamiya decal sheet. The result is very satisfying:










Quick update from the saturday training before sundays race (tomorrow):

First: What a great track! A lot of corners, following very quick on another, partly with the need to combine them to one corner in the line. Also real curbs that can be touched only very slight. Otherwise they will unsettle the car. That is what F1 needs.










I found a nice rhythm on the second run already. The setup changes I made, all worked very good. The car was great through every corner. I can go deep into it, turn fast and accelerate out good. The new Zoodiac body makes the car feel like it is pulled on a string. I like that very much. With old tires (the cloth already showed) I could do a 20.178s lap and many in between the 20.4s. I scrubbed in a brand new set for five laps and managed a 20.090s as my fastest time of the day. I ended up quickest of the day 

Very satisfying, but tomorrow is another day. Rain is forecasted for the whole day. Chris prepared a rain car. I will just change tires, springs and rear diff. Last time my car worked well with the dry setup in the wet. Lets see how it will be this time.

(6 july 2019)

[wtcc5 5899]

The race is over. It was all about weather chaos a lot of bad luck for Chris and a stubborn race director.
I realized tq easily. Always fastest by several seconds/run. The first qualifier was wet. I did what I could and then waited for Chris to run his laps to see how good/bad my run was. But Chris didn‘t start  After the marshaling duty I checked and he told me his motor died when he turned the car on. Somehow water from an earlier practice run must have found a way into his motor and short circuit it when he touched the switch. So no first run for him.



The second qualifier was on a dry track. Again I did my run and waited for Chris to show his pace. This time he started. After some laps his car started to make bad noise whenever he braked for a corner. It got bad, but he finished the run. This time his spur died. Consequently he had a slower run than me.
It stayed dry for the last qualifier. I could improve by two seconds and had a fastest lap of 20.157s. Now with a repaired car and perfect conditions I watched Chris start. Again his car made the „spur gear killing noise“. Chris was furious, but had no choice but to continue. So I got the pole position on a plate. And Chris had a similar bad start like I had in Bad Gögging.




After the lunchbreak the clouds got darker and thicker. We managed the first final in the dry. Chris and I had a good start and left the field behind. I drove like a beginner after the first corners, missing apexes, going wide, all this bad driving. Chris used my out-of-rhythm-time got through and left me behind. I tried to pull myself together. Until I had a decent rhythm again, Chris was more than three seconds up the road. At that time we nearly had the same pace. I concentrated on myself. Somehow the car had lost pace. Nothing else to do, but to continue as fast as possible. After three minutes I could hear a body scrubbing on asphalt and then Chris rant to himself. He touched one of the high curbes and his car needed to be marshaled. I could slip through and suddenly had a two second lead. My confidence was back. Opening the presented gap was my target. I was dominating the dry yesterday, so why not today. Keeping the concentration high, again the noise of plastic on asphalt reached my ear. It was Chris again. Unlike his error free driving he showed up to now, he made a second mistake. The gap now was much to large to deny my win if I stay out of trouble. Still I was to proud to let him get closer, but I couldn’t avoid it. Chris charged and did the fastest lap of the final (20.234s). I tried everything, but could only manage a 20.3s. So much for my „domination“. Chris was back in the game. At least I won the first final...



Shortly after our run rain came heavy. With it wind and thunder. The race director didn‘t think of stopping the actual final. The marshals risked their lifes out there under the trees and with the thunder so close. Us drivers thought this is stupid and called everyone under the paddock roof. The race was delayed until thunder and rain stop said the race director. But it never stopped and half an hour later the racing continued in heavy rain with 10cm deep puddles. Two drivers went out to better their overall positions in the VTA class. The cars survived somehow.
Then our class should drive. I had my car prepared as good as possible. I wished the race to be aborted, but another driver wanted to run (not Chris by the way, the car that went up in smoke earlier today was his wet car). With a stubborn race director like this even a third final was possible. I wanted to win! So we went on track and couldn’t even finish one installation lap before getting stuck in the grass by trying to avoid one large puddle. I again asked the other driver if he really really wants to do this. He wanted and we started. He got through, drove into the big puddle and it was game over for his electronics. I crossed the line one more time to make sure I won and went back into the pit.



The weather didn’t improve at all and finally the race director accepted that cars are no boats and ended the race. I don‘t know what to say. I was very lucky to win this race, with Chris having so much bad luck, problems and making two of his seldom mistakes. I had another fresh set of tires if it would have stayed dry. It could have been a close fight for two more finals...

 

(7 july 2019)

[wtcc5 5899]

What is the least fun in this hobby? Yes, cleaning the car (did I really write that  knowing my FF-01 thread).

Right after the second A-final, I dried up the car as good as possible. I also was careful not tilt the car, to prevent water from going anywhere dangerous for the electronics. At home I removed esc and receiver, opened the cases and dried wet parts. Today I dismantled the whole car:



There was dirt everywhere. Especially the motor had accumulated sand and dirt. The rear ball bearing was stuck. Both came back to life after I washed them with a lot of brake cleaner. I never thought the motor would get this dirty. You should have seen the sensorboard.

I found no damaged parts, just some drivetrain ball bearings needed to be replaced. The car is clean and setup again. Ready for the next race.

(9 july 2019)

[wtcc5 5899]

I keep on with improving the concept. A lot changed to the previous assembly. The springs are now fully separated and moved towards the front of the car. Two benefits arise from that layout. First: More weight is put near the center line of the car, and second: The springs are Awesomatix parts and have a limited/defined amount of flex. Before, the location would have asked for more flex. Now the springs are positioned similar to the Awesomatix and should do their job.

With the layout change come several new drawn parts. The front droop plate mount not only holds the anti roll bar now, but also the springs. The front arm changed its look to make space for the spring. Also the damper housing was changed.

In the next step I will draw the connection between steering hub and spring to achieve a change in spring preload while cornering.

Here now my solution to reduce roll. The steering arm will change the spring preload. The inner side will reduce preload and therefore the ride height. The outter side will experience an increase in preload and ride height. Because of the Ackermann angles, the inner side will always experience a greater preload change than the outter side.

I would have liked to have no increase of preload for the outter side, but somehow haven't found an idea, yet. Also I am unsure if the leaf spring end should be supported both ways...

CAD pictures again today. I would guess some readers are getting bored...  I don't want to hurry this version, haven't much time to draw in the last weeks and this concept is by far the most complex I have ever done. Again a lot changed compared to the previous post.

In front the droop screw insert was placed next to the spring preload arm. Therefore the arm and the preloadarm were redesigned. This change makes the access to the droop screw easier and reduces the bending/flexing forces on the arm caused by the spring.






More obvious changes happened at the rear. I (and my customers) always wanted to setup rear toe with turnbuckles and wanted to have active rear toe. On version 2 this was prevented by collisions with the rear swaybar and because of the tub chassis layout the turnbuckles for the rear would have become very short. This would have caused a nervous rear and was no satisfying solution. On version 3 the swaybar sits much lower. Still, the turnbuckle will be shorter than wanted, but nearly as long as the camber links and this is a length I can accept. Like in front the droop screw insert switched to the spring side. With the active rear toe assembly this change was unavoidable, because there was no way to evade all the turnbuckles to reach the droop screw. I redesigned the arm and as there is no active preload change in the rear (I have an idea how to do it, though) a new spring retainer was drawn. The droop plate and top plate are new also. The latter not only got new space for the active rear toe turnbuckle, but grew in the rear to allow the installation of vertical body posts. I tried to do something with horizontal posts, but found no benefit for my car concept.






I am very happy how this concept constantly evolves. I still need to redesign the plastic spacers underneath the top plates. Especially in the rear to make for an easier motor change.

 

(14.-19. july 2019)

[wtcc5 5899]

The drawings are in a final stage now. Right now, I feel like I finished all what I wanted to add. I am also quite happy with the geometry and forms. If I want to add one more thing, than it is a heave spring. I just need more knowledge for it... Well, I will need to sleep over this idea. A first check just revealed, that I have no space on the arm to implement another lever. Additionally, I don't want to use a full shock, but a standard sized spring with a knurled nut, or makes it sense to use a standard TC damper (like an full ULP shock) for this task?

So, what's new? I redesigned the dustcover and the bulkheads underneath the carbon plates. The diff dust covers now slip between the carbon plates and then get attached with one screw. This time I made sure, that even the large 3racing diff will fit underneath. In the rear the bulkhead got changed on the motor side, to allow an easy motor removal.






Then I implemented the horizontal body posts. Therefore the rear carbon plate got extended.




In a last step I added my new logo to some parts.




The chassis looks like an UFO and not like a touring car... Time to order all the custom and standard production parts (like O-rings and Awesomatix parts) and start building.

 

KR v3 chapter two Ordering parts

Time to let this car become reality. Except for the upper bumper plate and the battery mount, every part is new or received a revision to make it better. The suspension concept change also calls for a lot of new standard parts from other manufacturers. Posting a list of these is the first step in this chapter:

1. 2x5mm countersunk screws, 8 pcs.
2. 3x6x2.5mm ballbearing, 2 pcs.
3. 3x7x2mm ballbearing, 8 pcs.
4. Xray 303801 T4 arb 1.1mm, 1pc.
5. Xray 303802 T4 arb 1.2mm, 1pc.
6. Xray 303803 T4 arb 1.3mm, 1pc.
7. Xray 303804 T4 arb 1.4mm, 1pc.
8. Xray 302379 T4 C-Hub 0* right, 1pc.
9. Xray 302380 T4 C-Hub 0* left, 1pc.
10. Xray 302254 T4 2017 steering arm, 2pcs.
11. ARC R104013 O-ring 13x1mm, 4pcs.
12. Awesomatix SPR01S soft springs, 4pcs.
13. Awesomatix P09X progrssive spring holder, 4pcs.
14. Tamiya 54868 ballcups, 4pcs.
15. Tamiya 54869 ballcups, 4pcs.
16. Tamiya 53892 turnbuckles 3x10mm, 2pcs.
17. Tamiya 53644 arb ball ends, 4pcs.
18. Tamiya 53906 ballstuds 5mm, 8pcs.
19. Tamiya 9803041 arb bearing holder, 4pcs.
20. Tamiya 54248 turnbuckles 3x23mm, 2pcs.
21. Yokomo YRX12 pitching damper set, 2pcs --> Yes! My heave dampers 

These are all parts I need to order because they differ from earlier stages of this/or other projects. For the rotation damper pistonrods and small o-rings from the SLP shocks are needed, too, plus a lot of M3 screws in all sizes...

(22 july 2019)

[wtcc5 5899]

Hehe, thanks!

I don‘t know if the parcel service and the shops are reading here, too. Because all the parts are already delivered 



 

My heave dampers arrived:




I found the Yokomo YRX12 manual online and immediately started to assemble them.







They will be attached to the preload arms and just work if both front (or rear) arms are moved up simultaneously.

(26 july 2019)