Super Car - Desired Realistic Features

[DrJB]

With the upcoming Porsche, many are talking/speculating about what it'll have and what it won't, be it Ackerman steering, tilted kingpin axis, and else.

There are features that we have never seen in Lego official cars, and while most are not feasible with the current assortment of parts, others have been completely ignored. Here's one: an anti-roll torsion bar! I can of course name other desired functions, but was wondering what the community felt were easily implementable features that have not been seen yet.

For those who have not seen one, a torsion bar is a link between the left and right tires that 'forces' the two sides to have similar vertical displacement, so that the car's roll angle is minimized. It is implemented typically on mid-high performance cars where good 'handling' is a must. The smallest car I've seen with a torsion bar is the Ford Focus SVT, and I'm sure there are many more.

Edited February 14, 2016 by DrJB

[Saberwing40k]

Actually, what you are talking about is an anti roll bar. A torsion bar is a type of suspension that utilizes a twisting element to absorb shocks. Many early Citreons have them, like the 2CV. Also, Ackerman correction has been implemented, at least in 8880. I'd have to think about it, there are a number of features that have never been implemented that could be.

[Beard]

I would like to see Lego's implementation of dual-clutch transmission. I would like to motorize and RC that. Very interesting.

[AlphaX]

I'd love to see clean implementation of a brake system. Also a gear shifting system would be cool.

[Moz]

I suspect that the Technic designers are committed to keeping the steering setup fairly simple, with mostly right angles and avoiding the 8880 style "these five parts only work with each other and only do one thing". It's also fairly tricky to get all the odd angles working together to produce smooth, easy steering while keeping the wheels flat on the ground throughout the steering and suspension travel. I think a lot of people would be unhappy if the new Porsche had VM Bug style "wheels go all over the place when the suspension moves", and it'd be really, really obvious with a wide, flat wheel profiles that go on this car. So we're unlikely to see a new set of special steering parts to give angled kingpins. But given their apparent ability to make new, specialised parts for every darn thing I could easily be wrong.

What I'd like to see are a few more of the new connectors. We have been seeing quite a few of them, and it'd be nice to keep adding to that.

[dr_spock]

Wouldn't independent suspension be better than torsion bar? If we are going for realistic play features: I would like to see airbags pop out if you crashed.

[DrJB]

Actually, what you are talking about is an anti roll bar. A torsion bar is a type of suspension that utilizes a twisting element to absorb shocks. Many early Citreons have them, like the 2CV. Also, Ackerman correction has been implemented, at least in 8880. I'd have to think about it, there are a number of features that have never been implemented that could be.

We'll call it 'anti-roll' bar then ... but I must say that in out 'loose' terminology, some people in the automotive (in the US) call it a torsion bar because it typically is a long rod that twists. Hence the name. Maybe the other reason is that the system you're talking about is 'unknown' on this side of the ocean, as I do not recall every seeing a Citroen car here. Oh yes, I thought the French call it 'Barre de Stabilité'.

[DrJB]

Wouldn't independent suspension be better than torsion bar? If we are going for realistic play features: I would like to see airbags pop out if you crashed.

Torsion Bar and Independent Suspension are NOT mutually exclusive. In fact, the Ford Focus SVT has an independent suspension in the rear, together with a torsion bar. The reason for the torsion bar is rather simple: It prevents one tire from lifting (loosing contact with the road) so that the vehicle retains maximum lateral grip during turns. I'm sure people with vehicle dynamics expertise will add to this, naturally.

Wouldn't independent suspension be better than torsion bar? If we are going for realistic play features: I would like to see airbags pop out if you crashed.

Hopefully NOT made by Takata ...

[Saberwing40k]

We'll call it 'anti-roll' bar then ... but I must say that in out 'loose' terminology, some people in the automotive (in the US) call it a torsion bar because it typically is a long rod that twists. Hence the name. Maybe the other reason is that the system you're talking about is 'unknown' on this side of the ocean, as I do not recall every seeing a Citroen car here. Oh yes, I thought the French call it 'Barre de Stabilité'.

I have never heard a trained mechanic call an anti roll bar a torsion bar, which is in and of itself incorrect, as it would be a torsion spring. Also, it's not unknown, I was just using Citreons as an example, VW Beetles and others have them.

As for features, I'd like to see a realistic gear shifter, more like 8880, and maybe some different types of suspension, rather than double wishbone or live axle. I'd actually like to see adjustable seats make a return, see how they could handle that. Another nice feature would be simulated hydropneumatic suspension, with just pneumatics.

[deehtha]

I've never heard it called a torsion bar on this side of the ocean. I've only heard referred to as an anti roll bar or an anti roll stabilizer bar.

I think the 1996 ford rangers used a torsion bar in the front suspension.

[deehtha]

I'd like to see a proper dually pickup truck with the extended cab, not the ugly thing that was 42029.

There are a multitude is different suspensions out there, something different would be nice. Multi link or macpherson, or even ford's old ttb front suspension

Functional door handles would be nice.

Or a return of the exotic doors themselves ( gull wing or lambo style)

A functional convertible.

What about a minivan with two sliding doors, and seats that can folded and rearrange ( like a Chrysler ).

[Lipko]

Some Racecars and formula cars use springs for the anti-roll system.

Some McLaren cars uses bending bars.

https://scarbsf1.wordpress.com/category/ferrari-f150/

Edited February 14, 2016 by Lipko

[nicjasno]

It's also fairly tricky to get all the odd angles working together to produce smooth, easy steering while keeping the wheels flat on the ground throughout the steering and suspension travel.

If you want any kind of realism, You do NOT want to keep the wheels flat on the ground throughout all the motions. That's the whole point.

[Grosse Kind]

Antiroll or sway bars as we refer to em could be a bit complex on plastic. They require a twist and return motion that while you will get some flex out of an axle if you thin it down in the guts to a round profile and let it act in torsion theres a higher likelihood that with any real motion it'll shear rather than return in time. Other thing is my vehicles of choice use longitudinal bars and the fact is if you get a good size scratch on them they act a a stress riser and they'll shear/crack/shatter under load and go off like a rifle report. E Type jags, near all 60's chryslers, various 4WD and light commercial vehicles, and numerous other cars use the same system on their front end. Plus god only knows how many cars bootlid and bonnet stays before gas struts became the pitiful norm that they are today.

As i couldn't see a sensible way of making a lego axle behave reliably i used a rubber axle connector in twist to semi springload the liftback hinges on my 8880. It isn't a torsion bar as such as it's the anchor point (rubber cross slot) that does the "give" as opposed to the axle, but the principle is there.

Could be adapted in principle with a pair of axles at paralell to each other feeding out of each side of a rubber bush with right angles each end feeding to the lower control arms but will in my opinion be fine, but why spoil the handling adding stiffness side to side vs except for 8865 what is generally either mushy or ridiculously heavy spring rates that make it behave like a wallowy yank-tank or the other extremity like a gokart.

I've built a quick simple example here i wouldn't bother trying to mount it on ant of my babies as though it adds a touch of realism will just upset the suspension compliance and playability.

This shows it in torsion as it would behave with one control arms spring in full rebound and the other in full compression.

Dr JB: never heard a sway bar described as a torsion bar as it isn't a torsion bar as such while it has to flex out of torsion when unloaded to go the other way rather than constant but varied tension in its operation. Shall we just agree you've got the incorrect term irrespective of whether its in common use or not?

[nicjasno]

Even the reinforced thing that i use here in the e30 mockup chasis is too soft for my taste. Your version with the rubber bits is unrealistic and will have no effect.

[allanp]

I once made the chassis for a 8880 sized blues mobile (dodge monaco). It used 12M axles as torsion bars for the front suspension. For the weight of just the chassis, engine and drive train it worked very well. Incredibly well in fact. But if I had completed the car the weight might have been too much I think. For prototyping purposes I held one end of the 12M axle fixed using a 24t gear mated to a worm gear which allowed me to adjust it while building. Worked great. Only about 5M of axle was free to twist.

[Lipko]

It is possible to make anti-roll system which relies on prings instead of torsion bars. One of the systems I posted doesn't have torsion bars, and a variation of the McLaren setup could be built with springs too. I'm planning a off-roader chassis at the moment that will have a setup similar to the McLaren setup, I think it should work well, but I'll see.

[Grosse Kind]

Hi LPE, quite a fan of your works.

Just a quick clarification as to my example having been only that. I slipped parts i have in my collection together to demonstrate the principle less so than as a prototype for implementation. Generally i don't build anything of any great mass so though it isn't going on would have some similarities in workings to that of what it is based on as far as mounting points/fuctionality/return to centre characteristics if used in a lightweight applcation with more or less rubbers for increasing stiffness to taste as deemed necessary. Not saying its going to do much to control body roll at any great speed as i make non-powered push alongs but the principle works. I'm still predominantly a "square piston" boy so ultimate realism isn't so much my thing.

https://commons.m.wikimedia.org/wiki/File:Alfetta_front_suspension.jpg

Allan,

So your worm gear was as per the thread on the adjuster bolt to vary tension? I like that as a solution! Was there a good deal of consistency amongst the axles as to spring rates? Chrysler generally used/sold bars made to very specific tolerances as well as being marked for placement handing of left or right side as well as which end was anchored to the chassis and which was at the wheel end. I've seen people use 0.850" bars on one side and 0.890" on the other for use in dirt oval speedway racing here in oz and though 40 thou doesn't sound much the tension side to side variation is something to behold.

[nicjasno]

Chrysler had torsion bar springs that were adjustable in height. The cars still had anti roll bars.

[Grosse Kind]

They did indeed Nic, but could work effectively without them as witnessed by their only being standard equipment over here from about 73 onwards across the range rather than just the prestige or sports models. And even then, only ever on the front end. Rear axle was live with leaf springing but handling is markedly improved with its inclusion from the aftermarket.

[allanp]

Yeah, the worm gear did the same thing as that screw. I didn't try different axles or different colours of axles (I think the different colours may actually be slightly different but didn't think to try it at the time). I just grabbed 12M black axles at random and they both seemed pretty consistent with each other.

[scarface_le_fou]

Chrysler had torsion bar springs that were adjustable in height. The cars still had anti roll bars.

indeed, I agree

Edited February 23, 2016 by scarface_le_fou

[Blakbird]

Chrysler had torsion bar springs that were adjustable in height. The cars still had anti roll bars.

My old 1972 New Yorker had torsion bar front suspension with adjustable height. It was really convenient to work on the suspension because the preload could easily be relieved just by backing out a bolt. Compared to using a spring compressor for coil springs, it was much easier. This car also had a huge sway bar connecting the two sides of the front suspension.

I miss that car.....

[jonny789]

I'd like to see a supercar that is not the typical sportscar but has a rather bigger interior with back seats and 4 doors. It would be nice to see some clever system to fold seats, adjust seats (distance from pedals and adjusting height too). It would be great to have a rather elaborated interior built with ONLY classic system elements because we know how satisfying that is, a realistic (8880 style) shifting gear (5+R), maybe a system for working wipers (it would require a very clever mechanism just as in real life).

Just like someone mentioned: actual lockable/operable doors would be brilliant.

So all in all more and more amazing mechanisms to witness while building and then to childishly play with and for me less power functions are desired.