The "What Are You Working On?" Thread

[Kasti]

Close, Mitter DKW - Formula Junior 1960

What an excellence idea to build this car.

Formula Junior with 3 cylinder 2stroke engine
This will be an unique experience for everyone...
No motorbrake... blue cluods of burned oil coming out of the exhaust pipes... what big fun

 

[aphidgod]

If you have any data, please feel free... we don't have much.

 

[Kasti]

Mitter later used lotus cars equipped with his dkw engines(lotus 18 and 22)
There are hints he used AU 1000 engines(SP version)
980ccm 2 stroke engine liquid cooled
55 hp/4500
88,3 NM/3500
The exhaust on the model seem to more usefull to 4 strokers.- 2 stroke exhaust always have an expansion conus and a follwing conus to establish an gas relection in order to prevent the fresh gas to leave through the exhaust(2 strokers don`t have valves...). Mitter must have used 3 of those typical exhaust types(each cylinder has an own).
The dkw engine was later equipped with an autoluber, but race tuned 2 stroke engines used a fixed oil/fuel mix.

I will take a look in an old, but very good book , there are dozens of 50/60 racing engines described with datas and ways to tune them to more power outpout named "(i hope i translate now correctly)- fast engines analysed and improved" I hope this race engine is described there(just like the famous dkw V3 cylinder 2 stroke engine, the MB formula 1 engine and the Moto Guzzi V8 500ccm)

 

[Kasti]

Searched and found something.
It is described how the dkw factory racing department devloped that engine. The so called HL(high performance) engines have usally an increased power output of 50 percent.
Means for the 980ccm starting with 55 hp(1000 SP) at 4500 rpm
then went changing carburators type and a lot of things like increasing compression, ignition, racing exhaust and so on...
best would got up to 80 hp or more in race trim.
We have to keep in mind that formula junior allowed 1100ccm and it would be likely that Mitter increased the engines capacity by more bore, io to get some more horses. DKW gets 10 Hp by increasing from 900 to 1000 ccm engine. A plus of 10hp will be also fine in comparison for increasing to an 1100 cm engine.
The max output will come with higher revs up to 5500/6000(much more isn´t very healthy with 76mm stroke and developed in the 50ies)with around 90hp-(Melkus Formel Junior which had 90hp with a 3cyl 2 stroke and 1050ccm) - quite a good engine this times and more than enough for this formula in 1959.

The homepage of the historic FJ racing
http://formulajunior.com/

Have found some datas about the Melkus Formula Juniors

wheelbase
1959: 2150mm 1963: 2300mm
wheel track front:
1959: 1280mm 1963: 1300mm
wheel track rear:
1959:1280 1963: 1350mm
weight: 400kg

 

[Kasti]

As promised... except my memory was faulty, it's not in the book but actually just a quick wikipedia check.

40% methyl alcohol
32% benzene
24% ethyl alcohol
4% gasoline

I found a data sheet of the devlopment of those engines

Auto Union
16cyl V
1934 Type A 4,36 litre 68x75mm 295 hp/4500rpm piston speed 11.2m/sec
1935 Type B 4,95 litre 72,5x75mm 375hp/4800rpm pist. speed 12.0m/sec
1936 Type C 6,01 litre 75x85mm(bore stroke)520hp/5000rpm pist. speed: 14.2m/sec
1938 Type R 6,33 litre 77x85mm 545hp/5000rpm pist. speed: 14,2m/sec

Mercedes Benz
8cyl row
1934 M25A 3,36 litre 78x88mm 280hp/5800rpm pist. speed 17 m/sec
1934 M25B 3,99 litre 82x94,5mm 350hp/5800rpm pist. speed 18,3m/sec
1935 M25C 4,31 litre 82x102mm 400hp/5800rpm pist speed: 19,8m/sec
1936 M25E 4,74 litre 86x102mm 480hp/5800rpm pist. speed: 19,8m/sec
1937 M25F 5,55 litre 94/100mm 600hp/5800rpm pist. speed: 19,5m(sec

12cyl V
1937 W125 5,57 litre 82x88mm 646hp/6500rpm pist. speed: not confirmed

In 1938 a limit of 3litres and 1939 1,5 litres
Auto Union
1938 Type D V12 2,99litre 65x75mm 485hp/7000rpm pist speed17,5m/sec
1939 Type E V12 1,48litre 58x70mm 327hp/8500rpm pist speed15,9m/sec

Mercedes Benz
1938 W154 V12 2,96litre 67x70mm 470hp(W163spec 490)/8000rpm pist speed: 18,7m/sec
1939 W165 V12 1,49 litre 64x58mm 275hp/8500rpm pist speed 16,6m/sec

just to compare
Alfa Romeo
1949 158 8row 1,49 litre 58x70mm 334hp/8500rpm pist speed: 19,8m/sec

 

[A3DR]

Searched and found something.
It is described how the dkw factory racing department devloped that engine. The so called HL(high performance) engines have usally an increased power output of 50 percent.
Means for the 980ccm starting with 55 hp(1000 SP) at 4500 rpm
then went changing carburators type and a lot of things like increasing compression, ignition, racing exhaust and so on...
best would got up to 80 hp or more in race trim.
We have to keep in mind that formula junior allowed 1100ccm and it would be likely that Mitter increased the engines capacity by more bore, io to get some more horses. DKW gets 10 Hp by increasing from 900 to 1000 ccm engine. A plus of 10hp will be also fine in comparison for increasing to an 1100 cm engine.
The max output will come with higher revs up to 5500/6000(much more isn´t very healthy with 76mm stroke and developed in the 50ies)with around 90hp-(Melkus Formel Junior which had 90hp with a 3cyl 2 stroke and 1050ccm) - quite a good engine this times and more than enough for this formula in 1959.

The homepage of the historic FJ racing
http://formulajunior.com/

Have found some datas about the Melkus Formula Juniors

wheelbase
1959: 2150mm 1963: 2300mm
wheel track front:
1959: 1280mm 1963: 1300mm
wheel track rear:
1959:1280 1963: 1350mm
weight: 400kg

Thanks man, very useful info!! I guess those track and wheelbase are the maximum allowed values.
I've had the track width data but not the wheelbase, lucky for me it's within the limits for 1960 at 1818 mm, and the track width is 1220 mm (considering I've only had pictures, no blueprints or CAD data at all).

 

[Fat-Alfie]

I was so happy to see that you and Jason were working on this. Having watched quite a few Formula 3 races from the 50s and 60s (whilst researching for my Circuit Charade project) I am sure a car like this will be amazing fun to drive in AC.

Thank you (both)!

 

[ALB123]

I don't know what kind of game you're playing, but that is unacceptable! That's it. Trash the project and start over. How can you have your pudding if you don't eat your meat?! Before anyone starts going crazy, I'm just teasing. Gary's attention to even the smallest details is second to none. I love watching the suspension and steering systems do their things in open-wheel vehicle replays. I'm sure what you've been working on You have left me in awe once again, @garyjpaterson...

 

[garyjpaterson]

I don't know what kind of game you're playing, but that is unacceptable! That's it. Trash the project and start over. How can you have your pudding if you don't eat your meat?! Before anyone starts going crazy, I'm just teasing. Gary's attention to even the smallest details is second to none. I love watching the suspension and steering systems do their things in open-wheel vehicle replays. I'm sure what you've been working on You have left me in awe once again, @garyjpaterson...

Haha. yeah I know its awful. Will start again, my bad

Did you not see this one though?

**** it, started on the cables anyway. Thats one corner done, hope I can get it working ingame.
Yeah some of them move a little unnaturally and clip into each other but it good enough, travel is so small ingame it should be fine.

In all seriousness, I'm having a lot of trouble getting this to work in game... I have 20 skinned meshed (5 per corner), and for some reason I'm finding 2 of them don't work properly and I have no idea why!

Spent all evening last night getting it to work in 3ds, but its getting pretty messy with all the moving parts. I'm also finding the skinned meshes are out of place ingame/kseditor compared to 3ds, only by a few cm but its annoying...

 

[HenkySA]

my friend cancelled out the #77 Barwell because he had too much works in his hands. and passed it to me a few moments ago.
luckily no need many reworks as the base design is quite similiar

 

[A3DR]

Haha. yeah I know its awful. Will start again, my bad

Did you not see this one though?



In all seriousness, I'm having a lot of trouble getting this to work in game... I have 20 skinned meshed (5 per corner), and for some reason I'm finding 2 of them don't work properly and I have no idea why!

Spent all evening last night getting it to work in 3ds, but its getting pretty messy with all the moving parts. I'm also finding the skinned meshes are out of place ingame/kseditor compared to 3ds, only by a few cm but its annoying...

5 meshes per corner? can't you get away with attaching all the wires and hoses on a single mesh, so you'll have only 1 skinned mesh per corner? After all the movement for all the wires/hoses is the same, follows the suspension movement. That'll eliminate a lot of possible problems.

 

[garyjpaterson]

5 meshes per corner? can't you get away with attaching all the wires and hoses on a single mesh, so you'll have only 1 skinned mesh per corner? After all the movement for all the wires/hoses is the same, follows the suspension movement. That'll eliminate a lot of possible problems.

Yup (that's 5 wires, 2 of which I already did combine, plus a spring). Definitely considering it if possible, might look a little more janky at points but if it works it'll be worth it. The dummy situation I have just now is just crazy...

Ever since trying to sort out these skinned meshes, all my other animations seem to be getting messed up, and no idea why - I'm sure they were working before! Like all my pullrods are offset or pointing in a slightly wrong direction now, despite working perfectly in 3ds... I think I'm going to have to start these animations from scratch, and really test each element before moving on!

Green line is where the pullrod should go, red is where it actually is.

 

[Kasti]

Thanks man, very useful info!! I guess those track and wheelbase are the maximum allowed values.
I've had the track width data but not the wheelbase, lucky for me it's within the limits for 1960 at 1818 mm, and the track width is 1220 mm (considering I've only had pictures, no blueprints or CAD data at all).

I´m always happy to help.

Regulations for Formal Junior by FIA FJHRA Technical and Eligibility Regulations – Edition 3.4

FJ 1:cars build and raced before 31.12.1960
FJ 2:cars build and raced after 01.01.1961
Minimum wheelbase: 2000mm
Minimum track: 1100mm
Maximum body width: 900mm
Minimum ride height: 60mm
Minimum weight: 400kg(1000ccm engines: 360kg)
Maximum rim width FJ1: 5 inch
Maximum rim width FJ2: 6 inch
But there is one sentence in it:"The track and wheelbase must not be altered from the original manufacturer`s specification or if it is not available one for which period evidence exists." The tolerance for track is 1% and for wheelbase 1,1%
So no need to alter your 1818mm wheelbase. In RL you could go racing with it. A chassis perfectly made for tracks like Ahvenisto.

One hint for building the 2 stroke exhaust system. On images from historic motor bikes they are easy to compare with. I would recommed a look at the Kawasaki 500ccm H1R

 

[A3DR]

One hint for building the 2 stroke exhaust system. On images from historic motor bikes they are easy to compare with. I would recommed a look at the Kawasaki 500ccm H1R

Excellent info! I'll look into the wheelbase / track measurements, and make sure everything fits.
About the exhaust, there's not much else to do with it, the only difference I've seen is a muffler welded to it:

Without it:

 

[mclarenf1papa]

Seeing as Acura failed to give this video a proper check-over before going public with it I think I have some ideas for a weekend project.

Those numbers are totally readable.

 

[Kasti]

Excellent info! I'll look into the wheelbase / track measurements, and make sure everything fits.
About the exhaust, there's not much else to do with it, the only difference I've seen is a muffler welded to it:
View attachment 206052

Without it:

View attachment 206053

I would prefer the"without muffler"version

Man, this muffler is soooo ugly and a later installed part cause of some today`s sound regulations on certain race tracks... Please.. don´t...

Surprisingly they made a 3in1.. not so good on a 2-stroke engine, especially if you want max power. But that times it was often done with car engines, mostly in order to smoothen the 2 stroke "bite", the rough kind of suddenly increased power output, very common to high performance 2 stroke engines. But i never saw a data sheet which proofes this theory, last time i saw this kind, was in the 70ies parts catalogue by some exhaust manufacturers for 3 cyl Suzuki GT Kawasaki KH engines... one one of the best ways to ruin them...(Guess why it was never used from Suzuki or Kawasaki with their race bikes...)

Can`t wait for the 2 stroke sound and this awesome car.

A little sound impression i found(of course without muffler...)

 

[HarryRiedl]

I would prefer the"without muffler"version

Man, this muffler is soooo ugly and a later installed part cause of some today`s sound regulations on certain race tracks... Please.. don´t...

Surprisingly they made a 3in1.. not so good on a 2-stroke engine, especially if you want max power. But that times it was often done with car engines, mostly in order to smoothen the 2 stroke "bite", the rough kind of suddenly increased power output, very common to high performance 2 stroke engines. But i never saw a data sheet which proofes this theory, last time i saw this kind, was in the 70ies parts catalogue by some exhaust manufacturers for 3 cyl Suzuki GT Kawasaki KH engines... one one of the best ways to ruin them...(Guess why it was never used from Suzuki or Kawasaki with their race bikes...)

Can`t wait for the 2 stroke sound and this awesome car.

A little sound impression i found

Amazing engine sounds the 2 strokes have. The cars sounds like huge angry chainsaws with that great off throttle crackle.

 

[Kasti]

Amazing engine sounds the 2 strokes have. The cars sounds like huge angry chainsaws with that great off throttle crackle.

The sound of the Mitter Formula Junior is just stunning. Sadly 2 stroke engines nearly totally vanished today.

 

[aphidgod]

Tricky color to get right...

 

[Kasti]

Excellent info! I'll look into the wheelbase / track measurements, and make sure everything fits.
About the exhaust, there's not much else to do with it, the only difference I've seen is a muffler welded to it:

Don`t want to annoy you, but the exhausts shown seem not to be the originals.

By watching the posted video with Gerhard Mitters own 1960 Mitter FJ driven by his son, imo both exhaust systems on the pictures shown, seem to be altered and modern replacement(the used material is another hint). The extreme long pipe on pic 2 is altered, only io to keep noise, smoke and exhaust gases away from driver(the muffler version was never used and build in the 50/60 ies)

The original Mitter exhaust is a much more a 2 stroke typical one.

It has more length between the cones,this one was build for maximum power on high revvs and has the common short small pipe at the end, the way they were build.
A pic with the original exhaust:
http://formulajunior.com/marque/mitter-dkw/

And Mitters original exhaust looks better and sounds aaaawesome...

Perhaps you may use this one?