[WIP] High performance car

[Rudivdk]

Hi everyone,

I really enjoying sharing the final build process of my previous moc familycar, so I decided to create a WIP topic for my new project as well.

It is in very early stage, and I do not expect to be able to post updates dailly, but I found the opinions of the community very helpful in the creation process. So I hope to get some nice feedback and tips this time as well.

It will be a high performance car, sort of a road version of DTM racer.

I will try to include an 8speed gearbox, controlled by sequential shifter. I have some ideas already, but not yet built. It will have advanced geometry suspension setup and as my previous MOC I want to include full interior this time as well.

Below a quick snap of current process. Only front end bodywork has been roughly modelled, and I am starting with front suspension now. I am limiting myself on (orange) parts for body, because I want to be able to create this in medium blue/red combo as well (assuming 42077 rallycar will be medium blue... fingers crossed).

Let me know what you think so far and what you would like to see included. I haven't made up my mind on most of the car, so I am open to all suggestions.

Front end WIP:

Edited May 26, 2018 by Rudivdk

[Jurss]

looks good . Audi, Nissan?

except that air inlets, they tends to "rice".

[Rudivdk]

Just now, Jurss said:

looks good . Audi, Nissan?

except that air inlets, they tends to "rice".

No specific brand or model, but front single frame grille is definately audi signature... I want to go with something like Audi RS, BMW M or Ford ST look.

What exactly do you mean with air inlets comment? Not sure I understand you there (no disrespect meant...).

[Didumos69]

Great start! Excited to see a new WIP from your hands !

[Rudivdk]

Just now, Didumos69 said:

Great start! Excited to see a new WIP from your hands !

Thanx! Be patient though, I'm not a fast builder  (familycar took me two years)...

[BrickbyBrickTechnic]

Interesting. Great shaping. One question: will the chassis be as advanced as in your van (different specs, of course- just equally awesome)?

[Rudivdk]

Just now, BrickbyBrickTechnic said:

Interesting. Great shaping. One question: will the chassis be as advanced as in your van (different specs, of course- just equally awesome)?

I do intend to create realistic chassis again. Different specs and different lay-out (RWD or AWD, longitudinal engine), but having a rigid structure as a basis is a must for me.

On suspension setup I actually want to improve (steering pivot inside wheel, camber, caster, kingpin, ackermann, possibly even adjustable)

[Jurss]

35 minutes ago, Rudivdk said:

What exactly do you mean with air inlets comment?

those two not technic things on hood

[letsbuild]

I'm following this topic, the start looks great! I look forward to progress!

[Lox Lego]

Once again you've captured my attention! I find it pretty wild you started with the complete front of the car before framework. That is different style from the norm. I totally love the shaping you've produced, can't wait to see more of it!!!

[KD123]

Nice work shaping the front.   Add more rice on the hood (air intake) and it might even look like a Subaru.  Nice work! I'm hungry now. 

 

[Rudivdk]

18 hours ago, Jurss said:

except that air inlets, they tends to "rice".

 

7 hours ago, KD123 said:

Add more rice on the hood (air intake) and it might even look like a Subaru.

Ah now I get it...

Actually I think I might ditch the intakes, I want the total design to be smooth. Will do something else with the hood though, it needs something to break the large surface...

[nicjasno]

Looks like this is going to be an audi. Nice sculpting.

[Rudivdk]

Hi all,

WIP update: front suspension (unequal length double wishbone with pushrod) setup created and already quite refined (frame/chassis is just mock-up, not final yet):

The old steering knuckle (white) makes it possible to have the steering pivot inside the wheel and the SLA (short-long-arm) setup gives some advanced geometry, whilst keeping the entire setup low on parts (=lightweight). The custom pushrod works surprisingly well, in this specific setup it gives limited travel (intentional) but the suspension is quite hard with the yellow shocks. Will have to see what it does with total chassis and bodywork attached. Maybe I have to revert to medium shocks in the end...

I was looking around for some gearbox inspiration and found that the idea I had in mind is actually already done: @Charbel's 8-gear sequential gearbox. Had never looked at that design before, but it is equal to all I had in mind including 4x2 gear setup, 'once per rotation' switching mechanism for 2gear and even all 8 exact gearratios... So instead of inventing the wheel on my own, I will continue on Charbel's design. Will probably have to change the lay-out of components to fit my build, but it sure saves me a lot of time. 

[emielroumen]

Just now, LvdH said:

The suspension setup looks really interesting. I've never seen someone use the old steering hubs before. 

I remember I broke a few back then while playing with the 8865 Test car and Jeep, so they might not be as durable as the Porsche hubs.

[Rudivdk]

21 minutes ago, emielroumen said:

I remember I broke a few back then while playing with the 8865 Test car and Jeep, so they might not be as durable as the Porsche hubs.

Hmmm, time will tell how they hold up in this build... For me the model will be mostly for display, but I might have to keep my kids away from it then...

[nicjasno]

I broke some 8880 hubs aswell.

[Rudivdk]

Maybe I have been lucky with production batches or so, but I hardly broke any parts from my collection so far. At least none of the more special parts like hubs. But it does not hurt reminding myself that these part are 30years(!) old now...

[Lox Lego]

I've never seen that hub before! That is one wild suspension setup. Very cool!

[Rudivdk]

Made some progress tonight, got the proportions of the car lined out:

Added some wide sideskirts:

And started on rear diffusor:

But biggest update is this...

While building, I found a way to make body and chassis separate, similar to 42056 Porsche:

I hope I can get it all rigidly built, because I really like this separation. So I've got myself a new challenge...

[Jurss]

Good progress.

That suspension geometry is not really correct, in real car world it would be OK, if geometry was otherway, so that distance between swingarms at the frame is bigger, than at the hub. Also, by connecting shock absorber to lower swingarm, there is possibility, that under the load it will pop out of the hub. At this geometry, it is also impossible add some connector between upper and lower swingarm, to prevent that. But I like that connection of shock absorber to suspension. 

I think, that You could try to turn this

around, and make all the suspension more compact.

 

Edited December 12, 2017 by Jurss

[Rudivdk]

@Jurss I have seen examples like this with higher distance at the hub (mostly on older racecars). But yes, I've taken some artistic freedom in designing the suspension. I actually wanted the shock to be that far forward, so there is room for the engine above and behind front axle.

In the end I think I will have to swap the shocks for medium or soft, yellow ones are too hard. So popping will hopefully not occur. But yes, that might be a flaw in the design in end... Will have to wait and see how it behaves with full car weight.

Edited December 12, 2017 by Rudivdk

[Jurss]

That first picture is confusing, by the first sight, it seems that there is positive camber, which would be wrong. After analysing structure, it seems, that it is negative, so it could be then OK.

[Rudivdk]

At uncompressed state there is almost no camber, slightly negative. When fully compressed it has quite a lot of negative camber, allowing the wheels to actually snug inside the wheelarches without touching them. When fully steered it turns to positive camber on the inside wheel only, which is OK considering the G-forces acting on the car while turning, increasing the load on the suspension on the outside wheel. With this behaviour both wheels keep maximum contact surface with the ground. 

Edited December 12, 2017 by Rudivdk
Update on positive camber while steering

[Aventador2004]

Also, may I add rudivik, the wheels stay flat during other roll on the rear wheels because of the offset camber, the outside: negative- inside: positive.