TA06 - First touring car build and first time racing

[Jonathon Gillham 4605]

17 minutes ago, ThunderDragonCy said:

Yeah, i was quite keen on one of those as its one of the few plastics that aren't available reinforced, but the aluminium one was only shipped in kits. It was never a 5XXXX number hop up. I haven't seen one yet. There are a few other slight differences as i am running 55mm shocks and reinforced plastic shock towers rather than 50mm shocks and the later carbon towers of the -R. I didn't want the expense of the towers and the shocks all at once and i already had the reinforced towers on the car. Mine also has TRF419 suspension rather than 418, and still running rear dogbones as i can't see the point of going to unis at the rear when these are so smooth. 

Thats something I've wondered about - what is the advantage of universals on the rear? My TA07 and race kits have them, but I've never noticed dogbones lacking.

Nice looking TA06, it looks like you've ended up in a similar place as my TA07 is at. Exdept you race yours, mine hasn't seen asphalt this year!

[ThunderDragonCy 7873]

10 minutes ago, Jonathon Gillham said:

Thats something I've wondered about - what is the advantage of universals on the rear? My TA07 and race kits have them, but I've never noticed dogbones lacking.

Nice looking TA06, it looks like you've ended up in a similar place as my TA07 is at. Exdept you race yours, mine hasn't seen asphalt this year!

I think unis are ultimately a bit smoother, and you don't lose driveshafts if you flip a camber link off in a crash, plus the unis i have seen in the TRF kits on the rear seem to use aluminium shafts so they will be lighter. I think it's one of those marginal gains things, but given that unis are one of the most expensive hop ups there is much more time in my driving than something like that. I feel like every hop up i have done has improved the car - it definitely felt more settled with the TRF arms and aluminium shocks, it needs the sway bars for racing, the bearing steering set is really slop-free, the front unis don't chatter and the aluminium blocks are solid, the reinforced plastics have improved ths feel as i have added them (shock towers especially). Can't see rear unis doing that. Hence why it's also still running kit steel turnbuckles and pivot balls. 

Didn't realise you had not raced recently. That's a shame. I have never raced a buggy, but i am enjoying the on road i door option when the weather sucks. 

[Jonathon Gillham 4605]

9 minutes ago, ThunderDragonCy said:

I think unis are ultimately a bit smoother, and you don't lose driveshafts if you flip a camber link off in a crash, plus the unis i have seen in the TRF kits on the rear seem to use aluminium shafts so they will be lighter. I think it's one of those marginal gains things, but given that unis are one of the most expensive hop ups there is much more time in my driving than something like that. I feel like every hop up i have done has improved the car - it definitely felt more settled with the TRF arms and aluminium shocks, it needs the sway bars for racing, the bearing steering set is really slop-free, the front unis don't chatter and the aluminium blocks are solid, the reinforced plastics have improved ths feel as i have added them (shock towers especially). Can't see rear unis doing that. Hence why it's also still running kit steel turnbuckles and pivot balls. 

Didn't realise you had not raced recently. That's a shame. I have never raced a buggy, but i am enjoying the on road i door option when the weather sucks. 

That all makes sense re the universals. Given you've done the TRF419 suspension i wonder how much difference there would be between yours and a TA07 now.

I've raced offroad all year, but the onroad cars havent been out except the F1 cars going to the school. I even bought a new motor for the TA07 to comply with club rules (went to the NZRCA spec motor so no choice) and its been soldered up and not run. Weather didnt play nice, the days I was able to race it was rained off if it didnt rain it clashed with offroad, and while I could go indoors its a saturday night and indoors isn't as good as outdoors. No shortage of racing though. A BIG shortage of good racing but thats another story

[ThunderDragonCy 7873]

7 hours ago, Jonathon Gillham said:

That all makes sense re the universals. Given you've done the TRF419 suspension i wonder how much difference there would be between yours and a TA07 now.

I've raced offroad all year, but the onroad cars havent been out except the F1 cars going to the school. I even bought a new motor for the TA07 to comply with club rules (went to the NZRCA spec motor so no choice) and its been soldered up and not run. Weather didnt play nice, the days I was able to race it was rained off if it didnt rain it clashed with offroad, and while I could go indoors its a saturday night and indoors isn't as good as outdoors. No shortage of racing though. A BIG shortage of good racing but thats another story

I would love to have a spin with a nicely done TA07 to see. I suspect the 07 will still be quicker as it's lighter and the drivetrain is lower friction, but mine is in a nice place now i think. Need to get one of the good guys at the club to give it a drive to see what they think. 

[ThunderDragonCy 7873]

After two failed paint cans i finally got my new race shell finished. Protoform Spec6 (the modrrn iteration if the Mazdaspeed6). 

It should be more neutral than the rather aggressive Zooracing Hellcat i had before. Looking forward to giving it a spin. When i driven recently in the street it seems really settled even with the old shell, so i think i am getting somewhere. I have upped the damper oil to 500cst from 400cst and swapped the pistons for those interesting tapered hole options that come with yeah racing shocks. I had a bit of on throttle oversteer on corner exits but went from softest pink to medium silver front bar and its settled down. Hopefully got the setup nicely neutral now. Fingers crossed! 

 

[ThunderDragonCy 7873]

Inspired by the part you can buy for the TT02 I designed a top deck for my TA06. 

The chassis has quite a lot of twist flex between the rear transmission and the battery case and the reinforced chassis isn't available anymore. I thought this would be an interesting option. Quite pleased it fitted up first time!

It picks up off the top gearcase holes with M3 x 8 screws and washers to stop them hitting the motor. The ring shape with holes is to allow a fan mount new this blocks the original. 

At the front i had to pull the diff cap off and replace the m3 x 8 screws holding the front shock mount bulkhead with M3 x 16 items. The deck drops on the extended screws and then secure it with nuts

The extra holes were for adding extra fixing to other screws on the tub with standoffs but i got these a little way out. 

The twist stiffness is improved a little but not as much as i hoped. I think a development would be adding some anchor holes ahead of the motor where the stiffeners attqch to the rear of the battery case. That would really stiffen up the rear. 

Still, looks nice, can't hurt and glad it fits. 

[svenb 3759]

Nice! 

Problem with the 06 is chassis twist down the length of it, your idea is a good start but as you may know it needs to anchor to the sides. 

Are you using the carbon battery plate and reinforced chassis? 

I Raced my 06 on very limited grip surface so chassis flex helped, carpet would need a rather rigid set up. 

Good job designing it mind👍

[svenb 3759]

There's the carbon side plates as well. 

Just read your post again sorry! Carbon chassis is no longer available 🙄

[ThunderDragonCy 7873]

34 minutes ago, svenb said:

There's the carbon side plates as well. 

Just read your post again sorry! Carbon chassis is no longer available 🙄

I have seen the carbon side plates but i hadn't thought about the stiffness they might add. I think i might be in for a version 2 with pick ups properly placed for those front holes and some option to hook up to the inboard stiffener screws. 

[ThunderDragonCy 7873]

Little step forward tonight. The seals (o ring and diaphragm) on the yeah racing dampers have been a bit troublesome. The o rings are quite variable in size so it has been hard to get the friction the same on all damper shafts. One would always be sticky. And i find the very soft diaphragms frustrating as they make rebuilding difficult by warping and moving and generally not being helpful. I finally lost my patience with them and got tamiya replacements. 53576 oil seals allowed me to build the dampers first go in 5 minutes. Top job. Replaced the o rings with blue X rings 42214 i had spare from my aeration shocks. Not sure sure on this. All the shafts are super smooth and consistent, but with only one seal (two in TRF shocks) i am a little concerned they will leak. Still, at the moment they are much improved so i am happy. 

[TurnipJF 9181]

On 2/4/2020 at 6:54 PM, ThunderDragonCy said:

Little step forward tonight. The seals (o ring and diaphragm) on the yeah racing dampers have been a bit troublesome. The o rings are quite variable in size so it has been hard to get the friction the same on all damper shafts. One would always be sticky. And i find the very soft diaphragms frustrating as they make rebuilding difficult by warping and moving and generally not being helpful. I finally lost my patience with them and got tamiya replacements. 53576 oil seals allowed me to build the dampers first go in 5 minutes. Top job. Replaced the o rings with blue X rings 42214 i had spare from my aeration shocks. Not sure sure on this. All the shafts are super smooth and consistent, but with only one seal (two in TRF shocks) i am a little concerned they will leak. Still, at the moment they are much improved so i am happy. 

Good move! I gave up on the Yeah Racing o-rings after building one shock, replacing them with Tamiya red o-rings which work just fine with excellent consistency. I'm guessing your x-rings will work even better.

[ThunderDragonCy 7873]

1 hour ago, TurnipJF said:

Good move! I gave up on the Yeah Racing o-rings after building one shock, replacing them with Tamiya red o-rings which work just fine with excellent consistency. I'm guessing your x-rings will work even better.

Good to know. I think red o rings might be the one for these. Hopefully getting to the track at theweekend so we'll see if they still have oil in after 20 minutes of track use. 

[ThunderDragonCy 7873]

OK, this one's going to be a longer post, and a little less about the car and more about the 'first time racing' bit.

Due to the way things worked out recently I couldn't race for a couple of months, then managed to get down 2 weeks in a row. Two weeks ago I went racing and by the end of the night I was ready to throw the towel in. I had my brand new Protoform shell and tweaked shocks on the TA06, and I put my old ZooRacing shell on my recently built TT02 Type S as a spare/maybe I'll run it for fun. I ran two laps in practice and broke a c hub on the TA06. No spares, so that's out. Main reason I crashed is that I put tyre sauce on before I left home thinking they would be spot on to drive straight away when I arrived 40 minutes later. WRONG! The tyre sauce just absorbs/goes off, so the car had little grip and understeered really badly. So, lesson one new racers - tyre sauce 5/10 minutes before use maximum. Have to say I was a little shocked to break it so easily though. I know Tamiya C hubs are a real reliability issue for racers, but I had hit a LOT of stuff before in the previous four races and they had been fine. Unfortunately the TT02 Type S was a terrible handful to drive despite it running really nicely in the street when I have been setting it up, and for some reason the steering arm popped off under certain impacts despite being super tight and brand new. After retiring from race 3 of four with this issue and the handling getting progressively worse as the grip came up, I took my bat and ball and went home thinking maybe this isn't for me. I'm not able or willing to race every week, and all I really wanted was a nice handling car I could drive without getting too frustrated when I did race. The lack of places to test and tune is a real pain for people like me who probably just need 2-3 hours on a representative surface to run and get some advice to get a car dialed in. 

Anyway, I posted on here and on the club FB member group about this, and I got a lot of support and advice, from the members in particular. The annoying thing about touring cars is they are so sensitive compared to buggies. If a buggy is a bit off, it can still be fun to drive. If a touring car is a bit off (like bad choices on tyre sauce for example) it's undriveable. Anyway, going through the car, the advice was tyre sauce at the event, check my steering angles, and my setup. Bring spares! Steering is interesting. I'm new to modern radios and their many adjustments and it's taken a while to figure out what's what. Anyway, they guys said due to the tight nature of the track get +-30deg steering angle. I put the car down on some paper, drew a line with the wheel in pencil then turned full lock and did it again. Borrowed a protractor from my daughter and measured. 22 deg. My first port of call to check things like this is endpoints, but actually after some advice it seems the best bet is put end points to 100%, and use the dual rate to reduce the throw. I am now running 100% endpoints (using the turnbuckles and subtrim on the Tx to get it even left to right) but only 67% on dual rate. What this does (which is brilliant for a newb) is calm the steering down. I had been trying the expo on the steering which is slower around the straight ahead, then quicker to fulll lock, but I couldn't get on with this. Using lower dual rate actually slows the steering across the whole throw, so now I have linear (zero expo) but low dual rate and it feels really good. 

Another recommendation was sorting out the brakes. I had been complainning of oversteer into corners whatever I did. They said take all drag brake off, so you get no braking effect at all when you come off the throttle. Then turn your max braking force down to 25 or 50% so you can hit the brakes but not just stop on the spot the moment you touch them. Seemed a bit odd to me as I wanted to slow down for the corners, but they are good guys so I changed my setup.

Finally, they said slow the car down to give me time to think and figure stuff out. So I turned my motor timing down from 42 deg to 35 deg an my throttle end point to 90%. 

I also double checked my setup and somehow my ride height at the front was 2mm too high. Given I had mucked about changing seals on my shocks I had clearly managed to get this wrong and hadn't check. So, setup gauge out, I checked everything with battery on board. 5mm ride height front and rear, 2 deg rear camber, 1.5 front. 

Got the opportunity to race again the following week, so along I went. 

I had some spare c hubs this week, which was good because I broke 2! Again, practice, got flipped and hit hard at 90 deg, straight onto the front axle. Bit frustrating, btu I was in Heat 6 so had 30 mins at least to change it. The key thing was that actually the TA06 has a pretty good balance now, and the extra steering throw really made a big difference in the tight circuit. Promising.....

Race 1 I kept myself to myself, but was tidy, and the car was pretty easy to drive. No drag brakes is brilliant. The car doesn't get unsettled at all off throttle, and the scrub of the high grip tyres when you turn in means you do slow down so you don't need to brake much. I think I was braking once at the end of the main straight if I got a clean run down it. Lowering the motor timing made the car less jumpy on the throttle, which was easier to drive on the infield, and it wasn't massively slower down the main straight. Very good! I could see the car rolling on it's springs as I turned in (I'm running softest sway bars front and rear), but my feeling was that it made it nice and easy to drive, so after the previous week I thought I would quell my inner tinkerer and leave it alone. I should also point out that I DIDN'T COME LAST! 4th out of 6. Chuffed to bits!

Race 2 was a bit scrappier as the grip had come up and bit and the guys I beat in the previous heat had got their cars dialed in a bit better. Still had a really good run though, and improved my fastest and average laps times by over a second and did an extra 2 laps compared to race one. I got nailed into the barriers and the car felt a bit odd after, but not badly so. You marshall the race after yours so I promptly forgot about the odd handling.....

Until 5 minutes before Race 3 when I was giving the car a quick once over and found another broken C hub! I was panic'd now as I had both a spare and my TT02, but not really enough time to prep either. The break was held captive by the suspension arm and had clearly happened and held in Race 2 and hadn't made the car undriveable, so I rolled the dice and lined up for Race 3. Again, went well, but I was cautious and desperately jumping out of the way of other cars. It held (unbelieveably), but I didn't improve. Same number of laps, still not last, but slower. 

Race 4 I had replaced my C hub and was up for having a go. The grip was high now, and I put only a tiny bit of sauce on the inside of my front tyres as everyone recommended. Everyone was also in their groove and we had another car from the other TC heat. The race was brilliant! Lots of dicing, but pretty clean and I really felt like I got in a rhythm. I went quicker again, and a lap further again. Ended up last but one in 17.5 TC overall as the other couple of guys I was dicing with in my heat turned out to be in Clubman class, but given my car is eligable for clubman (being tub chassis) I was pretty happy with that. 

I hope this helps people like me who are having a go at this for the first time. I feel like I understand a lot of the mechanics of this pretty well and I still found myself at sea with it all. I'm a bit annoyed at suddenly breaking c hubs all the time, but I think it might be my new wheel nuts which are thinner than the nylocks I was using, and because of my wide front setup I only had 4mm thick hexes up front which shows a lot of threaded end of the driveshaft beyond the nut. I suspect this is allowing shock loads to be quite concentrated where before they might hit the face of the wheel. I've measured my car width and put 6mm hexes on which is right on the squeaky limit of 190mm wide across the front, and put some thicker nylocks back on. Hopefully this will help on the reliability front. In the meantime I've ordered 3 pairs of c hubs from rcmart! 

I'm am desperately trying not to tinker too much with the car before the next race. The shocks are a bit squealchy, so I think my fears about the X Rings weeping might have come to pass, so I'll give them some fresh (same!) oil. I'm going to put medium sway bars front and rear to try and take away some of that roll I could see and maybe make the car a little more responsive. Hopefully not too much! 

Finally, I cannot recommend Broxtowe Model Car Club enough for being serious about racing, but not too serious, and helping me out. 

 

[ThunderDragonCy 7873]

Bit of an update. Went racing last weekend. The track was seriously tight and technical this week and the only change i had made was the medium sway bars. The car had more understeer and was definitely harder to drive on this circuit. Again, trying to be good, i minimised tweaking and went for more additive across the front tyre, which helped a bit, and getting some advice on driving. I am finding because of running the front diff almost solid (2 million oil) it's definitely more settled towards understeer on the throttle, but it takes some commitment to drive like that. What i DIDN'T do wasbreak another x hub now i have the slightly wider front hexes and thicker nuts like i had before. And i hit the barrier plenty! This definitely seems to me to be the key to relibility with tamiya c hubs. However, my front end is now 3mm wider than it was, which does take away grip. The thought occurs as i type this that it could have contributed to the more understeer balance. Some thicker hexes for the rear to balance this up i think! Regardless, i was still not last, but at least 2 laps per heat slower than the faster lads. 

I managed to leave my sway bars at home because i have been messing about with the kit i am designing for the TT02, so i was a bit stuck, but in the final race i rolled the dice removed the rear bar all together. It was definitely better but still not spot on. My friend at the club who is into Tamiyas was watching me and also noticed the pronounced body roll. After chattibg about he suggested much stiffer springs and leave droop to be what it will be. I currently run the medium 53440 front and soft rear, and these are the only spribgs that will give me 5mm droop front at 5mm ride height. Anything stiffer doesn't droop as much. He said to forget droop for now and just go stiff on the springs to make the car less lazy. So, i have gone white extra hard front and blue hard rear, just set the ride height to 5mm and ignored the droop (which will be much less now). I will also go back to soft sway bars with the increase in spring rate. We' ll see at the next race in a few weeks. 

Couple of things i am working on. I decided to get a blinky esc, so my 10bl120 has been sold and i have a justock xr10 60a coming. Whilst i have the electronics off, i have been on a bit of a shapeways/designing stuff tip of late so i though i would give this a go

I have 3d modelled the master steering arm and beefed it up for being plastic, then created a mirror version. This will hopefully allow me to run the servo on the right next to the belt and the esc on the left to tidy up the wiring and not have it crossing the belt, like on the TA06 MS. I have ordered it in the stronger, more rubbery PA11 material which has been great on my Thunder Dragon uprights. Given how often i hit things this will get a lot of hammer so hopefully it's strong enough. I have done a loose fit on the servo and it should all fit. The plastic servo try won't fit as it's handed, but to try it out i am going to swipe the symmetrical (and right side mounted) tray off my FF03 to see jow it goes. If it's good/permanent i'll either mod the stock part or get the 84410 carbon job. 

[ThunderDragonCy 7873]

Finally got the part last week, and decided today's project would be fitting and testing. 

This is the chassis as it stood, with ESC and servo removed. 

Fitting was pretty straightforward. I found that the standoff boss i modelled in copied from the plastic kit part doesn't work with the yeah racing aluminium steering set i have. Luckily all i needed to do was cut the boss off flush with the arm and it all fit fine. In the usual way, before fitting i drilled out the 3mm hole with a 3.05mm drill, and the threaded holes with a 2.5mm before tapping half way. This gives the threads on the screwthreads a start then they self tap the last couple of turns which makes them tight and stay put. Here it is installed

Next was to sort the servo flip. I had a spare TA06 servo tray in kit plastic because one of the reinforced sprues i bought for something else had the serbo tray on too. As you can see, the tab on the left stops it fitting. 

I cut the tab off and trimmed a couple of other places until it slid in nicely, then used the holes in the tray as a drill guide to drill the deck. This worked a treat. I put a block of wood under the deck to drill and it all went nicely. 

On the underside you need to countersink the holes. After a disaster trying to do this with a 6mm drill on my TRF211 and just tearing a 6mm hole through the deck, i have just done this by hand since then. Stanley knife at an angle, round and round. Keep test fitting screws until the heads are flush. 

And fitted. You can see how much i trimmed off the left side

First test fit up and the belt and braces securing nut i gave on the servo saver interferes with the belt. Plan B

Rerouted the belt by lowering the tensioner and running the lower run over it. Not sure if this is better or worse. I removed the nut from the back of the servo saver and added a 2mm spacer on the front so the bull screw thread is flush. 

Once that was working, i measured up the wires on the new justock ESC and soldered up the motor, then caregully installed and stuck everything down. The servo wire is routed through the battery compartment bejind the shorty battery which easily avoids the belt. Much neater! 

Gave it a run out, and it works! Even survived a couple of kerb hits. It was testing. Honest. 

Shut up! 

Anyway, it was the first time i had run the car with much stiffer springs too (white front, blue rear) and it drives so nicely! Even on the bumpy tarmac at 5mm ride height it was really planted and responsive. I think i now realise running soft springs causes lota of bottoming out which really unsettles the car. Really great that it feels so good, but slightly frustrating that it will be months until i can track it. Hey ho. Here it is all dressed up

I'll putting the steering arm on Shapeways soon. 

[ThunderDragonCy 7873]

This will be the last post for this project, end of the road. It has taught me a lot, but having run it today on something other than Sorex tyres i think i have been doing this chassis a slight disservice. On Sweep 34 treaded tyres today as a final shakedown now its back together, the balance was much better than almost any time i have run it. Seems i don't get on with sorex tyres! Hopefully it's off to a good home. It's over on ebay now.