Thursday, 1 November 2012

F113 Update

It has come to my attention that this car would be illegal under the current British rules (and other places are considering similar rules) as the suspension mounts for the front are just outside the body. Kinda makes me re-think a little about the whole F1 front suspension issue and when does scale appearance become subsidiary to car performance and innovation. 

I think the problem may stem from what people "expect" a suspension to look like. I think most identify with a rose joint style suspension which is quite easy to see the characteristics of. However F1 cars use flexures and have done for some time. Its actually quite feasible that the suspension joints ARE outside the body. Certainly in this picture of the Red Bull RB8 its almost impossible to tell where the suspension arm ends and the tub begins.

My best guess based on the picture and the technical description that went along with it is that the molded carbon fiber additions cover the actual flexures, which these days are made from carbon fiber, though some are still made from Titanium and bonded to the arm, while the thick carbon blocks visible at the bottom of the tub are the end of the flexures bonded to the tub. The covers would be 99% for aerodynamic considerations, but I can't discount needing to have the joint covered for rules purposes as I don't have intimate knowledge of F1 rules. Most of suspension movement actually occurs outside the tub.

What this says to me is that while the current F104 etc suspension appear scale they are actually not representative of real F1 suspension so its hard to use the scale argument as a reason to not allow a particular suspension. Each suspension should be assessed on its merits to representing an F1 suspension and the new 3racing suspension is actually getting closer to current "real" F1 suspensions, with the FGX option front suspension probably the closest.

So what does it all mean? I am not really sure but I still want a F113.

Sometimes its not just about RC

Let me state from the start - I do NOT condone deliberate drug cheating in sport. Those people deserve to be caught and punished, but with the news that Anthony West has failed a doping test (most likely because of using a decongestant while trying to ride with a cold), I think its time the anti-doping/drugs hysteria that's gripping the world's sports has to end! 

The World Anti-Doping Agency's list of banned substances is over 8 pages long with drugs listed paragraph style rather than in point lists. I started to count them but quickly gave up when I got to over 40 in the first paragraph of steroids alone, NOT including their alternate names. IN the stimulants section I counted over 60 items, again not including their alternate names, which in some cases can have 15 or more alternate names. To make it even MORE difficult each section is finished with a line that allows unknown substances to be included simply because of having similar effects.

We hold our sports stars in such high esteem that its hard to imagine, let alone accept, some think that cheating is the only way forward, but at the same time there are many who simply work hard and give their all for their sport. At the same time, with very few exceptions, they are not chemists and I personally think it is unrealistic to expect them to walk around with a list of every banned substance every time they go to the pharmacy or shopping. In reality the banned substance list numbers into the hundreds when you include all the alternate names that chemicals can be marketed under. When you consider that the vast majority of us can't even be bothered to check the additives in our foods why do we expect our sports people to make exhaustive checks of every chemical that might be in a nasal spray, something we would buy from the chemist without even a moments hesitation?

In the case of Ant West, the chemical he failed the test on is very common in nasal decongestants and some dietary supplements and it's stimulant properties are considered weak and in some clinical tests, non-existent. It is NOT required to be listed in the ingredients of some products and even if it IS listed can be listed under 1 of 18 DIFFERENT names! Some of which sound decidedly herbal in nature.

One point I want to put out there for thought is what is the definition of "performance enhancing"? I consulted many online sources including a paper published in a Harvard Law journal, as well as grilling my Human Biology educated partner and the fact is that its an incredibly complicated subject which, for the main part is over-simplified by most sporting bodies. Yes steroids and blood doping provide obvious performance enhancements, but so can non-banned substances such as Tylenol or other such drugs which can relieve muscle soreness, or an asthma inhaler which can open airways and improve respiration. What about dietary supplements and vitamins? They obviously do aid the performance of the athlete, but most anti-doping bodies would never consider this "performance enhancing". 

Pain meds are a personal interest because of my interest in motorsport and in particular for this blog, MotoGP. Many riders, at different times, have ridden with varying amounts of pain medication which allows them to ride, but again this is not considered "performance enhancing", but its hard to imagine someone riding with some of the injuries motorcycle riders have ridden with in the past (broken bones, torn ligaments etc) without the use of pain medication to mask the effects of the injury on their riding ability. Then there is the whole subject of custom manufactured braces etc. Recently a celebrated MotoGP rider had a serious accident and the only way he could compete was with a custom made carbon fiber brace to support his injuries. Is that not also "performance enhancing"? Many professional tennis players require the use of braces and other wrappings to ensure they can complete matches - Performance enhancing? What really muddies the waters is that the governing bodies of some sports WILL define a pain medication as a performance enhancing drug but others won't! How can that possibly be acceptable?

This blog has gotten to the point where it could turn into a rant and that's not the intent but I do think we have over-simplified a serious and complicated issue in order to both feel appeased in ourselves that something is being done and for the authorities to always appear as if they are doing something to justify their positions AND their remuneration. It's worth noting that the USADA's pursuit of Lance Armstrong only kicked into high gear because of 2 factors - 1) Refusal of the U.S. Justice Department to pursue the case in the Federal courts, as it has done with other USADA cases, and, 2) After the USADA's $13.7 Million a year ($9 Million provided by taxpayers) no questions asked, budget started to be queried by members of Congress. It is also worth noting that since the Armstrong case, legislation has been tabled in the U.S. congress to force the USADA to under go more oversight examination to make sure in can justify its activities.

Ok, back to my base point. I don't condone deliberate doping/drugs in sport, but I also don't believe that the onus should be forced completely back onto the sportspeople to ensure they are not unknowingly or accidentally taking a banned substance because the ability to know EVERY banned substance is practically impossible. The Anti-Doping bodies MUST do more than stand there waving a big stick around. If governing bodies of sports want to ban every single substance that MIGHT have some stimulant or other possible performance enhancing effect, than maybe they should also take on the responsibility of providing athletes the list of APPROVED products they can use, in-particular for everyday items we take for granted like cold and flu remedies. Too simply say a particular chemical is a banned substance without taking any responsibility upon themselves to help athletes avoid that substance is LAZY and, IMO, points to a reactive rather than proactive approach to the problem.

Next time - I WILL write about RC. I have been playing with some new goodies and the results have been positive.

Monday, 8 October 2012

Hiatus continues...

Still enjoying the break but there is a couple of opportunities coming up that might get me back to the track. With the move on back to Queensland happening just after Christmas and having everything packed up for the month away recently there is a part of me thinking it will be easier to keep things packed up... but then again...

About the most interesting thing I've seen are the testing pics of the 3Racing F113. Its looking good and seems to have pulled bits of inspiration from just about everywhere. The front is a bit crowded and I am not really liking the look of the shocks used on the test car but we'll see what the released version looks like. The new front end has lots of adjust-ability built in with roll center, camber, droop all easily changed. However not sure about castor but again will have to wait and see.

Here are some of the pics 3Racing has released - 

Wednesday, 5 September 2012

Back in Nomad Mode

On the Road Again

There is not much happening at the moment as my partner and I are back in nomad mode up the west coast of WA. Everything is packed up in boxes and will be for at least the next month, and might stay there as, in a couple of months time, we will be making the trek back across Australia so my partner can start her new job in Toowoomba. There is an on-road club there but at the moment they only race 1/10 tourers and minis, though it appears they did race F1 in the past. I've always intended buying a new tourer once we were settled in one place so that might have to happen.

On that note a couple of things caught my eye over the last couple of weeks on RedRC. First was this new F1 car from Kyosho. Its nothing ground breaking and follows the set pattern of most current F1's, with a pod rear suspension, though it is interesting that it appears to be 200mm and uses F103 wheels and tyres. The front suspension looks nice and chunky but how strong it is will depend on the quality of the plastic. Not being very experienced with Kyosho products I can't comment, but its nice to see more manufacturers taking F1 seriously again.

I am still waiting to see proper pics of the 3Racing F113 before I decide what might be my next F1 purchase.

Second item of note is this new tourer from ARC! The main point of interest is that it is 200mm rather than the usual 190mm. Why this interests me is, that for a VERY long time, I've not understood why there has been divergence between electric on-road and nitro on-road. I know a bit of the history of electric on-road so I can understand why they chose 190mm, but I've less information on why nitro went with 200mm, especially as some of the first commercial nitro tourers that I raced were 190mm, though we used 3mm offset wheels to reach close to 200mm anyway, because some other brands had chosen 200mm. I've also found 200mm cars a little easier to set up but that could just be an idiosyncrasy of mine.

I'm also a bit sad as this year I won't be attempting any major events. The last couple of years, despite all the traveling I still managed to attend the Queensland and South Australian on-road titles (a token effort I have to admit but I was still there, and 7th in Stock Tourer at the QLD's is ok), and I only just missed getting to the 2011 Australian on-roads due to a bit of timing issues. This year though I won't get to anything and there is definitely part of me missing it, made more obvious by the fact that, yet again, I'll be reaching QLD (where the 2012 National's are with F1 included) probably a little over a month after the event! Hopefully once there is a bit more stability next year I can do a few more events.

Until then I just gotta keep them wheel rolling.

Monday, 20 August 2012

Race Day 05-08-2012

Its been a while since I've done "serious" racing. I've done most of my racing at a club that's very new and while we get a far bit of track time, it's all pretty laid back and no overly serious. I decided it was time to gauge where I was with my car setup etc.

WCMRC are the other outdoor club in Perth racing F1 so I decided to make the 45km trip. Its a track that's been around a fair while, starting as a nitro track before houses started to encroach on it. The electric club took it over in 2010 and have been getting it back up to a top quality facility, hosting the Australian Titles in 2011. The club offers most current electric classes but on the day it was F1, VTA, Mini, Modified and 1/8 Electric. I had intended to run only F1 but due to lack of numbers I offered to run Mini as well. This stretched my battery supply to the limit because I had decided in advance to not take my charging gear with me.

The Track
Built in the late 80's, it doesn't appear the surface has ever changed much. The electric club appears to have resorted to using "tennis court" paint to revitalise the surface and increase the grip level. This is quite common around tracks in Australia that have the money to do so. The only real downside I've observed is that, if it rains, it can take quite a while to dry. The track also has quite a bit of elevation change.

After setting up I quickly hit the track for some practice. Now we have to remember I've done most of my recent running on a fairly low grip track, so it was almost a shock to feel the amount of grip available. Thankfully the base setup I have been working on proved workable from the start and I could focus on learning the track for the first run. 2nd run was more learning but I was playing with radio settings to increase my steering rate and reduce brakes. I didn't feel there was much point in changing any car settings until I had a comparison against other cars.

Heat 1
The club uses staggered start qualifying so its all against the clock. I made a dreadful start and ended up off the track. The grip level and my diff settings weren't quite in sync (this carried on all day to be honest) but once back on the track I was able to run competitive laps times, working myself back to 3rd qualifier for that heat. Compared to the regular runners I could see a couple of places I was losing time to them. Most obvious was the S section after the banked first corner around until the entry to the back straight. Through this section the car was slow to change direction through the S section and then it under-steered through the next section onto the back straight. I realised watching other races that the under-steer was, in part, due to the line I was taking, but the rest was all car set-up.

Heat 2
I tend to find running more than one car drastically affects the amount of time I can devote to car set up. I tend to resort to simple and obvious changes, which can sometimes make too drastic a change. In this case the simplest and most obvious change to the car which was a change of front tyre compound. I changed from Shizimu F1 to F3, however this totally destroyed the balance at low speed. Reducing the steering rate made a slight improvement but I decided after a half dozen laps to pull in and make sure I didn't cause an incident by spinning out in front of someone else. Annoyingly I set my fastest single lap of the day with this set up but it wasn't drivable over a race distance.

Final 1
I qualified 4th overall despite dropping out of 2nd heat. Finals were normal grid starts. For the first final I had returned to the original tyre combination but made a castor change. Wrongly as it turned out. This was also the first time I had a really good indication of just how much my diff was slipping, as I was barely able to hold onto 4th as the race started. The race was pretty uneventful which wasn't really surprising as I was still learning the best lines around the track. The car was still slow to transition but was a little improved as far as under-steer was concerned though I think this was more because of my cranking up of the dual rate on the steering again.

Final 2
The only change I made was to tighten the diff a little but at the start it still slipped far to much. This race was a little slower over all but I couldn't pinpoint any one reason. I hadn't made any significant changes so I wasn't expecting much, but I did manage a 3rd place.

Final 3
A quick inspection turned up a very gritty diff so any other changes were forgotten to do a diff rebuild. One thing about racing in WA is the sand. Everything is built on sand and it tends to get into everything. I'm using a 3Racing out-tuned diff and this uses a similar thrust bearing combination as the F104 "Pro" diff, except it uses an alloy spacer instead of thrust washers. In practice I am suspecting this reduces bearing life and I think in this occurrence this was the problem. I didn't have a replacement so rebuilding the rest of the diff made little improvement.

I had a good first lap but that was followed by 2 dreadful laps and that put pay to any decent result. Luckily everyone seemed to be having an off race so I came back to 4th by race end. It was interesting to note that even the cars that didn't have any real problems were a lap slower than early in the day. I think the track was getting slicker as the track became more shaded. 

Overall I think it was a pretty good day considering it was my first racing visit. The biggest surprise or realistation was how little grip my "home" track has in comparison and also how much better race days etc could be organised. I am not sure if I will get the chance to race there again as my partner has accepted a job which will mean moving back to the east coast, but if I do get a chance I definitely have some setup directions to try.

Wednesday, 25 July 2012

Front Suspension

The good ol' f103 front end definitely has its fans and its worked pretty well for many years. There are a few variations on the theme, such as the one that comes with the F109, but not everyone considers them improvements.

The main disadvantage with the original F103 front suspension is lack of adjustment. While this ensures strength (which is obviously a good thing), serious racers tend to want a bit more of all the technical bits in search of that last 10th of a second. The F109 achieves some of this with the supplied front end allowing castor and camber adjustments, but the downside is the original plastics are soft or prone to easy breakage. There are some alloy hop-ups but these have their own issues and also seem to be getting harder to get.

Doing some reading online, I came across and American F1 blogger who makes up his own version of an Exotec F104 front end but wider to suit the 200mm width. It's actually VERY simple to make and most bits are probably in a serious racers spares box already. 

Minimum you will need - 
* F104 front suspension mount (plastic or alloy)
* 5mm ball ends
* 5mm ball studs
* 45mm turnbuckles (I used 42mm because I had them but longer would be better)
* original 3Racing upper ball mounts 
* Xpress Alloy upper arm joint set - part of their 1/10 4WD Mini. The plastic versions seem to be almost non-existent, but the alloy ones are still around in online shops etc, and they are cheap enough.

Ignore the big orange thing - its just a bumper

 I still use the original version though the the "creator" has since switched to a slightly different version which he says offers some advantages in ease of set-up. I didn't have any turnbuckles long enough but I also wanted to just test the concept. It takes a bit of fiddling to get it exactly right, as well as a bit of modifying. For example the original writer says that the F104 suspension mount fits straight on top of the F109 lower suspension, but I found that it needed about 3mm ground off one end to allow it to fit as the lower mount is "stepped" around the mounting holes.

Its surprisingly slop-free for a suspension with so many ball ends, but it seems to have less movement that the original 3Racing front end. It is totally different to adjust though as the rear turnbuckle affects camber and the front affects castor, but they also both affect each other so adjusting one changes the other (this is one area the newer version is supposed to be better). It is a little frustrating at first until you work out in which direction each one affects the other, but once that issue is sorted it comes together quite well.

I fitted this to my F109 that I use with a Le Mans body so its not directly comparable to my straight F1, but as both chassis did have a similar basic setup (castor, camber, springs) when I first started with them, I feel I can use the feedback with a fair bit of confidence. So far the LM hasn't seen as much track time as the F1, but this setup does seem to induce a little more high speed under-steer in the car but at the same time the car feels more stable throwing it into corners. Given that I use a 10T brushless set-up in the LM compared to a 17.5 in the F1, this is a actually good change, but since I use a higher down-force LM style body the induced under-steer is a bit puzzling, but I am sure with a bit more track time I can get on top of it

The original version of this suspension is here

Friday, 13 July 2012

Its all in the springs

The single largest area that needs work on a standard F109 is the side springs. It is also the area that seems to be the most contradictory when reading online information. Some seem to get the car to handle fine using the standard kit or option springs and others need to make serious modifications. The only pattern I can find to this is that most of the people making the standard springs work appear to run foams on carpet.

My view (and I've discussed this with others and they agree) is that the original side springs are simply too soft to support the pod when turning under power. The springs "collapse" for want of a better word. They are also too soft to make the pod return to center when rolling from side to side. This makes the car react as if it is tweaked and causes the car to spin out far to easily. I was able to use the hardest option spring and a bunch of shims to put a lot of tension on the springs when I started looking for a solution but in the end I knew I had to find different springs.

Most seem to do the CRC spring mod.

However, CRC parts are not the easiest to source for me as ordering from the U.S tends to be quite expensive if you want any form of express freight, and not ordering express can lead to waiting for months for an order to arrive. I was able to source Associated springs more easily, though this meant I had to devise my own mounting system. Unfortunately I didn't take any pictures at the time but its turned out to be quite simple involving 2 5mm ball studs and small amount of cutting to the original spring seats. This allows me to also adjust pre-tension and therefore tweak. It also doesn't require any modifications to items such as the upper chassis pivots.

I decided to go straight for the 6.25lbs springs which is the hardest spring Associated make for their 12R cars. This may have been a bit over over-kill as even the 5lbs spring is considerable harder than even the hardest of the 3Racing springs. However on-track performance is what counted and the hardest springs had worked thus far.

Follow the leader

The front suspension of the F109 is lifted almost completely from the F103, but with a 3Racing spin on it. compared to even the most advanced Tamiya front end the 3Racing one has more adjustment available. Now to some this is a good thing but to others in makes the front end fragile and a bit sloppy. Personally, I hover in the middle as far as my opinion of it.

As it's supplied in the box it is all plastic. I had read about that in advance so when I ordered my kit I ordered a few extra bits, mostly the alloy castor mount and the 3.5mm offset front uprights. The castor mount was well worth it as the kit one is rubbish. It flexes and moves pretty much as it wants and, according to others online, breaks pretty easy. The alloy one isn't perfect as it seems to induce even more slop into the front suspension but a few well placed shims seems to cure that for the most part. Remember, you don't want to remove all the slop because it will make the car darty and sensitive to bumps, but you don't want so much that it feels vague and unresponsive.

Hop-up castor block - numbers on it are relative to original castor not an absolute value
The 3.5mm uprights are something I used on my F1's in the 90's and they do the same job now. They calm the steering down and make it smoother and less aggressive. Because the F109 has a different chassis and battery arrangement, it has a LOT of steering and I've found anything that calms it down is a good thing. It's also unusual in pan car world not to use offset uprights and most big name 1/12 and 1/10 pan car chassis use offset uprights as standard. Tamiya have also recently released a new hop-up upright that allows either 0mm or 3mm, plus other options for the steering and ackermann. Not the cheapest so they might need to wait a while before I try them.

I also modify the upright so that I can create some ride height adjustment. I trim off some of the excess plastic and also use a slightly longer suspension pin. It doesn't give a lot of adjustment (3mm in this case) but it can be enough given the right situation. Right now I am running on a fairly bumpy track so I have it as high as possible.

Another simple mod to do is polishing the suspension pin. This gives smoother suspension movement. Combine this with using something like diff grease or AW grease to give a dampening affect on the front (not unlike damper tubes on pan cars). I also use Associated 1/12 springs instead of Tamiya or 3Racing springs but this is a personal preference thing.

Overall though, the original 3Racing front end doesn't have a lot of fans. Most people that express their opinions online seem to dislike it and switch back the carbon re-enforced suspension from the F103. They also say that they don't miss the adjust-ability from doing this. I say this is BS. In a world where, even at club level, people are looking for every last tenth of a second they car ring from their cars, the last thing you want to do is take away 2, pretty important, adjust-ability options! 

I also say to those that say they are fragile and break as soon as it hits something - don't hit things! I've used the original front suspension for over 6 months racing in both F1 classes and sometimes mixed classes as well due to numbers on the day. I've had my share or hits and crashes (one so hard it bent the motor shaft!) and yet the front end has withstood them all. Even now the only problem is wear as the pivot ball's in the suspension are starting to get loose, but 6 months of racing most weeks I am not going to complain, and at a bit over $15 for a complete front end its not hard to keep a few in the parts box.

Thursday, 12 July 2012


And no, I don't spell them the American way :P

One of the biggest influences on how well my F109 performs has been finding the right tyre combination for the track I race on. Its a small club and still building up so things like track prep are fairly basic, but that just means a bit more of a challenge. 

There are masses of information regarding F1 tyres scattered over the various forums and sites on the 'Net, but I've struggled a little to make that information apply to my situation. Sometimes it's not always obvious the sort of surface or prep they use and that can make a big difference to tyre choice. One of the first things I had to get straight in my mind is that,to me, it appears some of the tyre manufacturers have started using the same reference number or compound name for their tyres but it is actually different front and rear. I believe this is particularly true of Shizimu who have labeled their tyres either R or F and then a number, but most seem to run the same numbers i.e. - F1 and R1 together or F3 and R3 together. Given that an F1/R1 combination gives the same grip balance as a Ride B/A combination (which are advertised as B=hard and A=soft) one has to assume that Shizimu have decided to simplify matter and just make their rear tyres softer/grippier than the fronts. 

However this idea is totally mine and may not be reality! It DOES however, reflect how the car performs on that brand compared to others.

So here is a list of the brands and types of tyres I've tried and my results and opinions of each.

Kit Tyres - Equate to Medium Front tyres and Soft Rears. According to various forums etc these tyres work on carpet. My experience was that they are too close together in compound to get any balance. Traction goop on the rears helped a little but they only became really driveable using the good ol' superglue ring around then outside of the fronts. However given how this wears off over the course of a race it's not ideal.

Zen – Another foam tyre brand – At first I was determined to go foam instead of rubber so I sourced 25 compound rears and 30 and 35 compound fronts. These are nice tyres and come pre-mounted and trued on nice strong rims. The 25  rears are very similar to the kit rears and the 35 fronts are very similar to the kit fronts, so delivered a similar balance. 40 and 45 fronts are available but I couldn't source them at the time I was experimenting with them.

After a brief flirt with foam tyres and having watched the other F1's at my track run around quite happily on rubber I decided rubber was the better option. However, as they were all running F104's I had to seek out my own combination.

Ride – Usually recommended as B(hard) fronts and A(soft) rears. This is an option recommended for F103 cars (and touted to work anywhere) so I tried it on the F109. With some tyre sauce for the rears this might have worked better than it did but I prefer not to bother with being that serious at club days. Its about fun after all. There was better balance than with the kit or Zen foams but given the typical conditions of my track they were still hard work to get around the track consistently.

Shizimu – Initially I could only get the R1 and F1 tyres to try. To be blunt this combo offered no improvement over the Ride tyres as far as balance front to rear, though they did appear to offer slightly higher grip overall. Using Shizimu R1 rears with Ride B fronts did make a car that was almost consistent and drivable but once pushed hard in a race situation it just becomes too easy to make a mistake, as the car feels on the limit of grip all the time. I've now sourced the R3/F3 combination which is supposed to be preferred but as I've found a different combination that works I haven't tried these yet.

TRG – TRG make a LOT of option parts (some breathtakingly expensive) for the F103 and F104, so a lot fit the F109. I read about the TRG Superion tyres being used in Asia when it rains. A VERY sticky tyre but so far proving to have surprising durability. So far these have done at around 25 runs, without any real loss of performance. They come pre-mounted on an excellent quality rim, though they aren't glued as they don't put the inserts in. I've only used the rears but there is now at least 1 other F109 and a Tamiya F103 (newer arrivals) using TRG Superion on the rear and TRG Hards on the front.

At present I am using a combination of TRG Superion on the rear and Shizimu F3 on the front. This is giving me an excellent and FAST combination with nice balance front to rear. Each end seems to have the grip it needs when it needs it. They also suit my driving style which is important. I also have this combo on my F109LM which also works very well despite having a much higher down-force body compared to a standard F1.

3Racing Out Tuned Ball Differential For F104

As the title suggested this hop-up is designed for the Tamiya F104, but like so many options parts for the Tamiya F cars it can be fitted to the F109.

Almost since day 1 Tamiya cars have had the simple but annoying diff setup of having the thrust washer in the wheel. Changing tyres meant disassembling the diff and then have to reassemble it once the new wheels/tyres had been fitted. If you are like me and consider diff settings very important to your overall setup and car balance (unlike those that simply do them up) then this soon becomes majorly inconvenient.

So when the I discovered the F104 Diff housing set, commonly referred to in these parts as the "Pro" diff, I though my problems had been solved. Unfortunately not, as the pro diff, while making wheel/tyre changing more convenient, actually makes adjusting the diff even more difficult by putting the adjusting nut in behind a little cap which has the stud for the wheel nut on it. I've also found this cap and stud to be a weak area, having broken the stud off on more than one occasion, and Tamiya being Tamiya you have to buy a whole new diff set to get a spare.

3Racing Diff as it comes out of the packet

The 3Racing diff takes the pro diff idea one step further by engineering an adjustment ring and thread behind the spur gear between it and the motor mount. This allows adjustment of the diff without removing the wheel at all and thus far holds the setting very well during the course of a race day. Building it is not that different from the F104 diff with the main differences being the threaded diff joint and the adjustment ring and o-ring and the removal of thrust washers to be replaced with a aluminium spacer. At first this concerned me more than the rest but once built makes for a VERY smooth diff action and very precise adjustment.

Installed on car
Cap in place

Cap removed showing main diff nut - Initial adjustment is still done with this nut

 Simply adjust the diff as per normal before fitting a wheel. Adjustment is then made by inserting a 1.5mm hex driver into one of the holes in the adjustment ring and turning the opposite side wheel. Adjustment done. So far, on the track it has worked very well, holding the setting without changing and being a very consistent diff generally. In my opinion this is a very worthy upgrade and given its less than $15, it is bargain bling as well.

Adjustment ring

A few things to be aware of. Firstly it does move the spur gear closer to the wheel in order to make room for the adjustment ring, though it doesn't change the width of the car or move the wheel etc. It's only a couple of millimeters but I've read that it can be enough to make it hard to mount pinions on some silvercan motors. There has been no issues fitting pinions to the brushless motors I use. Secondly - the first one I bought the diff joint (the long black bit in the picture) wasn't machined straight. This made the diff wobble and wasn't usable. Finally you WILL need the shorter F104 axle or (as I did) cut down the F109 axle.

Monday, 9 July 2012

Not the best day!

Not the best day for racing. Cold and wet until about 10:30 before the track dried enough to have a few runs. I focused on my 109LM as it had new suspension to try. I copied it from one I'd seen on another blog and it seems to work quite well, though I think the base settings suggested have induced too much mid to high speed under-steer, though low speed steering and balance still seems nice.

Most exciting part of the day was when the car, which just happens to run a 1/10 version of Mercedes CLR body, decided to emulate it's 1:1 cousin and decided to try turning into a plane (real life example here ). In my case it was the location of a ill placed and unnoticed rock on the track that caused the front to jump up and then it just kept going as the wind got under the body.

This is the end result - 

Given some of the issues I've been having with high speed cornering maybe I should go in search of some more front downforce - just in case!

Also not a good day numbers wise. I've never been a supporter of the "race every weekend" style of club, and I think its starting to have a negative affect on this one. Also, there have been some strange comments about the time of year and the weather. I tend to just check the weather forecast and if it predicts dry/fine then I prepare to go racing. This silly thing about "wet winter" and not being conducive to on-road racing sounds like a pretty lame excuse in my book. If you want to go do something else just say so.

Friday, 6 July 2012


I've been racing RC cars for about 20 years now and I've decided that it might be fun to write about some of the stuff I am doing and racing. I probably should've started a couple of years ago when I was doing a bit more, whereas now I am focused mostly on F1, but I have raced pan car, 4wd tourers in most classes, mini and nitro (tourer and 235 2wd). I've done a lot of state level events but only one National level event. I could say I've managed to avoid most Australian Titles but the truth is I've just never had the budget, the time, and the location all match up at the same time. Even in 2011, I arrived in Perth just 1 day after the Australian Titles had been run.

So this basically this will be a bit of reminiscing and commenting on things I feel are important or interesting. I'll also write about my current racing activities (as much as they are).