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Discussion Starter #1 (Edited)
How do I make stock HO AFX cars faster?

Since I'm new to this stuff I've got several questions. I'm sure others have wondered this when they get spanked by the locals on a track, but how do I make my HO cars faster? I know the tires make a difference, but for example: Take the new AFX Chapparal car. How do I make it faster besides new tires? I know if I've got lots of money to throw around I can do anything (I don't), but what do you mere mortals do to improve your stock cars without breaking the bank?
 

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Depends on what you wanna do. If you wanna corner fast you gotta get those traction magnets closer to the track. You can either buy shorter tires or grind the stock tires. Silicon tires do grip better, but sanding a stock rubber tire makes them pretty sticky too. It helps to keep them clean also. We use tape to clean our tires. The motor magnets can also help with downforce on these cars. To do this you have to create a happy medium between the front and rear tire diameters. To increase the performance of a stock car there are many things you can do. Keep the chassis as clean as possible. Try to eliminate all the friction points you can, wheels rubbing on chassis, tires rubbing on chassis or body, chassis or magnets dragging the track or rails(Don't grind thos tires too short). Any friction point you can eliminate will help the car go faster. A light weight oil with a pin applicator can help. The last cheap-o one I saw was at Advance Auto. You can also order a Pro-Long pin oiler from NAPA($5 I think). These cars don't need much oil either. Just a tiny bit between the axles and chassis, the gears, and on the motor bushings. Be very careful when oiling th brush side of the motor! Oil on the com and brushes can kill the performance of an electric motor! You can also try changin the gears to a lower ratio. Stock might be 7 pinion 25 crown gear. You can use a g+ or tyco curve hugger crown gear these are around 20 teeth for more top end on those long straights. If you run on a road coarse stock gears will do you fine. It also helps to adjust the pickup shoes so that all of the flat part is touching the rail and that the joint between the shoe and hanger is clean(fine grit sandpaper 600). You can also stretch the pickup shoe spring a little to increase the tension, this can make a big difference in some cars. If you stretch them too far it can cause handling and performance problems so stretch in moderation. This is all I can think of off the top of my head.
 

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The cheapest upgrades for a SG+ in order of increasing cost:

1) If you have more than one SG+, and if the rules allow, look for one with two-dot gray traction magnets. If you find a set, make sure you put them on your fastest chassis and use that one as your race chassis. $0.00

2) Make sure the entire step on your pickup shoes are making contact with the rails. $0.00

3) Use a lighter weight body. The Chappy is kind of heavy. $cost varies depending on what you've got.

4) Try advancing the timing all the way. To do this simultaneously push the drivers side of the endbell down and the passenger side of the endbell up. The endbell pivots on the front of the arm shaft. There is a guage on the bottom of the endbell that shows the timing setting. If the car runs worse after making this adjustment, try other settings and use the one that works best. $0.00

5) Make sure the copper tabs that provide electrical contact from the endbell to the pickup shoe hangers are making good contact with the hangers. I use a tiny screwdriver or a #5 Xacto blade, twisting it slightly to press the contact against the hanger. $0.00

6) Adjust your shoe hangers for better performance. This involves bending the bottom of the hanger where the rear curve of the shoe hangs a little bit forward with a small flat bladed screwdriver. I usually bend if forward about 30 degrees. Make sure you check and readjust your shoes (item 1) after you do this. $0.00

7) Replace the stock rear wheels and tires with wheels from a Tyco 440X2 and mount some silicone tires on those wheels. $0.00 - $2.50 depending on whether you already have the parts.

8) Replace the stock rear wheels and tires with dual flange Wizzard or BSRT wheels mounted on a new Tyco or Wizzard 0.059 axle, with a 23 tooth BSRT or Slottech crown gear, using brass spacers instead of the gear boss. Use silicone slip-ons on the wheels. $2.00 wheels + $1.00 axle + $2.50 gear ($3.50 for Slottech) + $0.25 spacers.
 

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Discussion Starter #4
Thanks for your replies.

mtyoder said:
You can either buy shorter tires or grind the stock tires. Silicon tires do grip better, but sanding a stock rubber tire makes them pretty sticky too.
So here's a question---how do I make sure the tires stay round if I sand them?

I'm not really following you AfxTwo on adjusting the timing on the motor, but everything else sounds easy enough to do. Guess I need to just tear into it and see what happens. Another question pops to mind: Does the body weight matter that much? I figure the stock bodies are more durable than the aftermarket ones, so maybe just a "race only" body might fit the bill. Where would I look for something like that?

Thanks again for all your help!
 

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So many inexpensive things you can do to an original AFX pancake motor:
-Shim the magnets closer to the arm with a little tape
-Try original AFX silver pick-up shoes (available on e-bay)
-Experiment with gearing: bigger crown gears for short tracks; smaller crowns for long
tracks.
-Clean the dirt off the rear tires with either tape of very fine sandpaper (its amazing
how much speed you loose to spinning tires).
-Try using silicone rear tires; much better grip.
-Keep the bottom of the arm clean but never use sandpaper to do this!
 

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...Take the new AFX Chapparal car...
You won't be able to follow the timing thing, it doesn't apply to the car you mentioned which if it hasn't been changed by someone after purchase is an SRT chassis.

Most of the electrical tips AFXToo mentioned will apply. The magnet and timing tips wll not. You can play with traction magnet configuration. Make sure at the very least one is north face down and the other is south face down. From there you can play with downforce setup (N-S vs. S-N). On a heavy rail this can make a big difference depending on your driving style.

One thing I've noticed about every Chapparal I've had my hands on is that the body is very tight, which could be distorting the chassis and causing a ton of friction. And yes they are very heavy.

Sanding tires...there's a million ways to do it. Chuck an old axle/wheel into a dremel or even a drill, then using a multi-grit nail file have at it. Some do it "on the car", placing a pice of fine sanpaper under the tires with the car on the track, gently lowering the running car onto the paper (good to be ambidextrious this way lol).

The SRT is a great chassis, it doesn't need a whole lot to make it wicked fast. :thumbsup:

AFXToo briefly mentioned it, and since you mention racing at the local track, above all, before you go hog wild on a car.....make sure you are aware of any rules that might be used. All the here-and-there tips in the world do you absolutely no good when your car is sitting in the DQ box.
 

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Good old 3M, Scotch, or Duck brand Duct Tape. :thumbsup:

Be aware that any old cut-rate dollar store duct tape doesn't cut it. I'd like to try Gorilla Tape, but I'm afraid it'd pull the tires apart. :freak:
 

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Coupla things to keep in mind while truing.

Whether you true on a seperate mandrel or on the chassis the axle has to be straight and the rim has to be concentric. What ever gadget you use to drive your mandrel should be given some consideration as well. A drill/dremel with excessive runout sorta defeats the purpose and yer tires will be "waboed". Care should be taken with the "on the chassis method" as it can ruin a good motor quickly if your not patient and just let it fry.

In most cases a quick scuff is all it really takes to smooth out the contact patches and round off the sharp edges. I prefer to use the mandrel method first for the rough stuff and then assemble the chassis and drop it on some light sandpaper to even things up side to side.

I also prefer to run the chassis in reverse for the final scuffing. This prevents the drive train from binding up and smoking a perfectly good armature if ya happen to slip. This way I dont have to be overly ambidextrous like Swamper mentioned. The trick is to let it float gently and give it a little wiggle from side to side so that you dont cut concentric grooves in the tire.

Todays modern slip on silis will disort and lump a tire irrepairably if you wing them up too fast. So watch your RPM when mandrel truing in a dremel. Mounting the tire to the rim with adhesive can help with tire to rim float/expansion. A hotrod chassis can also float the tires and distort a soft compound slip on sili when your using the drop method. So always watch your speed whatever method you choose.

As Yoder pointed out bone stock hard rubber tires can really benefit from some truing. Makes a huge improvment right out of the can and best of all truing is darn near free.

For inbetween/maintainence scuffing a scotch brite pad works excellent when tape wont clean the tar off.
 

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Good old 3M, Scotch, or Duck brand Duct Tape. :thumbsup:

Be aware that any old cut-rate dollar store duct tape doesn't cut it. I'd like to try Gorilla Tape, but I'm afraid it'd pull the tires apart. :freak:
I use blue painter tape, but don't like the smell of it.

There's an electrician's tape that's for binding things together that I want to try next, rather than the insulating stretchy black stuff.

Make sure it doesn't leave residue too.
 

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faster

well i heard that if you dip the end of a knife in canola oil and smear the oil along where the axles and the cogs are they go faster
 

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Garlic breath? Better brush!

Tx, For the most part AFX gear racks are pretty free wheeling...but not all.

Some guys like to lightly gently buff the plastic gears with a wire wheel. I prefer to lap the plastic gear sets with ultra bright toothpaste. Same procedure as brass gears. Water rinseable is cool.

Of course you could use any plastic polish.

I was pleasantly surprised with the minty fresh results.
 

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just a cheapskate Jimmy LOL!

The idea actually came to me on the Magic bus four gear projet. I needed to eliminate as much friction as possible with the extra gears for the dually. It was a little gritchy anyway because it was a hodge podge paybay SOE build that I fixed for Zilla. I remembered reading somewhere about Heloise say you could polish plastic with tooth paste. How bad could it be? By "gum" it worked awesome

The water washable part is the really cool. I just spoot some simple green on the chassis and agitate it with....gulp....a toothbrush. LOLOLOLOL. Rinse thoroughly and blow it off with compressed air. 10 out of 12 dentists approve!
 

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just a cheapskate Jimmy LOL!

The idea actually came to me on the Magic bus four gear projet. I needed to eliminate as much friction as possible with the extra gears for the dually. It was a little gritchy anyway because it was a hodge podge paybay SOE build that I fixed for Zilla. I remembered reading somewhere about Heloise say you could polish plastic with tooth paste. How bad could it be? By "gum" it worked awesome

The water washable part is the really cool. I just spoot some simple green on the chassis and agitate it with....gulp....a toothbrush. LOLOLOLOL. Rinse thoroughly and blow it off with compressed air. 10 out of 12 dentists approve!

I hope it wasn't Robis toothbrush! LOL
 
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