IndyCar Series

[RicME85]

That was my initial thoughts when they first showed the new car in the rendered images the other month.

[Jolle]

I see these cars still have the “Monger-hook” to lift the car.

Although pleasing to the eye, I generally don’t like one-make series. This is why I’ve been in love with F1 since the mid-eighties, the constant development battle between constructors.

How much can Chevy and Honda change about the car? Only wings?

[Sevach]

Right, silly me. Front wheel of the incoming car has a higher angular velocity and will want to drag over the rear wheel on the moment of impact.. That and a car's inertia pushing it to the only place it can go.

so, it seems the new cars are less safe than in the past in this respect?

Very much so, I don't understand why, after making such a point of including the rear pods on the original DW12 design to prevent wheel to wheel contact that they've now dropped it.

When you rear end a car in a speedway you go flying, fairing or no fairing, the fairing is obliterated instantaneously.

Wheel to wheel contact is less dangerous than when your nose goes up (which was what happened with Webber, wheels never touched on that one).

I see these cars still have the “Monger-hook” to lift the car.

Although pleasing to the eye, I generally don’t like one-make series. This is why I’ve been in love with F1 since the mid-eighties, the constant development battle between constructors.

How much can Chevy and Honda change about the car? Only wings?

Only engine, when the DW12 first came out it also had a generic aero package produced by Dallara itself, aero packages developed by the engine makers where added later.

[WaikeCU]

Right, silly me. Front wheel of the incoming car has a higher angular velocity and will want to drag over the rear wheel on the moment of impact.. That and a car's inertia pushing it to the only place it can go.

so, it seems the new cars are less safe than in the past in this respect?

Very much so, I don't understand why, after making such a point of including the rear pods on the original DW12 design to prevent wheel to wheel contact that they've now dropped it.

When you rear end a car in a speedway you go flying, fairing or no fairing, the fairing is obliterated instantaneously.

Wheel to wheel contact is less dangerous than when your nose goes up (which was what happened with Webber, wheels never touched on that one).

I see these cars still have the “Monger-hook” to lift the car.

Although pleasing to the eye, I generally don’t like one-make series. This is why I’ve been in love with F1 since the mid-eighties, the constant development battle between constructors.

How much can Chevy and Honda change about the car? Only wings?

Only engine, when the DW12 first came out it also had a generic aero package produced by Dallara itself, aero packages developed by the engine makers where added later.

The idea behind the DW12 was great regarding safety, but the fairings are another piece of body that can fall off a car just as easily. You don't want that at a speedway going +200mph. Remember Indy 500 this year, how many full course cautions we had because of debris? Not sure if any of those debris were parts of the fairings.

Still, it doesn't prove the fairings won't send cars flying, when you look at the Franchitti accident and that's just on a regular road course.


And this does prove it still happens on a speedway:

[NutritionFact]

Hy guys, sorry but is in german, but ams is a good source for pics.
The new 2018 indy car tested by Montoya (Chevy)

They wrote a brave step into the future, i think one step back too much.

It looks cheap, simple and not spectatcular, ok its sleek and in case of an accident they have not soo much debris. [url] https://www.auto-motor-und-sport.de/mot ... 93828.html

[toraabe]

And they have changed the floor to generate more downforce than previous. This to encourage close racing, and make it possible to overtake. Hopefully they will allow the same kind of floor in F1

[wesley123]

And they have changed the floor to generate more downforce than previous. This to encourage close racing, and make it possible to overtake. Hopefully they will allow the same kind of floor in F1

You really take every chance you get to promote super-duper amazing never actually proven to be true ground effects.

Also;



They don't really seem to be all that much different. I am 99% certain that the underbodies are identical(the leading edge is identical, and the diffuser itself also, so it is safe to assume that the rest in between would be the same as well). A part in the design of the new indycar was with costs, and because of that they carry over a large part of the DW12.

[jjn9128]

And they have changed the floor to generate more downforce than previous. This to encourage close racing, and make it possible to overtake. Hopefully they will allow the same kind of floor in F1

You really take every chance you get to promote super-duper amazing never actually proven to be true ground effects.

Also;
https://cdn-4.motorsport.com/images/mgl ... ndycar.jpg
http://www.autoracing1.com/Images/Photo ... vyRear.jpg

They don't really seem to be all that much different. I am 99% certain that the underbodies are identical(the leading edge is identical, and the diffuser itself also, so it is safe to assume that the rest in between would be the same as well). A part in the design of the new indycar was with costs, and because of that they carry over a large part of the DW12.

The 'increase' in underbody downforce is only relative to the 35% reduction in overall downforce. So it's mostly because of a reduction of downforce from the top of the car, i.e. no more winglets above the wheel pods and simpler front wings.

All they've done to the floor for the road course kit is to allow a strake in each half of the diffuser, plus there is a cover which can go over the mandatory floor hole - which is left open for ovals/speedways. I think there is also a domed 'semi-skirt'/skid which can be used on the ovals/speedways. So there is a subtle increase in floor downforce, but that the floor now produces 66% of total downforce is mostly because the total downforce has been reduced. Ironically the floor of an F1 car also produces about 60-65% of its total downforce, it's just a different design - flat with a diffuser rather than 'wing' shaped.

The drivers also wanted a more positive front end on road courses, i.e a forwards COP, part of this is helped by the floor hole cover on road courses, but also the rear wing is producing less load now.

Formula 1 has gone the opposite direction, wanting more downforce, and consequently more drag. Bigger wheels and a less efficient diffuser (compared to the indycar floor) are also not helping cars follow, plus the immense complexity of the front wing and bargeboards and holistic nature of the aerodynamic packages, the cars aren't really comparable.

[toraabe]

Even though ground effect or not, the much simpler aero package makes it simpler to follow. Another thing is how the dirty air is compared to F1.

[jjn9128]

Even though ground effect or not, the much simpler aero package makes it simpler to follow. Another thing is how the dirty air is compared to F1.

You are correct to some extent that a simpler aero package should be less affected, but I believe the main difference is total downforce, which is some 15-20% lower on the indy car. From numbers I found for the original DW12 vs a modern F1 I would say that's a Cl of -2.8 vs -3.5 based on reference area of 1.5m^2, or a difference of 70 points of downforce. So if we assume the the new body kit is producing forces similar to the DW12 rather than the manufacturer kits, then the absolute effect of a 20% loss of downforce for an indycar will be smaller than on a F1 car, a loss of 56 points of downforce compared to 70 points, a 50% loss is 140 points vs 175...etc etc. So the more downforce you have the more you will lose in a wake, and the greater difference the driver will feel because of it.

I would say the dirty air effect is predominantly caused by momentum deficit in the wake, so linked to the drag of the vehicle. Drag of an F1 and indy car is approximately the same, Cd is somewhere between 0.8 to 0.95 based on a reference area of 1.5m^2, so the absolute momentum deficit should be similar. However, the way the aerodynamic package moves the air behind the car is important, and I think the lower aspect ratio rear wing the indy cars use is important for driving the wake from the floor and wheels over the top of a following car.

The main benefit of a single make series though, is that the package can be tested in a wake and tweaked to run better, which cannot be done in F1 - firstly as the teams all design different cars in complete secrecy, but also because they are limited to simulating a single vehicle in their wind tunnels/cfd.

[Michelada]

Apparently there might be a slight overall increase in the underbody downforce. According to this article: http://oppositelock.kinja.com/the-secre ... 1691381347 Dallara purposefully made holes to the front part of the underfloor to artificially decrease downforce when the aerokits were introduced. In the universal aerokit the holes are no longer there.

One compromise common to all cars, and one that eluded me until Slipstream pointed it out, is the gaping hole between the radiator tunnel and the sponsor blocker. Look below at this "floor" on the old DW12 (right) and the new hole on the Honda (left). The story goes that this solid floor is worth around 300-400 pounds of downforce(!) and that these new aero kits may be good for around 1000 pounds of additional downforce! Seeing as this is a LOT of downforce, a compromise was necessary somewhere. Cutting out that relatively small hole from between the blocker and the tunnel was a way of dialing back some of the incredible gains expected from these new aero kits.

[jjn9128]

Apparently there might be a slight overall increase in the underbody downforce. According to this article: http://oppositelock.kinja.com/the-secre ... 1691381347 Dallara purposefully made holes to the front part of the underfloor to artificially decrease downforce when the aerokits were introduced. In the universal aerokit the holes are no longer there.

Indycar have been quite good with releasing videos to explain the new aerokits...
road/short oval: https://www.youtube.com/watch?v=nCUHvkIP8Ng
speedway: https://www.youtube.com/watch?v=WNy08hKebHA
safety: https://www.youtube.com/watch?v=riJPs1d8Rm8

I don't like how they talk about 'wake turbulence' because that's not so much the issue in a wake, but I accept they have to simplify things to some extent. I also don't how they talk about percentages, because it doesn't define what it is a percentage of - i.e. when they talk about a percentage increase of the floor downforce is that relative to total or compared to the manufacturer kits?

Race cars are also hugely complex aerodynamic systems so blocking the hole in the floor may locally increase downforce, but that can affect downforce production elsewhere. The smaller front wing will affect how the air flow affects the underbody, or where the front wheel wakes end up. No beam wing will reduce the base pressure and the diffuser pumping will be less strong. The new shape of the sidepods may induce more lift on the upper surface of the car which can affect how air flows to the floor...etc

I said in an earlier post that there will be an increase of floor downforce, but it is not a significant one. With the 35% reduction of overall downforce the percentage contribution from the floor increasing by 18% does not equate to a big increase in absolute underbody downforce.

[johnny comelately]

Surprising fact:
The 2001 Season became a embarrassment for CART. At their event in Texas, the cars were so fast and the banking was so steep that the G-Forces were causing drivers to fall unconscious, leading to the race’s cancellation.

[johnny comelately]

Further to the above:
You can read about the full situation here. 6 CART Teams entered the Indy 500 for 2001 and took the Top 6 spots. CART star Alex Zanardi lost both legs during the race at EuroSpeedway. After a few missteps, canceled races and officiating errors, Honda and Toyota announced they would leave CART at the end of the 2001 Season, leaving Ford as the only engine manufacturer in CART. Roger Penske, Co-Founder of CART, announced in November that Team Penske would switch to IRL in 2002, with Chip Ganassi announcing the same thing weeks later. CART would declare bankruptcy after the 2003 Season.

[johnny comelately]

This article just keeps giving: https://www.carthrottle.com/post/wgzeqg7/
"Attendance was far lower than it should have been and, in 2003, IRL had its worst case scenario when trying to rebound. At the final race at Texas Motor Speedway, Kenny Brack was severely injured in an accident with only a few laps remaining in the Championship race. Brack would sustain 214 G’s in the accident, the most a human has ever survived. Then, at a tire test at Indianapolis, Chip Ganassi was testing with his two drivers for the 2004 Indianapolis 500. Scott Dixon had completed his test, and new driver Tony Renna would go out on October 22nd. On his 4th Lap, something went wrong. Renna’s car spun on the back straightaway, lifted into the air, and went through the catch fencing. To anyone there that day, it is said to be the worst accident in Motorsport, and it would have put an end to racing had it happened on race day. Renna’s car had shattered when it hit the catchfence. Bodywork, Engine Parts and parts of Renna were found throughout the Turn 3 grandstand, and even outside the track. No video has ever been released of the incident, and the IRL gained a lot of bad press out of the incidents.