|
M03 BUILD UP OK, so you want to build an M03. Well it aint hard. Most of us can do one in about an hour and a half - without instructions! What we're going to do here is build up a car, with a few little hints and tips that we've learned over the years. It might not be the perfect set-up for your track, but it'll be a good starting point. No it's not meant for experienced people (although you may find something new) it's mainly for first timers to help save them from mistakes. Are you ready? Here begins the lesson!
| | See those suckers? Spray em out. Motor spray or electrical contact cleaner is fine. Do each one individually and get all the gunk thats inside out. It doesn't take long and makes a huge difference. Then when they're done, put 2 or 3 drops of a quality oil on them. Thats all you need. Don't drown them in oil, they don't need it. If you've got blue seal bearings you can lever the seals out. It's up to you whether you put them back in or not....We don't. Stick them on some needle nose pliers and spin them. If they spin for 30 secs, you're on the right track. If they spin for more than a minute then WE are worried, you might beat us! |
| Here's your choice, gear diff or ball diff. Now listen carefully..it really doesn't matter which you use. We have had equal success with both. If you go the gear diff route then the best option is to just put a SMALL amount of grease or silicone lube inside. Stuffing the casing with anti-wear grease or anything just results in it leaking all over the place after a while. It's just not worth it and it really has no bearing on performance. Resist the temptation to add extra shims or anything to 'lock' the diff. It accelerates wear dramatically and leads to failure, pretty quickly. You'll find that the normal diff action is fine. Ball diff? Then buy the TA03 one and build it exactly as per the instructions. Only difference? Use anti-wear grease instead of the standard diff lube supplied.Don't take out bits or anything, just build it. The only other thing we're going to change here is when you tighten it. Just...umm..tighten the crap out of it, and leave it. Want a little more security? A dab of Loctite on the screw will ensure that it never comes undone unless you want it too. Job done. It really is as simple as that. Assemble it into the chassis with the nylon gear on the r/hand side.
On this particular car we're going for the gear diff option. Simple, reliable and require very, very little maintenance. And for us, that rocks! |
| OK, assemble the rest of the transmission as per the instructions. Feel like putting hollow carbon gear shafts in? Don't bother...the shafts don't rotate, so the advantage of carbon ones is? Well there isn't one.
We use the standard steel ones. With all the gears in, put the 2 chassis halves together (Just rubber band them together) and then put an outdrive in each side of the diff. Now spin the transmission using the outdrives. You need to listen for any sounds of the gears scraping internally. 99% of the time there won't be. But if there are...you need to find out where. We've had to dremel out about 3 chassis in total, hopefully you'll never have to. No evil scraping sounds? Yay! Pull the halves apart and give a short burst of silicone spray inside onto the gears - not too much! Now, before you forget, screw on the battery holders to the chassis. You wouldn't be the first to forget... Then reassemble the lot. Don't tighten the crap out of the chassis screws. Just nip them up. Check to make sure that the gears spin freely again. If the chassis screws are too tight, the gears will bind.. Another thing that trips people up are the outdrive bearings. If they're not seated correctly then they'll cause drag. Check them - twice. |
| Assemble the front suspension as per instructions, but leave the uprights off for now. You might wonder why we're not using the stainless suspension shafts? Well, we aren't keen on them. The clips tend to come off, and to be honest we've never had any trouble with the standard ones. It's your choice, but we wouldn't bother with the stainless ones. It's just one more thing that can go wrong. Once it's all assembled, lift each side up and let it drop. It SHOULD fall under it's own weight. If it doesn't, you've almost certainly got some screws too tight. Just go through them one at a time. Sometimes the screws that are holding the arms together are the culprit, making the arm jam on the C hub lower.
If you haven't already noticed, we're using the M03M front suspension. It's the toughest of all and you don't need to use alloy uprights if you don't want to. However if you like the bling factor, the M03R blue alloy ones will fit straight on. |
| Now its time to deviate from the instructions a little. If you can afford it, get yourself some of the 53597 Universal joints. They're one of the few hot-ups that are worthwhile. They reduce a lot of wheel chatter while you're turning compared to the standard dogbones. Oh, and don't forget to put an 'o' ring in the outdrives before final installation. This will stop the outdrive from 'backing out' of the diff. Use a silicone 'o' ring not the rubber one supplied in the kit. The rubber ones deteriorate over time and you don't notice it because it's hidden from view.
When you're assembling the uni, make sure to use threadlock on the grub screw, or you'll be in a world of pain if it backs out while you're racing. Assemble the uni and the front upright together, and then screw that assembly to the front suspension. Make sure to not tighten the kingpins too much or the uprights will bind in the C hubs. Test them after installation to make sure that they're free with no hesitation. |
| Time to move onto the rear. Here it's a matter of personal preference to some extent. We usually mount our receivers in the rear of the chassis. So, what you see here is the receiver, wrapped in foam, about to go in. The foam prevents it being affected too much by vibration, and also ensure that it doesn't move around too much. You can still access the crystal and plug/remove leads easily. Put it in place, and then screw the chassis halves together. You might also want to put your ESC in the back as well. Once again, personal preference reigns supreme here. In this build our ESC will be on top of the chassis. By the way, anyone that tells you that it HAS to go inside or the Centre of Gravity is too high, is fooling themselves. It really has no noticeable effect at all, usually. Most of us have all gone back to top mounting again for convenience. And we haven't been able to detect ANY change in our cars handling since.... However, in high traction situations, that's when the C of G CAN be a tuning aid. So in that situation you may want to keep everything low. If you're running a Hobbywing brushless system then the ESC will need to go on top. It wont readily fit inside.
|
 |  | | Most of the rear suspension goes together as per kit, with..a few exceptions. The M03M and 2006 Cooper kits come standard with 2 degree toe-in rear uprights. We advise that you use these as they make the car much easier to drive. Or you can use the 1.5 degree bling alloy ones off the M03R.
If you like a really twitchy and hard turning car, then use 0 degree rear uprights. But most people are better off with the 2 degree. In this instance we've opted for a change from the standard fixed length upper links, and have installed the adjustable ones from the M03R. They only alter the camber by around .5mm, but it's a nice little tuning aid to have if you're struggling for rear end grip and nothing else is working. Once it's all together, make sure that the suspension falls under its own weight just like you did on the front. |
| Join the front and the back together and we have most of the car! Now you have some decisions to make. Shocks.....
The standard ones in the kit aren't great, you are better off switching to some oil shocks.
Now for some home truths, rc-mini style.
You do NOT need TRF shocks, by all means buy some if you want the bling factor (hey we all like some blue bits!) but they don't actually work any better than plastic ones. Nearly all of us run plastic ones here. Our recommendation is the 50746 plastic 'Super-Mini' shocks. Super-mini refers to the size only.... These shocks have a shorter body and you can set them up for super-low minimal travel, or with extended length to get extra droop. Get 2 sets because they come 2 to a pack. Get yourself some extra springs while you're off buying your shocks too. The 53333 set is perfect to start with. If you really, really want alloy shocks, get the 54000 TRF shock set which is specifically sized for minis. |
| OK, now to explain some things that a lot of people seem to get hung up on. On the far right in the pic is the super mini shock disassembled. See the little plastic spacer sitting above the shock body? That is on the parts tree that comes with the shocks. Slip that over the rod before you put the rod in the shock body. With that installed your overall shock length will come out at around 56mm end to end. This is around about perfect for a race mini and we'd advise that you start with this set-up. Leave the spacer out, and the shock length extends to 61mm end to end. This extra length (commonly called droop) is a valuable tuning tool if you're struggling for grip, or if you're running on a particularly bumpy track. The car will still settle to normal height on the short springs, but the wheel can stay on the ground better on bumps and such as the chassis rises and falls.
Now, build the shocks according to the instructions. Use the 2 hole pistons, or use any others if you want. Oil? The stuff that they come with is fine.
What the? Are you kidding?
No we're not. The bottom line here is that an M03 doesn't weigh very much, doesn't go all that fast, and more importantly the shock travel is going to be maybe 3-4mm maximum, if that. And, over that tiny distance the oil weight and amount of piston holes simply don't have time to have any significant impact on the shock performance. Yes there will be a difference between maybe 10wt and 80 wt, but what you need to remember is that there are other factors (like driving!) that will have way more impact than what the shock oil and pistons will have. How do we know? We've done back to back tests again and again....and it truly doesn't matter. Which is cool, one less thing to worry about! |
| "But I've got no money, I can't afford oil shocks yet!" Is a cry we often hear.. Don't fret, help is at hand. See the friction shock set-up above? It works... Just lob some spacers (fuel tubing or 'o' rings are fine) on the shock shaft to get around 5mm or so in total. Then assemble the shock as per instructions but cut the rubber tube to about 8mm for both ends. Yes, the shock shaft with the spacers fits INSIDE the black rubber tube, INSIDE the shock body. Make sure to lubricate the inner of the black rubber tube. Doing the friction shocks this way will drop the ride height a lot and they will work surprisingly well. You can even use the standard springs too. |
| Included in the shock pack are a set of ball joints. Screw these into the shock towers and lower arms on both the front and the rear. With these on you can snap your shocks on and off a lot easier.
Now, springs...Are you ready for another surprise? They don't matter as much as what you might think they do.. Generally we recommend harder front and softer rear. Say, blue (hard) front and yellow (medium) rear. And we swore by this setup for years. Then Tim just thought he'd try something different, and put reds (soft) all round. And...it still worked fine. In fact he put the car into 3rd place at the biggest meeting of the year! What we're trying to say here is that the 'correct' spring rate isn't as critical as a lot of people might want you to think.
Herein lies a lot of the 'problem' with Minis, people are so used to their Touring Cars being so critical and responsive to correct setup, that they assume the same applies to Minis, and it doesn't. With a Mini, generally 'in the ballpark' is going to be close enough, so don't sweat it. Mini is all about having fun and driving, don't lose sight of that. At the moment, all my cars are running blue front, and yellow rear - and they work beautifully. |
| This is the much maligned standard servo saver unit. To be honest it actually works pretty well and we're quite happy to use it. The optional Tamiya 50743 Hi Torque servo saver is...well not very good. Very brittle and prone to breakage. However, Tamiya have recently released a new alloy horn set (54120) that combines with the (51000) Hi Torque servo saver set and the combination of these two is very good. If you hanker for something more than the standard item, this is what we recommend you go for. Tamiya 53527 turnbuckles ARE a real good idea. Mainly for the adjustability aspect as much as the extra strength. If you install them as we have here then both sides adjust in the same direction. We have it set so 'forward = tighter' Makes it a lot quicker to adjust (and easier for us to remember!) |
| Umm, you'll probably be needing a servo round about now. The good news is that an M03 will work quite well with even a budget special one doing the job. But...well you know what we mean. You don't need a gazillion dollar super digital one, but a slightly better mid-range servo will be just that little bit quicker in response time etc. The one we've got in here is an old school KO Fet servo but its perfect in a Mini. Oh, the blob on the servo saver? Blu-tack (Sticky-tak in the US)...if the screw does work its way out, the Blu-tack will keep it from disappearing. |
| In this installation we've put the ESC on top of the chassis. Its actually slightly offset to the right and is only fixed to the right hand chassis half. The servo lead wraps around on the right hand side of the ESC and is held in place with double-sided tape for neatness. The reason its all biased toward the right is that this way you can split the chassis halves and not have to remove the ESC or servo, they remain on the right hand chassis half.
The leads run down into the hole between the front and rear chassis and plug into the receiver. By the way, if you want/need some really good double-sided tape, head down to your local auto parts supply store. The stuff they use to hold on car side mouldings is quality stuff and quite cheap too.
Now, what type of ESC? We've used a reasonably hi-spec MRT unit here, but that's only because we had one. You do NOT need an expensive ESC in a Mini. The TEU-101 that a lot of the kits come with is just fine. |
| Your mini will come with an RS540 motor, but if you want to go a little quicker (don't we all?) then this is THE motor for minis. The Tamiya RS540 Sport-Tuned (sometimes just called a black can)
These are perfect for minis and have pretty much become the default mini race motor all around the world. However if this is your first mini, stick to the kit motor initially. The pinion we've got on here is the 20 tooth (53509) flourine coated one. It's MUCH harder and will last forever. We've NEVER worn one out. |
 |  | Now it's time for some setup... With the motor and a battery in, put the car on a level surface. With the shocks assembled as per standard (and no external spacers) you'll find that your mini drags itself on the ground quite a bit. We obviously don't want that. Now we're not going to go into the absolute specifics of individual setup, what you want is for the lower arms to sit level with the ground, simple as that. External shock spacers will do that job for you.
Don't fall into the trap of measuring your ride height and becoming obsessive about it, going down that path will just end up leaving you confused. Start with the arms level and make subtle alterations to the ride height as necessary. If you cant get the desired effect with spacers, thats when you look at spring changes. Just remember, ONE change at a time, then test.... You want it just slightly higher at the rear than the front. The benchmark test here is that the chassis will scrape under racing conditions, but just a little. |
| If you've assembled your steering links according to the manual, they should probably look just like this now. Don't worry if they don't, each car is ever so slightly different. Now, note that you MUST adjust your steering links with the car at race height. Which means motor and battery IN the car.
Then look down from on top and adjust until the wheels are perfectly parallel. This is the best place to start. When first built the cars don't have quite as much freeplay, so parallel is fine. So, what happens with toe-in (wheels pointing inward) or toe-out (wheels pointing outward) Well, a little bit (1-2 degrees) of toe-out will make your car turn better. This is a valuable tuning aid when running Type A 60D's because they don't turn as well. Toe-in will make your car more stable in a straight line. But...try to opt for either parallel, or a little bit of toe-out.
Don't worry that the setting changes as the car moves up and down. This is a common fallacy. On the track the suspension only moves a couple of mm, not the 10 or so that it moves if you hold it off the ground. Don't spend ages shimming things or changing balljoints to get rid of the slop. It achieves nothing. The cars are designed to work with a certain amount of slop, it does NOT hurt them. Tighten it all up and your car will suddenly be awful to drive. Leave it alone, and concentrate on your driving instead. |
To space, or not to space, that is the question..... We've answered this elsewhere on the site, but it's worth repeating. It does NOT matter which wheelbase you run. Any one of them is fine. I repeat again - It does NOT matter which wheelbase you run
At our biggest meeting of '07, the top 3 cars were all different wheelbases. If that's not proof enough, we don't know what is. Go to the 'events' section for a full run down on that. Just pick whatever bodystyle you like, and the appropriate wheelbase. Here's what they look like just for comparison purposes. Some people will try and tell you that there's an appreciable difference between the wheelbases, we've yet to see proof of it. Sway Bars? Don't put any on to start with. Run the car without at first. You'll find that in 99% of situations you don't need them. If you're just starting out it's just another thing that will confuse you. Heatsink? Well...we don't think they actually work. Not the Tamiya factory one anyway. The only heat transfer is through the two mounting screws. It's just dead weight although the bling factor is nice. Wheels? Well the Swift wheels are the strongest of the Tamiya ones, and HPI are easily the best of the aftermarket. Your choice.... Tyres? We can't even begin to unravel this one. So many differing surfaces make this a minefield. Talk to other local racers, see what they run. Now, get out there, and DRIVE! |
