@Eelen: Yeah MS PRO is quite a balanced and fast chassis, though I had to set the front angle to 10 degrees with O-rings on the rollers to clear the track. Roller width/length: 95mm/130mm. Motor used was Torque-tuned (3.5:1) with stock terminals and no bearings in the gear. For the double jump so long the car is fast enough it should clear it without problems. The trick is to fly over the 2nd jump.

@TMY KIA: Frm the pics and the specs your car is ok. You might wish to use bearings and gold terminals for your chassis. Roller-wise I'd advised using rollers of similar diameter for front and back. Since the smaller the diameter, the greater the rolling resistance. In other words your front rollers are actually impeding the rotation of your rear rollers, resulting in a slight loss of speed.

Zippo Lighter fluid won't damage your bearings. Just suspend your rollers inside the liquid and let it sit overnight the dirt and all will settle at the bottom.

For the height of your rollers it's good to have the front set of rollers positioned in line with the axle of the car. Since this is where your roller is in line with the centre of gravity (in most cases) and little energy will be lost trying to balance the car if you set the front rollers too high or too low.

Ultimately the speed of your car should be relative to the track. setting and the motor. When I used to raced last time I'd always used a small 2 lane track (consisting of 8 curve pieces and 2 straight pieces) and I'd let my car run on the outer lane for 15 laps to test the speed of my car. If your setting is efficient it should be able to complete 15 laps with Torque Tune in around 11-12 seconds.

@GL91: I stay in Singapore so I cant answer you. Chassis-wise MS PRO is supposed to be the fastest chassis around (theoretically) but each chassis has its own pros and cons. If Super FM is for tech and TZ-X. VS is for speed, the MS PRO should be somewhere in between.

Edit: Copper > gold for electrical conductivity, so should stick to stock terminals. Apologies for mistake

This post has been edited by 13lack.12ose: Feb 14 2009, 11:37 PM

@David: Thx for the compliment. Don't think I'm a master lah, just sharing what I know with you guys. I am sure I have alot to learn from you all as well ^^.

@TMY kia: No Prob. Wish you luck ^^. Usually I remove the front bumper of my chassis so that I can set my front rollers much lower.

[quote=david tamiya,Feb 11 2009, 08:26 PM]
[quote=13lack.12ose,Feb 11 2009, 06:36 PM]
@David: Thx for the compliment. Don't think I'm a master lah, just sharing what I know with you guys. I am sure I have alot to learn from you all as well ^^.

i cant teach as well as u

[/quote]

I'd be in KL on the 18th and 19 Feb. Hope will have time to go down to TU

No Prob. Will be leaving on 19th evening so hope have afternoon to play @ TU in the afternoon.

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Added on February 12, 2009, 9:15 pm
Some tips and ideas I'd have. Feel free to discuss and correct me if I am wrong. I based my settings on Tamiya rules so I might not be able to share much on other settings which I am not familiar with.
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Roller Settings

Maximising Cornering Speed via Tilt Cornering: Roller Width 105mm, Roller Length 110~125cm Front roller in line with centre of gravity/ car axle. Roller angle should be at minimum ~ 1-3 degrees. Front roller Height < Rear Roller height. 3rd set of rollers (balancing rollers) is optional but should have a smaller diameter than your main rollers. The aim here is to achieve a tilt cornering, ie the outer rims do not touch the track at all during cornering, greatly reducing cornering drag. A narrow wheel base would allow for an easier tilt, though a wider wheel base can achieve a faster cornering if tilt cornering is achieved.

Tech Course: Roller Width 90mm~95mm. Balancing roller preferably placed in front as low as possible (ie having faster reaction time for the car to return to track during a jump). Angle should be 5~10 degrees depending of difficulty of track. O-rings and rubber caps for rollers can be added to help the car stay on track. (Might not be the fastest setting to clear tech tracks, just based on my own experience).


Reducing Resistance:

Resistance is what slows your car down. There are many types of resistance: i) contact friction, ii) weight, iii) aerodynamic drag.

i) Contact Friction- Points of contact for moving parts should have as little resistance as possible. Using ball bearings for all moving parts is essential. Place a spacer (those used for ball race rollers) in between the wheels and chassis help reduce contact friction.

ii) Weight- Contrary to popular belief, a heavier car might not be a more stable car. I'd be using a bit of science here to explain.

For every action there will be an reaction. ie a force that acts in the opposite direction to the forward applied force. All cars have a centre of gravity (CG). This CG remains at rest if the car is at rest. However when the car moves forward the CG will move back. Thus this explains why SFM are very good for tech tracks.

Now we look at the equation F=ma, where F is the resultant force, m is the mass of object and a is the acceleration. If our cars are heavy, this means our m is of a higher value. Given constant acceleration, the heavier car will have a greater momentum when it jumps thus making it fly further.

But what do we have to do in order to let our car remain light yet stable (in terms of weight). The answer is to shift the CG as close to the front as possible. This is why SFM and MS PRO are considered quite stable chassis. Either that or use mass dampers (old school set up of stacking rollers in stabilising pole is an example of this) that can alter the position of CG during jumps. Besides, a lighter car can achieve better acceleration and reach top speed much faster.

iii) Aerodynamic Drag

An aspect I feel many seldom pay attention to. Try using covers that have as little perpendicular surface as possible. This is why covers with low ride height tend to run faster as well. Some good covers would be Strato Vector, Tiger Zap (Super FM, TZ) Astute, Super Avante (Zero, VS) as well as T.Shot Mk II and Veldaga =P (MS PRO)

Having "tunnels" on the covers (air intake > air out-take) will create an area of low pressure inside the tunnel, creating downforce. Secondly the air coming out from the tunnel will also give that extra push to your car.

This effect was tested on my old Boomerang Fury with a ride height of only 2.5cm. The time without cover was 0.5s slower than when I put the cover . I intend to add this to my currrent ride when I can find clear plastic pla-plates.
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This post has been edited by 13lack.12ose: Feb 12 2009, 09:20 PM

@ freedom: lol paiseh. But I assure you take your time to read it would help you much

Haha, then study hard la

@ sonic_cd: You're right. Goes to show how the designs of recent tamiya cars sux (exception Avante and Thunder Shot Mk II)

@TMY kia: Np, share share tips so all can improve on the car, only then can the hobby grow ^^

Eelen you going for the Khatib race tmr?

Consider it done, setup wise will have to ask the winners tmr, unless I am one of them

Anw, just want to confirm if the terminals used on MS Pro chassis are made of copper. Cuz I just did a check and copper has a higher conductivity than gold.

see you tmr then.

Hmm if this is the case how come there is still gold plated terminal? I know for old chassis (Super 1, TZ) they used brass or something else, thus the need for gold plated terminals. But since we now have copper terminals then aren't gold plated terminals unnecessary?

Btw Happy Valentines Day dudes and dudettes

Yeah agreed. Stock Terrminal on MS PRO > Gold plated terminal

X2, that is why it's gd now that we have such forums to share tips for every mini4wd ethusiasts to improve their cars

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Added on February 14, 2009, 11:10 pmWorking in a shop with few customers has its privileges besides getting to ogle at ladies. This is what I've found whilst serving the web on slot cars (not Mini 4wd, but those that you can control with a wire trigger) to see if there are any useful info.

http://slotcarillustrated.com/portal/forum...isplay.php?f=90

Lucky find. In actual fact, motor layout for MS PRO, and rear/front mounted motor can be called inline and sidewinder

And this is the best find I feel worth sharing:

How Torque affects weight transfer: http://slotcarillustrated.com/portal/forum...ead.php?t=27555

Much implications, because this means that:

1. for MS PRO chassis, the torque from the motor will actually "lift" the left side of the car
2. for rear motor chassis like VS, the torque will press the front of the car.
3. for SFM, the torque will lift the rear car (another reason for the superb stability on SFM)

Another one worth sharing would be:

Tyre width and traction comparison: http://slotcarillustrated.com/portal/forum...ead.php?t=26725

Yet to digest it and see how it can be applied to Mini 4wd, though I feel it would be helpful.

This post has been edited by 13lack.12ose: Feb 14 2009, 11:46 PM

Nono, Sliding damper works by changing the direction of the car during cornering, thus improving speed. I have been using this part since I started competitively back in 97.

We know that if front roller width> rear roller width the car will be faster during cornering because the direction of the car is shifted away from the track wall and more towards the direction of the turn. This means the tendency for the car to push against the track wall during cornering is less, and energy is more efficiently used for turning.

Using sliding damper has 3 advantages:
1. Faster cornering speed: Sliding damper works on the above principle during cornering. In fact it helps in wave sections as well since it smoothens the rapid change in direction.

2. Best of both worlds: Because sliding damper only changes direction during a turn, you can maintain an equal roller width for front and rear on straights---> good for jumps and straight speed

3. Absorption: It can help absorb centrifugal force experience in a turn, making the car more stable.

Do note though for effect 1 it only works if you install the sliding damper at the rear. Putting it in front will have an opposite effect.

Do a small test and you'll see

@B-mecha: The new part has a wider width so when you install 13mm rollers the roller width will be the maximum of 105mm. Also the material used is reinforced ABS so it is less prone to bending compared to the old sliding dampers.

This post has been edited by 13lack.12ose: Feb 15 2009, 12:29 AM

Surething! Looking forward to it

Now modding my chassis for tmr's race

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Added on February 15, 2009, 1:29 amBtw David, do you think it's good if we set a car that can be used for testing various effects next time? In this case we can have 2 cars, 1 car used as a control whilst the other is used to test various mods and effects.

This post has been edited by 13lack.12ose: Feb 15 2009, 01:29 AM

lol ok. I think stock is gd then we can limit the variables and get individual results of our testing more accurately.

I hate mini-humps, I hate mini-humps. Hyper-dash took my SF to the moon, and torque tune showed us how to somersault a mini4wd (Yes, somersault).

Even till the very last minute and the very last ticket, the scorching sun did not dampen our will to clear it. So close yet so far away. When we thought we'd be getting a new record, the 360 degrees loop+ hump hammered the very last nail to our determined but futile efforts.

But what falls will rise again. As the night beckons our racing spirit resurrected and we fathomed the unthinkable---> using hyper-dash pro on fresh batteries to conquer the dreaded bridge lane change.

And succeed we did.

After a day of scarred cover (yes, the mini-hump gave my SF a nice long souvenir), flying wheels and tyres, I have to say, it was a glorious day indeed.

Chill la boss, the pics are with Eelen. Give some time la

Btw I am keeping the setting when I tested the hyper-dash so when we are at TU this week we can test again.

Photobucket is still taking centuries to load its photo uploader so I shall do a quick reply here b4 posting the settings I used for the previous 2 races.

@Eelen: Thx for the pics and the mass dampers. It really helps in the mini-hump. And the tyre too. Yesterday night after helping to keep the track still cannot find my tyre.

@David: Ok. I will let you know tmr what time I'd be going. Will be bringing my car and a hyperdash/ torque tune. Buying parts too

@B-mech: Nice meeting you yesterday. Perhaps we can go to Stargek when we both are free for parts.

@TamiyaAye: There is no best chassis imho, since the positioning of motor will affects its centre of gravity and torque bias, leading to different characteristics. Thus, there is only chassis best suited for a particular track. If you are more into the technical tracks Super-FM would be your best bet. If you are a speed freak like me 1. MS-PRO, 2. TZ-X and 3. VS are gd (in order of personal preference).

@TMY Kia: You see the track pics the mini-hump I kanna killed there

@Kay86:
Ans1: I would opined that since friction in ball bearing is negligible, the larger roller would have a faster cornering speed. Reason 1: larger circumference leads to better track-to-track movement (since tracks have slight irregularities at joints) Reason 2: larger rollers have less rolling resistance ie less energy loss (for same distance travelled, smaller roller needs to spin more). Of cuz this is if u do not put O-ring on the large rollers.

Ans 2: Get 2 rulers and place the edge on the centre of front tyre leading to the centre of rear tyre. You will see that it coverges into the centre. leading to straight running stability. Thus, Narrow front wide back will improve straight running. Conversely wide front narrow back will improve cornering (not recommended). Using narrow tyres will naturally reduce drag thus leading to faster speed and longer battery life. Narrow all: speed>stability. Wide all: speed<stability (converse for tilt cornering).

Ans 3: I feel 12~13cm (the setting I run in, depending on rollers I use) gives the best bang for the buck. A shorter roller length will allow for more fluid corner/wave transition, whilst a longer roller length will improve on the stability of the car, esp @ bridge section.

Ans 4: Tilt cornering is dependent on the centrifugal force as well as relative positioning of your CG and rollers. The moment your car exits the corner there will be no tilt and the car will naturally rest on 4 wheels. With the length of the jump, your car should jump straight no problems.

I see Tom Ghody Special, Liberty Emperor Black Special and Big Bang Ghost all 1st edition releases

Setting on 08 Feb 09 @ Tampines:

Winning Bracket: 21.69s~22.42s (6 placings, all SFM)
My time: 22.76s




Motor: Torque Tuned
Gear: 3.5:1
Roller Stats: Width 95mm; Length: 130mm; Angle: 10 degrees (might have slight error, since I used a 10 degree spacer but did not take into account of chassis angle)

Setting on 15 Feb 09 @ Khatib:

Winning Time: 25++s (too tired did not remember)
My time: none

Setting used to clear mini-hump:

The mass dampers worked wonders for the mini hump on my car. Need help and tips on clearing mini-hump. Much Appreciated.

What is the diameter difference for your rollers? Prolly a pic would be good too. Usually you would want your car to tilt only very very slightly. (2mm difference for top/btm roller diameter.)

I presume you are single front double back roller setting. If this is the case yes shifting the top-back rollers up will reduce the tilt. But it would be better to lower the btm-back rollers since too high a roller position (esp for tilt cornering) is a tat too risky. Setting your rollers low gives a bit of inert downforce and speed as well.

I suppose your tilt when jump is right turn---> right tilt down, left turn---> left tilt down?

This post has been edited by 13lack.12ose: Feb 17 2009, 08:56 AM