What if somebody built a faster lapping road car?

[Greg Locock]

re bikes vs cars, here's some actual data

http://www.phillipislandcircuit.com.au/ ... hilisl.pdf

http://www.phillipislandcircuit.com.au/ ... ne2012.pdf

Sadly no F1 cars in there, but as a rough comparison V8 supercars lap record at albert park at 1m56, F1 1m24

[aussiegman]

Ahhh, Love the Island!!!

Same holds for Eastern Creek (note that there is a fair time differential between fastest laps but they are still relative)

A1GP - 1:19.1420
Time Attack Nemo Evo - 1:25.0200
V8 Supercar - 1:31.7301

Superbike - 1.31.655
Supersport - 1.33.989

Quick summary, generally cars are faster around a track than bikes.

[markp]

It is more likeely someone would build a faster track car than a faster road car. Driving on a road has many different compromises to a track so a no compromise track car will be faster. To the member that posted that great info on tyres thankyou but do you beleive these road legal semi slicks could wothstand cornering load equal to or greater than would be required to lap at f1 speed?

[Cold Fussion]

Ahhh, Love the Island!!!

Same holds for Eastern Creek (note that there is a fair time differential between fastest laps but they are still relative)

A1GP - 1:19.1420
Time Attack Nemo Evo - 1:25.0200
V8 Supercar - 1:31.7301

Superbike - 1.31.655
Supersport - 1.33.989

Quick summary, generally cars are faster around a track than bikes.

The Nemo is one of the most insane cars you could really envision driving on the road, and it is still no match for an even a A1gp car. Being 6 seconds faster than a v8 supercar on road tyres probably means it is faster than a GT2 car on slick tyres, if not a mid 2000s spec GT1 car.

[Greg Locock]

Does the Nemo have an effective fan system for downforce? No. Therefore it is not optimised for unlimited circuit racing.

[SiLo]

It would probably be easier to simply get an actual F1 car some tax and insurance and get it on the road...

[markp]

Same principle as that road legal formula ford with the 1 litre engine that laps the nordschleife on road tyres the same if not quicker than many hypercars. Whats the point it would be so expensive and may not work you might as well buy a roadcar a van a trailer and an ex f1 car.

[michika12]

Bugatti Veyron Super Sport (268mph) This version of the original Veyron still has the same 8.0 litre, 16 cylinder engine but upgrades have pushed it into the record books .. look cools, I need to have one! LOL

[Cold Fussion]

Does the Nemo have an effective fan system for downforce? No. Therefore it is not optimised for unlimited circuit racing.

The point is the Nemo stretches the definition of a road car significantly. It's already 6-7 seconds faster than a v8supercar, 5 seconds faster than a sr3 radical. The Nemo is probably running very close in lap time to the SR8 radical and caparo t1 would around eastern creek, and neither of these are close to being as fast as an F1 car. Once you go beyond a v8 radical or a caparo t1, you have to ask yourself on how much of a roadcar it is.

[markp]

Can someone give an idea of the outlines of such a roadcar and what present technologies could achieve this. Are we saying you can have a great drive on the road turn up at the circuit and lap faster than F1. If so with an unlimited budget what would the car have to include? Possibly something like a Caparo T1 but with every element turned up to 11. Japanese gt used to be quicker than gt1 they would have to be fully derestricted have various other parts added and still wouldnt get close then you would have to make compromises for the road. Remember any outlandish aero pieces would have to pass pedestrian safety crash tests as well, lights have certain regulations, number plates all of which may compromise the extreme aero that would be required.

[Greg Locock]

Well let's see, say we want 5g downforce, 1400 kg mass, 4 m^2 underfloor area. So we need a pressure of 5*10*1400/4 Pa, call it 20 kPa or 3 psi. You need a straight line top speed faster than that of an F1 car, with the fan off. You need something like the straight line acceleration of an F1, which with AWD should be fairly easy. You don't need the same power to weight ratio, because you won't slow down as much in corners, and you don't have to provide all the aero drag of an F1 all the time. Your brakes will have to be pretty damn amazing.

So now you can do the hard work. like I said Lapsim is a good approach, or you could create VGG plots as someone else suggested.

[machin]

I'm skeptical whether the sliding skirts needed for fan-based downforce would get through the UK's Single Vehicle Approval (SVA) test... so I'd shy away from using that technique on a road car...

I thought I would add a Group C Sportscar chassis option to my online Virtual Stopwatch program, complete with XJR-9 and XJR-12 body styles (in Le Mans trim). The default settings have a Jag V12 race engine and slick tyres, but you can also choose one of a range of alternative engines (including the Bugatti Veyron Supersport W16 -but remember to change the diff ratio to match this engine's low redline), track-day or fully grooved "sports" road tyres, and 4WD!

The Group C cars didn't have active aero, but they did have fully developed ground effects venturi tunnels, making them the most efficient downforcing producing racecars of all time, and, being two seaters, would appear to be the ideal basis for the challenge car (I think any real "roadcar" would have to have a minimum of two seats).

You can see how close it would get to an F1 car's 59 second lap of the Dunsfold Sprint Track, as used by TV's Topgear show, by launching the Virtual Stopwatch App, on the link below:-

http://www.competition-car-engineering. ... emans4.htm

[Greg Locock]

"I'm skeptical whether the sliding skirts needed for fan-based downforce would get through the UK's Single Vehicle Approval (SVA) test... so I'd shy away from using that technique on a road car..."

Why would they deploy during an SVA test? What is this test, a paper exercise or an inspection on a hoist? In fact I'll go further than that, you shouldn't be using the fan on public roads either, since any failure in any of the systems will result in a spin off, which is acceptable on a race circuit but not on a public road. All a vehicle inspector will see is a series of slots under the car.

[wrcsti]

Couple things -

I believe whoever was saying a truck would create a lot of "grip" because it's heavy was speaking purely in terms of pounds of lateral force (which is true)... and did also mention it would have more mass to accelerate (also true)... and yes the end result is less acceleration capability.

And then theres also the innertia of all that weight going around a corner. It would cancel out the ammount of extra friction the tires have as they now have more side load. Thats why racecars are light and then have downforce. If weight was the answer wed see them runing higher weights and cutting downforce.

[g-force_addict]

So far, from your replies, tech details to build such a road car slowly emerge:

* Monster-displacement forced induction engine
Of course in a road car engine displacement isn't limited so you can build a 20L V-24 beast if you want to.
Likely you'll use forced induction (banned in F1 for now) as you get way more power with only a modest increase in engine size and weight.
You can even experiment with rotary engines or even a geared turbine.

* Active fully adjustable suspension
You need sticky tires for the track, yet you need to make them last long enough on the road. This only can be achieved by adjustable suspension.
You'll need zero camber for road use and maybe to make sticky tires last at the end of high speed straights at the track. Also you need negative camber for track corners.
You need low ride height for the track, yet not so low height for speed bumps on the road.
You need pro-ackermann on the road, adjustable to anti-ackermann in the track.

* Huge brakes
On the road you are not size limited at all. You can even use many brake discs for one wheel if you want.
Although road car brakes would need to work well when cold.

* Variable aerodynamics
You need moderate downforce for low and medium speed acceleration turning into low downforce (and drag) for high speed acceleration yet turning into high downforce for braking and cornering.
In a road car you can use F1 banned technologies like wheel fenders, a roof, venturi tunnels, driver-adjustable wings (maybe even adjustable-angle venturi tunnels), exhaust blown diffusers or even fan powered ground effects ala Brabham BT46B (hell even turbine powered ground effects too!).
You can use a much bigger air brake than the Bugati Veyron does, maybe using the entire roof for increased area.
Likely such hyper road-car would be heavier so you'll need much more downforce to get better downforce to weight ratios.
The big challenge would be a reduced front overhang to get a decent ramp approach angle for road use while still having huge downforce.

* Driver aids
Like ABS, traction control, variable-aero-control, active suspension, computer controlled everything, etc.
For an added bonus you can use ultra-accurate GPS devices automatically adjusting the car as they travel thru the track.
Maybe even a co-driver.