# Sticky  Question for the Tjet. Builders



## Joe65SkylarkGS

So, I can get a tjet to handle pretty good .I'd say with the best of them .

My .Dilemma is, I can't get them to wind up and really scream down the long straights like some of the built chassis I got from guys like Hiram and Al aka adj350. They actually sound like a little turbo is in there!!!

Is it arm selection or magnets??? What am I not doing right???

Al, what am I missing bud???


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## Rich Dumas

Have you read this article? https://drive.google.com/file/d/0BzLR42NthGeCaDVSOEhLOVRybkE/view?usp=sharing
A fast car has everything optimized! What are you using for armatures? Most of the NOS armatures that you can buy today are not very good. Sometimes worked up armatures that you can buy are little better than average. If you are going to enter formal races you have to build cars that conform to the rules and in most cases you would be stuck with an Aurora armature. You might try a few Dash 2 lamination armatures, those are better on average than the NOS Aurora armatures that are available today. They are not better than a good Aurora armature, but finding a good Aurora armature can be a challenge.


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## Paul R

I'll agree with Rich on one point. A fast car has everything optimized. Dropping in a dash arm isn't going to fix everything. The top builders out there are turning out faster and faster cars even as the supply of Aurora armatures has supposedly disappeared. There is no silver bullet to getting top speed out of the car. What I have found is it takes time and trial and error to get to a well tuned car.

Here are some of the things I focus on:
1. Matched magnets. Getting them as close as possible in readings to each other. Orient them so armature rotation is towards the stronger end of the both magnets. 
2. Noise. If you have a well tuned gear train, it should spin free with little to no sound. If it doesn't check for slop in rear axle movement. Is it wobbly? Lots of side to side play? Is gear mesh smooth? Gears lapped? Good match between top plate and chassis? Good match between pinion and crown? A larger axles (within the rules) can help with axle slop. Spaces can help to position crown gear for good mesh with pinion. Different crown gear/pinion combos may need to be tried.
3. Power. Shoes restricted. Since you say handling is good, this may already be taken car of. Make sure bottom of shoe has good contact with the rail across the entire length of the shoe. You should not see any burn marks if the shoe is setup correctly. Make sure it is not over-restricted. This will help the handling, but will show as burn marks on the shoe and will mean you are not getting enough juice to the motor. the peak of the brush spring should be parallel to the bottom of the chassis so the brush will have even pressure and good contact. Arm should have a flat comm in relationship to the bottom of the chassis and the comm should be surfaced to ensure it is smooth.
4. Wheels and tires. Make sure they are on straight and all four wheels are touching the track

Some things to look at, but the bottom line is time and tweaking. I spend far more time tuning a car then I do building it.


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## Dslot

There is also a very thorough and very well illustrated article "Tuning the Pancake" in the stickies at the top of this forum. It says "Part 1" but it links to Part 2 in the first post.

-- D


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## Boosted-Z71

Where do you start, Pancakes are a brutal mix of friction, poor electric connections and yet they appear so simple, I mean its just a slot car.

Joe, most of the gains that I see come from eliminating friction, everything has to roll smooth, and either straight or perpendicular, friction leads to heat, heat kills everything.

Just as big of a player is the electrical connection from the shoes to the arm and everything in between. Seen many shoe hangers loose, bends on shoes that when compressed have very limited electrical connection, dirty hangers, brush springs that lose tension, brushes that spin or poorly adjusted for the proper contact and the list goes on and on. 

An am radio makes a really good audible oscilloscope for testing the electrical condition of your car, set the radio to no station, just low static, rev the car near the radio and you will hear the car rev on the radio. The less you hear of the car the better electrically that the car is, listen and keep tweaking to the minimum noise level with no popping or cracking 

I have a bullet from KC-slots that I test all my cars against, I dont stop tweaking until it can outperform his car or it goes in the box as a above average runner. 

Good armatures are a real needle in the haystack to find, physical and electrical balance as well as com plate flatness, shaft straightness, weight, many factors to make a fantastic arm. Pretty easy to find a good runner, really tough to find the screamer. 

Boosted


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## ajd350

Joe65SkylarkGS said:


> So, I can get a tjet to handle pretty good .I'd say with the best of them .
> 
> My .Dilemma is, I can't get them to wind up and really scream down the long straights like some of the built chassis I got from guys like Hiram and Al aka adj350. They actually sound like a little turbo is in there!!!
> 
> Is it arm selection or magnets??? What am I not doing right???
> 
> Al, what am I missing bud???


Hopefully we can schedule a stop here when you and Tom are out for the show and I can show you some things that will help.

Lots of good info already in this thread to get you going.


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## Joe65SkylarkGS

Damn .OK guys. I have lots to consider lol .

Al hopefully we can do that. Problem is with the show and sat nite conference room deal is time will fly by!! 

Thanks everyone who posted. You guys are awesome. 

Good to see there are still some good guys here on HT. I'm still a fan or this site regardless of what some may think and say. 

Tom introduced me to this place a while back and I still enjoy it. Met lots of good people and made many many friends ?


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## Paul R

I think there is a good group of T-Jet guys in your area. A day spent testing and turning with a few other guys is the best way I have found to improve the performance of my cars. Hands on training as it were.


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## slotking

in general the dash arm will make the car faster.
but like some arms are still faster than others

as we all know removing friction is key, but some folks do not add enough brush tension.

I do have some videos out there that show you various tips and tricks like simply stop the brushes from spinning at the video library.


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## Boosted-Z71

Just to add to Mikes comment on brush spring tension, the position is also very important on how the spring holds the brush in the hole, Its all covered in the tuning guide how you want the brushes angled just setting in the chassis. 

Boosted


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## slotking

on the how the brushes sit can be changed depending on what your driving style.

for example

most of the top racers' cars I have tried to drive just do not fit me.
the just coast so much.
my cars have built in brakes so i can drive deep into the turns.


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## Rich Dumas

Many groups that race T-Jets do not allow you to use the brake connection. If you manage to get all of the friction out of the car and it has a good armature you will have plenty of top speed, but the car will want to coast. My club allows brakes and I use a controller with variable brakes, since I am used to that it is difficult for me to run where brakes are not allowed.


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## brownie374

Rich Dumas said:


> Many groups that race T-Jets do not allow you to use the brake connection. If you manage to get all of the friction out of the car and it has a good armature you will have plenty of top speed, but the car will want to coast. My club allows brakes and I use a controller with variable brakes, since I am used to that it is difficult for me to run where brakes are not allowed.


I have been making the transition to no brakes,it isn't easy after running them for 45 years!But in our group the fast guys don't run brakes.


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## rholmesr

brakes only slow ya down


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## ajd350

.....so does the wall

LOL


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## brownie374

ajd350 said:


> .....so does the wall
> 
> LOL


I know that!:freak:


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## slotking

> Many groups that race T-Jets do not allow you to use the brake connection


not talking wired brakes

brakes built into the car is what I do.
I only use the 2 wires on my stage III


But just to note, I have talked to some top drivers who get better times using the brake wire.(in practice, not at races)


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## alpink

in a three wire controller, non-electronic, doesn't the trigger/throttle have to be completely released in order to invoke braking based on the design and wiring of the controller?


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## slotking

yes

you are correct


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## Joe65SkylarkGS

I myself like a nice loose car that coasts!!! 

You'd be amazed how fast they can be coasting!!! 

The stronger the magnets the more stop they have . I try to use stock weak magnets!!!


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## slotking

I got to race some fast guys with all that coast

They noticed how I pulled away from them at the end of straight and was gone!

but it does work around driving style


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## Rich Dumas

My club runs T-Jet SS cars, but we allow controllers with brakes. The controller that I use is a modified Cidex Omni with an added coast and brake control. People that race to Fray or ECHORR rules just leave the brake wire disconnected. If you really have the gears meshing smoothly and the car is fast in a straight line it will want to coast a bit. A few years back I was racing side by side with a rather well known driver and builder. We werre were going neck and neck for three entire heats on a medium sized oval. He started out racing with his brake wire disconnected, I was running with brakes, but I had them turned down. Going into the corners I would always outbrake him and pull ahead. I knew that I had an advantage with that so I took it easy to avoid coming off, we give a one lap penalty for each off. Finally he decided to hook up his brake wire, so he had full brakes, now he would usually overbrake and I would pass him going into the corners. We were side by side going down the back straight as the clock counted down and when the power went off I coasted ahead for the win.


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## toomanyhobbies

Paul R said:


> I'll agree with Rich on one point. A fast car has everything optimized. Dropping in a dash arm isn't going to fix everything. The top builders out there are turning out faster and faster cars even as the supply of Aurora armatures has supposedly disappeared. There is no silver bullet to getting top speed out of the car. What I have found is it takes time and trial and error to get to a well tuned car.
> 
> Here are some of the things I focus on:
> 1. Matched magnets. Getting them as close as possible in readings to each other. Orient them so armature rotation is towards the stronger end of the both magnets.
> 2. Noise. If you have a well tuned gear train, it should spin free with little to no sound. If it doesn't check for slop in rear axle movement. Is it wobbly? Lots of side to side play? Is gear mesh smooth? Gears lapped? Good match between top plate and chassis? Good match between pinion and crown? A larger axles (within the rules) can help with axle slop. Spaces can help to position crown gear for good mesh with pinion. Different crown gear/pinion combos may need to be tried.
> 3. Power. Shoes restricted. Since you say handling is good, this may already be taken car of. Make sure bottom of shoe has good contact with the rail across the entire length of the shoe. You should not see any burn marks if the shoe is setup correctly. Make sure it is not over-restricted. This will help the handling, but will show as burn marks on the shoe and will mean you are not getting enough juice to the motor. the peak of the brush spring should be parallel to the bottom of the chassis so the brush will have even pressure and good contact. Arm should have a flat comm in relationship to the bottom of the chassis and the comm should be surfaced to ensure it is smooth.
> 4. Wheels and tires. Make sure they are on straight and all four wheels are touching the track
> 
> Some things to look at, but the bottom line is time and tweaking. I spend far more time tuning a car then I do building it.


Paul, I have a question. How important are matched magnets, say on a scale of 1 to 10? I have not used any sort of matched magnets but I'm willing to drop the coin for a magnet matcher or matched magnets if they are that important. Also, are you saying in no 1 to have the magnets oriented so the spinning armature sees the strong part first while rotating? 


Thx in advance,

Dominic


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## alpink

Dom, you can use an inexpensive digital scale with a clear lid to get a reading from individual magnets and rate them.
what Paul refers to, I think, is whether the magnet seems stronger on the top or bottom.
since the armature stacks sit a little below center when in the chassis, the field should be strongest at the bottom.
if you would like an actual magnet matcher, I can supply you with one.


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## Boosted-Z71

Matched magnets are not a must for a fast car, you can have poorly matched magnets that are strong and still be fast. With that being said they are a must if your trying to maximize a car, its one area that gains are noticeable on how the car acts, cooler running armatures, smooth performance and power are things you will notice with a good set of matched magnets. Think of it this way, matching magnets is just another tool to use to tweak everything you can from the car. You also need to consider the strength of the magnet for the racing / rules your going to participate in, some guys build with weaker magnets for more rpm & coast, others build with stronger magnets for increased torque and braking, its a trade off. I can also tell you that some armatures like more magnet while others do not, I cant explain it but I have seen it in all forms of winds. 

You dont have to drop big cash for a magnet matcher that is going to give you numbers to compare, you can pick up steel balls, pins etc and get a fairly good idea on the strength magnet to magnet, I have also seen a compass attached to a scale and as you slide the magnet towards the compass you watch where it pins the needle on the compass towards the magnet, farther distance = stronger magnet. 

The theory of positioning the strong end of the magnet to see the armature first, is to use that to pull the arm through the rotation, and then the weak end of the magnet has less effect on the exit and will show increased rpm, where if the magnet is installed with the strong end on the exit of the rotation it could act like a brake, trust me there are several magnetic fields on a t-jet that easily act like a brake system, axles, cluster gear shaft etc. 

Boosted


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## Joe65SkylarkGS

Dominic, no need to buy any special magnet matcher, there are a few ways to do it,

1st way is to get some small metal ball-bearings and match by picking up the same amount on each mag 

2nd way, the way I do it is, Harbour freight sells a small digital scale, with a clear plastic lid, now you turn it on and see the pull the magnets gives you .It's a negative number bbut it works great

http://m.harborfreight.com/1000-gram-digital-scale-60332.html?utm_referrer=direct/not provided.


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## Boosted-Z71

Joe you can also check the downforce the car applies to the track this way

Boosted


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## Dyno Dom

Al, Boosted and Joe GS--do you place a magnet on top of the plastic lid for the reading?


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## alpink

dynodom, yes.
drill some little holes above the buttons to allow access during use.
try to center the magnet above the scale platform with the magnet "U" shape upside down.
use a sharpie to draw where the magnet is on the plastic lid so that you put all the rest in exactly the same place.
the scale will read in negative numbers, so write them down for each magnet.
after you have matching pairs, you can try stuff, like measuring the pull of each end of the magnets and top and bottom strength.

other suggestions forth coming


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## Dyno Dom

Thanks, I'm always looking for more! :thumbsup: Our inline guys are beginning to "drift" toward pancake racing with the AW/JL and Dash chassis.


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## Boosted-Z71

Dyno stick with the Dash or Aurora platforms, 10X better than the JL/AW, I have built them all, an AW chassis is kinda like a Craftsman lawn tractor, if you use it much your going to need a good welder and some spare steel to keep it together.

Boosted


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## toomanyhobbies

Dyno Dom said:


> Thanks, I'm always looking for more! :thumbsup: Our inline guys are beginning to "drift" toward pancake racing with the AW/JL and Dash chassis.


Dom, I'll contact you and Wally via email tomorrow. I'm having a race this Sunday based on these very chassis. I'm setting up pit tables to try and accomadate 12 to 14 people. I'll be in touch. 

I'll process the rest of this info in a few. Thanks to all who replied!

Dominic


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## toomanyhobbies

alpink said:


> Dom, you can use an inexpensive digital scale with a clear lid to get a reading from individual magnets and rate them.
> what Paul refers to, I think, is whether the magnet seems stronger on the top or bottom.
> since the armature stacks sit a little below center when in the chassis, the field should be strongest at the bottom.
> if you would like an actual magnet matcher, I can supply you with one.


Al, I'll contact you via email as well.

Also, when I meant dropping the coin for a matcher, I meant the spin dr matcher for less than 100 bux! Portable and repeatable results. But if I can get by without it, that's all the more money for race parts! 

Dominic


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## toomanyhobbies

Boosted-Z71 said:


> Matched magnets are not a must for a fast car, you can have poorly matched magnets that are strong and still be fast. With that being said they are a must if your trying to maximize a car, its one area that gains are noticeable on how the car acts, cooler running armatures, smooth performance and power are things you will notice with a good set of matched magnets. Think of it this way, matching magnets is just another tool to use to tweak everything you can from the car. You also need to consider the strength of the magnet for the racing / rules your going to participate in, some guys build with weaker magnets for more rpm & coast, others build with stronger magnets for increased torque and braking, its a trade off. I can also tell you that some armatures like more magnet while others do not, I cant explain it but I have seen it in all forms of winds.
> 
> You dont have to drop big cash for a magnet matcher that is going to give you numbers to compare, you can pick up steel balls, pins etc and get a fairly good idea on the strength magnet to magnet, I have also seen a compass attached to a scale and as you slide the magnet towards the compass you watch where it pins the needle on the compass towards the magnet, farther distance = stronger magnet.
> 
> The theory of positioning the strong end of the magnet to see the armature first, is to use that to pull the arm through the rotation, and then the weak end of the magnet has less effect on the exit and will show increased rpm, where if the magnet is installed with the strong end on the exit of the rotation it could act like a brake, trust me there are several magnetic fields on a t-jet that easily act like a brake system, axles, cluster gear shaft etc.
> 
> Boosted


Thanks for this, Boosted. This helps alot. 

Dominic


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## slotking

just to note
i have a video out there on using an iphone app to gauss mags and cars


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## toomanyhobbies

Thanks, King.

I tried that method. I also tried the compass and ruler, and the picking up ball bearing method..none of these were for me. 

Dominic


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## toomanyhobbies

Joe65SkylarkGS said:


> Dominic, no need to buy any special magnet matcher, there are a few ways to do it,
> 
> 1st way is to get some small metal ball-bearings and match by picking up the same amount on each mag
> 
> 2nd way, the way I do it is, Harbour freight sells a small digital scale, with a clear plastic lid, now you turn it on and see the pull the magnets gives you .It's a negative number bbut it works great
> 
> http://m.harborfreight.com/1000-gram-digital-scale-60332.html?utm_referrer=direct/not provided.


Thanks, Joe! I'm going to see if my scale will work the same way. It is similar, but only a small area under the plastic is magnetic.

Edit: It figures..the plate on my mini scale is aluminum!

Dominic


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## Rich Dumas

I have a magnetometer and I measure all of the magnets that I have. I have never done any testing to see how much a big mismatch in the readings will actually hurt performance. All of my cars have magnets that are matched to within 20 gauss. Magnets can be stronger on one end or the other, so just turning one magnet upside down can take a tenth of a second off of your lap times. Outside of using a magnetometer I don't see any good way of finding the strong end of a magnet, but with pancake cars it is easy enough to experiment with magnet orentation.
As far as the Johnny Lightning/Auto World cars go those can be as fast as Aurora and Dash cars. The usual pancake car tuning tips mostly apply, but they do do have at least one unique issue. Take a look at this article:
https://drive.google.com/file/d/0BzLR42NthGeCRzB0RXRwZkxMXzQ/view?usp=sharing


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## rholmesr

Just as a quick R+D experiment last year I tested a good fray car that had matched fairly weak magnets. Then I swapped it out to matched strong magnets. Then I put in strong front/weak rear and then a weak front/strong rear (in other words very badly matched magnets).

As you can imagine, the car ran fastest (straight line speed) and least brakes with the weak/weak. It ran slower but had the most punch and strongest brakes with strong/strong and handled a little better in the turns it seemed. The weak/strong and strong/weak ran the same in my opinion and had characteristics between the two extremes. With the weak/strong or strong/weak combos, however when you turned the wheels it would really 'clunk' the armature to the strong side of the magnet whereas with better matched magnets you didn't get that kind of behavior.

Lap times were best with the weak/weak setup and slowest with the strong/strong setup. But you have to keep in mind that my track is a pretty fast tub track and this was in the fastest middle lane. On a more technical track I probably would have gotten the best times with the strong/strong setup.

I came away thinking that maybe matched magnets are not all that important.


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## slotking

> .none of these were for me


no problem

the app thing looks weird cause the numbers move a lot,
but the key is find the same spot each time and let the mag set.
the readings will settle down to a small range for the ball park reading.
I also find it repeatable


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## toomanyhobbies

rholmesr said:


> Just as a quick R+D experiment last year I tested a good fray car that had matched fairly weak magnets. Then I swapped it out to matched strong magnets. Then I put in strong front/weak rear and then a weak front/strong rear (in other words very badly matched magnets).
> 
> As you can imagine, the car ran fastest (straight line speed) and least brakes with the weak/weak. It ran slower but had the most punch and strongest brakes with strong/strong and handled a little better in the turns it seemed. The weak/strong and strong/weak ran the same in my opinion and had characteristics between the two extremes. With the weak/strong or strong/weak combos, however when you turned the wheels it would really 'clunk' the armature to the strong side of the magnet whereas with better matched magnets you didn't get that kind of behavior.
> 
> Lap times were best with the weak/weak setup and slowest with the strong/strong setup. But you have to keep in mind that my track is a pretty fast tub track and this was in the fastest middle lane. On a more technical track I probably would have gotten the best times with the strong/strong setup.
> 
> I came away thinking that maybe matched magnets are not all that important.


Awesome! I knew someone in T jet racing land did this! Thank you so much for testing this and sharing!!

Dominic


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## Dyno Dom

Boosted-Z71 said:


> Dyno stick with the Dash or Aurora platforms, 10X better than the JL/AW, I have built them all, an AW chassis is kinda like a Craftsman lawn tractor, if you use it much your going to need a good welder and some spare steel to keep it together.
> 
> Boosted


Boosted, good info, Thanks. :thumbsup: We are beginning and learning. 
Honestly, there wasn't prior interest in the Aurora chassis simply because no-one
had them and weren't willing to pursue and sort parts. Interest developed as the
AW/JL and Dash chassis became available as most in the club preferred to buy
both chassis and aftermarket race items new from known vendors. IMHO, it offers
a general sense of level playing field while still introducing new participants to pancake level racing with growth and support for the hobby.


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## Joe65SkylarkGS

Dyno Dom said:


> Boosted, good info, Thanks. :thumbsup: We are beginning and learning.
> Honestly, there wasn't prior interest in the Aurora chassis simply because no-one
> had them and weren't willing to pursue and sort parts. Interest developed as the
> AW/JL and Dash chassis became available as most in the club preferred to buy
> both chassis and aftermarket race items new from known vendors. IMHO, it offers
> a general sense of level playing field while still introducing new participants to pancake level racing with growth and support for the hobby.


Dom, some of the latest AW chassis run good. I know a few guys who run em .Basic tuning, ya know eliminate friction, add Silicon tires and enjoy!! The flamed 67 Nova's come to mind that were good chassis.


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## slotking

with the strong/strong vs weak/weak will vary based on driving style and/or layout.

it also varies based on the arm.

I had 2 cars that I wanted to make faster, and as I played with various changes, I put in some newer strong dash mags and the car was faster on the dyno then the weaker aw mags.

But in general, stock t-jet mags should provide more RPM than strong DASH mags


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## Boosted-Z71

My biggest complaint about the AW chassis is the rear top plate gear & cluster shaft, when you get them running fast the plastic gear that is pressed on will slip, and the hole in the top plate for the cluster gear shaft is huge and very sloppy. We also saw many shoe hangers that were mis-aligned and loose, but that is an easy fix.

Boosted


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## Rich Dumas

Most of the pancake cars that I tune often have armature shaft, axle and cluster gear shaft holes that need to be closed up for best performance.
I wrote separate tuning articles on Aurora, Johnny Lightning/Auto World and Dash cars because they can each have problems that are unique. An article that tried to cover all three types would probably be too confusing. The unique thing about JL/AW cars is that most of the gears are plastic. The cluster gear shaft is splined so the plastic driven and drive pinion gears won't slip, but the cluster gear shaft is actually too short. Very often the cluster gears are not assembled correctly so the end of the shaft is not in the base chassis. If that is the case the whole assembly will not be supported at the lower end causing it to tilt sideways and the gears to bind. Just fixing that problem can make a huge difference in the way a car runs.


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## Joe65SkylarkGS

Rich Dumas said:


> Most of the pancake cars that I tune often have armature shaft, axle and cluster gear shaft holes that need to be closed up for best performance.
> I wrote separate tuning articles on Aurora, Johnny Lightning/Auto World and Dash cars because they can each have problems that are unique. An article that tried to cover all three types would probably be too confusing. The unique thing about JL/AW cars is that most of the gears are plastic. The cluster gear shaft is splined so the plastic driven and drive pinion gears won't slip, but the cluster gear shaft is actually too short. Very often the cluster gears are not assembled correctly so the end of the shaft is not in the base chassis. If that is the case the whole assembly will not be supported at the lower end causing it to tilt sideways and the gears to bind. Just fixing that problem can make a huge difference in the way a car runs.


Any pics?


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## Rich Dumas

I did not take pictures to illustrate the procedure that is included in my article. Pictures would no have shown much because everything is so small, I could have done some graphics, but I thought that a verbal description would be good enough. Take a look at the article and get back to me on that.


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## slotking

I find making the chassis holes small enough that the axles and motor shaft do not turn really increases the handling!!

I have yet had a car setup this way de-slot:wave::devil:


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## Rich Dumas

It might be a good investment to buy a drill blank that is a 1/1000 or so bigger in diameter than the axles that you use. You can use that to test the size of the holes before you close them up and to make sure that the fit will not be too tight. You should also be aware that stock axles from the same maker are not always the same diameter.


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## LDThomas

When I am shrinking axle holes and armature holes, etc., I always go a bit tight. It is simple to bring them back to perfect. Insert the drill blank of choice into your Dremel and then insert into the chassis. Turn the Dremel on and it will basically melt the hole to the exact size of the drill blank. Result - perfection.


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## yellerstang

It will melt quickly if you dont use a lot of oil. I prefer to ream anything like that by hand, but, if it works for you its fine with me too. Thats what I like about this forum, so many personal ideas and techniques. I like to read them and try to apply the info to what I think I know and what I believe to know. Sometimes, I dont know crap....


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## yellerstang

*Drill blanks and other stuff*

Oh, for those who may not know... McMasters and Grainger have tons of cool items you can use with your hobby. Besides decent hand tools, you can a lot of neat things to use at the bench. Braid is an example. Check around, many more if you search their sites. Just an fyi to put out there today....

drill blanks too


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## rholmesr

McMaster-Carr is awesome.
Drill blanks for use on t-jets and other slot cars with the McMaster part number:

.059" (1.5 mm) 2900A222 -- Same size as a tyco rear axle. 

.061" (1.55 mm) 2900A223 

.0625" 3009A114

.063" (1.60 mm) 2900A224

.0635" 3009A267

.065" 2900A225 -- Great for checking t-jet chassis flatness on a gauge block.

.067 (1.7 mm) 2900A226 

.049" (1.25 mm) 2900A216

.051" (1.30 mm) 2900A217


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## slotking

melting is better
it hardens the plastic and provides less friction


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## LDThomas

I never like to remove material. There is no way to put it back. Melting in place, in my opinion, is the better solution by far. Slotking nailed it.


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## Bill Hall

Bookmarked that nice list. Thanks for sharing!


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## ajd350

Agreed, LD. You can move plastic around many times, but once it's taken away, it's forever.


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## Dyno Dom

If AW/JL rear axles are .062" and need to replace crown gear and axle with new,
is .061" an adequate choice? Would the melt method work with slightly larger size axle?


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## slotking

yes
thanks for the list


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## Joe65SkylarkGS

I think we should make this thread a Sticky ?


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## Rich Dumas

If you check a lot of JL axles you will find that the diameters will vary. I always replace JL axles with a drill blank. Since you can close up the axle holes it does not matter as much what diameter axles you use. If I am blueprinting a car I swage the axle, armature shaft and cluster gear shaft holes, then use a drill blank to check them. Everything must be as close of a fit as I can get so the the axle, armature or cluster gear shaft will turn without binding.


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## Joe65SkylarkGS

Rich what is the standard tjet blank size?


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## Rich Dumas

I use 0.063 inches.


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## Dyno Dom

Rich, will that size drill blank work with a new replacement AW/JL Crown gear without epoxy? Also, do you use splined axles?


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## Boosted-Z71

Dom, I sand blast my gage pin axles where the gear sits, and just a drop of super glue or loctite makes a wicking bonding agent that works really well, all you need to do is rough the area under the gear. HF makes a nice little sand blaster that looks like an air brush, it works really well for this.

As far as size, I use mostly 0.063 or 0.0635 Gage pins you can get in .0005 sizes and they are only a couple bucks a piece from Mcmaster carr, get class ZZ pins, great finish and they stay straight. 

Boosted


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## Dyno Dom

Boosted, Thanks for good info. :thumbsup: I'd like to replace some original
AW/JL rear axles with better quality and new Crowns. 
At some of the HO shows I've purchased drill blank axles and some Crowns. Unfortunately, I recently was told the vendor I bought them from doesn't sell factory fresh parts but rather full chassis that are parted out and bagged. I'll have to try a set but do you think
a Crown that has been stripped from a prior axle will have further issues?? 
Our rules for what we call Fracas cars are AW/JL and Dash chassis utilizing
original chassis, arm and gears. Either Manufacturer motor mags can be swapped
and electricals, guide pin, axles, rims and tires are open per legal width.


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## Dyno Dom

Which Locktite is best to use to secure crowns on axles??


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## Rich Dumas

A 0.063 inch axle should work without glue. If I expect to race a car I replace the stock JL/AW crown gear with a CNC one like RT-HO sells. It is also possible to swage a stock crown gear for a tight fit.


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## Boosted-Z71

I have used loctite 638 & 648 retaining compounds, both work well, just a drop, super glue works well too, it just takes longer to setup.

Axle diameter is not the issue with whether the gear is tight, the surface finish on a gage pin is so smooth the gear will still slip on the axle, roughing it up and a drop of glue takes care of any worries and you still have a polished axle.

If your rules allow it the really slick axle material is a hypodermic needle, they are stainless, hollow and polished, they wont take as much crashing but still pretty strong and you eliminate the magnetic effect from the rear magnet to the axle, trust me it exists and this axle makes a huge difference. 

Boosted


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## alpink

agreed, there are folks selling hollow stainless steel axles


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## Boosted-Z71

Here is a chart for the needles to use for axles 










You can get them in bulk on Ebay, cut to length and your in business 

Boosted


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## Dyno Dom

I p/u a tube of Permatex green as it is similar to Locktite. Each of those thread locker products are intended to apply after assembly. I didn't use it as the AW Crown I purchased works on the new drill blank axle so I'll keep it on hand as needed. Our rules don't allow aftermarket gears, good info Boosted and Rich!


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## Joe65SkylarkGS

Question guys, what can I do to revive the original t-jet tires??

I need to tune up my 100% stock t-jets for the Drag Race sat, and the tires are a little tough. I need to soften them up and try and get some bite and life back in them.

I don't have the old wintergreen traction compound around anymore. 

What else works?


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## yellerstang

Hey Joe, there are several types of tires out there that look just like originals. Some are silicone based with a rubber blend, some are some type of silicone. Its late in the date to try to get this stuff online now, since the race is so close...

I bought oil of wintergreen online a few months back. It will treat rubber tires, it will eat JL and AW tires. Quickly.

You can try softening up your tires with motor oil, but I would glue them to the rims, true them up, then treat them. Motor oil works for this, but not as good as oil of wintergreen. Btw, they say you can get this at drug stores, but every place I checked said no.... online only. Good luck. Hope to see you at the drags. Jess


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## yellerstang

I read once that oil of wintergreen is primarily used in the printing industry to soften rubber rollers on printing machines....


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## Joe65SkylarkGS

Ah, thanks.

I think I have some TQ upstairs now that I'm thinking about it.


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## toomanyhobbies

I got my oil of wintergreen in a Vitamin Shoppe. 

Johnny Lightning/Autoworld and Dash tires are NOT legal in stock t jet class for Al's drag race. (FYI, the original Johnny Lightning front tires work almost as good as silicones!) I asked Al about this before last race. I'm not aure where he gets his supple NOS tires though. 

Oil of wintergreen dabbed on with a toothpick just before you run will yield the traction you seek Joe! No wipng needed. Get the shoe pressure right for the launch though!


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## yellerstang

The Dash tires have a silicone base to them, but for drag racing they just don't work so well. Rubber tires with treatment are the best way to go, at least for me.

Some of these tires look the same, they may be made by the same people, I don't know... but, there is a difference. 

Model Motoring has rubber tires. They also sell some that are silicone based. So, beware of what you buy. His rubber tires are decent, as are original Tjet if you can find some that aren't dried out. 

You can figure this out really quick when you go to sand them. The rubber will sand and true up easily, not so much with the silicone based tires. You can sand them, but it takes a lot more effort.

And yes, I agree, JL tires really work well. But, they are wider than stock Tjets and they cannot be treated with Oil of Wintergreen-it really eats them.

Jesse


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## Boosted-Z71

Just be careful with the wintergreen, it is considered a toxin if your exposed too much to it,, also it will soften rubber tires and it will change the diameter of the tire, I have had them grow and shrink so its a 50/50 shot on what will happen to them. 

Boosted


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## Joe65SkylarkGS

The ONLY tires allowed are stock tjet tires. No silicon of any kind.


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## alpink

Jess, let us be clear ....

in 100% stock t-jet class, ONLY stock t-jet tires are allowed!

not silicone
not D-Jet
not Auto World
not Johnny Lightning

it is very important to use only original Aurora manufactured parts in 100% stock t-jet class .... EXCEPT for motor brushes which may be any Copper/Carbon brush manufactured for pancake chassis.

I don't want someone to think that because they saw in print somewhere that replacement skinny ribbed silicone tires are allowed in 100% t-jet class that the rules have changed in any way.

I am sure you didn't intend anything more than to be helpful

ONLY ORIGINAL AURORA BRAND T-JET TIRES MAY BE USED IN 100% T-JET CLASS

.


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## yellerstang

*tires*



alpink said:


> Jess, let us be clear ....
> 
> in 100% stock t-jet class, ONLY stock t-jet tires are allowed!
> 
> not silicone
> not D-Jet
> not Auto World
> not Johnny Lightning
> 
> it is very important to use only original Aurora manufactured parts in 100% stock t-jet class .... EXCEPT for motor brushes which may be any Copper/Carbon brush manufactured for pancake chassis.
> 
> I don't want someone to think that because they saw in print somewhere that replacement skinny ribbed silicone tires are allowed in 100% t-jet class that the rules have changed in any way.
> 
> I am sure you didn't intend anything more than to be helpful
> 
> ONLY ORIGINAL AURORA BRAND T-JET TIRES MAY BE USED IN 100% T-JET CLASS
> 
> .


Well, this changes everything. I did not realize that it was Tjet tires specifically. I bought Model Motoring replacement RUBBER tires. All of my cars are set up with these. These tires are sold on Ebay as a direct replacement for dried up Tjet tires. 

I really doubt if I have enough time left to change over to tjet tires from the replacement tjet tires (they are rubber, not silicone). I have cars prepped for me and my brother, do I dont know if I can get this done in time for Saturday's race.

Im not complaining or bitching. I am a rule follower, not a rule breaker... I thought these tires were OK to use... 

Jess (Al, call me if you can after 5:30 tomorrow) 

Jesse


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## Rich Dumas

Wintergreen only works for a short time, but if you are drag racing that is all you need. It used to be possible to buy oil of wintergreen (methyl salicylate) at just about any drug store, but it is actually somewhat toxic, so it may now be more difficult to find. People that use rubber tires on 1/32nd cars often treat them with suntan lotion or 3in1 Oil. NSR makes a treatment for their rubber tires that should work OK.


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## Mexkilbee

I know this is a little late, and maybe people have already found this out or other better solutions, but the car detailers out there will possibly know this. Wurth, a German company, makes a product called "Rubber Care". It is a better Armorall. I have placed t-Jet, Tyco, AFX, Tomy and other hard rubber tires in it. (It comes in an aerosol, spay it into a small jar). Let sit overnight, the tire will swell to twice...four times its normal size. Take tire out, wipe off excess and continue to let dry on hard surface. Two to three days latter it will be back to its normal size and be soft and supple. Better than new. Your results may very, but for me it works wonders.


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## Rich Dumas

One thing that I don't like about using natural rubber tires is that they can harden up with time and will respond to various treatments. Someone might come up with great tire treatment that he is not willing to share and thus have an advantage. If you are trying to level the playing field you might be better off using tires that do not require soaking in mouse milk or snake oil to work well. The skinny Dash T-Jet style silicone tires that I have look just like original Aurora skinny T-Jet tires and seem to have about the same grip as untreated rubber tires. The Dash tires would not respond to any treatment that I am aware of beyond simple cleaning.


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## slotking

the Greenbrier Thunderjet challenge use stock Aurora tires and we use various chems to soften them
people have used brake fluid, lacquer thinner, wintergreen, RC car tire softeners.

The cars really hook up well.

I never soak my tires, I applied my chem choice only to the OD of the tire. I would do it 2 or 3 times a day for 3 weeks and worked well enough that I had to soften the shoe springs to stop the car from wheeling out of the slot


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## yellerstang

*Dash tires*



Rich Dumas said:


> One thing that I don't like about using natural rubber tires is that they can harden up with time and will respond to various treatments. Someone might come up with great tire treatment that he is not willing to share and thus have an advantage. If you are trying to level the playing field you might be better off using tires that do not require soaking in mouse milk or snake oil to work well. The skinny Dash T-Jet style silicone tires that I have look just like original Aurora skinny T-Jet tires and seem to have about the same grip as untreated rubber tires. The Dash tires would not respond to any treatment that I am aware of beyond simple cleaning.


The Dash tires seem to be ok, but if you are racing these tires they do have some issues. I have found them difficult to true on the hub. They dont like to be sanded. They dont glue to the wheels very well either. They are great for collector cars more so than dedicated race cars.

As Im sure a lot of guys know, it can be tough to find a decent pair of original Tjet tires that approach the .400 size, at least before truing. I have found that I have to sort through a number of tires to find some that match in height and width.

I have also found that if the Tjet tires are over treated with anything, they may grow inconsistently. I have had them trued and race ready, then found the contact surface to be lop sided after treatments. That condition only happened if I repeated coatings on the tires, I also found that they will go back to the proper shape if not treated further. Maybe someone else has seen this too?

I have found that on my track, the original Tjet tires when glued, sanded, trued, then lightly treated with oil of wintergreen will out perform anyone elses Tjet replica tires on the drag strip. If you clean the Dash tires with denatured alcohol they will hook up ok, but not as good as the original Tjet rubber tires.

Your results will vary... take it with a grain of salt, so to speak. Test the tires and treatments, then tell us if you agree. Thanks

Jesse


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## Rich Dumas

If you want to true the Dash tires you can put them on a drill blank or just the shank of a regular drill bit. Short lengths of PVC tubing would keep the tires from moving around.
You may have noticed that I said "level the playing field" in my earlier post. If you want your races to be a contest for people that can dope their tires the best just continue as you have. People that want to eliminate all of the uncertainties associated with rubber tires might consider using a spec silicone, Gel Claw or urethane tire.


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## alpink

Rich, I am going to have to take exception to your comment "If you want your races to be a contest for people that can dope their tires the best just continue as you have. "

Jesse and many other racers have helped all others with "doping", truing and other aspects of getting the most out of stock original Aurora Thunder Jet 500 tires and parts.
at our races.
the only ones without equal set ups are those who don't want help.
you seem to have quite a bit of experience and knowledge about many aspects of racing and I find it alarming that you would make such a comment or pass judgement in that manner.
Jesse has done quite a lot of testing, trial and error, and shared all his results with everyone and anyone who cares to read and/or listen.

thank you for all that you do for the hobby.
I know that, in general, you intend to always be helpful.
but, too often, you come off as condescending!


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## yellerstang

*Tires*



Rich Dumas said:


> If you want to true the Dash tires you can put them on a drill blank or just the shank of a regular drill bit. Short lengths of PVC tubing would keep the tires from moving around.
> You may have noticed that I said "level the playing field" in my earlier post. If you want your races to be a contest for people that can dope their tires the best just continue as you have. People that want to eliminate all of the uncertainties associated with rubber tires might consider using a spec silicone, Gel Claw or urethane tire.


Hey Rich,

No harm, no foul. At my home track I gave out a few dozen of the Dash type silicone based tires to try and get my friends interested in a stock, spec style drag race class. We have raced only Tjets on road course and drags for a long time here. Just fun, no big deal. My friends are a little bit on the conservative side, they buy lots of Weird Jack tjet sized silicones (bags of blems). The glue them to th rims, true them up, and race them until they are just worn out.

They were not interested in my idea, of course. One big problem with the WJ tires is that if you dont use double flanged wheels, the glue bond breaks and the tires come off during a race. Nothing breaks if you are not using it.

I have, over the years, adapted some of the rules from popular events out there so that I can go race elsewhere and have my cars come in to spec without drama. For most home racers, its what is fast and cheap. I tried Jelclaws a few years ago. I found them to be expensive and really did not work well at all on our stock cars. Then I tried the Dash and Model Motoring tires that have silicone in them. Great for show cars, cheap too. But, not so good for racing. I did buy some plain rubber replacement tires from MM, but I dont know if this same tire is still available out there or not. They worked just like stock Tjet tires, since they were rubber as well.

So, its all about what you want, how you prep them, and what you are willing to spend and put up with. Choices.

At my home track, my stock Tjet skinny tired class will allow any ribbed stock sized tire, as long as its the same style, width, and appearance as a stock Tjet tire. That is rubber, rubber/silicone, but no pure silicone type tires. Thats my choice here, but the guys who take the time to prep the original tires will have the edge.

As I write this, I am in the hunt for a Trackmate timing system for my drag strip. I am nearing completion of a basement repaint and have everything else that I need to build my new road course and drag strip. So, if anyone knows of a timing system for sale, please foward this to them. Thanks.

Happy racin, *** We dropped the hot inline cars years ago because it became too expensive and too intense. We love sliding the Tjets around, cheap fun! ***

Jesse Shipe
Shamokin, Pa.


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## Mexkilbee

The Wurth "Rubber Care" never made the stock tire better than it was the day it was placed on the hub at the factory. If that. So I never felt bad about using it, and no one I raced stock tJets with did either. I was free with the info and shared the jar of tire goo. 
Not only great for racing but for the shelf queens tires that you wanted to keep fresh.


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