Tamiya 1/24 Mazda 787B

JonMW · Post by **JonMW** » Sun Dec 21, 2014 2:00 pm

The plan is to do a pretty detailed Mazda 787B, as I have already done the white/blue #18 car this time I will go for the LeMans winning #55 (the only Japanese car winning LeMans). Also got the Top Studio turned alu and etch wheel set, Scale motorsport PE and carbon decals, Hobby design detail set and MSM declas.

DBMiller · Post by **DBMiller** » Sun Dec 21, 2014 3:17 pm

Another modern vehicle, super!

rubegoldberg · Post by **rubegoldberg** » Sun Dec 21, 2014 4:29 pm

nice! those wheels look cool.

JonMW · Post by **JonMW** » Wed Dec 31, 2014 3:41 pm

Wile waiting to start I did a short review of the kit and the aftermarket parts here http://intscalemodeller.com/viewtopic.php?f=98&t=10531

rubegoldberg · Post by **rubegoldberg** » Wed Dec 31, 2014 4:52 pm

very cool. will be following this one.

for cutting strips that are uniform width i've seen some guys rig up a two-blade scalpel setup. they put a spacer between the blades to set the width of the strip.

ScaleArmorBuilder · Post by **ScaleArmorBuilder** » Wed Dec 31, 2014 5:08 pm

That four rotor sound...

Post by **Twokidsnosleep** » Thu Jan 01, 2015 4:55 pm

Wholy cow what a a build
That is a ton of aftermarket stuff

JonMW · Post by **JonMW** » Sat Jan 03, 2015 11:03 am

Group C

The roots of the Group C category lie in both FIA Group 6 and particularly in the GTP category introduced by the ACO at Le Mans in the mid-1970s. GTP was a class for roofed prototypes with certain dimensional restrictions, but instead of the more usual limits on engine capacity, it placed limits on fuel consumption. The FIA applied the same concept in its Group C rules. It limited cars to a minimum weight of 800 kg and a maximum fuel capacity of 100 litres. With competitors restricted to five refueling stops within a 1000 kilometer distance, the cars were effectively allowed 600 litres per 1000 kilometers. The FIA hoped this would prevent manufacturers from concentrating solely on engine development; in the late 1970s, a few manufacturers (especially Porsche and Lancia) had dominated sports car racing by simply increasing turbocharger boost pressure, especially in qualifying trim — the 3.2 L Porsche 935 was capable of more than 800 hp. Engines had to be from a recognized manufacturer which had cars homologated in the FIA's Group A Touring Car or Group B GT Car categories.

While the consumption requirement meant that cars needed to conserve fuel early in the race, manufacturer support for the new regulations grew steadily with each make adding to the diversity of the series. With the new rules, it was theoretically possible for large naturally aspirated engines to compete with small forced induction engines. In addition, all races were to be contested over at least 1000 km — usually lasting more than six hours — so it was possible to emphasize the "endurance" aspect of the competition as well.

Ford (with the C100) and Porsche (with the 956) were the first constructors to join the series. The traditional turbocharged boxer engine in the 956 was already tested in the 1981 version of the Group 6 936. Eventually, several other makes joined the series, including Lancia, Jaguar, Mercedes, Nissan, Toyota, Mazda and Aston Martin. Many of these also took part in the IMSA championship, as its GTP class had similar regulations.

Mazda 787b

The Mazda 787 and its derivative 787B were Group C sports prototype racing cars built by Mazda for use in the World Sportscar Championship, All Japan Sports Prototype Championship, as well as the 24 Hours of Le Mans from 1990 to 1991. Designed to combine a mixture of the Fédération Internationale du Sport Automobile (FISA) Group C regulations with the International Motor Sports Association (IMSA) GTP regulations, the 787s were the last Wankel rotary-powered racing cars to compete in the World and Japanese championships, using Mazda's R26B engine.

Although the 787 and 787B lacked the single lap pace of World Championship competitors such as Mercedes-Benz, Jaguar, and Porsche, as well as Japanese Championship competitors Nissan and Toyota, the Mazdas had reliability which allowed them to contend for their respective championships. The reliability of the cars eventually paid off in 1991 when a 787B driven by Johnny Herbert, Volker Weidler, and Bertrand Gachot went on to victory in the 1991 24 Hours of Le Mans. This remains as of 2014 the only victory by a Japanese marque as well as the only victory by a car not using a reciprocating engine design.

A total of two 787s were constructed in 1990, while three newer specification 787Bs were built in 1991.

At its heart, the initial design of the 787 was an evolution of the 767 and 767B designs that had been used by Mazda in 1988 and 1989. Many mechanical elements of the 767 were carried over by Nigel Stroud when he designed the 787, but with some notable exceptions. Foremost was the replacement of the 767's 13J Wankel rotary engine. In its place, the brand new R26B was installed. The custom-built R26B featured a nearly identical layout and displacement, but included new design elements such as continuously variable intakes and three spark plugs per rotor instead of the 20B's two. This allowed for a maximum power output of 900 hp (670 kW) which was limited to 700 hp during the race for longevity. Porsche's five-speed gearbox was retained.

Other modifications made to the 787's design included a relocation of the radiators. Initially placed beside the cockpit on the 767, a new single radiator was integrated into the nose of the 787. Air moved from the blunt nose of the car underneath the bodywork and through the radiator before exiting at the top of the nose. A Gurney flap was affixed to the radiator exit to increase front end downforce. This new radiator location also meant a redesign of the doors of the car, where the old radiator design had been located. The intake in front of the door and exit behind were no longer necessary and were thus not included, giving the 787 a smoother bodywork design on top. To aid in rear engine and brake cooling, intakes were placed on the side bodywork, immediately above the exhaust cooling vents.

As before, Stroud's monocoque design was built from carbon and kevlar by Advanced Composite Technology in the United Kingdom. Carbon fiber body panels were affixed to the two initial chassis that were built in 1990.

1991 Le Mans 24h

The 1991 24 Hours of Le Mans was the 59th Grand Prix of Endurance, and took place on 22 and 23 June 1991. It was also the fourth round of the 1991 FIA Sportscar World Championship season.

An entirely new complex along the front stretch was built, housing modern pit stalls, garages, and the new observation suites built above the garages.

As for the race, the grid line-up was an unusual affair. 1991 was supposed to be the first year the World Sportscar Championship ran to the new '3.5L' rules, which meant a new breed of sports-prototypes. Although TWR-Jaguar, Mercedes-Benz and Peugeot all built cars to the new regulations for the 1991 championship series, the amount of privateer teams was low and there was simply not enough of these new cars to fill the grid. The FIA allowed the first 10 spaces on the grid to be reserved for the fastest qualifying 3.5L cars from the World Sportscar Championship, while the rest of the field was made up of older formula Group C cars. In another twist, some teams which had 3.5L cars, but entered previous year's championships with Group C cars, were allowed to enter their "obsolete" but more reliable (and for Le Mans in 1991, quicker) Group C racers. In the case of TWR Jaguar and Mercedes-Benz, their 3.5L cars (the XJR-14 and C291 respectively) failed to qualify and instead they raced using their XJR-12 and C11 models. Peugeot Sport on the other hand only had their 905 model to race, with 1991 being their first full season in sportscar racing. Being the only factory team running the 3.5L formula, the French marque had the honour of starting 1st and 2nd, even though they had only set the 3rd and 8th fastest qualifying times.

Mazdaspeed entered three cars and a spare. One of them was a 787 from the previous year, numbered #56, driven by Dieudonné, Yorino and Terada and two brand new 787B's. One of them was driven by Maurizio Sandro Sala who replaced the newly retired Katayama, Johansson and Kennedy numbered #18 (001) and the #55 (002) car of Weidler, Herbert and Gachot making its only appearance in its only race.

Unlike the other two cars which were painted in their standard blue stripes on white livery, #55 had an outrageous bright orange and green scheme in honour of a main sponsor, Renown, a Japanese clothing manufacturer which had been supporting the team since 1988 by providing all their clothing for the events.

The spare car was another 787 from the previous year and also qualified, but took no further part in the event.

Mazda was not the favourite to win, but the three Mazdas started on 19th (#55), 23rd (#18) and 30th (#56), despite being the 12th, 17th and 24th fastest qualifiers respectively. The new 3.5 litre cars were given the first grid positions, moving everyone else back by seven places. On the day before the race, team manager Ohashi decided to drop his usual conservative strategy and instructed the drivers of the #55 car to drive as if it were a short sprint race.

The decision was made based on the reliability of the cars demonstrated in the Paul Ricard tests, as well as the car's exceptional fuel economy, which meant that the carefully learned driving techniques intended to preserve the fuel allowance were no longer a critical part of the team's strategy.

In the early stages of the race, the #55 car made its way to third place with the #18 car behind it 2 laps down. The #18 had a lower gear ratio setup meaning the car used less fuel but was 20 km/h slower. The #55 moved into second place when the Mercedes-Benz C11 of Michael Schumacher, Fritz Kreutzpointner and Karl Wendlinger spun off and later pitted with a gearbox problem. It soon became obvious that the leading car had slowed down to preserve its fuel allowance and an air of disbelief spread around the Mazda pit as it became obvious with six hours to run that there was a chance of victory.

But to take the win Herbert had to stay in the car two stints longer then planed to reduce the time spent in the pit. Problem was that he didn't get his drinks bottle refilled in the remaining pit stops. This strategy meant that Herbert could take the win after 362 laps. But as he came back to the pit for the podium celebrations he collapsed from dehydration and was taken to the medical center while his team mates went to the podium to receive their trophies. 20 years later right before the start of the 2011 Le Mans Herbert finally got to stand on the podium after taking the 91 winning car for a demonstration lap.

[youtube]81zhOQ5PvaE[/youtube]
Turn up the volume for this, the sound of the four rotor wankel is something special.

JonMW · Post by **JonMW** » Sat Jan 03, 2015 11:14 am

Sprue shots

JonMW · Post by **JonMW** » Sat Jan 03, 2015 1:55 pm

Started building the wheels yesterday, went together without any problem and looks better then the kit ones. Still need to add some details like a pin wash and air valves.

Started with six gold colored PE parts that needs to be stacked.

Glued them together with CA glue. I used rod in the center hole to line up all the parts. Also added the PE part with the bolt heads.

Centers in the turned aluminium rims and the wheel nut. The nut still needs a bit of paint.

The front wheels have a aerodynamic cover that is a bit thick in the kit. So I'm using a PE one from the Hobby Design kit.

Started folding (or twisting) the fins 90 degrees using tweezers.

All assembled, I might change the three small PE rings to a tube as I think it's a bit too short and the layers of PE will be a bit too easy to see.

Test fitted on the rims, the fit is really good, almost don't need any glue to hold them in place.

For the tires I used my normal method of using a M6 bolt, nut and two large washers to hold the tire in a cordless drill.

And then sanding the mold seam using a white thinny stick.

The tires on the rims, still need to paint the Dunlop logos on the tires and maybe some other markings as well. The fit on the rims is a lot tighter then on the Tamiya ones and pretty much perfect.

Tomtom12 · Post by **Tomtom12** » Sat Jan 03, 2015 2:41 pm

Great start, I built this kit before I joined the forum with a lot of the after market parts you are using be carful with the carbon decals the rear engine bay ones are a bit tricky to get in place and the instruction are not the best also have the book never stop challenging which tells the history of mazda racing some great pic, good luck.

JonMW · Post by **JonMW** » Tue Jan 06, 2015 7:20 pm

Thanks, yea the SMS carbon templates sets can be a bit bad ill fitting from time to time. Not sure ow much of it I will use or if I just make my own templates, saw that the carbon pattern for the interior is wrong.

Have started removing the molded in details so I can replace them.

Started with the dashboard, a lot of switches to remove.

Some of the switches removed and turned aluminium ones from Top Studio test fitted. Will need to order some more different ones as well.

The rear jack point and rear wing mount from the kit and the new PE one, the PE one is still missing some details like bolt heads.

Test fit on the engine, have also removed the rear anit-roll bar. I'm thinking of cutting off the ignition coils as well to make it easier to carbon decal the plate over the engine.

Tomtom12 · Post by **Tomtom12** » Tue Jan 06, 2015 9:49 pm

Well done, great work on the rear wing struts, keep it going.

Thumboy · Post by **Thumboy** » Wed Jan 07, 2015 9:08 am

Amazing looking project - I love the wheels and a very nice start. good luck with all that p.e.

Thanks again for your help with the Honda, I am sure I will need more before I am finished

Les · Post by **Les** » Thu Jan 08, 2015 6:37 pm

This build is shaping up nicely! Those after market parts are really taking the look of kit up a notch. Nice updates in your thread, looking forward to your future installments.

JonMW · Post by **JonMW** » Fri Feb 20, 2015 8:07 pm

No updates in a long time but there has been some work done. I've gotten all the carbon decals done on the interior, most where from the Scale Motorsport template set, but I needed to make some extra one as well. Did this using some Tamiya masking tape that where cut to shape on the panel that needed covering and then transferring it to the decal sheet.

Have also got most of the engine painted and ready for some details. Gearbox was painted Alclad magnesium and the engine in AK True Metal aluminium and gun metal. Next will be to add some plug wires and oil lines.

Tomtom12 · Post by **Tomtom12** » Fri Feb 20, 2015 9:08 pm

Looking good Jon, great work on the carbon fibre what are you using to soften them,
Engine also looks good keep the updates coming.

David

Homerlovesbeer · Post by **Homerlovesbeer** » Sat Feb 21, 2015 12:50 pm

Woa this is great, a magic build. I remember when Mazda won Le Mans, a huge effort by them.

Your work is amazing, I'd love to be able to produce work like you.

Bravo!

JonMW · Post by **JonMW** » Thu Apr 02, 2015 11:14 pm

Ok so it's finally time for an update on this one. I haven't really done too much on this up till a few days ago due to the modern armour build. I have started adding some PE parts to the car.

First up was the drink bottle holder, this comes from the Hobby Design PE kit. The PE is made from steel and is a bit hard to roll so I started with annealing the part using a normal lighter.

Rolled it to shape.

And attached it to the interior and painted it using AK True Metal aluminium.

Next up is the brakes.

All the PE is from Scale Motorsport except for two of the rotor faces from Hobby Design.

All put together, the outer part with the vent holes where also annealed.

This is the catch can mounted to the back of the car and used to collect oil, fuel and water spills so they don't go on the track. Cause if they do you get a "meatball" flag (a black flag with a orange dot for mechanical problem) and you need to pit and fix it.

As there is a PE strap for it I sanded off the molded in one.

Since it's a 5 liter jug I figured it could be useful for other projects ass well as junk in the bed of a pick up or some thing similar. So I glued it to a sheet of styrene and made a small box around it.

Mixed about 10 grams of silicone with 2% hardener.

This is the silicone that I use it's a really slow curing one which is good as all the air bubbles have time to rise out of the mold.

Poured it in and let it sit for about three hours.

Then you have a small block of silicone.

With a negative impression of the part.

Some resin mixed equal amounts of both parts.

And 15 minutes later there are two jugs. Next up will be drilling out the handle and adding the PE. Then I can start painting all chassis parts.

JonMW · Post by **JonMW** » Fri Apr 17, 2015 10:49 pm

I'm starting to feel the time running away on this one. I hoped to have the body painted last weekend, but that didn't happen and I only managed to get the first color of four done on Wednesday. So now I really need to get the rest of the painting done this weekend so I can get started on all the decals. Have gotten some stuff done on the chassis, the interior and the engine have been attached.

And more PE to add, the front splitter is a bit thick in plastic so that was cut off and replaced with parts from the Hobby Design kit.

Also the vents in the front fenders where cut out using Tamiyas PE saws and sanded smooth.

A bunch of PE parts where cut off the frets, bend to shape and glued together, these where also from the Hobby Design kit.

This is the first stage of masking for the green paint. The problem is that both the green and the orange are very translucent and getting the colors to match on all four of the body parts can be a bit of a pain.

Post by **Twokidsnosleep** » Fri Apr 17, 2015 11:43 pm

AWESOME!!!

You just made my 1/16 Ferrari F 40 vents...sweet
That is exactly what I am going to use
Thanks!

Your Mazda kit is coming along very well, don't stress the time...such a masterpiece is ready when it is ready

JonMW · Post by **JonMW** » Sun Apr 19, 2015 8:53 pm

Thanks, the thing is I really don't like not meeting a deadline so I'll keep pushing this as long as I can to make the deadline.

And I have gotten a bit closer to that, managed to get all the colors on the body and only had one small spot where the paint lifted. But that should be easy to fix. So next up is a coat of clear and then start the decals.

The orange is very florescent, so much that it is irritating to the eyes if you look at it for too long.

Post by **Twokidsnosleep** » Mon Apr 20, 2015 12:30 am

Looking good, that paint is something else
Lots of decals to go onto her as well
You will need a drink or 10 when you are finished

JonMW · Post by **JonMW** » Tue Apr 21, 2015 9:08 pm

Got started on the decals tonight. All the "stitching" is done, just need to make some cuts around the front wheel vents to get them to conform better. I was a bit worried about the decals as I have never used decals from this company and some aftermarket decals can be a bit problematic some times. But these work great, comes off the paper easy, don't tear and lays down nice, so this might be easier then I first feared.

JonMW · Post by **JonMW** » Wed Apr 22, 2015 9:24 pm

Rest of the decals are on. I used a mix of the Tamiya ones and the aftermarket ones made by MSM Creation as the Tamiya ones where a lot sharper. Next up is some paint touch ups and then a coat clear.

Homerlovesbeer · Post by **Homerlovesbeer** » Thu Apr 23, 2015 11:12 pm

Looking good, nice job!

JonMW · Post by **JonMW** » Sat Apr 25, 2015 1:58 pm

Thanks! But I'll have to redo most of it at a later date.

Went to put the final coats of clear on the body today, using Zero Paints 2k clear. The reason I use that clear is that it gives a really nice shine and don't harm the decals. Or at least usually don't harm the decals. I've used this clear for some years and never had any problems, even tried to put some spare decals and flooding them with clear without any problem. For this I started out with around five really thin coats and then a final heavier coat, and the decals just started to wrinkle and everything went to hell. So I'll have to order some new decals, strip the paint and start over again. And no way I'll be able to do that in the coming five days so I'm out of this GB, this will at least for now go into the stash of started and not finished kits to hopefully be finished at a later date.

Post by **Twokidsnosleep** » Sat Apr 25, 2015 3:37 pm

Damn, that sucks
Sorry to see this happen on such a promising build
The clear is getting under those decals somehow

Homerlovesbeer · Post by **Homerlovesbeer** » Sun Apr 26, 2015 4:17 am

Holy smokes I'd be devastated! You must be feeling really depressed about it

shortCummins · Post by **shortCummins** » Thu Apr 30, 2015 5:12 pm

thats tuff Jon, better luck with the next set

JonMW · Post by **JonMW** » Thu Apr 30, 2015 7:17 pm

Thanks, I have a new set of decals on the way from HLJ so this will be finished.

martin57 · Post by **martin57** » Thu Apr 30, 2015 7:43 pm

Excelent work like it a lot well done

Kamika007z · Post by **Kamika007z** » Sun Sep 20, 2015 3:13 pm

Hey Jon,

I was reading up on this build and it looks absolutely fantastic!

Were you able to finish this project since April? If so, could we see what the final result looks like?

Thank you!

JonMW · Post by **JonMW** » Wed Sep 23, 2015 8:47 pm

Kamika007z wrote:Hey Jon,

I was reading up on this build and it looks absolutely fantastic!

Were you able to finish this project since April? If so, could we see what the final result looks like?

Thank you!

After the mishap with the clear I put it back in it's box and put the box at the bottom of the pile of projects. I just took it out the other week and the body is now sitting on my desk waiting to get striped so I can repaint it. As soon as I'm done with my Spitfire and J21 this and the Star Wars SIG is next, that should hopefully be by the end of the month.

Kamika007z · Post by **Kamika007z** » Thu Sep 24, 2015 12:11 am

Can't wait! Thank you!

JonMW · Post by **JonMW** » Sun Oct 25, 2015 9:39 am

Finally took the time to put this in some brake fluid for a few days to strip the paint. It needs a light sanding and then I can start the repainting.

Kamika007z · Post by **Kamika007z** » Sun Oct 25, 2015 2:59 pm

Awesome!

Post by **Twokidsnosleep** » Sun Oct 25, 2015 3:13 pm

Impressed that you will give her another chance after she hurt you so bad
It looked awesome once and you will make it look that way again
Good for you for not binning it

Any idea what the clear/wrinkly decal reaction was ???

Kamika007z · Post by **Kamika007z** » Sun Oct 25, 2015 4:51 pm

I think the clear coat got under the decals because they may have not fully dried or bonded to the body yet.

JonMW · Post by **JonMW** » Tue Dec 08, 2015 10:05 pm

Finally made some progress on this, first color is on, only three to go.

barryf1fan · Post by **barryf1fan** » Thu Jan 24, 2019 8:56 pm

I know this is an old thread, but has any more work been done on this?? I have one of these to do, and as it is my favorite Gr. C car I would like to do it right (to my abilities anyway).

Any insight on where to get paints, tools, etc., etc., in the US would be greatly appreciated!!

-Barry

OlaHansson · Post by **OlaHansson** » Thu Jan 24, 2019 9:09 pm

Love the car!
Well done, to bad about the clear...

Have the Renown kit and PE and paint and the Hasegawa 767B
Will use this build for help and guiding!

DRUMS01 · Post by **DRUMS01** » Thu Jan 24, 2019 9:24 pm

CRAP!.... This is one of my favorite LeMans cars. Put is back for a time (say 1 other kit) then come back to it.

Wash, Rinse, Repeat....

Ben