Model: (Click to see more) 58367: F103GT Chassis Kit
Status: Project
Date: 15-Jul-2006
Comments: 7
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After 2 long weeks of waiting, the new chassis arrived. It's inspired on the 'old' F103 formula one chassis - with a bunch of options included: doubledeck chassis, active front suspension, ball bearings, height-adjustable gear case. Also, the newly designed rear diff / wheel hubs are really cool. The differential has some new parts, it has (nearly) no slip.


I want to make my 100+ km/h car out of this chassis, but it will take some work. Some optional parts were added from the go: carbon rear shaft (not available for F103GT yet), titanium screws, small size servo, 63T spur and 24T pinion. This is the most radical gear ratio possible with this car - unless you modify the gear box... Hmmmm... Contemplating...


The new rear suspension was made to fit touring car rims. The spur is from my old F102 chassis, the diff pressure plates are from my old F103. Also note the cooling-holes in the motor.


I removed the pressure-plates and damper, and replaced it with a solid rod.

I made an 8 cell pack with 2/3 cells, 1200mAh. I'm not sure if these can deliver the power I need when I need it - but, when charged, they deliver 12V...


My brake fets on the Novak 410 HPC are probably shot - they will need replacing... I also need to find a decent shottky diode. This one started smoking after 30 sec at full throttle. :s

Comparison: My TBO2R car wheighs in at 1580 grammes - ready to race. This chassis, in combination with 8 2/3 cells, is 1053 grammes. This should make a big difference on a fast track.


It has a 9D motor, with 1:2.625 gear ratio... Also, the wheels have a larger diameter than the old F1 tyres. So torque will be low - but top speed huge!


Now, if I want to get a 100+kph car, I will need an accurate reading of its actual speed. So I bought the Venom speed meter, which is sort of a mini-telemetry system for RC cars.


I installed the magnet on the rear axle, and glued the sensor to the rear of the gearcase. It works!


First test of the speed meter, placed on top of my workbench (no resistance, drag, etc... ) with a nearly dead battery: 166kph. Of course, this is completely free-running, and proves nothing. I need to get it out to my testtrack pretty soon.


To decrease wind resistance, I also added a new body: Audi R8C. It's a lot lower than other touring car bodies, so should inclease speed. I'm just not sure what it will do for my downforce...


I gave the car a quick test run, I was too curious as to the result. Here it is: 104 kph! I succeeded! Now I'm just going to see if there's any more speed I can get out of it. To do this, I will need to move the car's weight a bit more to the front, to keep the car more stable. I will design a custom chassis to provide more rigidity and probably add a 7th cell. I also need to add active cooling of some sort to keep the speedo cooler - after about half a pack it shuts down - overheating protection. Will also add an aluminium motor mount. I will also be closing the wheel arches for the rear wheels.


I also repeated the test of the free-running car, but this time I used a fully charged pack. The result: 190km/h!


I had one crash during testing, at about 80 km/h. Result: lots of scratches on the body and spoiler, and a severely damaged antenna pipe. Other than that the car was fine.


If anyone else has suggestions on speeding it up, please send me a mail. Thanks!


Check out the movie as well!

I narrowed down the front tyres to about 1.4 cm.

If you liked those pictures, you should see these...
108 kph achieved !

Comments

bugged

15-Jul-2006

Could always add another pack of cells, 14.4 volts ! lol...give that ago...

Ohh and fancy a quarter mile with my pro street bug

Coopsy

7-Sep-2006

Removing the rear wing will reduce drag, though the offset of that could mean the rear end is a bit lighter....it's certainly an idea, anyway! Just keep us posted on any developments.

6-Oct-2006

Hi there, maybe you could get a body with less drag (waterdrop shaped) to improve the top speed... it will have to be a custom one though...

6-Oct-2006

Maybe the ratio is too low and its overloading the motor and overheating the esc. A competition esc and factory team IB4200shv cells would be better. Keep pushing, nice project ...
TP

killerkip

6-Oct-2006

as far as I can tell, this is just about the best body available. I am - however - looking into a HPI gallardo, which is sort of arrow-shaped, but it's higher than this one. All I need is time, so I can add a different rx (Spektrum - no antenna) and other gear ratio. I also need to cut the rear end off this body. I have reached 108kph, and my target is now set to 125

boy racer

22-Oct-2006

you could try the lipo's theay are lighter and give more performance,verry nice project

31-Oct-2006

Your Crazzzy geeeza!!


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