# Magnatraction/Xtraction



## mtyoder (Jan 3, 2004)

Like the tjets the gears are a killer for these cars. One tip that was passed to me is the 19t super II crown gear (if rules permit) for road coarse racing. It keeps the motor rpms up during cornering. Adds more braking too. On long straits you will lose some top end.


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## dlw (Aug 17, 1999)

These need nearly the same tweak/tune-up tips as their older cousins, the tjets and TuffOnes. Here they are:


1 - Disassemble chassis
2 - Check for out of round tires, untrue rims, and crooked axles. Replace any untrue rims, tires and/or crooked axles. Also check the underside of the chassis to see if the comm brush holders stick out. They should be parallel with the chassis. Not correcting any protruding brush holders could short out a track.
3 - Put a drop of oil where metal goes through plastic (axleholes, armshaft hole) and under armature gear. Wiggle and spin the axles and arm to work the oil in.
4 - Check the contact patch of the pickup shoes. Gently bend shoes to get an even wear pattern down the center of the shoes.
5 - Check rear gears for excess slop. A few light taps with a punch should fix this. Careful not to make it bind the gear. After correcting it, reassemble chassis.
6 - Check front and rear rims for little nubs (where they were plucked from the 'tree'). Gently sand them off.
7 - Lube the gears with lubricant of choice, then run them at slow speed (break-in period) for 5-10 minutes. Then run them at slow speed in opposite direction. This breaks in the gears.

Now reattach the body........You car should run much smoother now.


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## A/FX Nut (May 28, 2004)

Magna-Tractions are the chassis I've had better luck with. We can't shim our magnets in our Magna/XTraction class.

With the Magna-Tractions some magnets are thicker than others. Put the thickest magnets in the chassis you can and make sure they are as equal in strength as possible. They won't move around and cause the armature to wobble. 

Magnet strength can be tested with a gause meter or for us bare bone racers lower the magnet in a small cup of BBs. Count the BBs you have picked up and repeat the process for the other magnets. Find the north and south magnets that are equal or most equal.

The rivets that hold the pickup shoe to the plate that holds the com spring and brush can be tightened by placing on a piece of metal and tapping the other end with a nail punch. This can and often increases electrical conductivity. 

I hope this helps, Randy.


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## A/FX Nut (May 28, 2004)

In addition I stretch the com springs to the top of the brush holes. It can be a bear to get it back together but the increased pressure makes great electrical contact. You may or may not have more brake. 

But the peformance is noticable. Randy.


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## dlw (Aug 17, 1999)

Yes, checking the comm springs is a good idea (especially for older MT's or any car that hasn't been ran for years). I've even come across new XT's that had compressed comm brush, and/or pickup shoe springs, too. A little stretching is all it takes. It definitely makes a difference.

Just be careful you don't shoot them like a rubberband.


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## dlw (Aug 17, 1999)

Here's a chassis parts breakdown (From JackoFalls' Gallery). Should help newbies with assembly/disassembly of heir cars:










The light bulb (part #8621) is not on the regular XT's, so disregard it. But the upcoming Flamethrower series is coming, so it will be pertinent shortly.


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## dlw (Aug 17, 1999)

Just bumping this to the front for those folks who got new XT's and need help tweaking and tuning their cars.


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## Xence (Oct 2, 2007)

I'm kind of a magna-nut. I might have gone too far. I took and bought some crest or whatever it was and actually started lapping my gears. I know that there are probably other ideas on the 'slurry' people will use for this but this seems to work for me. Car is quieter after this is done. That's for sure. 

Now another thing as well that I start doing was on all of the metal contact points I took my dremel, put a wire wheel on it, turned it to the lowest speed possible and cleaned all the electrical contacts for the cars. This also seemed to make the cars run just a smidge better. After while all of these little smidge's add up to one great big smudge so don't discount the small stuff folks. An alternative to this might be to get one of those jewelery cleaners and just use water inside of it instead of say the cleaning solution stuff.

One thing I noticed as well though is that with the next AW/XT springs these do not seem to work real well for where the brushes go in the old Aurora/AFX cars. They seem to stick up to high. Anyone had any luck using the new parts on our old cars?


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## afxgns (Jul 6, 2006)

Pretty much all the electrical parts are interchangable.

Below is a link to an article regarding these chassis. I wrote long ago, but it still works for most folks. I couldn't find the second installment but I will try t5o look for it later.


http://howorld.fsmra.com/archives/howto/tuneup/mt_tim/02/mt_tune2.html


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## Dragula (Jun 27, 2003)

one of the big problems with running a magnatraction for a long period of time,is the motor brush springs heat up and lose there tension,I had a run of 2,000 berillium(sic) springs made,especially in a drag car,they really turn it on!
Christian


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## afxgns (Jul 6, 2006)

Dragula said:


> one of the big problems with running a magnatraction for a long period of time,is the motor brush springs heat up and lose there tension,I had a run of 2,000 berillium(sic) springs made,especially in a drag car,they really turn it on!
> Christian


If you replace the brush spring with the pickup shoe spring, you eleminate this.
You need to be carefull of the tension though! Not too much.


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## sjracer (May 25, 2008)

Afxgns, I read your article on the howorld website years ago but , I believe it was incomplete I think it left me hanging after I compress the pickup shoe spring, I wasn't sure if you put both sets of springs in the chasis or not. I also was wondering what type of racing you did road course or drag and if you drag what are the best times you've run? I am more of a drag racer and I 've seen times in the low nines to high eight-tenths of a second. A friend told me he's seen time in the seven- tenths of a second area. And yes these are stock. I struggle to my cars to run 1 second in the quarter mile forget under it so any and all help is appreciated.


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## afxgns (Jul 6, 2006)

I mostly run on ovals,but I could see were the oval settup would be a good place to start with a drag car.
I DO NOT put both sets of springs back in.Just be shure to squash them down before you try putting it back together.

I did find the entire article and I can post it here if you like.......

LMK


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## sjracer (May 25, 2008)

Yes please post the artcle afxgns, I need a few pointer to attemt to lower my times by 2-3 tenths of a second consistently. After reading the tyco artcile on the site I lowered my times to the lower nine -tenths and upper eight-tenths, hopefully your article will do the same. Now one of the guys I race with was telling me to cut one loop off of BSRT afx pick up shoe springs, I guess this will give you the same effect as compressing the spring. Although the parts are interchangeable are some springs and other stock or aftermarket parts better than others. Are the xtractions magnests better than a fresh pair of afx, which rims tend to be truer, gears better etc.,,,?


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