GT12 Racing
 

The BRCA rules can be found here. It is not a national class in the US, yet.

We will be trying the GT12 class in Madison, WI @ MARCCA this fall. There are technically 2 classes, but as the rules state: if there are less than 20 entries they run together sorted by qualifying times.

The 2 classes are GT12 Super Cup and GT12 Production Cup. Most if not all of us are going to set up for GT12 Super Cup (13.5 1S blinky with diff allowed). We've been making a lot of noise in the SupaStox thread as that seams to be the preferred chassis, but the class also allows Mardave and TIC cars. Rumor has it that Zen Racing will also have a chassis soon. Our club will also allow 21.5 2S to start with a change to straight 1S at some point.

Just so everyone knows what the costs are like, the chassis with tires must sell for less than 100 British Pounds (163.00 at this moment). If you haven't had a look please check out the SupaStox thread. You need a painted body, electronics and you're set to race. The diff makes rear tire wear very low.

The bodies are very realistic as are the tire widths and diameters making this not just a great racing class, but one that is fun to watch.

Anyone have a timing setting for 13.5 1S on a Turnigy Trackstar?

All the way up...grind...up some more.

Nice! I did find a post saying that max timing is roughly 40*. I think there is enough motor there to keep up with the rabble.

Transferred from the SupaStox thread. ;)

Don't turn it right up! These cars weigh 950g, or about 30% more than a 12th car. Go as high as you can without giving the motor a caning, and make absolutely sure the motor peaks out half way down the straight.

It is all too easy with these cars to wind them up and think they are going fast, when in fact all you are doing is piling heat into the motor. They have to be geared down in order for all that weight to be accelerated promptly and the motor to peak out on the straight. HTH :)

I was thinking about setting rollout to 75mm and adding 1 timing mark at a time. I have the motor checker with, but even with a slave I'm not sure I'm getting real results when I tune the motor for 1S. I would think efficiency is efficiency at reduced input voltage. I'm replacing my Z3R as I'm trying to prove a point about cheap club racing.

I started collecting parts today for the supastox to run GT12. Picked up four 13.5T motors in a cheap package deal: 1 used- Reedy, 1 used- LRP, 1 new/ 1 used- certified 5% D3.5s w/ 2 extra tuning rotors. I already have 2 Speedpower 6500mah 70c 1S lipos. Ordering a Trackstar GenII 120A 1S ESC soon, kind of annoying that the program card is only available from China...

I'm assuming MARCCA racers don't need to worry about the BRCA approval lists:
motor list
http://www.brca.org/sites/www.brca.o...0v6%20pdf1.pdf
battery list
http://www.brca.org/sites/www.brca.o...14%29%20v4.pdf

If you think it's still in good sportsmanship, it should be alright.

Nice second chassis John...seems to go just fine.

Well the batteries are on the approved list at least.

The wife will be piloting the supastox, so it will be turned down to her comfort level. So the D3.5s shouldn't be a problem. I can't pass up a good deal when I find one, especially on my budget. I could put the Reedy Sonic in considering it's on the approved list, but it has a full season on it... Compared to the D3.5s were one is new, and the other only has Snow Birds on it in a 1/12th scale...

The Sonic should be too. Tear it apart, clean the bearings and it's good as new.

Third chassis in the works, full upgrades and diff. Comes with an unpainted G903 (Audi) body.

Last night I ran car 2 for the first time. Trackstar/Turnigy electronics and motor were very quick. A few quick tests on the motor checker to get the timing better and one gear change and off it went. Very quick on the straight! Came off at 117* after 8 or 9 minutes of nose to tail running with celt's car. I was not driving as my trigger finger may be broken, so thanks to Tazio Nuvolari for stepping in.

I may do that to the Sonic, she doesn't need anything faster then that anyhow. So at what point does a motor need to be retired? any obvious signs? I recall reading somewhere about the magnets weakening with age or something like that?

Third chassis, nice! So you now have 3 supastox and Stan has 2 right?

If anyone comes across a used supastox for a decent price and doesn't want it let me know! I haven't bought a kit yet... try'n to do this on the cheap.

Don't have my second yet...

Dang still waiting huh, that's no good. Someone needs to light a fire under that guys you know what! People...

You got me pushing forward on the supastox, the close controlled racing is to much fun to miss out on!

Oh crap, I PM'd a guy about an assembled supastox kit w/ unpainted body during lunch. Just realized that's probably the third chassis your referring too. Did you buy it already? I haven't heard back from him yet.

Well, I can't corner the market, but I can keep my eye out for fair deals. My intention is to sell the 3rd one to a club member. I'll know more once I have a shipping date or better yet car in hand.

I PMed him last week as the last update was June 27. He PMed me, It's paid for.

Ok good to know... I saw his post this am saying still for sale and got excited. Then I realized the car you described was one in the same:(...

Let me know how much you want for it if your selling it. I don't need the body, I want to try the Protoform.

No worries, should be today.

https://encrypted-tbn1.gstatic.com/i...V_jaDZk_0aWmAw

PFM-12

Well, MP4-12C anyway. In Stan Garvin orange.

Stunning, no?

I ran a Dynamite and Reedy Sonic Mach II in mine. The Dynamite was on about 30deg at 68mm rollout and the Reedy on 35 deg with 65mm rollout.

The Reedy was better across the run, but initially I over-geared it at 70mm rollout. When I realised it was not revving out on the straight and dropped the ratio to 65mm rollout, it was better all round.

Every motor/timing combination is different, but I feel that 75mm is too high on this car. Taking the weight and the inefficient suspension into account (there's more wheel scrub and you have to slow into the turns as the car is more inclined to rollover in sharp direction changes) a lower rollout allowing the motor to rev and pick up speed quickly was faster round the lap. YMMV. HTH :)

You might even have to paint up some black wheels.

Last night I ran my Reedy at 64mm RO and it was indeed perfect.

Not much I don't like about the car actually. I value the simplicity and durability.

Our cars were pretty evenly matched and mine wasn't lacking acceleration. What was your timing and tire measurement? I have to get a new caliper... The Trackstar goes from it's zero point and maxes out around 35* actual. It also happens to be the point where I get an additional 2000 rpm at a cost of 1.6 Amps compared to the out of the box 19500 rmp @ .8A. I actually went from a 31 pinion to a 33 pinion and motor temps were still unreal, 117* @ 8 minutes. Rollout was somewhere near 71mm.

Absolutely. I've ordered some. Being made here in the states, I will guess it's the body of choice soon.

I will guess that once you have tried a Kamtec Ascari body (also sold by Schumacher as the Type A) it will no longer be the body of choice! ;)

Running the "light" version of that body now.

Awesome!

955g, running weight.

Reedy 13.5@35 degrees
70/32
46mm rear diameter

Tim was getting me just a pinch in the long straight, and I was getting it all back in the infield.

That's called racing...

It was pretty intense and fun to watch. Tim said go taller, but I don't see why. Any taller and loses punch. I thought the gearing was just about dead on for both cars.

I have a couple F types, regular weight and they're nice. Good looking and perform excellent. I have a Supastox with the Audi body coming and will get to try that too (or a fellow racer). The Ascari is very nice though and A main and Stormer have them. These are nimble little buggers that are just pure fun to drive!

awesome!
 

Added I think two or three more drivers to the GT12 class.

Trigger finger is still fudged. Wish I'd have been there to help push them in the right direction.

2 more racers now have cars. All SupaStox so far. 1 car needs some new tires and a GT body. The other was an almost finished kit in need of a couple more parts, electronics and paint. It will probably be ready for next week. My pair went through some more shakedown and are ready to run, I wish I was. The action is very intense with nose to tail racing and normal occasional bumping is not a problem. The cars can handle a tap and hold their line. I watched 2 of our guys run for 19 minutes swapping the lead a few times per lap. 1S 13.5 speeds might be a little intimidating beginners, but very easy to get used to. Looking forward to our first actual race day!

5 cars on the track at once, some fast in the infield, some fast in the straight. Its a dogfight every lap. If you have not studied the class, now is a good time! Soon we'll easily be able to have 10 or 12 a time. What a great feeder course for LMP 12th scale classes.

We ran an actual race day with this class and had a blast. With 13.5 1S the cars are deceptively fast, but allow for great racing. Everyone is running Schumacher SupaStox at the moment, but always room for a Mardave or TIC. The cars can take a beating and keep on running if the occasional accident does occur. We now know the best kept RC secret the UK has has been holding back (or we've been oblivious to). If you have a chance to drive a GT12, do.

Any more racing stories, results, setups or car demos to post? Let's hear about them.

Bump!

GT12 is going strong in a couple places other than the UK. We're still growing the class locally. We now have a racer with a Zen. It looks promising against all our Schumachers.