BRM GROUP C DISCUSSION

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This topic contains 21 replies, has 5 voices, and was last updated by porsche917 porsche917 1 month, 1 week ago.

Viewing 15 posts - 1 through 15 (of 22 total)
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  • #14203
    porsche917
    porsche917
    Moderator

    All – Any notes about the upcoming BRM 1/24 scale Group C series should be posted here.

    To start this topic off I have attached my story on how to prepare your BRM Group C car.  Enjoy.

    BRM Group C Car Set Up How To

    #14204
    Radial TA
    Radial TA
    Participant

    S-021SS Lightweight Aluminum Wheels/Sponge Tires for Gp.C Cars

    BRM Lightweight aluminum wheels with glued & trued sponge tires, for Gp.C cars S-021SS 28.00mm x 15.5mm for BRM 1/24 scale Porsche 962, Sauber C9 Mercedes, Toyota 88C  Minimum size for class legal is 26.5mm

    • This reply was modified 2 months, 3 weeks ago by Radial TA Radial TA.
    #14210
    Radial TA
    Radial TA
    Participant

    BRM 1/24 tuning tutorial shows the brass weight kit for our cars.  132slotcars has the kits.  Do you know if we will need those weights on our track.  I suspect they are more than our track will need for traction and handling if the sponge tires are good.

    #14249
    BarkingSpyder
    BarkingSpyder
    Participant

    Yeah … that is a ‘goldilocks’ doc – “just right” amount of verbiage – Thanks Marty!

    Randy – your point is good – so basically don’t glue in the weights until a few rounds of practice with sponge tires hints that you actually need weights. Some up front or in the center is highly probable (based on experience in Dallas in 2014-15 with these – but that was a longer track with less tricky turns).

    ... Fire up the willing engine, responding with a roar! Tires spitting gravel, I commit my weekly crime... Rush - Red Barchetta

    #14340
    BarkingSpyder
    BarkingSpyder
    Participant

    When will rules be posted?

    ... Fire up the willing engine, responding with a roar! Tires spitting gravel, I commit my weekly crime... Rush - Red Barchetta

    #14342
    Avatar
    ALEREAL3D
    Participant
    #14343
    Radial TA
    Radial TA
    Participant

    Steve and I were working on my Sauber and discovered the gears are binding somewhere each revolution.  If the offside wheel is moved out a little the mesh is looser and binding stops but the mesh might not be transmitting power fully.  What AW gears are available and will the pinion and gear be spec’d for our series?  I’m seeing only one or two on various sites.

    I will wait until we get the motor decision too.

    • This reply was modified 2 months, 1 week ago by Radial TA Radial TA.
    #14352
    porsche917
    porsche917
    Moderator

    The rules for BRM, including what gears can be used, have been added to the BRM home page.

    #14369
    Radial TA
    Radial TA
    Participant

    Where did members get the metal plate for baking the chassis?

    #14370
    porsche917
    porsche917
    Moderator

    Randy – you can check a local machine shop and see if they have any surfaced metal plate available for sale.  You can usually pick some up for $20-$40.

    #14373
    Radial TA
    Radial TA
    Participant

    The rules do not include the usual weights must be inside the car or other weighting verbiage.

    I also notice three different motors are legal which I take to mean the discussion about some motor being unreliable is not an issue.

    #14375
    porsche917
    porsche917
    Moderator

    Randy – The rules were updated a couple of days ago to include the verbiage of having the weights inside the car and not visible.

    The motors all have different RPM and Torque ratings to I am going to leave those open choice.  The black motor that is in all the newer models will work fine so I wouldn’t worry about changing it.

    #14376
    porsche917
    porsche917
    Moderator

    The trouble with wheels/tires……….

    In spending a couple of hours running the BRM Group C cars today with the goal of “rubbering in” the track I found there was little if any improvement to the cars grip.  I called Alan at 132slotcar to get his input and learned that the BRM wheels/tires I have spec’ed in the rules are a hard compound of foam and will only hook up once the track has many many hours of running.  The Scaleauto ProComp 3 tires we used to run are softer and would hook up better but Scaleauto no longer makes the replacement BRM wheels.  In looking for a suitable option tonight I discovered Scaleauto produces a wheel/tire that is .5mm wider (16mm vs 15.5mm) and 1mm smaller diameter (27.5mm vs. 28.5mm).  Unbelievably, I had mis-ordered a set of these wheels months ago and have them in hand to see just how they will work on the car.  I mounted them to a Porsche, Mercedes and a Toyota and they fit perfect on all three.  The lower profile also allows the car to sit lower in the rear and that can do nothing other than improve the cornering.  I will be taking the cars to the track on Sunday to see how they work.  I will update the forum and change the rules if needed.

    #14379
    chapracer65
    chapracer65
    Participant

    When the decision to go to foam tires was brought up last year, I appeared to be in the minority in opposing this change.  My criticism was two-fold: first that the change was unnecessary.  We had a problem with Revo Slot tires last year but a different rubber tire could have been chosen. We ran the ScaleAuto cars with rubber tires and they ran fine.  They were slower than other series cars but were controllable and we had no issue with tire wear.

    My other criticism with foam tires is one of principal.  I did not participate in the Thingie/wing car racing of the 70’s and 80’s so I have no nostalgia for foam.  My love of scale slot racing is centered on scale.  Regular rubber (and urethane) slot tires correspond quite well to 1:1 tires, even to different tire compounds and grip/wear compromises mirroring their real-life counterparts.  I have never seen foam rubber tires on a real car.  The foam tires are dependent upon tire treatment.  While the “tire cleaner” may not be as messy as other tire goop/glue, it nonetheless leaves dark streaks on the track.  These streaks detract from the scale look of the track (this would be mitigated if the track surface was black).  There is nothing wrong with wing cars, black streaks on the track and super-fast lap speeds but to me this results in a more toy-like sport rather than one based on scale racing.

    Now, my above philosophical comments do not address the issue at hand, and I am not recommending a return to real rubber for this series.  The different ScaleAuto wheel/tire may prove to work well enough.  The BRM and RevoSlot foam tire series to be run later this year may well prove to be provide worthy variety for ASCC racing series, as the rally track (and the unlimited Christmas race) already does.  I am merely stating my personal preference for real rubber and true-scale racing.

    #14380
    Radial TA
    Radial TA
    Participant

    What does this mean?
    <ul style=”box-sizing: border-box; overflow-wrap: break-word; color: #444444; font-family: ‘PT Sans’, sans-serif; font-size: 14px;”>
    <li style=”box-sizing: border-box; overflow-wrap: break-word;”>The diameter of the rear tires must not be less than <strong style=”box-sizing: border-box; overflow-wrap: break-word;”>5mm at the start of the race.

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