To continue a conversation I was having down the pub, Reynard have marketed the ground effect Inverter as a track day tool, citing remarkable grip levels from an underbody shape banned in many areas of proper motor racing. Given the freedom from rules cars built just for track days enjoy, and keeping to closed wheel vehicles, to costs that do not require an F1 type budget, and remembering noise emission is now an almost all embracing issue, where would you look to use this regulation freedom to build something different? Movable aerodynamics? Fuel freedom? Suspension freedom (a big kart perhaps, I recall these being banned from the hills as they were getting seriously quick, safety was cited, those running them cited sour grapes from owners of exotica being beaten by a "Go Kart"). Various suspension compliance stipulations killed those off.... Wheel and tyre size and compound freedom? So what technology would you use to build something faster than the norm, embracing a relative freedom from regulations?

That's an underconstrained problem. In a similar vein yacht design is underconstrained, which means that at a club level we race boats against each other that have different capabilities in different conditions, and were designed to different 'rules', and so rely on performance based handicapping, which is absurd.

So decide what your objectives are and then take it from there.

Fan car ala' Chaparral! predictable (assuming it all holds together) and adjustable down force at any speed. The problem then becomes that you caould go so fast that if an accident happens it will be a big one and there is usually very little safety gear at a track day. Also you would have such a speed differential that it other drivers could become a problem. I'd also point out that simply going fast may not be the big lasting thrill most people expect...getting the best out of something on the day becomes more important.

This had already start with the Camparo T3 and a couple of others but the Reynard is a bit more available (if you call 35,000 pounds sterling cheap that is).

Won't be long before people start killing themselves driving machinery they shouldn't be especially with the closing speeds of various vehicles on track days.

The question is why bother? The thing about motorsport is to win, how do you win in a trackday? Any time I have gone for a play on a track I am not driving at competition speed really more playing with the car.
My idea of a toy car would involve reducing grip not increasing it.

I think the appeal to some may be the freedom to try something technically new, or something technically old that was stopped in the past, but modern materials or technology allow a new take on, rather than the pursuit of outright speed per se. The big kart idea appealed to me, as it could be relatively cheaply built, and modern bike engines are very compact, light, powerful and freely available. 10 inch slicks are off the shelf.

gordmac: For sure, you can't win at a trackday, they just give pretty good value for money for those of us who want to blow away the cobwebs after a stressful month, and (in my case) no longer want the financial and time burdens of following a race series which to an old timer seems to offer poorer value for money annually. I am building a cheap(ish) RWD car on very modest wheel sizes, and to run on none slick tyres, with an excess of power to grip, which, to me, is as much fun to drive as a sports prototype with a LOT of downforce but limited power, or an F3000 with a lot of both. The sight of an Inverter at a recent trackday got me wondering where else one might turn for technology often banned in current UK race series.

well, over here trackdays are timed and there is a lot of effort put into getting better laptimes (although it isn't fair as those are run what you bring trackdays)

Reminds me of the scene from '40 Year Old Virgin' where Steve Carrell has the elaborate lead-in to a wank.

I know it is pointless but people take it seriously and spend quite a lot of money on it..

This is _all_ racing.

Why do people buy and rent ex. F1 cars to use for track day events? Why buy a BMW M3 CSL when you can buy the cheaper M3, a car with less grip which according to you is more fun. Given the grip the F1 car has, it can't be any fun all to drive, or can it?

I think you have missed the point here. People buy track day cars like the Inverter for the same reason some people buy F1 cars. It's a driving experience that simply can't be compared to slower cars. I think there are many people who would want to have a F1 car or a similar racing car in their garage to take to the track on weekends, but in reality they can't afford it. So, then the question becomes; how can you design a car that is cheap to buy and own, a car that doesn't require a dozen experienced mechanics to run while at the same time offer the performance only a very expensive racing car could, preferbly without killing its owner?

Fair point. There are also the issues of risk and cost: A race weekend in my home state will cost a minimum of $1,500-2,000 if all costs are taken into account - Entry $475 + fuel + tyres + travel + accommodation + crew etc. A circuit sprint (the timed version of a trackday with classes) will cost $150 Entry plus expenses...so say $500. Cost of prep is vastly different too.
The risk issue is simple enough - apart from historics - there is a greater risk of damage to the car when you are racing...and you cannot use your everyday driver.

Track day car choices are sort of interesting... if you just want to go fast on the cheap, most any old formula car will do nicely -- and will also be relatively easy on tires, brake pads, etc. Pretty hard to beat on a cost per fun-mile basis. However, lots of people pick the exact opposite, say a Corvette or suchlike. Slower and far more work and $$$ to maintain, but the type of fun they are interested in. More representative of street cars or street driving, the type of automotive enthusiasm they are rooted in, I suppose. People will naturally gravitate toward what they like.

I'm curious. What would it cost to run and maintain "any old formula" car? The idea that that is a cheaper route than a modified street car is counter-intuitive to me on the surface of it. And-if that's truly the case then perhaps I've consistently been barking up the wrong tree.
I always presumed that a retired formula car still required expensive staffing to operate, much less maintain.

Bear in mind hardly any track day operators in the UK will allow open wheel single seaters, so if that is what is meant by "Formula Car" there's an immediate problem

At least in the UK there is a motorsports series where most of the events have space for pure technical innovation ... hillclimbing!

There you can run open wheels, the running costs are not cheap but the limited running does minimize wear and tear costs and there is no risk of other competitors hitting you. Of course it is not everybodies idea of racing but if technical content matters to you it is one of the few places left

My dream hillclimb car is a backbone chassis with driver on one side and a gas turbine helicopter engine on the other sucking through a large honeycomb panel edged with skirts, ducted to the intake, and suspended from the wheel uprights.Plus an electonic clutch downstream of a transmission brake (BIG) so as to be able to cut power to the wheels whilst keeping the gas turbine fully spooled up.

I actually think the hillclimb regs for specials might allow it ( not sure on the skirts though)!!

You can buy old Formula Continental/F2000 cars for $10K USD all day long. No crew required. At a Mid-Ohio, Gingerman, or similar track it will be 10-15 seconds a lap quicker than most any street car and much easier on tires, brake pads, clutch, etc. To be safe you will want to go through the car before you run it -- bearings, bushings etc, but that is true of any street car as well. The major expense will be in miscellaneous -- towing, travel, hotel and meals, driver equipment and safety updates, etc.

If you are into fenders you can buy an old sports racer (though they are not as numerous) or an obsolete SCCA production class car. Equally cheap. There is nothing that depreciates faster than a race car that is no longer competitive -- pennies on the dollar. Not going class racing can save you a ton of money. It costs big bucks to be competitive against similar cars, but if you are just racing against your own lap times suddenly it becomes a lot cheaper.

Of course the challenge is also fitting into the old formula car.

For most of us at least.

Depends which one, look through the race car ad sites, this is one of my favorites over the years - don't let the big price cars scare you, I have seen some very cheap cars at this site... http://www.race-cars.com/ also the ads in race car magazines.

The only worry I have about 'old formula' cars is safety, a 70's/80's anything gives very little waist up protection and many of them are flimsy in the interests of saving weight.

A very cheap way to go can be unfinished Kit cars, you can get some wild gear there cheap if your willing to finish off a few details after someone has burnt out on the project or can't get a road license for it. Also hill climb specials that don't fit elsewhere can be cheap.