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S.Stew 11-24-2014 05:28 AM


Originally Posted by Pulse_ (Post 13677285)
Hi, I'm back in 1/12 after this long outdoor season. Just raced my 12R5.2 yesterday on a new track in Belgium (MRCC Charleroi) and we had a lot of fun.

I have a few "noob" questions

- what are the minimum and maximum tire diameters to drive in good conditions? is this range of dimensions different compared to a tire that will allow the best performances?
Very generally, Larger tires are better for low grip, smaller tires better for high grip. When grip is high, smaller tires can help prevent grip roll. For club racing, I start tires at 41mm Front, 42mm Rear. You could use them at a larger size, however larger tires tend to chunk easier so there isn't always value in running them big.


- is there a way to prevent the sides of the tire foam from being damaged?
Running them at a smaller diameter is the best way to prevent it. Otherwise you can use a thin coat of CA glue on the sidewall, but this will change how the tire works as the glue stiffens the sidewall.

- what are the minimal and maximal ride heights for front and rear?
I usually don't go any lower than 3.5mm front or rear and not higher than 4mm. If the track is really bumpy then maybe a bit higher - 4.5mm.


- what are the tires (compound) to always have in the box (indoor carpet)? local tracks are very tight in dimensions and I'm using magenta/pink jaco right now
This will depend on what class your running. For stock, Black/yellow or Black/Graylow seems to work just about everywhere. Lately we've been using Blue or Green rears and black/dbl blue/blue fronts depending on how much steering we need.


- what bodies do you recommend for small tracks? just need a strong one
The Protoform 12th scale bodies seem to hold up really well. I just started using the Strakka and it's a good bit more durable than what I was using.


many thanks!

My Answers/opinions in Red :nod:

jdeadman 11-24-2014 05:30 AM

1) For club racing I run a Larger tire for longer use of each tire. Usually start 44mm and run them down to the wheel.
Fronts I start at 43 and run them till they are no longer useful usually about 40mm

For big races Rear 42 fronts 41

2) Making them smaller is the best way to limit "Chunking" Also you can runa bead of CA on the edge but as the tire flexes it will break off and you will have to keep on applying it .

3) min is 3mm F/R All depends on the track I run for our club racing 4mm (it's bumpy)

4)That all depends on where you run but kepp a set to test with from yellow right to Magenta Rears and pink to Black fronts once you find the right tires for that track you will not change much

5) Any of the Protoform Thick (.030") bodies will hold up. but are heavier and again it depends on the class you are running (Stock or Mod)

metalnut 11-24-2014 08:18 AM

Not sure if you guys are aware of the trick to prevent sidewall chunking that I picked up from a local mod driver... when you're done cutting the tire down, go at the edges with a file. I'm not talking about just rounding the edges... you go in at a 45* angle first and grind down until you start grinding the outside rim. You do this on both sides and should see a white line as the wheel spins (if you're using white rims). You then round the foam from there. This creates funny looking tires but it protects them from chunking as the rim takes any hits first.

Pulse_ 11-25-2014 09:18 AM

thanks for the answers :)

as a side note I'm running 10.5 stock for now

just need to find some used sets of tires to try them out

if anyone has a few sets in different compounds for sale (europe), let me know ;)

what happened with corally? are they still releasing 1/12 pan cars? just went on their website and there are no kits there anymore

BoneCrusher 11-25-2014 11:45 AM

Trackstar 13.5
 
Anyone successful finding a good motor timing and rollout for 13.5 Trackstar motor in blinky 12th scale?

Thanks,

Ivan

SlowerOne 11-25-2014 01:40 PM


Originally Posted by metalnut (Post 13676737)
I'm still running the 3 kit washers on the front. I didn't realize those could make a noticeable difference, that's something I can try too. And yes, I'm running 2mm washers under the castor blocks and the shorter top brace from the 12R5 kit. I do realize that slows camber gain and thus makes the car lazier, though I admit I haven't try to run it with kit setup. That's something I can try too.

Thanks for all of the ideas guys, stuff I should have thought about but didn't!

It's not the camber gain that makes the car more reactive, it is the raising of the roll centre. A roll centre closer to the CofG allows the car to transition side to side faster. Camber gain is a bit of a mirage in 12th cars - look at the success SpeedMerchant have with their car on fixed camber with no gain.

The front suspension compresses maybe 1.5mm or 2mm at the most during roll. Move the front suspension that amount and look at the amount of camber that is gained - it is very (very!) small. The real affect on transition is that the shorter wishbone effectively raises the outer pivot and that in turn raises the roll centre.

I recently went back to kit set-up at the front with one washer inside on the front axle and the car flicks easily left to right, turns in and rotates well and is much more responsive to drive. Give it a try...! ;)

metalnut 11-25-2014 01:55 PM


Originally Posted by SlowerOne (Post 13680819)
It's not the camber gain that makes the car more reactive, it is the raising of the roll centre. A roll centre closer to the CofG allows the car to transition side to side faster. Camber gain is a bit of a mirage in 12th cars - look at the success SpeedMerchant have with their car on fixed camber with no gain.

The front suspension compresses maybe 1.5mm or 2mm at the most during roll. Move the front suspension that amount and look at the amount of camber that is gained - it is very (very!) small. The real affect on transition is that the shorter wishbone effectively raises the outer pivot and that in turn raises the roll centre.

I recently went back to kit set-up at the front with one washer inside on the front axle and the car flicks easily left to right, turns in and rotates well and is much more responsive to drive. Give it a try...! ;)

I think I remember reading something along those lines a while back, thanks for the explanation. At this point in time the car needs something to make it come alive, so I can give all these ideas a shot. It's a bit weird because my buddy is running the same car with an almost identical setup, and his apparently carves corners. I'll have to swap with him and see... maybe it's just my driving "style" (and I use that term loosely) that's the problem.

marcvanderzon 11-25-2014 02:25 PM

Hi metalnut

Add reducing droop to your list. It has helped me a lot with increasing steering and in general just helping the back end of the car rotate.

Thanks

Marc

metalnut 11-25-2014 03:38 PM


Originally Posted by marcvanderzon (Post 13680941)
Hi metalnut

Add reducing droop to your list. It has helped me a lot with increasing steering and in general just helping the back end of the car rotate.

Thanks

Marc

I assume you mean pod droop? Below 1mm?

EDWARD2003 11-25-2014 04:21 PM

Here in Japan there's a top Yokomo Factory driver who runs an associated front end. Check out his setup.

http://www.teambomber.jp/waistmountain14.2.16.pdf

The above setup is for asphalt. Please note : The upper arm block (castor block) is not a standard associated block, it's one of his own designs, which you can buy. It has various offset positions that you can use. What it does in the above and below setup is it moves the upper arm pivot point +4 mm outward. This allows you to maintain the same camber gain you were previously running but also run wider front track which will offers more front stability.

The below setup is from the Japan Nationals stock class. This car was on rails, and posted the fastest lap and could of easily won the title if not for a few driver errors.

http://www.teambomber.jp/R12_Bomber_20140706_kuroda.pdf


I tried his castor block setup and used this setup. Stupid me, I placed the blocks in the wrong orientation (Japanese Kanji is difficult to read off of paper, where were you Google Translate!). I ended up moving the pivot point - 4 mm inwards. This basically eliminated any for of camber gain. The slow tight infield sections were fine, however, the high speed sweepers and infield sections it pushed hard like a dump truck. And I mean HARD.

EDWARD2003 11-25-2014 09:22 PM

Kyosho Plasma revisited... I'll be honest I kinda gave up on this chassis. I couldn't figure out why it was handling the way I wanted it to. Lone behold it was my lack of knowledge of 1/12th setup that was the main factor. Obviously. :)

Ever since switching over to R12C3, I've learned a lot and still learning. So, all the knowledge I've gathered and put into my Plasma Ra. I went back to the chassis and looked over everything... First off...This will sound embarrassing, I thought all the shims in the bag were required to make the track width 172 and 168.. So I used them all... Boy was I wrong.. Little did I know, my track width front and rear was out, and I mean way out. The rear was 182 mm and the front 174.. Talk about dump truck.

I removed all the spacers with 172 mm rear and 166 mm front.

Afterwards I did a test run. What difference it made. It drove so much better, but it still needs more work.

Check out how she handles now. I might add an additional 1 mm spacer to widen the front a little to help with stability.

https://www.youtube.com/watch?v=1gFuFbG_eCo

InspGadgt 11-26-2014 12:48 AM

Not bad...looks slightly loose

EDWARD2003 11-26-2014 05:00 AM

Temperatures where in the 10 degrees Celsius range and I was running TR-12. The AMR should cure the mid corner oversteer.

marcvanderzon 11-26-2014 09:00 AM


Originally Posted by metalnut (Post 13681103)
I assume you mean pod droop? Below 1mm?

Yip pod droop. I adjust up and down to get a nice balance. Some people at my track run 0 I run about 1.5 but its an outdoor track with some bumps so carpet may be very different.

Never seen much written here about front suspension droop. Not sure it's something that you adjust on a 1/12 car.

RedBullFiXX 11-26-2014 09:04 AM


Originally Posted by EDWARD2003 (Post 13682067)
Temperatures where in the 10 degrees Celsius range and I was running TR-12. The AMR should cure the mid corner oversteer.

Looks really good imo
I too like the TR-12


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