New supercar, old rubber

[durbster]

For no particular reason, I wondered whether a modern supercar would look cooler on big, fat 1970s tyres.

So I quickly mocked it up:




What do you reckon? I think it does.

Bring back fat tyres!

Here's the originals:

[Lowtimer]

I like it. It looks proper '70s sports racer.

[Fleckers]

i like both sets of wheels

[ReaperCushions]

Much prefer the older ones here

[Lowtimer]

Early LP400S looks similarly fab on small wheels and squishy tyres.

[framerateuk]

Looks fantastic on the "old" wheels.

[Shenanigans]

Don't think they would fit over those brakes but I like them

[Mr Whippy]

You can't fit huge brakes under the smaller wheels though. But I'm sure there are ways around that issue.

I think as long as it's functional then fine. Iirc the suspension in these is such that the lowest ride rate is nice and soft any way so not really sure a big squishy tyre that can't have it's energy controlled/damped will help this kinda uber sports car.

Hrmmmm.

[unpc]

I love a bit of sidewall. I'm still running my Alpina on 16" steelies instead if the 19" standard fit wheels and I'm loathed to change them back but I'm a bit odd like that. I've gone right off low profile tyres and big wheels.

I wonder what the Macca would look like on steelies...

[ChemicalChaos]

Mr Whippy said:

You can't fit huge brakes under the smaller wheels though. But I'm sure there are ways around that issue.

I think as long as it's functional then fine. Iirc the suspension in these is such that the lowest ride rate is nice and soft any way so not really sure a big squishy tyre that can't have it's energy controlled/damped will help this kinda uber sports car.

Hrmmmm.

Inboard brakes.... (reduces unsprung weight, too)

[ging84]

if you look at the size of the brakes on the actual ones
you will see why they can't do that any more

[durbster]

ging84 said:

if you look at the size of the brakes on the actual ones
you will see why they can't do that any more

Yep, I get that.

What inspired me was looking at some old Le Mans footage and trying to work out why the old cars look so damn brutal compared to today's equivalents, and the main thing that stood out was the big fat tyres.

[Mr Whippy]

ChemicalChaos said:

Mr Whippy said:

You can't fit huge brakes under the smaller wheels though. But I'm sure there are ways around that issue.

I think as long as it's functional then fine. Iirc the suspension in these is such that the lowest ride rate is nice and soft any way so not really sure a big squishy tyre that can't have it's energy controlled/damped will help this kinda uber sports car.

Hrmmmm.

Inboard brakes.... (reduces unsprung weight, too)

Yeah it's always an option. I'm not sure why we don't see that on some cars, there must be some really good engineering reasons why it's avoided so much?!

Dave

[Triumph Man]

[quote=Mr Whippy]You can't fit huge brakes under the smaller wheels though. But I'm sure there are ways around that issue.

quote]

UFO brakes anyone?

[ChemicalChaos]

Mr Whippy said:

Yeah it's always an option. I'm not sure why we don't see that on some cars, there must be some really good engineering reasons why it's avoided so much?!

Dave

The fact that they're a complete bd to service or change, would be my guess - usually requires dropping the diff and carrier

[Lowtimer]

Mr Whippy said:

Yeah it's always an option. I'm not sure why we don't see that on some cars, there must be some really good engineering reasons why it's avoided so much?!

Dave

I think the main drawbacks are packaging, cooling and in some cases lack of accessibility for maintenance. The advantages are a reduction in unsprung weight for driven wheels (for undriven wheels you would lose some of that because you would have to put in a brake shaft, like a drive shaft).

So for a 4wd supercar they might make sense, but if your car is RWD only then it becomes more complicated to do all four as the front brakes are generally the bigger ones in any case..

It's an interesting subject actually. Some good debate from an F1 context, but much of which still applies to road cars, here:
http://www.f1technical.net/forum/viewtopic.php?p=1...

Edited by Lowtimer on Thursday 3rd April 13:58

[ChemicalChaos]

I've seen a number of old F1 and F5000 cars with inboard front brakes, connected by a short shaft from the hub.

I agree it doesn't solve the issue of packing them in the middle of the front of the car though

[kambites]

Purity14 said:

You could go for a smaller disk, but have a caliper that runs 360 degrees around the entirety of the disk?

Wouldn't help. The issue with small discs isn't that you can't get the braking force because the contact patch is too small, it's that you don't have enough surface area to keep the things cool. Ceramics help because they can run at much higher temperatures.

I think manufacturers use huge brake discs because it's the cheapest way of slowing a car effectively. If the market demanded smaller wheels, solutions to the braking problem would be found.

[kambites]

Indeed, but having more of the disc covered in pads does not, in itself, help. As you can see from that image, the components are covered in cooling fins and I suspect the whole system is designed to be used with a forced-air cooling system. I can't imagine it does wonders for unsprung mass, either.

I'd imagine inboard brakes would be cheaper and probably easier to engineer.

Edited by kambites on Thursday 3rd April 14:35

[Lowtimer]

Trust me: $350K is a lot in car terms, but mere pocket change if you want to go shopping for low-volume bespoke manufacturing from major military-industrial aerospace suppliers.