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Playing Around With The Mega G 1.7

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  • Speedhoppy
    started a topic Playing Around With The Mega G 1.7

    Playing Around With The Mega G 1.7

    There have been a number of posts about the Mega G, in both long & short wheelbase versions. More than a few posts about improving performance, by "flipping" or substituting the chassis magnets for stronger ones, gear/pinion changes, new wheel/tire combination both front and rear, changes in brush barrels, etc. There is a current post right now by JLM Racing ("Yobear"), which has a lot of information.
    Like a lot of Forum members I don't belong to a racing club. But, I read, I ask questions, and try a few things, because while I like the Mega G cars overall, I like to "tinker" to a limited extent, to improve the performance on my particular layout. Most every "set" car can usually be improved with rear tire upgrades to the standard hard rubber tire, but as can be seen from previous posts, more can be done. So, as best as I can, I will share what I discovered. It's nothing earthshakingly new; but it validates some of the things that have been suggested, and in one particular change, really opened up my eyes.

    THE PROBLEM: While the Mega G 1.7 is very smooth on wider radius turns, it does not do well on tight turns; on my track, that's the entrance/exit to my "Double Split Chicane" (with squeeze tracks sandwiched in between):



    And my chicane just before my main grandstand (made up of 6" & 9" segments):



    These are tight "S" turns, but they can be negotiated; just slower than the Mega G 1.5, as well as my other cars with a shorter wheelbase. Generally, the Mega G 1.7 front end would lift off and deslot the car, although sometimes it would swap ends and spin around backwards. I generally put this down to the longer front end of my Audi R10's and Peugeot 908's catching on fencing or barriers, but in looking closer, that was not the case. I assumed that the guide pin placement behind the front axles was part of the problem, but that could not be addressed, (unless someone fabricated something like Nico has shown on the Forum, but is not available here). So, I looked at what others were doing with the front end, and used that as my starting point. I have not "flipped"/changed magnets; I wanted to see what could be done without that modification, and try it if my "fiddling" didn't give me the results I needed. So, here are my three comparison chassis, unmodified except for new, lower front ends, and upgraded rear tires:



    Left:Car#1- Front end a standard BSRT solid front end off my "G-Jet" (when I went with an independent front set up for that chassis), .352 dia. according to my BSRT Tire Template, with original Mega G rear hubs mounting .456 Jel Claws. Center:Car#2- Wizzard solid front end (.356, and swapped off my Wizzard Storm & P2E, when I went independent on the front for both those chassis), with original Mega G rear hubs mounting .460 A.J's silicones. Right:Car#3- Wizzard Independent front (.354), with Wizzard rear hubs mounting .440 silicone coated sponge tires (an old pair I had laying around and just wanted to try).
    Nothing nobody else hadn't tried; the Mega G front end needs to come down, which gets the guide pin a little deeper in the slot and slight lowering overall gets the chassis magnets closer to the pickup rails. I don't have an electric timing system; but I have a "feel" for my layout, and I can see where my particular chassis/body combo has strengths and weakness. I wanted to negotiate those tight chicanes better; THAT was my goal here.

    RESULT: Cars #1 & 2 improved overall on my track with the lower front end combos/ rear tire changes, but the solid wheel/ axle combos DID NOT improve on those chicanes; it was obvious that the solid front wheel / axle combos were binding in the tight radius turns, and still threw the car out of the turn (although the speed through the chicane had improved slightly).

    THE WINNER: Car #3, with the Wizzard independent front end and Wizzard lower profile rear wheel/tire combination. That car (with Peugeot 908 body) has no binding due to those independent spinning front wheels. That made more of a difference than simply lowering the chassis.

    CONCLUSION: I'm going back to Lucky Bob's (it's near my home office), and picking up more independent front ends for my Mega G 1.7 chassis, and experiment further with slightly lower profile rear Wizzard wheel/tire combos.

    DISCLAIMER: This was not a "scientific" test; just a guy tinkering with his cars, trying to make a particular chassis (Mega G 1.7) get around his particular track better than it had before. Layout design/turn radius of a particular track will probably yield different results, as well as any other changes one might be making as well. But it was a relatively simple swap, that made a bigger difference than I first imagined it would. At least in my case, I now know better........
    Last edited by Speedhoppy; 01-25-2019, 08:35 AM. Reason: Added pictures/ sentence revision/correction

  • model murdering
    replied
    Oh man! I totally agree. It makes a night and day difference.

    Like many things "slot car" there is much lost knowledge. Champfering tires goes back to the golden age. I prefer both inside and outside champfering, because a chassis slides both directions. No matter what, you always have an opposing inside edge barking, while the opposing outside edge is biting. If you're REALLY loose, those subtle sidewall angles help you get across the rail, and back; if your lucky or good.

    Additionally, as silifoams go, flow-able silicone over a sharp 90 degree sidewall isnt a reliable edge for the silicone to flow over, leaving the transition between the contact patch and the sidewall quite thin and vulnerable. Whether you are sliding your car around with abandon or just need a little slip at the ragged edge of adhesion, attention to the sidewalls is important.

    As for the width? It's long been established by slot drag racers that "ever wider" rears isnt necessarily more efficient. At some point the added weight becomes a detriment rather than a tractive advantage. If memory serves Super Dave has some documented ET's that support the theory.

    Leave a comment:


  • RichD
    replied
    I always thought that those cars had narrower rear tires to make room for bigger traction magnets. You could try putting narrow tires on an older car with smaller traction magnets, such as a Tomy Super G+ or a Wizzard Patriot to see if the car would be faster.

    Leave a comment:


  • Speedhoppy
    replied
    POSTSCRIPT/ FOLLOW UP- When I wrote my ORIGINAL conclusions, I had taken note of the winning combination having lower profile, silicone covered sponge tires from Wizard. As I have been transitioning over to this type of tire/wheel combination (I still use slip-on tires on many of my cars) , I had simply assumed the increased traction/ handling was due to the tire diameter and construction. What I had NOT taken into consideration (but have come to appreciate) was the narrower, round-edged characteristic of the tire, which allowed just the tiniest bit of "slip" through those tight corners. The wider and/or flat-edged tire didn't have the same "give"; it just pulled the car out of the slot sooner than the round-edged tire. When I started acquiring Viper Chassis, I noticed they all came with smaller diameter, narrower, rounded-edged tires. And they (being a advancement on the original Super G+ chassis, like the BSRT had been) handled every corner of my layout (Tomy sectional) and Fastlap's custom Bowman track with equal aplomb, on LESS tire!

    So, why isn't the wider the tire, the better handler (for a given chassis) in the corners?

    When it finally sunk in, I was embarrassed, because I should have known. It's because slot cars (unlike real cars) don't have a differential (which allows the inside drive wheel to turn slower than the outside drive wheel in a turn); they have a solid axle, so BOTH wheels turn at the exact same speed. Therefore, the WIDER the rear tire for a decreasing radius turn, the more chance the torque of that axle (and traction from wide tires) will flip the car out of the slot.

    I have been experimenting with narrower Wizard silicone-coated sponge tires (both black, orange, and red colors), on all my "commercial" chassis: LifeLike (M & T); Tomy (Super G+,Turbo/SRT, Mega G); TYCO (440x2 "Pan" & "Narrow), and the results have been gratifying. Faster speeds in the turns (due to less torque-twist), especially the tighter turns.

    Lesson learned? BALANCE the front end (whether independent or low profile/lightweight) with lower profile, high quality round-edged NARROWER rear tires of quality (whether you prefer slip on or combined with a wheel is up to you), go with lower profile pickups, and you are on your way.........
    Last edited by Speedhoppy; 09-21-2017, 05:45 PM. Reason: Additional sentencing

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  • Jensen B
    replied
    Originally posted by PPRSLOTS View Post
    Thanks that makes sense now... now the hard part how would you know if somebody swapped magnets around if running all box stock?

    O yes I do have a pocket gauss meter so that would work.
    Or use a magnetix stick and mark the poles and use as a tester stick.

    Leave a comment:


  • Jensen B
    replied
    Originally posted by Gareth View Post
    How can you have 16 different ways to align two magnets? Or are you including rotating the motor mags in conjunction with the tractions?
    You could do that too.

    4 side to each magnet then flip, is 4 more, flip the motor magnet (doesn't change the polarity) and make the same moves with the traction magnets as before = 16 combo's.

    Leave a comment:


  • Backmarker
    replied
    Originally posted by Gareth View Post
    How can you have 16 different ways to align two magnets? Or are you including rotating the motor mags in conjunction with the tractions?
    I'd like to know this trick also.

    Originally posted by woodcote View Post
    Thanks Mike - I just use a cheap Desk Top Publishing (DTP) programme - PagePlus - and then export as a jpeg image file.
    Thats not amateur work my friend!

    Leave a comment:


  • woodcote
    replied
    Originally posted by Backmarker View Post
    Andy has the coolest graphics to explain things. Do you make them yourself Andy? Id so, what program are you using?
    Thanks Mike - I just use a cheap Desk Top Publishing (DTP) programme - PagePlus - and then export as a jpeg image file.

    Leave a comment:


  • NicoRosberg.
    replied
    It can only be a combination of rotation and flip, although Bob doesn't say all would make a difference.

    With square traction magnets you could actually have 48 options.
    Last edited by NicoRosberg.; 04-23-2014, 11:22 PM.

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  • Gareth
    replied
    How can you have 16 different ways to align two magnets? Or are you including rotating the motor mags in conjunction with the tractions?

    Leave a comment:


  • neorules
    replied
    With the G's you can always re zap the magnets to change polarity. With the Storms there 16 different ways to align the tractions. Same with G3'ss and Slottech ss if you can rezap.

    Leave a comment:


  • Backmarker
    replied
    Andy has the coolest graphics to explain things. Do you make them yourself Andy? Id so, what program are you using?

    Leave a comment:


  • NicoRosberg.
    replied
    Google 'BSRT g3 build lenjet' to see how to flip magnets in the SG+-based G3.
    Last edited by NicoRosberg.; 04-23-2014, 07:53 AM.

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  • Jensen B
    replied
    Slotbob

    The SG+ magnets have a fixed orientation one positive, one negative and they are a different shape each side so cannot be flipped nor moved.
    However all the examples I have are in the high downforce mode.

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  • NicoRosberg.
    replied
    Originally posted by PPRSLOTS View Post
    Thanks that makes sense now... now the hard part how would you know if somebody swapped magnets around if running all box stock?
    A field checker should in theory work.

    I use one of the magnets in a telescopic holder and carefully bring the magnet in it towards those in the chassis

    Leave a comment:

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