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2017 - OAPR LMP

Garry J

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The 2017 OAPR LMP Specifications V2.1 - (acknowledging its origin being the 2012 OEPS Guidelines)

OAPR – Open Australian Prototype Racing


Any true 1/24 scale representation of a 1/1 LMP (Le Mans Prototype) car that has raced in the American Le Mans Series or the European Le Mans Series or the World Endurance Championship between 2008 and 2016
All liveries must be of scaled down 1:1 appearance, however colour combinations and liveries from other modern (year 2000 to present) race cars may be used.

The Oreca Racing 'FLM' Formula Le Mans car is not classified as LMP1 or LMP2 in either the LMS or ALMS and therefore is not permitted to run in the OAPR. However, the Oreca 03 as raced in 2014 in LMP2 is allowed to run.


2.01 Minimum total weight: 160.00 grams
2.02 Maximum front spur: 83.00 mm
2.03 Maximum rear spur: 83.00 mm
2.04 Minimum ground clearance at the start of the race: 1.00 mm
2.05 Minimum ground clearance during and after the race: 0.40 mm
2.06 Minimum front rim outer diameter: Ø21.00 mm.
2.07 Minimum front wheel starting diameter at the start of the race: Ø25.20 mm
2.08 Minimum front wheel width 6.00 mm
2.09 Minimum front rim width 6.00 mm
2.10 Minimum width of front tyre contact area 6.00 mm
2.11 Maximum front wheel camber angle: 3.00°
2.12 Minimum rear rim outer diameter: Ø21.00mm.
2.13 Minimum rear wheel starting diameter at the start of the race: Ø 26.50 mm.
2.14 Maximum rear wheel diameter at any time: Ø 27.70 mm.
2.15 Rear wheel width and contact area always 13.00 mm – minimal rounding of edges are allowed.
2.16 Maximum width of main chassis plate: 78mm


3.01 The race motor will be the NSR 25Evo long can. Unopened and always with the wrapped label intact.
3.02 The spur gear is fixed at 44T M50 pitch.
3.03 The pinion gear may only be a 11T or 12T M50 pitch - but must be nominated by the race organisers when the event is announced.


NB! - The chassis is completely open provided it adheres to the specifications in these regulations. You may use any commercially available chassis, mix parts from various chassis, modify any part of the chassis as you see fit and even build your own chassis.
4.01 Only one part of the chassis that is allowed to enter the track slot, and this part may not have a longer contact area than 27 mm.
4.02 Differentials are not allowed.
4.03 Magnets are only present in the motor, and are not allowed anywhere else on/in the chassis.
4.04 Chassis must have vertical movement, some of which must be sprung for suspension purposes.
4.05 All chassis assembly must be by means of bolts and nuts, no self-threading screws, solder or glue may be used.
4.06 The motor cannot be affixed to the chassis with solder.
4.07 Minimum and maximum wheelbase must always be centred within the front and rear wheel arches of homologated bodies. Here is a list of all the currently homologated bodies and some of the wheelbases:

- Acura LM (112.2mm)
- Aston Martin AMR One LM
- Audi R10 (122.3mm)
- Audi R15 (124.5mm)
- Audi R18 (121.3mm)
- Lola Aston Martin Coupe LM (118.9mm)
- Lola B10 LM (112.2mm)
- Lola B12 Coupe LM
- Oreca 03 LMP2
- Pescarola (115.2mm)
- Peugeot 908 Coupe LM (120.8mm)
- Porsche RS Spyder LMP2 (117.3mm)
- Porsche 919 LMP1 - V1 (2014)
- Porsche 919 LMP1 - V2 (2016)


5.11 The front wheels must make contact with the track or techblock over the full 6 mm, or more.
5.12 The use of cambered front wheels does not void in any way the rule regarding the minimum diameter, or the rule regarding the contact surface with the track or the tech block.
5.13 Front wheel diameter for cambered front wheels will be measured at the largest present diameter, which has to be respecting rule 2.07.

5.2.1 Rear wheels are always Scale Auto ProComp 3 or Plafit rubber - both being 'Black Magic'. If handout tyres are used, the event organiser must specify the brand and the size when announcing the event. Tyre dressing of any kind is not allowed during the official practice, qualifying or during the race. The race tyres may only be cleaned using tape or Shellite supplied by the OAPR/race organization.

5.03 SPUR
5.3.1 None of the wheels may be visible when viewing the assembled car from above. Spur will be measured over the complete rims left and right, including wheel inserts.

5.4.1 All 4 wheels of the car must be fitted with 3-dimensional (flat sheet or photo edged not allowed) wheel inserts, resembling the wheels of the real 1:1 car, during the entire race duration


6.01 Only vacuum formed 15 thou clear bodies are allowed. Provided these bodies have been homologated by the OAPR organisers.

6.21 Body must be manufactured and/or assembled from one or more of the following materials: PVC, PET, PETG or Lexan.
6.22 The exterior of the body has to accurately represent the 1/1 car. This is to the discretion of the scrutineers to judge(s). No widened, stretched, flattened or smoothed silhouette style bodies will be allowed.
6.23 The same materials are allowed for the interior, windows etc., rear wing, diffuser and small add-on parts. Lexan is allowed for a rear vertical aero wing e.g. 2011 Peugeot 908, etc. All wing mounts must be the correct shape and can be made from rubber.
6.24 The body must cover all chassis and axle parts, so that no chassis part or axle part is visible when the car is viewed from above. This also includes the guide or any part thereof.

6.31 Interior must contain at least the following 3-dimensional items:
Dashboard (optional).
Steering wheel,
Painted driver figure with arms and legs,
Painted head/helmet combination in a hard plastic material.

6.41 Bodies must be equipped with:
Front windshield and side windows if existing on the 1/1 race car
Front splitter if existing on the 1/1 race car
Rear spoiler /wing (may be made from flat sheet)
Rear view mirror(s) (optional)
Wiper (s) (optional)
Rear diffuser (optional)
Light inserts. (These are the plastic moldings that fit behind the outer light lenses and are normally mounted inside the body).


7.01 Functioning lights have to be present at least during night racing. These lights have to be installed (even during day racing) on their original 1/1 positions on the car.
7.02 Front lights: minimum two lights in total, one left, one right, yellow or white color, bright beam.
7.03 Rear lights: minimum two lights in total, one left, one right, red color, diffuse light.
7.04 Cars must always be fitted with light inserts even if no actual lights are fitted.


8.01 No working on cars during lane changes or track calls. All work on cars must be done during racing.
8.02 Any part bigger than 20mm (wheel insert size and bigger) that come off the car, must be put back on the car in it's original position. Tape may be used to do this.


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  • 2 weeks later...

Hi guys,

As we approach the end of another racing year and the start of a new one, it will be good to get some feedback on this class. The OAPR LMP class in it's current form is now 5 years old and very little has changed in the ruleset, during this time. I guess the old saying of - 'if it is not broken, don't fix it', comes to mind.

The only thing that has changed, is the advent of new classes - like the Lexan GT3 class - which is now pushing the speed envelope by comparison. It is with this in mind and pressure to maintain it's position as fastest racing class, that maybe we should consider a couple of suggestions which have been made.

Please consider the following for us to include into the regulations for 2018:

- reduce the total minimum weight to 150g

- open the pinion choice to 11 OR 12 (being a driver choice rather than a race organiser choice)

I know there are other options like wider rear tyres and 30K motors. However neither of these are realy viable at this time. The longcan motor does not readily allow for wider tyres and a majority of current chassis designs in use will not be able to accommodate wider tyres within the maximum rear spur of 83mm. It was also an original design focus not to 'glue' the cars to the track with wide rubber, but make them drivable with some on-track movement of the car for the driver to control. A faster (30k) motor has been extensively tested on both shorter and longer tracks and the difference in lap times is very little. A byproduct of the faster motor is reduced drivability which will simply increase the gap between faster and slower drivers, which in turn will impact on motivation to compete in this class.

Thanks for your positive consideration.


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I agree with you Jan regarding keeping the motor the same. I like the idea of opening up the pinion choice, and I do think reducing the weight and combined with the relaxation of the pinion restrictions would make the cars more responsive = faster lap times. After all they are our pinnacle class.

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Agree Jan.. with the success of GT3 cars snapping at the heals of the LMP class I would rather see the LMP's faster ( don't cobble the speed of the GT3's) and as the premier class let the cars have the legs they need. The 25000 rpm motors  are fine.. I think there is value in changing the rules to read any long-can 25k motor. With the weight  coming down I can see the potential of running up to a 13t pinion for LMP... . let the racer choose the motor of his choice..  the grunt your SRP long-can motor offers is a real weapon and may convert a few racers away from the NSR.  I'd love to have the choice.

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I think some of the changes could kill off participation in the class.

Hornsby will be a GT car for Greg and myself.

for me, I really liked this class because I knew if I built a car, I'd be at least competitive because I didn't have to figure out the right gear ratio, which motor to run, and any other variables.

If the suggested changes go through, It may just become a class for the super tuners.

ive got 3 Gary Johnson Chassis' to build and "tune" for Hornsby after my success at SlotFest, which is funny, because all I did was pull it apart to polish the brass, otherwise it was exactly as Gary sent it to me.

the problem I saw at SlotFest was that the GT cars had a 12t pinion, where as the LMP only had a 11t pinion, maybe just swap them over.

yes, I could take a drill to my current chassis, but where do I drill the holes? no thanks, I'll just wait until I can buy a revised one from Gary, then I'll know I have the same as the winning guys.

think hard before changing something that already works perfectly!

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we ran a "open ratio" lmp sprint race earlier this year and i swapped to a 12:44 which made the car faster without going to a 30k. the current lmp races in europe they are running hawk retros (which are short cans) with 9:46 and still the 13mm tire.


and to be honest... if it isnt broken dont fix it...

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Thanks for the well considered responses - I think we are getting a clear indication of where this might end up - not much change. I will not be making any changes to the ruleset until the end of December, but if any changes are adopted, they will be effective as from January 1st, 2018. This will help organisers/participants of events (early) in 2018, to embrace possible changes with enough warning.





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General feeling at Dapto from talking to some guys is change the pinion (car is quicker at around $2.00) but not the weight (car is quicker with major modifications). Personally, I wouldn't want to take a dremel and drill to an exotic European chassis to try and cull 10g to 20g out of it. Also means quite a bit of chopping to a SLP2 chassis for the guys on a budget.


Personally, I think the LMP's could drive a 13T pinion with an NSR til the cows come home on any track at 160g, and be a hoot to drive. 




- Cam

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I will just add; this class was never intended to be only a 'out-the-packet' or buy RTR. It was aimed at everyone - those that want to buy and race, those that want to modify and race, but also those that want to design and make their own. It is absolutely an individual choice when it come to the chassis - as long as it fit within the specifications. Look closely at the specifications and you will realise that it is even possible to make your own rims, axles, guides and braids - if you choose to.


All we have done is to have a set of specifications within which the chassis and body must fit. To that we have added a motor and gearing specification, plus the usual generic bits and pieces.


Thanks for sharing your thoughts - all of which will be considered, within the parameters of the original class vision. There is no intention to make this a commercially orientated class - even if some guys may choose to 'share their designs and offer them for sale.





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is speed the only objective.???   its amusing to see that when we discuss slot car racing we use analogies to actual racing.  When you compare this class to GT3 class and initiate the discussion because GT3 is quick or as quick,  that is exactly what you are doing.

Actual racing changes rules for technological reasons but also cost and ease of participation and TV audience.  And they fail every time.

i would resist any change just to go faster because another class is too quick. Perhaps you should slow GT3 down. My participation in slot cars is based on ease of entry, sensible cost and good close racing. (ie :translates into close results accross the majority of the field not just the top 1 team which quite often happened) 

I pay good money for these chassis , i don't feel comfortable having to toss them out cause they are too heavy.

By the time we acquire a chassis , set the car up, get it looking good, get it competitive, "the rule makers" change the rules.   Who does this suit??   i agree with Brett and the others. 

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This class was always aimed at the pointy end.. this is not a kit class and never was.. as a scratch builder from way back I was attracted because we finally had freedom of choice. After years of being trapped in cookie cutter chassis world I though I would build a far better something but in reality the quality of perfect CNC cut cars from Red Roo, Gary J, Plafit and a host of Euro suppliers for this class far exceed my Dremel and filing abilities.

So.. in the interests of keeping everyone out there racing and keen with the cars they've got and for the good of racing in this class I concede cutting up perfectly good cars is not in the best interests. So.. that leaves it to Cam's suggestion.. go for taller gearing.. I'd still like a slightly lesser weight say 155 g ? as  I've had to add weight to most of my cars to get up to 160. 

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A little feed back from Dapto tonight. I put a 13t pinion on my LMP Garry chassis . The car was still really nice to drive and faster for sure . Cam was doing 5.1 laps easily. I think he said his new Porsche was around a 5.3 lap. Think that they could handle more speed for sure . I personally don’t want to change a chassis that is so well balanced. I don’t have the equipment or engineering skills to produce such a special piece of kit . I also don’t want to spend more money on a class that I run in once or twice a year . I love driving the car so I hope that a sensible low cost solution can be found . I don’t know if another gear ratio or even up grade to motor is needed , but much prefer those options over major modes to exciting awesome chassis . I do understand the concept completely that it’s a open chassis and you can make your own . But as I said, very few of us can, yes there are a lot of other classes that cater for blokes like me but if you want this class to prosper you can’t kill off competitors. My thoughts anyway. 


Cheers Pagey 


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  • 2 weeks later...
  • 3 weeks later...

Hi guys,


It has been suggested that we include some alternative 25k longcan motors and not only have the NSR 25 Evo. It was even suggested that we make the motor completely open to any 25k longcan motor. Personally I would like to see us being specific if we go this way. So can we please get your specific suggestions for 25k longcan motors to be included in the 2018 ruleset. Should this idea fly, then we will ask future event organisers, to specify one of the motors listed in the ruleset for their particular event.


Again, thanks for your considered opinions.



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1 hour ago, Camber said:

I’d like a 35k long can motor to get these cars performing like they should on larger competition tracks. If FLM can comfortably run a Cheetah, these should easily run a 35 long.

I'd be up for a 35k motor too  .... 


For me , there needs to be a distinguishable gap between this class & GT3, in Melb i was faster than all but 1 of the LMP cars with the GT3, this tells me it needs some tweeking 

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