GT12 Help..

[stucartwright]

Thanks Mark..
I know I should, sadly I am not on FB... :-(

[Danosborne6661]

Facebook page is good, but it would be much better to have a section on here.

The thing with the Facebook page is as soon as a issue is resolved, the post quite quickly vanishes, hense the same questions getting asked over again. Yes you can do a search but it's not easy to browse like a forum is.

The thing with having a seciton on a popular forum is everything is automatically archived so there's tonnes of information is there right away.

If your diff is kit, it will have a steel axle. Alloy axle is an optional extra to save 18g. The purple part of your diff is just the hub.

[SlowOne]

Axle bending - yeah it will happen. Cheapest option is to buy a spare and suck it up. Same for the chunking of the tyres, get some spares and live with it. Shoe Goo will only get you so far, if you run them out of the packet they will be more prone to chunking than truing them down. There's always another way - stop hitting things!!

Your driving progress will be measured by reduced spend on tyres and axles!!

The JFT option is fine but then you need new front axles and/or bearings so you can fit the JFT fronts. I'd stick to Contacts (reasons given above) and just try to curb your natural enthusiasm! With foam tyres, the best times are when you drive slower than you think you need to, so go slower and practice getting the right lines as close to the markers as you can at the highest corner speed you can maintain.

@Mark - on here we have quality, on FB you only have quantity!! Only kidding pal, each has their uses and it's nice to have some different uses on here.

[shinytopman]

Originally Posted by SlowOne

There's always another way - stop hitting things!!

LOL.......Slowone, i've been working on that, but im not very good at it!......

Shiny

[stucartwright]

SlowOne, wise words wise words... One would have to say, less barrier more apex would be a good way forwards to reduce chunks and bending of axles.. Oh the dramas a budding A finalist has to go through!!


Well the wagon is all set, and off to maritime I go tomorrow.

If anyone knows the earliest I can get there, I would appreciate it. I want to make good use of the GT12 practice this time. Last time I got there at six and only got one run after the TC cars ate into the GT12 time!!

Anyhow, am very intrigued to see how;
Lowered rear pod pivot
Front suspension conversion
Reduced weight from wire thickness
Soft rear springs

All act on the cars overall performance.

I will report on the performance on Friday, and all being well I hope to see some reduced lap times come my way!!

Many thanks again to all who have helped with me and my cars progression!

Best Wishes
Stuart

[SlowOne]

Stu, I am only guessing that hitting things causes chunking and bent axles, as I have no personal experience of this...

Good luck buddy. If there's one thing to make sure of, it is that you enjoy it.

[mark christopher]

Originally Posted by SlowOne

Axle bending - yeah it will happen. Cheapest option is to buy a spare and suck it up. Same for the chunking of the tyres, get some spares and live with it. Shoe Goo will only get you so far, if you run them out of the packet they will be more prone to chunking than truing them down. There's always another way - stop hitting things!!

Your driving progress will be measured by reduced spend on tyres and axles!!

The JFT option is fine but then you need new front axles and/or bearings so you can fit the JFT fronts. I'd stick to Contacts (reasons given above) and just try to curb your natural enthusiasm! With foam tyres, the best times are when you drive slower than you think you need to, so go slower and practice getting the right lines as close to the markers as you can at the highest corner speed you can maintain.

@Mark - on here we have quality, on FB you only have quantity!! Only kidding pal, each has their uses and it's nice to have some different uses on here.

you don't need new front axles to fit zen wheels to the Schumacher, just 4 flanged bearings the same size as the kit bearings.

pdw we have a very good community now on fb, even just had a lad who was scammed refunded by our influences.... but your right

jimmy is over seas at the moment, when he comes back he will add a gt section and has a moderator lined up, once done ill transfere some bits to here for you anti facebookers

[stucartwright]

So it was Maritime last night, and my word what a different car I had on my hands! Shave a full second off last weeks times and 2 seconds off my average, reducing the gap from best lap to average lap to only one second, "for me" a massive improvement.

The rear lowered pod along with the front conversion is an absolute no brainer; which one is having more affect I have no clue, to be honest, I don't care. Car has so much less body roll, a hair of understeer for a change, so I'm pumped about that!

Now for the downsides... I'm not sure if this is because of the much improved handling, but the car since last week feel much slower off the mark, and takes until quite a way down the straight to get up to top speed, and that is considerably down on other cars.

I can't help thinking my weight is still an issue; 1030kg with shell and battery. The wires seemingly have made very little difference. (Check out my photos for car setup)
I all tried some 90c 6200 1s batteries which if I'm honest didn't feel dramatically different, so I am writing with the aim that you can help with finding a bit more punch and top end...
Motor - Dynamite 13.5T
Esc - 1s Toro
Gearing - 70T (70 roll out)

I have to say, since reducing my wire thickness, this is the only electrical change, and with my ESc leads to battery a touch thinner than all the others, could this be the problem? And the reason why I saw pretty much no different between batteries?

As ever, look forward to your help... Roll on West Kent on Sunday I say!

Best Wishes
Stuart

[beale]

Were you getting any notching at slow speed? Could say you have a sensor fault
What end bell timing are you running?

[stucartwright]

I've checked that Beale, sadly no notching at all...

[stucartwright]

The end bell timing is pretty much at the max... where the + sign is....

[shinytopman]

Stu just put mine on the scales 987g in race trim.

Stu gearing last night was 49mm tyre dia, 70t spur and 34t Pinion so if math's are correct 74.73 rollout..

Bit long in MHO, but im only a novice to this myself.

[stucartwright]

Hi Sam...
Ive gone back to the 32 pinion, and sticking with the 70 roll out as you/and all recommend is a good working average.

I have switched my wires from those I had last night, on my esc to battery to the ones I had last week before the loss of power and it does seem to have helped a little... I also switched a tunrigy trackstar motor, that has an "alleged" more Kv and seems it has improved matters..

However, it does not appear to have fixed my weight issue..

Makes no sense to me at all..

When you say race trim Sam, do you mean with body shell and battery? I am weighing in at 1025/30grams...

HELPPPPP!!!!

The wires have not fixed the issue..

Its particularly annoying when you hear people have to add wight when they build it out the box.... What weight do I have that nobody else has.. Stange to say the least!!

Stu

[mark christopher]

I run my car at 950g you pulling an extra 80grams for nothing. Wire will loose some weight but you change to a thinner wire more for less pod tweak.

What servo,speedo, receiver do you run?

[SlowOne]

Gearing is too high by a margin. With GT12 cars you need to be at about 40deg of timing max and around 65/68mm/rev. The timing and gearing you have is why you are getting max speed at the end of the straight.

Because of the weight of a GT12 car gearing needs to be lower. At the weight you have it needs to be even lower! Talking of which I now don't understand why you are so far overweight. Please gives us the information Mark asked for so we can have another look.

Good to hear that the car is now handling better and some effort has been made to stop hitting things! Your 'difference' still suggest some *cough* variation in the driving department from lap to lap, but as you now have control of the car, that will come.

Whilst looking for more speed and less weight, focus on the consistency in every race. Just because you don't have the speed you need is no reason for hurling the car around - every race is a chance to get consistent.

The late, great Phil Davies when he first appeared on the scene was racing at Watford one time. He consistently hit the same corner lap after lap. I remarked to someone else that once he sorted that out he would be great. Multiple British and European Championships duly followed! Get consistent, then get fast.

Looking forward to the details requested so we can comment further.

[stucartwright]

Mark;
I posted in earlier thread;
Servo - Core RC (the one made for GT12)
Toro 1s (no different in weight to many others)
Receiver - Core RC standard size...

The guys like Sam (Shiny) run majority of the same kit as I do but mine weighs more...

And I've heard many having to add weight because they were under weight.

Without doubt the driving needs to improve, however I would say the car had/has very slow acceleration. And even the top end was still down on many of the cars in the A and upper echelons of B final, and to be fair my driving style/skill has improved dramatically since the cars handling which is really inspiring, but the throttle is close to flat out during most of the infield.... Which I am confident would not be possible with the faster cars... Not a chance.

Best Wishes
Stu

[Xracer]

Attachment 78538

Attachment 78539

I started using the carbon chassis and had to ballast up to the weight limit, I have now fitted the S1 chassis, after delaminating a few carbon ones ££££, added an RCS chassis decal and it hits 950 grams with the standard weight McLaren shell, my extra weight has gone where it needs to be, as low as possible and next to the ground!

Looking at your earlier photos there is definitely scope to reduce weight, the photos show everything installed, bar the wheels and shell of course!

[stucartwright]

Are you able to offer advise where exactly I can lose the weight, because apart from the servo, I see very little difference...??!!

Best Wishes
Stuart

[SlowOne]

Stu, just a thought - what are you using to weigh the car? I've a set of scales that read 10g under and get very erratic when the battery gets low. Have you tried using another set of scales, or taken your scale to the track and weighed other cars?

[Xracer]

Hi Stu,

well the first obvious question, are your scales accurate?

I use the SkyRC corner weight system and have checked the accuracy with a number of different weights and compared on digital kitchen scales, all compare within 0.1 grams so I have good enough calibration.

If so you are looking at 80 ish grams I believe, now that is just shy of 3 ounces in old money and quite significant.

My car uses Core alloy screws where impact does not apply any significant load or there is no resistance to a load, these are a third the weight of a steel screw and contribute overall.

So look at which screws you think you are happy to replace, weigh them, then divide by 3 that is what you would be putting back in alloy, I have 22 alloy screws in mine!

I also have 4 Core titanium screws on the king pins and 6 on the pod lower axle mount positions, these are half the weight of steel.

My receiver is a KO Propo micro with a KO RSx12 servo, 7.5 grams and 26 grams minus a couple or so for the shortened lead.

The motor wires are 14 gauge but with a thinner silicon insulation, mine are Tekin but Zen do an equivalent TQ wire.

My battery wires are 12 gauge but short.

All wires are as short as practicable without affecting the chassis movement.

The battery plugs are the soldered 4mm bullets that came with my lipos.

I have a custom lipo tray which actually locates the battery, can't imagine much weight saving there though but it is just over 1 gram!

Ceramic diff balls, longer life and weigh beggar all but cost!

64T CNC spur gear, kit moulded gears are not that accurate and may even be heavier!

Core titanium turnbuckles, half the weight.

Core bonded sensor lead as short as possible without being tight, length depends on motor port position.

Alloy Pinion, half the weight.

What is your motor weight compared to a TP 13.5T at 176 grams?

What is the weight of your lipos, my Intellect 7000's are 140 grams?

How much paint on your shell, you may be surprised at this one?

As you can see each item contributes, shortening a servo lead can save up to 5 grams depending on the wire gauge and original length.

You have seen my pictures, hopefully neat and uncluttered to the eye, well the only way I can reduce weight now is go back to a carbon chassis and use a lightweight shell but what is the point, I would need to ballast back to the limit!!!

A lightweight shell improves the handling though so is to be considered if my driving improves!!! I have some ready for painting.

The only thing that gets lighter are the tyres, oh and the body when bits fall off!!!

So happy weight chasing, losing it does cost ££ though!

Regards, John