jphanna Posted August 7, 2015 Report Share Posted August 7, 2015 Guys the rims with air holes that seem to be the latest fad. I have asked a few of my fellow race mates about them. they recon its just weight saving. Is there any science involved, or is it in fact just that weight saving? I would have thought that once the tyres and sealed with rims, that air cushion help with handling. Having the holes there means no air cushion effect anymore. Forgive me if this has been thrashed out on here before. Quote Shed People Mutual Admiration Society 2 times Australian National Champion 1991-Flexicar 1999- Group 12 Sedan Link to comment Share on other sites More sharing options...
Pauls Slots Posted August 8, 2015 Report Share Posted August 8, 2015 Unsprung mass John The lighter the better Quote Try Harder, if you dont fail your not trying hard enough Link to comment Share on other sites More sharing options...
David Carter Posted August 8, 2015 Report Share Posted August 8, 2015 that is my believe on it as well the lighter the drive set up is the more responsive the the motor will be these little motors are very sensitive to weight and friction I have taken standard alloy rims and drilled them solely for this reason why I drill standard rims instead of buying ones that are already done is to keep the cost down Quote Holdens rule the rest just drool slot cars are my drug, ATCC/Bathurst proxy host NZ Grp5 proxy host. Link to comment Share on other sites More sharing options...
Ember Posted August 8, 2015 Report Share Posted August 8, 2015 Really?? When as often as not people add weight elsewhere? Surely any weight in the wheels is where it's desirable, as close to the track as possible. And the Nth of a gram saved from each wheel? Quote Computers. They'll never catch on. Tiny Tyers Targa - The build saga continues - Aging wood - A recipe for staining wood - Don't take a fence - Step by step paling fence - An old shed for my new cars - Wooden garage under construction Link to comment Share on other sites More sharing options...
axman Posted August 8, 2015 Report Share Posted August 8, 2015 Simples... take 1 Mini Z and do nothing else but change to drilled wheels and you pick up at least 1/10th of a second per lap. Quote Link to comment Share on other sites More sharing options...
David Carter Posted August 9, 2015 Report Share Posted August 9, 2015 it is about removing weight from where you don't want it and putting it where you do want it adding weight is about getting better balance and handling lighter wheels and axle/gears are far more beneficial to performance than heavier ones as they are moving parts they is a science behind it all but I am not going to get it to that Quote Holdens rule the rest just drool slot cars are my drug, ATCC/Bathurst proxy host NZ Grp5 proxy host. Link to comment Share on other sites More sharing options...
BigMick Posted August 9, 2015 Report Share Posted August 9, 2015 (edited) I think you answered your own question Friday night John how much better did the Nissan go with the air/drilled rims. As Axman sez simples. FYI my 917 NSR had the same tyre as everyone else but I think it was the only one with the air/drilled rim. the only difference between my A and B car was that the rims. But I think your testing and improved performance with them on gives you the answer Mick Edited August 9, 2015 by BigMick Quote Link to comment Share on other sites More sharing options...
jphanna Posted August 9, 2015 Author Report Share Posted August 9, 2015 I did mention that the Nissan had a mid corner problem, in practice, but I put that down to other reasons which I had to figure out one possibility at a time. I relegated that car to the back of the tool box until as an act of desperation, I tried those rims at the last minute, and whallah.......the car settled down and was transformed into a beautiful race car. but the air holes did all that? who knows.......but I bought another set! Quote Shed People Mutual Admiration Society 2 times Australian National Champion 1991-Flexicar 1999- Group 12 Sedan Link to comment Share on other sites More sharing options...
BigMick Posted August 9, 2015 Report Share Posted August 9, 2015 I think there is something to it. I had two 917s same weight same gear same motor. One was better than the other the one with the air rim I am sold almost! Will try them on my GT3 with NSR tyre next week and then if I get an improvment Chris O will have another good sales night Quote Link to comment Share on other sites More sharing options...
axman Posted August 9, 2015 Report Share Posted August 9, 2015 (edited) I'm in nostalgia mode today.. so whereas I cant remember what i had for breakfast I do remember lots of slotcar stuff from the 70's and 80's.. go figure. Anyway, I digress... The story... Years ago when wing cars were just starting to happen one very clever person called Phillip Stoney kept upsetting the new breed of wing car racers by turning up at race events and with no practise ( he had discovered women ) and more importantly NO WINGS would top qualify for the event. One night after drinking far too much wine.. and no success with the ladies he told me his secret. Its all about the wheels and vibration in relationship to the gear mesh and magnets he said. After many more drinks he even theorised that running 6 tooth pinions the relationship of a 3 pole armature running in a magnetic field you had to "time" the pinion to the magnetic pulse. Phil worked for an instrument company so made his own VERY lightweight rims so I support what David and Paul said in the above posts. The rest of the story... Well... Phil would not even go to an event until he was satisfied that he had NO rear axle vibrational. To achieve this he would power up the chassis in his hand and then spend hours rotating and balancing the back end until it was creamy smooth. He even had a theory to match pinion teeth in even numbers to crown gears so it always meshed in the same place. He was also into Peter Brocks energy polariser... thats about when I stopped going out with him. Not because of the energy polariser but he always got the better looking woman so it was'nt good for my ego. Edited August 9, 2015 by axman Quote Link to comment Share on other sites More sharing options...
David Carter Posted August 9, 2015 Report Share Posted August 9, 2015 nice story axman hits the nail right on the head Quote Holdens rule the rest just drool slot cars are my drug, ATCC/Bathurst proxy host NZ Grp5 proxy host. Link to comment Share on other sites More sharing options...
jphanna Posted August 9, 2015 Author Report Share Posted August 9, 2015 Axman stories are what make this forum so good. I just got a simple question. why has it taken 50 years of slot car racing, across the world, before someone discovered air holes in rims makes a car go faster? Quote Shed People Mutual Admiration Society 2 times Australian National Champion 1991-Flexicar 1999- Group 12 Sedan Link to comment Share on other sites More sharing options...
Ratracer Posted August 10, 2015 Report Share Posted August 10, 2015 Hi all if you rev up rim with the tyre glued on to it you will see the middle section balloon as the rpm increases, centrifugal force 101. Drag car tyres work on this principle. It may be that the air hole sin these rims allow this ballooning to occur more easily as the air flow is less restricted. On the wheel weight issue there was a pot on one of the forums a couple of years ago which talked about the testing of light weight rims in a 1 to 1 Formula 1 team which indicated that there was a point at which lighter weight wheels actually decreased the car performance but not sure where the scale factor cuts in. From memory this discussion was led by Rick 1776, but I could be wrong. Ray Quote As Parnelli Jones the Indy 500 winner once said "If you are not out of control you are not going fast enough!" 2017 Plafit FLM Edurance Champion Team Thunderbird Link to comment Share on other sites More sharing options...
jphanna Posted August 10, 2015 Author Report Share Posted August 10, 2015 Thanks Ray, in 2013 when I got back into this, the standard rims were being replaced with air ride rims. I distinctly remember my first air ride rims. I had a recalcitrant scaley v8 falcon that had a dislike for cornering. not a good think to have for racing. air ride transformed that car. smooth car after that. one guy back then at my club, said he is stockpiling standard rims in case they ever 'come back'. maybe air rides without holes will be phased out soon. Quote Shed People Mutual Admiration Society 2 times Australian National Champion 1991-Flexicar 1999- Group 12 Sedan Link to comment Share on other sites More sharing options...
axman Posted August 10, 2015 Report Share Posted August 10, 2015 Hmm.. you got me thinking Ratracer.Years ago when I was actually fast and full of fresh ideas ( that spells young) and won the occasional race i came upon the same dragster theory/practise. I applied it to open Slotcar racing in the 70's. I would make aluminium rims in a cone shape.. large rim diameter to the outside, small rim diameter to the inside. The inside of the tyre had much more rubber (foam Tyre) so expanded and gave a taller gear ratio as the car picked up speed down the straight. The opposite happened in the corners as the large rim / small tire wall gave me the handling. Worked well with 1/8th axles and not much goo, but when goo racing and lightweight 3/32 axles/wheels perfect out of a packet became the rage spending hours turning my "cone" wheels lost it's appeal. Quote Link to comment Share on other sites More sharing options...
Sammi Posted August 26, 2015 Report Share Posted August 26, 2015 From the weekend's GP. Quote 1x Australian National Champion PhD/Associate Professor in Chemical Engineering for Slot Car Tyres Link to comment Share on other sites More sharing options...
jphanna Posted August 26, 2015 Author Report Share Posted August 26, 2015 thanks Sammi. great pic and proof that it is not a fad. Quote Shed People Mutual Admiration Society 2 times Australian National Champion 1991-Flexicar 1999- Group 12 Sedan Link to comment Share on other sites More sharing options...
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