# Another t dash question



## mrtjet (Dec 3, 2013)

Would you say that the dash magnets help the handling noticeably, or not so much? I ask because I like my handling to come from hand eye coordination and a heaping dose of skill.


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## Boosted-Z71 (Nov 26, 2007)

The only magnets that I have noticed making a difference in handling was Neo type mags, you could feel the down force and they measured almost the same as a magna-tracion on the down force scale. 

Boosted


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## mrtjet (Dec 3, 2013)

Boosted-Z71 said:


> The only magnets that I have noticed making a difference in handling was Neo type mags, you could feel the down force and they measured almost the same as a magna-tracion on the down force scale.
> 
> Boosted


Thanks. I would hate to see that the t dash is just another magnet car. Long live non handling assisted cars. IMHO


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## Rich Dumas (Sep 3, 2008)

Both Dash and JL/AW magnets are much stronger than any of the original Aurora T-Jet magnets. I have a magnetometer and I have measured about 950 gauss for both makes. Older Aurora T-Jet magnets were around 450 gauss, the strongest that I have found are the green/white ones. Aurora Super II magnets vary greatly in strength, I have several pairs that measure 1100 gauss.
In the case of T-Jets the magnets are further away from the rails than more modern designs. The amount of magnetic downforce that you get depends on the strength of the magnets and the distance from the rails with the downforce being proportional to the square of the distance. If you double the distance you will decrease the downforce by 75%.
I have done a great deal of testing to determine the correct tire diameter to use with my cars. Even though the magnetic downforce is weak it is still a factor. Generally as you go down in tire diameter and the downforce increases your lap times will go down. On tracks with long straights the loss of straight line speed is actually visible, but up to a point the increase in cornering speed will get you lower lap times.
You would expect that a car with stronger magnets would also produce more power. The effect of stronger magnets does not seem to be linear, I believe that is because motors with stronger magnets produce more back EMF. If you use magnets that are too strong for the armature you top speed will be reduced.


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## Boosted-Z71 (Nov 26, 2007)

A very large effect on a t-jet with some of the stronger magnets is the drag that is created on the rear axle, Take a chassis with only wheels, tires and magnets and roll it down a slight incline, now change the rear axle to something non-magnetic and do the test again, you will see a fairly large change in the distance the car rolls, this is all due to the magnetic effect on the axle, the stronger magnets you put in the car the worse this gets. Since the front axle is further away from the magnet in the car the effect on it seems to be negligible. 

Boosted


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## lenny (Feb 29, 2000)

Boosted-Z71 said:


> A very large effect on a t-jet with some of the stronger magnets is the drag that is created on the rear axle, Take a chassis with only wheels, tires and magnets and roll it down a slight incline, now change the rear axle to something non-magnetic and do the test again, you will see a fairly large change in the distance the car rolls, this is all due to the magnetic effect on the axle, the stronger magnets you put in the car the worse this gets. Since the front axle is further away from the magnet in the car the effect on it seems to be negligible.
> 
> Boosted


it's may be worth noting here that the dash axles are stainless steel (non-magnetic)


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## Boosted-Z71 (Nov 26, 2007)

Well that is a great bonus to the Dash-jet,

Lenny you built a great car for our hobby, I have several dozen, and they all perform well
Glad to see they are being adopted in the racing circles as well. 

Boosted


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## WooffWooff (Dec 23, 2009)

*Dash downforce*

The Dash magnets I've tested generally are 3 1/2 to 5 times stronger than stock and 10-20% stronger than JL magnets in the "head-on"/ horizontal plane, and with about 4 to 6 times stronger downforce (i.e...100 reading vs 450-475). Combine that strength with .326-.328 O.D. rear tires and you have a "magnet-car", no doubt about-it. There will be several at the "Fray" this week.


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## super8man (Jan 29, 2013)

It all depends on how low you can go! I'll be at the Fray later this week and can't wait to get out and race! Dash magnets are pretty standard. And yes, the magnets will also affect the natural braking (Fray cars in Ferndale don't have the third wire brake attachment on any of the tables/tracks). Locally in NorCal we run exclusively 2-wire hookups, even at home. Oh, and 326 may be a bit "tall", just hinting...


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## Paul R (Nov 3, 2009)

I think the answer depends on how the car is setup. If you are talking about a fray/ECHORR SS setup, then there is some down force coming from the motor magnets. If you look at HOPRA (www.hopra.net) Gravity class rules, a car with DASH magnets will not pass the "Lift Pin Test". For Fray/ECHORR SS you have the chassis as low as possible, there is a small amount of down force.


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## WooffWooff (Dec 23, 2009)

*Dash downforce...*

"a small amount" of downforce it may be, but a good set always turns me into a "great driver" compared to without the help. Of course just any 'ol set won't do. Strong or not, matched magnets won't necessarily have much downforce. I never even check for "matched/strength". I just try every - single combo available look'n for downforce, HUGE downforce.........it's there. Magnets have mysteries.


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## Rich Dumas (Sep 3, 2008)

If you check T-Jet magnets with a magnetometer you will soon find that the magnetic field is very irregular. Different people use different measurment techniques and would probably get different readings for the same magnet. In most cases you would be more interested in comparing different magnets, so an absolute value would not be as important in any case. What matters is getting consistant values for the same magnets, otherwise the values would be less meaningful. With a magnet matcher it is easier to get consistant values, but those might not tell you everything you could want to know about a particular magnet.
I recall that back in the mid '60s my cars had a lot of coast, all of those cars got stolen many years ago, so of course I never had a chance to measure the magnets. All of the Aurora magnets that I have now were probably made after 1968 and are probably stronger than the earlier magnets.
The strongest ceramic magnets that I have ever measured were the BSRT T2 traction magnets that they sold for Tyco 440X-2 cars, those were 1550 gauss.


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