GT12 Help..
 

Hi Chaps
A couple of questions about GT12 if I may

I ran for the first time last night at a meeting; my overriding issues were as follows, if anybody can shade any light.

Steering was extremely sensitive, front end digging in and making it a touch lively with the back end; Is this toning down the sensitivity of my steering dual rates? What do people have theirs set at generally? I also went harder with my suspension on the rear, mistake, softer was better!

Secondly, my diff/pinion mesh seems to make a slight grinding noise, but can't seem to figure out what it couple be? Could this be a bent drive shaft possibly? It seems to grab/grind at a certain point if I push along un-powered.

Any help or advice is greatly appreciated in advance.

Best Wishes
Stuart

Stuart, can you tell us what the car is and what the current basic setup is you have on it?

There may be many things so knowing what you have started with will narrow it down... a lot!

GT12 cars all handle well and are great to drive once you have the setup sorted. Give us a bit more info and we'll have you going in no time. :thumbsup:

Sounds like an SSGT.

Go to 50 front tyres and yellow rear springs. And reduce droop to 1mm all round.

The kit spurs aren't very true. Set your mesh at the tightest point on the spur so there's just the smallest amount of play. Or replace with one of the machined spurs.

Join the gt12 circuit UK Facebook page loads of info and help on there too 1500 + members

First up, I'm not on Facebook. Maybe one of only a handful who are not!! :cry:

Thank you guys for your replies...
I have ordered 50's for the front, and i will definitely apply the suspension change.

Regards to the setup I have;
I have hopped up the side damper conversion kit, but that's about it.
I had stuck with the standard setting that was applied when I built the car. When softening the suspension before the car definitely handled better, stupidly I went harder on the back during the meet and it definitely got worse. Stupid boy!

What I noticed with other cars was, a distinct lack of body roll which inspired me to harden my suspension at the time and other cars seems to have an element of drift of all for wheels during cornering.

The other question would be the amount of break people apply to their ESC, I have relatively little set (Toro 1s ESc) and I barely used as I suspected it would make it even more tail happy!

Look forward to your thoughts chaps.

Best Wishes
Stuart

The harder tyres will reduce your body roll (as the car will slide rather than roll).

Other major factors are ride-height (3.5 to 4.0mm depending on how bumpy the track is) and body height (see if you can trim the shell at the bottom and lower it on the posts).

Thats a great tip dale.. Trimming the shell...
Never thought of that, but I have to say, mine did look a little like a bus compared to a few others!! Will give that a go!!

Thanks...

Just check EVERYTHING on the car. Things like droop/tweak can be very sensitive on these cars, even a slight change on toe-out or ride height can make it handle completely different. If you're saying it's turning in hard then a slight amount of toe-out can do that.

You just need to look over it with a thorough eye.... and then get some of the quick boys at your local club to have a look too. There's not much people can suggest in less you post a full set-up sheet and then it would still be tough without seeing the car!

Thanks Dan....
Being new to the GT12, the more you read the more I get to see what people are talking about and how they set their cars...
It appears that the suspension springs is pretty constant throughout, green front, yellow/blue back.
Tyres give or take...
Droop seems different, i hear many say 1mm, some appear to have 2mm.. Where exactly do you measure the droop angle from?

Gosh, so much to learn... When I get back tonight, I will get the setup and post.. See what you all think..

From my untrained eye, my car looked - soft (body roll) too much grip front end... Very twitchy, turned on a sixpence and felt i could barely touch the steering down the straight as it would unsettle the car and make it roll... (Not that this happened, but that what it felt like)

Hope that makes some kind of sense... As i say, will post setup tonight..

Stuart

If you mean 'drag' brake, then Non.

With today's rotors it's not needed. If you still have to much just reduce your end point from 100% to 95% and so on until you find how much you like for a given track.

Another thing I found was to move the rear spring's out rather than the kit inner holes

Foam Tyres & Additive
---------------------------



Fronts
from the inside edge apply for 1/4 width and go from there. More width gives more steering. Apply lightly, they don't need to be ringing wet

Rears
full width all the time and wet but not dripping

Try to apply rears addy at 20 minutes before applying front

Foam
Make sure you have a radius on the inner and outer edges.


Some good info in here
http://www.brca.org/sections/subsect...-articles/1144

BRCA rules are that you don't trim the shell and lower it. Trim to the lines on the shell is all that is allowed. If you are never going to race a BRCA Regional or National then fine. Having tried this the biggest impact you can make is a lightweight shell - lowering the shell isn't that effective.

The lower-grip set-up in the instructions works for everyone everywhere. Changing tyre hardness is the best change to suit the conditions. If you are really stuck, then front springs are the next change.

It sounds as though there is problem with the build that is giving you issues, but let's see when your set-up comes on to the thread.

So... My setup...
Motor Gearing - As standard
Front Ride Height - 4mm
Front Toe In - 0 (Straight)
Ackerman Washers - 1mm
Camber Plate - If I am honest, I don't know how to measure this?? Looking on Chris Ashtons set-up, he says 2º - Is this altered by the little grub screw next to the spring pushing on the chassis?
Front Spring - Green
Centre
Roll Dampers - Oil as standard
O'Rings - Blue
Motor Spacer - 2
Rear Springs - Yellow (Were Blue)
Ride Height Adjuster - Was 4 Dots, just changed to 1 Dot
Diff - Yes
Rear Ride Height - 4mm
30g Weight - Yes
Rear Droop - No idea how to measure?
Rear Droop Screws - No Idea?
Rear Suspension Position - Just changed to outside holes

Ok Chaps... Over to you!!

Best Wishes

Stuart

Rear Droop was/is 2mm.... Just measured...

Camber is via the pips on the top beam, 1.5 is kit you change the beam for1 or 2 to alter camber

If you have the damper tubes and the blue Orings in the side links your way too stiff, use the tubes and no orings

Transmitter

Do you have any negative expo dialed in? If not try -15 to -20

If your using a Spektrum tranny you have to use positive expo though.

Negative expo calms the servo's initial responce around it's neutral point.

I had initially done nothing with my tranny.
It's a core RC; I had a chap mess around with it, reduced my dual rate and I think messed with my expo.

Any info on Tranny settings and their applications would be a great help if anyone wants to fill me in?

Restore steering defaults then do the following as written by Andy Griffiths in link. Refers to KO but same principle for all steering
http://www.carsrcracing.co.uk/?p=180