"Short Track" tuning my Racer Group 5's

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"Short Track" tuning my Racer Group 5's

Postby HomeRacingWorld » Fri Dec 06, 2013 7:28 pm

These models by Racer have sort of grown on me since the first release. No surprise really, the way they run go a long way in making them ideal for a wood track.

There are a couple items though that I just did not care for:

1. The smaller rear wheels/tires
2. The Motor

This is no way a complaint against the models. They were designed to be RACE cars and using the existing wheel/tire sizes just made sense. The body/paint work to my eye is excellent. They really did a fine job and it proves they do care about scale appeal.

So it is just my own personal taste as far as the wheels & tires go.

I decided that I would try a larger diameter tire to see if I could improve the looks as well as smooth out the overall ride.

After trying a couple different sizes, I ended up choosing the Paul Gage 21125's (XPG)

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Shown on Moby Dick, but they fit the Lancia and Capri as well.

What is nice about Pauls tires is that they can stretch over larger wheels than initially intended for. As well as having this larger diameter, the width is as wide as you can get for these anglewinder models. At least as wide as you can get without any drastic body mods which I certainly do not want to do.

They still needed some work though. First they needed the inside sidewall sanded/profiled. Needed to do this so the tires clear the inside of the chassis, ESPECIALLY the spur gear side where the pinion comes very close to rubbing.

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My preferred method to accomplish this is to use a emery board while the wheels are spinning in the tire razor. Just hold the board against the inside with light pressure and it will start the sanding process rather quickly.

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You need to loosen the gear and move it away from the wheel assembly while doing this side.

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Once the inside is sanded, then I true the tires as usual. I like using the 600 grit fine paper. Just sand until true, making sure you have sanded the entire face of the tire for that ideal contact patch.

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When you re-install the assembly, check to make sure the pinion is clearing the inside of the tire. You CAN move the wheel out slightly. You will just need to test fit the body to make sure you are not rubbing. I HIGHLY advise not to try and sand any material away from the inside fender well. The bodies are very thin and you will go right through it if you are careful.

QUICK TIP - if you want to raise the body in the rear, try these neat "doughnuts" by Professor Motor.
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They not only help raise the body, but also help in the sound department. It reduces rattle pretty well for those that care about such things.

I used one as shown on the Capri.

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Next is was time for a motor swap. I chose the MT-5 motor. It is milder than the Flat-6 but that is what my smaller track likes.

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Do not let the motor ratings fool you. This motor has plenty of power and speed. It also has a decent low end that I dial in rather easily.

Using this motor tamed these beasts right where I like them.

If you feel a faster RPM motor is always the best choice, think again. On smaller tracks that extra RPM does very little when they have no room to use it. Overall control is the sweet spot and sometimes a milder motor is just what you need.

But you would not bother reading this if you have a large home or club track anyway :)

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Here they are all finished. You might notice I chose to add lead in some areas, primarily on the Capri. This was just the beginning of the testing phase.

Notice how the Capri has actually the longest wheelbase, whereas old Moby is the shortest.

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Something you need to keep in mind while tuning for your own track.

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To my eyes these tires improve not only the looks, but overall performance. The lower profile tires give up a lot of cushion that leads to excess chatter and vibration. With these tires the ride is much smoother now and the grip is better in the corners.

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Overall I am very pleased. They drive much smoother and look a little better.

You will of course tune to your own personal liking. Hope it helps a few of you.
-Harry

"They didn't say you couldn't" - Smokey

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Re: "Short Track" tuning my Racer Group 5's

Postby HRWJim » Fri Dec 06, 2013 7:51 pm

Could not agree more with the motor change but again I have a small track. I had family over for Thanksgiving and naturally we ran slot cars. LOL We raced all the Trans Am cars and classics. Had a blast when my 10yr. old niece asked if she could run the Zakspeed Capri I had tuned similar to what Harry did. After about 5 laps she says to me " This is really smooth." I could not believe that came out of her mouth. But it does speak to how well these cars run with PG tires and MT motors. Jim
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Re: "Short Track" tuning my Racer Group 5's

Postby waaytoomuchintothis » Fri Dec 06, 2013 8:04 pm

That's a good solid fix, and I'll bet its good for other cars, too. I have a Lola that makes a lot of noise, barely dragging around the track, almost not touching. A little tire height adjustment might cure that. It needs some PG tires anyway.
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Re: "Short Track" tuning my Racer Group 5's

Postby ElSecundo » Fri Dec 06, 2013 10:42 pm

Boy, that improves the looks quite a bit. Just what these cars needed!
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Re: "Short Track" tuning my Racer Group 5's

Postby RazorJon » Sat Dec 07, 2013 3:42 am

some great tuning tips thanks Harry
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