need help with Corally C4

[Skyline_gtr_nos]

hi, i need help with my corally c4!!!

Ive got a drag coming up this weekend on a 100m track, im versing a petrol car and what im after is to make my car go as fast as possible.

Ive got a 10turn motor (42000rpms), and im wondering how to make my car go faster!!! im talking over 80 km/h, is this possible?

its probably doing about 60 km/h at the moment.

Do any of you guys know any gear ratios that would increase the top speed? ALso any other tips would be good!!

Thanks

[Rossco(2)]

what sort, number of cells are you using?... also how many amps are you charging at?

[icon]

see how many cells your esc can support and start dumping more cells in for higher voltage. gear accordingly, you want the revs to reach peak just before end of the straight. also if you overgear your car your esc can risk overheating. make sure the motor is nice and fresh, i suggest cutting the comm and using some fresh brushes.

[WillyChang]

quote:Originally posted by Skyline_gtr_nos

Do any of you guys know any gear ratios that would increase the top speed?

---

id="quote">id="quote">

*Any* ratio that's HIGHER (larger pinion, smaller spur) than what

you have now will obviously let your car have a higher top speed

- up until the point where your motor can no longer overcome

the drag caused by drivetrain & wind resistance.

8t motor and less are available... []

[killerkip]

I think it will be harder to keep it in a straight line with all that power... So set your steering output to the absolute minimum you can, making it so that when you steer, you'd have a rotating-circle (or how's it called?) of like 10 metres or more. Then, use very hard tyres in the front, and soft ones in the rear. Make sure your suspension is very stiff, and the car is as low as it will go without scraping the ground It might be a good idea to check out the track first, to make sure how many bumps etc there are. Use a large pinion and a small spur, set your engine to the highest power-consuming setting there is, and try to use new rear tyres - the bigger, the higher top speed. You will lose accelleration is you do this, but I think the top speed will compensate that... Distribute the weight slightly to the rear. Make the car as light as possible, and fit the lowest body you can find, cut the bottom so that it's a low as it will go on your chassis. This makes a LOT of difference btw (did the same thing in Tamiya EuroCups with my prototype-class... Every car was identical, but I was faster. Nobody noticed that my body was 8mm lower that the original... Even technical inspection didn't see - for an entire season [8D]) .

[Skyline_gtr_nos]

thanks for the help guys....

im currently using 7 cells (2000 sanyo) and im charging at 5amps.

---i suggest cutting the comm-----

I dont understand what you mean?

Also i will be buying new brushes before the race, the last time i was at the hobby shop i purchased a new spur and pinion. When i installed them the car couldnt take off and the motor was burning up, it could hardly move. I told the guy that i needed full on top speed and only a little acceleration. I think he got the wrong impression.

Anyway, i hope to win this race, because the guy im versing thinks electric cars are **** and slow.

He laughs when i tell him the worlds fastest rc car goes 111mph and its electric.

Thanks

[nismospeed]

well i hope you win mate....electric all way[]

post the result when you win!!!!

try using a nissan altima or dodge stratus body..they are very low and also the aerodynamics are good....ive seen a lot of ppl use these bodies and said they make a diffence...

good luck

[Rossco(2)]

---i suggest cutting the comm-----

I dont understand what you mean?

cutting the comm..... the comm or comutator is the gold coloured bit in your motor where the brushes touch. cutting the comm is when you use a comm lathe to machine off the top surface of the comm, thereby increasing the amount of power the brushes can transfer. skimming the comm is a very effective way of both making you motor faster and also maintaining it.

[mr_lister999.]

If you dont have a comm lathe, a bit of fine "wet and Dry" sandpaper and a drill also work. Remove the armature (the big long thing inside the motor) and grip the longest end of the silver rod in the drill. Turn on the drill and touch the paper onto the gold bit on the top until its clean. Keep the pressure even. Once its all gold with no black, its done. When finished, take a fine screw driver or a knife blade and clean out the 3 slots between each gold piece. Check there are no sharp edges and re-assemble. Always use NEw brushes when rebuilding and the old ones are out of shape and dirty. A comm lathe is better but this way costs nothing and is nearly as good. If your gold thing is black, you need to do this.

[terry.sc]

You might find this link interestinghttp://www.rccaraction.com/articles/need_speed.asp

[TWO STAR]

depending what type of speed controll you have,its hard to say.more cells will help you with speed & gearing combos..using smaller cells like the 1/2 sub-c sanyo high capacity 1000 mah cells will dump more power faster than a standard sub c type cell,ideal for drag racing.motor timing will also help in running faster,but you dont want to go too far or it will run unefficiantly.different types of brushes & spring set ups will help out also.getting all that power to the ground is tough,use lots & lots of traction compound(you will smell like colgate toothpaste at the end of the day)it will make your car "hook up" better.I personally run drags out here & so far ive hit 64 HPH on 6 cells,& 72 MPH on 8 cells with a trinity p-94 7 turn in a rail dragster.

[WillyChang]

quote:Originally posted by Skyline_gtr_nos

...the last time i was at the hobby shop i purchased a new spur and pinion. When i installed them the car couldnt take off and the motor was burning up, it could hardly move. I told the guy that i needed full on top speed and only a little acceleration. I think he got the wrong impression.

---

id="quote">id="quote">

No, LHS guy is dead right spot on...

.... if you're aiming for the Velodrome top-speed run. []

If its top speed continuously, then a banked oval can't be beat.

Think also of your tyres.

You'd better be running foams or belted rubber.

Unbelted rubbers won't have a chance at high rpm.