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When september comes the Dutch say: the "R" is back in the month..in this case the R of Racing. With Gary about to open the entries for the 2019 LM 24hrs, it is time to start working on the 2019 car, which will be a(nother) GT car. One that has not been seen on any slotrace track. But before I will be able to build that car I'm going to build 2 BMW M6's for the Rockingham and Best double features. One will be a M6 GT3 and one will be a M6 GTLM.

BMW M6 GT3 / GT-LM

In 2016, the BMW M6 GT3 replaced the BMW Z4 GT3, which had been in action around the world since 2010. Since then, the BmW M6 GT3 has been the top model in BMW Motorsport's customer racing range. The car is powered by a 4.4-litre V8 engine with M TwinPower Turbo technology. The power train has dry sump lubrication and generates up to 585 hp - with the whole car weighing less than 1,300 kilograms. The car won the Spa-Francorchamps 24 Hours in its very first season. Other technical features are the transaxle drive concept, a sequential six-speed racing gearbox, and powerful motorsport electronics. BMW Motorsport released an extensive Evo package for this car for 2018. The GTLM version is nearly identical to the GT3. Most specific differences are GTE rule driven.
The GT3 variant features the same sized (rear) tires all around, while the GTLM - which is homologated for IMSA competition only - has a slightly smaller tires on the front, per GTE rules (680 vs 710 mm).
The other difference in tires comes from the manufacturers themselves, as BMW Team RLL works with Michelin in GTLM and Continental Tire is the exclusive provider for the IMSA GTD class (open for FIA GT3). There's also a slight difference in aero between the cars, with the GT3 variant having two front dive planes, compared to one on the GTLM. Also, the GTLM car does not have a decklid spoiler.
"Fundamentally, the GTLM is a little more efficient car," O'Connell said. "Originally in the GT3 rules, they have a little bit more power than GTLM overseas. But the cars are very close (in IMSA). The chassis are virtually identical. The basic frame of the car is the same. There's just little differences in clutch and some of the systems that are allowed." (no ABS allowed for GTE)


Quite recently I was having a discussion about a new set of 1/32 slotracing rules. This rule set was to be open for GT3 cars from different makes. In this discussion a respected and experienced slotracer brought forth the following argument:

"Nobody in his right mind will ever enter a Carrera (BMW M6) car in a major multi brand competition".

Off course I had to disagree with him, even though from his point of view he was absolutely right.
If such a set of rules were to proscribe "Stock bodies and chassis" all Carrera cars would have absolutely no chance what so ever.
They would not be moving chicanes, they would be the concrete guardrails for the Black Arrows, NSR, Scaleauto and Slot.it cars to crash into. Luckily the rules my M6 will be build to give me plenty of room to take a stock Carrera and turn it into a competitive slot car.


Here are the dimensions of the 1/1 BMW M6 GT3/GTLM:
Length: 4.944 mm, Width 2.046 mm, Wheelbase 2.901 mm. Height 1.201 mm

Here are the dimensions scaled down to 1/32
Length: 154,50 mm Width:63,94 mm Wheelbase: 90,66 mm Height 37,81mm

And finally here are the dimensions of the Carrera M6 GT
Length: 155,00 mm Width:64,00 mm Wheelbase: 90,60 mm Height 39,00 mm

Build for competition...against peers
So far so good, the Carrera slot car is pretty damm good to scale. So what's the problem? Why did the respected slotracer deem the Carrera cars as so "uncompetitive"? Well first of all one should know that if raced against its peers (as in other Carrera cars) the M6 is pretty good. Yes its a big lump of a car, but along comes a long wheelbase to even out the performance against lets say a BMW Z4 or a Porsche 911 GT3 RS.
The same goes for the chassis, maybe not top notch compared to the "competition brands" but the chassis is straight & square, has steel axles with brass bearings, nice wheels (plastic) and grippy tires.



Build for competition...DiSCA style
With the advent of 3D chassis that are now widely available, upgrading a Carrera, Scalex or Fly car with a "competition orientated chassis has become a much easier job...For the M6 I will use a ProSpeed Chassis designed by Stefan Nalbach (D). Its a straight swap over, the chassis I picked is suited for an NSR pod and will be loaded to the hilt with comp parts.

Body mass
The main problem with getting a Carrera car on even footage with the "competition" is body mass. Carrera cars are well detailed, well build, but very, very heavy. It almost looks like they also wanted to recreate scale weight.
BMW lists the M6 GT weight as less than 1300kg (without driver) scaled down to 1/32 that would be 40kg. Ok maybe not true scale weight, but still, the Carrera M6 tips the scales at 113 gr of which 42gr is made up by the body!!!!! So this is where the first focus on this build will be..to become competitive with its 1/32nd DiSCA GT3 competition peers..the M6 will have to follow a very strict diet.
to be continued
With kind regards
Tamar​
 

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Can't wait to see this Tamar, it should look awsome! Every time I hear Carrera I have nightmares of weight reduction on the Hopeful 6 Ferrari 458's Good luck! Can't wait to see the laminated version 馃槣
 

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Hello Nick,
As usual I'm posting with a considerable back log, can't build, take pictures and write reports at the same time.|
The first M6 has already had its initial roll-out and first round of test runs. Without giving away too many spoilers, it does look awesome and its beginning to run awesome.
But I'm beginning to agree more and more with the "respected and experienced slotracer"

You do have to be absolutely bonkers to take on the Carrera M6

So, guilty as charged
innocent.gif
But in the end..it is worth all the effort and it will be a unique car.
 

Al Schwartz
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Just a small niggle:

"BMW lists the M6 GT weight as less than 1300kg (without driver) scaled down to 1/32 that would be 40kg."

Weight will scale with volume so the correct divisor is 323 = 32,768 so the "scale" weight should be 0.04 kg or 40g. Good luck!

EM
 

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Very refreshing to see someone taking a different stance on car building and preparation.

Good luck Tamar, I cant wait to see your progress with this project!
 

Premium Member
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Just a small niggle:

"BMW lists the M6 GT weight as less than 1300kg (without driver) scaled down to 1/32 that would be 40kg."

Weight will scale with volume so the correct divisor is 323 = 32,768 so the "scale" weight should be 0.04 kg or 40g. Good luck!

EM
Never was much into Beta studies at school, so had to learn that stuff the hard way in slot racing. Will bow my head and stand corrected when such wisdom is provided.
thumbsup.gif

So thank you EM, Any day you learn something new is a good day.

with kind regards
Tamar
 

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BMW M6 GT3 / GT-LM, Step 1, de-assembling the body
So I picked up a brand new analoge Stars&stripes RLL M6 GTLM for 鈧30. Which is about the same money you'd have to part with when acquiring a Scaleauto or Slot.it white bodykit. Undo the 4 Philips screws to separate the body from the chassis and you can start carefully cut away the excess melted plastic that keeps all the detail parts attached to the Body.
The first step will be to remove the tray interior, there are 6 mounting tabs which are easily identifiable. My preferred method to remove the excess molten plastic is by using a rounded X-acto knife. These are sharp enough to cut plastic and strong enough to pry parts loose.



With the interior removed you can now acces the 4 retaining tabs that keep the one piece front and rear window section firmly stuck to the roof. Here you'll have trouble removing the plastic with a knife (and using one might also risk scratching the windows) so this is the first opportunity to use your Dremel.If you want to be really prudent, apply masking tape to the inside of the windows. Carefully mill the excess plastic away until your flush with the clear center section.
The same can be done with the retaining tabs in the B-pilars for the side windows. Use a Philips screw driver to pop these tabs out of the B-pillar..with care. You don't want to break them. Once free from the B-pillar you can fold the side windows forward and "un hinge" them from the body.


Next step would be to detach the rear bumper from the body, Knife works best here, remove as little material as needed to pry the bumper off. After all weight reductions have been done you want to be able to "melt" the bumper securely to the body again. With the Bumper off, acces to the taillight lenses is a lot better. There too, take care to remove the minimum of "melted" material. Start on the outer tabs of the lenses first. If you can pop these out, the lens "un hinges" itself from the inner tabs.

The one piece headlight/Foglight cluster is the last big piece to dismount. Removing the melted material is a bit tricky here as the two tabs for each headlight cluster are very close to the clusters themselves. Again the rounded x-acto blade is your best tool here as any slip-up with the Dremel will damage the clusters.
To dismount the part from the body carefully slide your X-acto blade between the foglight clusters and the body splitter. The fog lights need to be pushed inward for them to "pop" out of their surroundings. Once they are free you can carefully "wiggle" the whole piece down.

So there you have it all parts removed and a Bare Body of 20,9 gr to start with and a lot of detail bits and pieces. Last tip in this post is one from Sweden. When ever I start a new project I use one of Ikea's "Glis" boxes to store and keep track of all the bits and pieces. At less than 鈧4 one of the best "Tools" for slot racing.

With kind regards
Tamar

[/TD][/TR][/TABLE]
 

Alan Wilkinson
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Tamar,
I love to read this type of article.
Really in depth thought process , well written, detailed steps taken and great pictures.
For those who say this is "bonkers", I agree, but that's what makes it a great little project😀,
AlanW
 

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Yeah, articles like this are greatly appreciated
thumbsup.gif
So informative and interesting with loads of content. Looking forward to more. Thank you for posting.

Matt
 

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BMW M6 GT3 / GT-LM, Step 2, reducing body weight
Hello Guys, happy to read that my posts are appreciated. Here's an update on how I put my Carrera M6 on a Diet. As with all weight loss programs...if you need to loose some fat, its a case of shedding tiny bits of weight when ever you can, where ever you can...although in some areas it was more like performing an outright liposuction. My preferred tools in such matters...the rounded #22 X-acto blade and these Dremel bits. The thing you want to avoid here is...heat.
The way to do so is to keep the revs low and your finger on the trigger, meaning place one of your fingers on the "other side" of the surface you're working on. If it gets too hot for your finger it will certainly be too hot for the plastic.

Working Top Down

Although the benefits of reducing the total weight of the body will be obvious, lowering the centre of gravity is more important than lowering the overall weight. Which is why I like to take things step by step, and as a rule start working from the top down. So on the bottom left you see the first and also the last big chunk you''ll be able to remove in one go" the weigth of the centre glass section.


Next area to address are the roof, the window-frames and the B & C-pillars which in true Carrera style can about 2mm thick in some places. Good practice is always to follow the shape of the exterior as close as possible. Which is why I placed two pieces of masking tape on the roof as a guide line for the "high" areas. I've highlighted the areas where I removed most of the material on the pictures. As a rule of thumb, if you can reduce the wall thickness by 50% you should be able to reduce the weight by the same percentage...but practice does not follow theory by 100%.
In some areas you need more material to maintain structural integrity...more so because this car will be raced digital.
On the right you see that after doing the roof and hood the M6 tipped the scale @ 20gr. Doesn't seem like much, but this picture was taken with the windows and the vacformed (BMW M3 DTM) interior. So the actual weight reduction on the bare body was more like 4gr.


Next up was trimming the one piece head/foglight cluster. There have been cars where Carrera used the center section for the front grille. Luckily for the M6 this is not the case so the whole section went in the bin. Trimmed the light clusters as close as possible (test fit- remove material- test fit again) and dumped the foglights into 90% isopropyl alcohol. Too bad the guys in the factory had managed to nudge the left foglight with their soldering iron as they hot melted the dive plates.

Not for the faint hearted
I did one more thing to reduce the weight of the clear parts, but this one is not for the faint hearted and should only be done if you're confident that you'll be able to succeed.!!

On the M6 its not only the body that is extremely thick, the windows are as well. After cutting away the center section there's no material left to trim, so there's but one way to reduce their weight and that is to sand them down and make them thinner. The stock side windows weight 1,2 gr, the rear window 1,2gr, the front windscreen 1,9gr . So by applying the 50% rule there's a potential 2,1gr to be gained here..well worth the effort.



To do so you'd best stick a fresh and sharp blade in your x-acto holder. Tape up the outside of the windows and carefully start scraping material away from the inside. For the narrow side windows its best to do this with horizontal strokes. For the more square rear window cross hatching will give the best results. The trick here is to avoid deep scratches, so after several passes, clean up the surface with some 1200 grit wet&dry. Repeat the process until the scale tells you you're at 55- 60% of the stock weight. Then start cleaning up the surface with 1200/2000 and finally 4000grit. If your personal stock doesn't go beyond 1200..sneak in to the missus bedroom and snag her nail polishing stick...if it can polish her nails...it will also polish your windows back to a near crystal clear shine. A last buffing with Johnson wax or Tamiya polishing compound will restore your windows to stock transparency.



After trimming all clear and body parts there are no big lumps left to remove, so instead of whole grams, you'll have to look for area's where you can shave a few tenths off. Find five of those and you do have a gram less. Its as simple as that. You provide the elbow grease and sweat, she'll loose the pounds (or grams in 1/32). It took me 4 nights of dremmeling, scraping, sanding and polishing to get the bare body down to 12,4 gr. Not the 50% I'd hoped for, but good enough for her to take a bath in the 90% isopropyl alcohol. After two hours soaking and half an hour with a toothbrush I now had a 11,9 gr heavy Carrera white kit.

to be continued

With kind regards
Tamar
 

Bob Chapman
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Stunning piece of craftmanship Tamar. Absolutely amazing.
Kudos on this great post
Bob
 
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Discussion Starter · #14 ·
2x6=8
M8GTE-wip01.png


I guess that by now most of you will have done the math and concluded that the answer to the "teaser" in the title isn't "12"

With Team Mission8 just having made its entry for the 2019 DiSCA Oxygen Le Mans 24hrs it is time to reveal the ultimate goal for this W.I.P to build the two BMW M6 cars... and that is to build and race BMW's latest ultimate GT.... the M8 GTE.

Its a big project (and I'm not just referring to the M8's size) to big for just one person to complete. Design work on the 3D model is already at an advanced stage with the first Master print due by late November. 3DP Chassis design and development already in full swing in
cooperation with ProSpeed. Decals and hopefully milled aluminium 5 spoke BBS wheels by Slotfabrik. Full light set by Z-machine etc etc.
First debut planned @ the Suzuka WEC race in Best, NL on Jan 27th 2019.

with kind regards
Tamar
 

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Hello Heath (and all other readers)

I'll most likely split these post into a separate M6 and M8 topic later on, I've been trying to catch up on my back log of build post on SF over the Holliday season.
Made good progress so far, but each update has also spurred some new questions posted which required replies etc etc.
Got a lot of pictures ready for updates on the M6 and the M8 but with the clock ticking ever louder for the Suzuka 6hrs time has become a valuable commodity.

But I can fully understand you asking for updates after 4 months of sheer radio silence on the M6 and M8 projects...so here's a small preview of the upcoming episodes.

(note: the following preview contains spoilers and some pictures may be considered disturbing for modelers)

Episode 3: From Dark Horse to Darkest hour

How the M6 GT3 became a dark horse for its first race in Mechelen ( B ) with some 3DP chassis tuning.
So dark in fact that besides smashing the pre race lap record....concerns over visibility on the dark Carrera track...

...lead to a last minute swap to a lighter livery. A decision that resulted in one of my darkest hours in slot racing.

IMG_9492.jpg


Episode 4: Plan B for Belgium
When the going gets tough..the tough get going. How Marc ******* (Wiggie) testbody became plan B for Belgium in less than 24hrs.
Back to black , bold and not so beautiful but with some new and fitting decals, the M6 GT3 scored 4th place on its race debut in the analog 10hrs of the DCSA in Mechelen Belgium.
plan-B.jpg


Episode 5: 3B modelling
How Babylon still rules when it comes to translating 3D models into 3D prints and Slotcars. Trails and tribulations of working with different 3D software platforms
This episode is most likely to create its own spinn-off series in 2019 as "mission8"
3d-modelling.jpg


Episode 6: Lament for a Lightweight body

With the M8 3d model running a bit late it was back to square 1 for the M6. But whatever I tried the Carrera body would always be a bit too heavy in DiSCA GTLM trim.
So time to create a M6 master, a silicone mould and do some lightweight lamination.
lamination.jpg


So there you have it, a preview of future 2x M6= ? topic posts to be made (although by now that title should be changed to 3x M6)
But as I mentioned before, most likely these episodes will be not aired before February
I hope you guys can understand and have a bit more patience
innocent.gif


with kind regards
Tamar
 

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Id missed this thread, great work, way beyond what I can be bothered to do. I mean, cutting the glass back is pretty serious, must have been time consuming. Surely vac formed windows must be easier?

Iv got the same Carrera M6 as pictured in the OP, beautiful looking car, would love it to be competitive.

I shall be watching this thread with anticipation for the next episodes :thumbsup:
 

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It was time consuming and it was worth it. If you could shave a total 2,2gr in the top of your body who wouldn't be bothered.
At the time of those posts, "stock" windows were required by rule, for both the Mechelen 10hrs and DiSCA GT3.
Luckily DiSCA rules have taken a more sensible route for 2019, from now on lightweight vacformed windows are allowed as long as there's no visible difference between the stock and the lightweight appearance.
Meaning that if you use them, you have to make damn sure they look like the OEM stuff, window streamer and window frames must be represented.

Sometimes its not just about the goods, but also about the looks
smile.png


The good news is that as a result of this build, a good fitting set of vacformed interiors and clear parts will become available (most likely via SV workz) and decals for BMW M6 liveries (window frames and streamers included) will be released via Slotfabrik.
So even though it will never be as nimble as a Scaleauto Z4 or a Scalex McLaren 12C, turning a Carrera M6 GT3 into a competitive racer will be a lot easier than when I started this project.

with kind regards

Tamar
 

Gary Skipp
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At the time of those posts, "stock" windows were required by rule, for both the Mechelen 10hrs and DiSCA GT3.
Luckily DiSCA rules have taken a more sensible route for 2019, from now on lightweight vacformed windows are allowed as long as there's no visible difference between the stock and the lightweight appearance.
Meaning that if you use them, you have to make damn sure they look like the OEM stuff, window streamer and window frames must be represented.
Not quite true, despite one hundred conversations about it :)

Vac windows have always been permitted in GT3 cars as long as they retained a stock appearance. As you go on to say, this meant that any vac window required seals and edges, streamers, wipers, windows, vents, fuel caps, numbers, whatever the original car had. The requirement prevents lazy builds and ugly cars.

For 2019 the only change will be to tabulate the list of homologated bodies withe a YES NO tick box for vac form windows. The original appearance requirement will still apply. The intention being that the lightweight racing cars will not be allowed to gain further advantages, but heavier stock bodies such as those by Scalextric, Carrera and SCX will be in order to increase their competitive potential.

It's not 100% necessary to do this seeing as we had unmodified Scalextric and SCX bodied cars showing the mettle for the past couple of seasons, but as you've shown with works of dedication like this, there will always be those seeking the absolute maximum performance from their car. The revision only closes a performance gap which is already, arguably, insignificantly small.
 
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