Splošna debata - iRacing

[mancSLO 1 945]

The Basics

Yellow Flag (Caution): Indication of an incident or debris on the track. No passing under yellow flag conditions. Pit roads are generally closed directly after a caution until the field is set, then pit road is open for pit stops. See this video of the use of a yellow flag. When the accident starts, the caution flag is waived and the field is frozen. Example

Black Flag: When someone is black flagged they have 5 laps to pit. Drivers get black flagged for either breaking a rule or having car problems that affect the track / safety / flow of the race. See this video of Jimmie Johnson being black flagged for jumping the restart: Example

Red Flag: The race is stopped, no pit stops can happen. Used in scenarios where unsafe for the vehicles to move across the racing surface, like in bad weather conditions or after a major accident requiring cleanup and/or work to the track itself. In this video, there is highly flammable jet fuel on the race track that needs to be cleaned, thus the cars are parked until cleanup is done. Example

Pit Stops: Short maintenance stop to allow repairs / new tires / fuel for a car to continue the race. A great explanation of a pit stop: Example

Drafting: I'll give you the short of drafting. Imagine you're driving on the interstate, roll down your window and stick your hand out like you're trying to give someone a high five. You immediately experience wind resistance blowing your hand back. Notice how hard it is to hold your hand steady? Now get behind a tractor trailer and do the same thing. Notice there's not as much wind resistance? That's because the truck in front of you is moving the air away from your line of travel. Less wind resistance against your hand, the easier it is (and less effort) to hold it up. Same goes in nascar racing. The vehicles are moving at a speed where wind resistance is holding them back under full throttle. Tagging behind another car allows you to maintain speed without having to fight the wind resistance, which usually means you're not using as much throttle. This sometimes allows for fuel conservation, and is a viable strategy. Also, under the same power load you may be a MPH or two faster than the vehicle in front of you, so the draft is used for getting a small speed boost to pass a vehicle. In this video, watch the M&M car: Example

Loose: Ever heard of drifting? Fishtailling? That's the definition of being loose. The rear tires are losing traction and are sliding out of control. Also called "oversteer." Watch the yellow car in this video, you see several instances of being "loose." Example

Tight: The exact opposite of "loose" obviously. The front tires are not getting enough grip, and sliding. "Understeering" is the term used here. Example from the truck series of a vehicle being "tight" and running up the track into the wall Example

Restrictor Plate: This is a plate that is installed in the engine, mandated by Nascar, to alter the racing of certain tracks. Their purpose is to limit the amount of air and fuel the engine consumes, thus limiting the performance of the vehicle to what Nascar deems as a "safe speed." A side effect of this is that the racing is usually very close and the performance gap is bridged. It is at restrictor plate races that underdog wins usually happen. Anyone who knows nascar knows what im about to post... Example Example

Roof Flaps: Ok, i know this really doesnt reflect strategy at all... but it is representative of the restrictor plate races, as well as any other race where a vehicle may be spun at a high rate of speed. There are flaps on top of the car that lift up when the car is travelling backwards. They are intended to prevent the car from flipping, as when a car is going backwards there is very little natural downforce. Video of a crash before roof flaps: Example Now in this video, the roof flaps engaged which prevented the car from getting further airborne: Example

Lucky dog: When a yellow flag waves, whichever driver was the first in the running order who was behind by 1 lap or more when the field is locked gets one lap "back". In other words he has one of his deficit laps erased. If he was down by 1 lap, that will put him back on the lead lap and allow him to compete with the leaders again. Seems kinda like cheating, doesn't it? So why do it? It's two-fold:

There was a safety issue for years, where when a yellow flag was initially waved, the cars would be able to race back to the start/finish line--at which point the order in which they cross the line would determine where they line up for the caution laps. If drivers were a lap down, but driving right next to the leaders at the time, they could attempt to race the leaders back to the start/finish line--if they crossed before the leaders, they'd get a lap back. However, there would clearly be times where that race back to the finish line would go right past the wreck or debris that brought out the caution. So they stopped the racing back to the finish, but used the Lucky Dog as a way to still give the best running lap-down driver a lap back. The SECOND reason to do this has to do with situations when the first driver 1 lap or more down is running in the middle of the pack. There's a little less incentive to be competitive back there since they can't beat the leader to the start/finish line. Well, that driver might be around another driver who is a lap down. So now those two drivers can race each other to be the first driver a lap down so they can get the Lucky Dog if a caution comes out. So: it makes racing among the lap-down drivers more competitive.

Wave around: During a caution, the lead lap drivers are permitted to use pit road 1 lap before the lap-down drivers are permitted to. If the lap-down drivers pit, they remain the same number of laps down as they were before they pitted. If a driver stays out during the entirety of the caution and does not pit, he can get 1 lap back. He'll literally drive past the pace car and lap the track, and join the field in the back of the pack just before the green flag waves again. This is called the "wave around", or "wave around lap". The downside to this strategy move is that the driver using the wave around did not get the chance to refill on fuel or replace his old tires. This is a great idea if the wave around is taken on a caution that broke out within a few laps of another caution ended during which time the wave around driver DID pit.

Competition caution: A competition caution is a caution flag thrown out at a predetermined point in the race. For example, they might throw one at lap 20. If a regular caution breaks out around lap 20 due to weather, debris, or a crash, it will serve as the competition caution. The purpose of the competition caution is to allow drivers and crews to make adjustments to their cars without sacrificing track position. Why do it? There will be race weekends where, for some reason or another (typically due to weather, however possibly due to very new mandated changes to the cars), the drivers will experience driving conditions during the race that they had not been able to practice for. Often times, these new conditions make it very difficult to set the cars up properly for the race. So the drivers race for a few laps, they and their crews figure out what needs to be changed, then the competition caution allows them to make the change without falling behind. During races that have a planned competition caution, drivers are not allowed to pit for gas before the competition caution. Any pit stops made before the competition caution (under yellow or otherwise) can involve tire changes, but cars cannot be refueled.

Really, there isn't anything that happens during a competition caution that doesn't happen during a regular caution--the primary difference is that for one reason or another, it is predetermined that a caution will happen at a certain lap.

Spotter: A specialized team member with the responsibilities of informing their driver of what is currently happening around him/her on the track. The spotter is vital to a driver, especially when an event such as a crash occurs on the track. You will often hear a spotter announce to his/her driver to "stay high", "stay low", or "clear, clear, clear", which indicates where it is safe to be on the track. Another vital role of a spotter is to safely navigate their driver through a successful pass of a competitor, announcing when the competitor is next to them, and when the pass is complete. Spotters will also sometimes pass information from their driver to another driver's spotter. An example of this is when a driver accidentally makes contact with another car and the driver asks his spotter to apologize to the spotter of the car he/she made contact with. Spotters for all cars usually sit next to each other in a booth or in a section of grand stands overlooking the whole track, much like the announcers. Spotters have a wide range of responsibilities but these are a few of the most important.

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Strategies

1. Short pitting

This is a tactic where a driver/team will attempt to erase some or all of a gap by pitting before another car. The strategy is that Car 1 and 2 will be on old tires nearing their 'pit windows'. Generally, there is some time lost due to old tires - lets say .5 seconds per lap. If car #2 is 3 seconds behind car #1, he can try to "short pit" car #1. The goal is to be out on fresh tires while car #1 is on old tires, thereby erasing .5 seconds per lap of the difference on the track.

2. Fuel Mileage

Coming down to the end of a race, teams will attempt to stretch their fuel mileage in order to gain or maintain track position against rival teams. With the EFI in the new cars its a bit more difficult to do, but you will see teams trying to stretch their mileage 'back off' (coast) earlier on entry to the corner, drive at partial throttle and even turn the engine off and roll during cautions.

3. 2 Tires, 4 Tires & Gas-and-Gos

Another strategy used to gain or maintain position on the track. In the pits, it generally takes 12-14 seconds to change all 4 tires and gas up the car. To try and gain an advantage, teams may chose to only change 2 Tires, which saves 3-5 seconds, or just put gas in the car and save even more. The downside of this depends on the difference in lap times between new tires and old tires. At tracks like Charlotte, new tires can make the car 1-2 seconds per lap faster, while at tracks like Talladega, the difference is marginal.

4. Rim-Riding (Queue Larry McReynolds: Hes gawn to the HIGHSIDE!)

While the preferable racing line at most tracks is for the cars to be close to the wall on the straights, and down on the white line in the corners - some drivers try to run the high line. This can help a car maintain its momentum better, and have an advantage at the end of the straights...which is coincidentally one of the best opportunities to make a pass. A car running the high line will actually drive farther, but since the radius of the turn is less, that car can achieve a higher speed through the corner and be at a higher speed exiting the corner, accelerating more down the straight. The goal of all strategies is to gain an advantage, and win the Race. Conveniently the best way to accomplish both of those (at all but 2 tracks - Daytona & Talladega) is to be the car leading the field in 'clean air'. The Gen-6 cars punch a BIG hole in the air and the large spoilers on the back create a lot of turbulence. This 'dirty air' affects the aerodynamic efficiency of the cars and actually can reduce downforce. The leader doesnt have to deal with any of this, and has a distinct advantage.

Car Adjustments

There is only one adjustment a driver can make by him(her)self in the car, and that's brake bias. The driver can adjust the brakes using a knob in the middle of the dashboard that either makes the brakes relatively stronger in the front or in the rear. This adjustment, like most, is made because the car is either too loose or too tight.

The most common adjustments made during a pit stop by the pit crew are: tire pressure, "wedge", "track bar", "spring rubbers", and tape on the grill...

Tape on the grill: the grill on a stock car is a very short and wide opening--it's NOT the decal that looks like a grill, though. The bigger the grill opening, the cooler the engine will stay while racing. The smaller the grill opening, the more front downforce (and therefore, more front tire grip) the car will have. So teams will try to keep the grill opening as small as possible while keeping the engine from overheating. There's only so far the grill opening can be widened, though: NASCAR dictates the maximum size of it.

Tire pressure: This adjustment is made before the driver pits, so that the tires can just be slapped right on and be ready to go when the time comes. Stock cars run tire pressures much lower than you have in your car--sometimes as little as 10 psi, so tire pressure adjustments are often in very small increments--sometimes as little as +/-0.25 psi, which would be announced as "they're taking a quarter pound of air out of the left front tire", for instance. That's another thing: tire pressure is adjusted individually so as to maximize grip. There are minimum tire pressures mandated by NASCAR, though, just like there are maximum grill sizes.

Wedge: This is an adjustment of how much force is applied to one of the rear springs.HowStuffWorks put it nicely: "Compressing the spring of a left-rear wheel or adding wedge puts more of the car's weight on that corner. This adds pressure to that end of the car just like putting the paper wedge underneath the table leg. As with the table, the corresponding diagonal corner of the vehicle gets more of the car's weight. So if you increase the tension in the left-rear wheel, the left-rear and right-front wheels will hold a larger share of the car's total weight than the right-rear and left-front wheels.

The reverse happens if you reduce the tension on the left-rear wheel's spring or subtract wedge. In our analogy, that would be equivalent to cutting short a table leg. It would increase the weight on the right-rear and left-front wheels. This is why a crew may need to adjust only one wheel when a race car needs to add or subtract wedge.

The diagonally related weight between the left-rear and right-front wheels is referred to as cross-weight or simply wedge. It is often measured as a percentage of the vehicle's total weight. When more than 50 percent of the car's weight is on the left-rear and right-front wheels, the car is said to have more wedge." Read more if you want to there--it's a pretty thorough page! The short of it: Decreased wedge makes a car looser (oversteer) by making the weight supported by the front wheels in a turn more even, while making the weight supported by the rear wheels more UNeven in a turn.

Decreased wedge allows a driver to enter a turn a bit faster, but makes it tough to exit since getting on the gas too soon might turn a looser car into a spinning car.

Increased wedge makes a car tighter (understeer) by making the weight supported by the REAR wheels more even in a turn, and the weight supported by the fronts more uneven. Increased wedge gives a driver more control as he exits a turn, but makes it tougher to enter it since he might not be able to turn enough to miss the wall.

Track bar: The details of what a track bar is are a bit above me, but thanks to this article , I understand it better. I'll let you read his words on what exactly it is, but here's the short of it: the track bar adjusts the angle at which the sideways force of the car moving through the turn is applied to the rear tires. If you raise the track bar, the force is applied to a higher point on the rear tires, making the car more loose, and if the track bar is lowered, the force is applied to a lower point on the rear tires, making the car tighter.

Spring rubbers: these are literally blocks of rubber that get inserted between the coils of the springs. They could be inserted at any corner of the car, however they are probably the most time consuming adjustment a team can make during a pit stop, so these are likely to be last-ditch effort adjustments. Here's what they look like, along with yet another thorough explanation I'll attempt to summarize for ya. Adding a spring rubber will "increase the spring rate", e.g. make the spring stiffer. Teams often start with spring rubbers already in the rear springs, and will add a spring rubber to the right front (or left rear) to make the car tighter, or add a spring rubber to the left front (or right rear) to make it looser.

Curiously, spring rubbers and wedge are closely related, as they impact how the car handles the cross weight through a turn.

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Technical Information

Drive Train: NASCAR Sprint Cup 'Gen 6' cars (2013-present) are 3300 lbs (~1500kg), with mandated left/right minimums of 1680/1620lbs respectively. (Without per-side limitations, teams would likely try to move more weight to the left on left-turning ovals, e.g. all but 2 races.)

The engines are somewhat 'old school' in design, using a single camshaft and pushrods to actuate the 2 valves/cylinder. They are 358 cubic inches (5.8L) in a v8 configuration and develop in excess of 850hp, typically revving under 9000rpm. They are normally aspirated and, as of 2012, fuel injected (with ECUs heavily regulated to be standardized across all cars). The fuel used is an 85% gasoline / 15% ethanol blend at 98 octane; the fuel cells are in the 'trunk' area and hold about 18 gallons. At the two 'superspeedways' (Daytona and Talladega) the engines are limited to 400-500hp by a 'restrictor plate' between the throttle body and intake manifold that restrict air intake. The size of these plates are determined by NASCAR, which aims for a top speed 'in the draft' right around 200mph. Teams are limited to one engine per weekend.

The engine is in the front, with the drive wheels at the back. They are connected through a 4 speed, manual; H pattern gearbox, using a clutch pedal on the floor. The transmissions are set up to allow shifting without clutch use as needed. Other than the two road courses and (depending on driver/car) Pocono, races are run in 4th gear (mandated to be 1:1) with the exception of pitting and cautions, of course. The transmission connects to the rear end, where you'll find a very tough limited-slip differential in a bog standard solid axle housing. Teams are given a choice between two rear-end gear ratios for each given race weekend.

While the front suspension is double-wishbone, the rear end is attached with two 'truck arm' trailing arms and a track or 'panhard' bar to limit lateral motion. There is a single coilspring and shock absorber on each corner. Spring rates or 'weight' may be mandated by NASCAR at some tracks (e.g. 500lb minimum rear springs at Daytona/Talladega to keep the spoiler in the air).

There is only one type of tire provided by Goodyear for any race weekend, but the construction and compounds change from track to track. Sprint Cup teams are not limited to any number of tires in a race weekend, but typically don't use more than 8 sets. The tires are slick radials mounted on 15” steel rims with 5 lug nuts.

Data Acquisition/Car Adjustments: There is no data from the car being sent to the crews during a race, aside from what the driver says verbally. The steering wheel has up to 2 buttons, one for radio and one as an emergency kill switch. The gauges are far closer to road cars than F1 or IndyCar, using needle dials to indicate RPM, oil temp and pressure, and water temperature. As noted above, other than steering, braking, and acceleration the only adjustment that can be made inside the car is brake bias. During practices (and after the race) teams are allowed to pull data off the ECU.

Pit Crews: Pit crews in NASCAR consist of 6 men: front and rear tire changers, front and rear tire carriers, a jack man, and the gas man. Crews may get permission from NASCAR to have an extra man 'over the wall' for windshield tear-offs. The pneumatic lug guns used by the tire changers typically operate in excess of 400psi. The gas man carries a ~90lb gravity-fed 'can' of fuel which is sufficient to fill the tank about ½ to 2/3 full; most 4 tire pit stops involve at least part of a second can. The crew may not go over the pit wall until the car is within 3 pit boxes of its own pit. Each car has its own crew chief, pit crew, and pit, which brings us to politics:

Teams: A given owner in NASCAR may own up to 4 cars. While not at the track, during practice, and prior to the race, these drivers/crew chiefs/crews may consider themselves teammates, share information on car setups, work out of the same shops,etc. Once the race starts, each car is typically operated as a single entity. There's too much ego in NASCAR for team orders. The pre-race information sharing also extends beyond a given shop: e.g. Stewart-Haas racing buys car chassis and engines from Hendrick Motorsports and may share information back and forth on what setups work for the given track and tire combination. Or they may not

 

[silicijeva dolina 1 254]

Nekaj me zanima. Fantje kako se kaj pripravite na tako dolgo dirko? Recimo, @mancSLO je napisal,da je dirkal 3 ure skupaj. To zna biti kar naporno za zadnjico,med dirko postaneš tudi žejen in morda ti jo zagode še mehur. Ok,mehur pač pred dirko izprazneš,kako pa kaj z pitjem? Ali pijete pač med postanki,ali imaste kako drugače to porihtano? Sam še nisem nikoli 3 ure skupaj dirkal. Letos bi se morda udeležil 6 urne vzdržljivostne , za to me te zadeve zanimajo.

[PEK 2 291]

Vse kar rabiš je pit. Mej liter (pa pol) vode pr seb, na ravnini in v boxih spiješ pa je.  

[urhpi 5]

Res je, rit zna kar bolet če imaš neudoben sedež. Sam sem imel bidon 7dcl, pil pa sem med varnostnim avtom ter na ravninah. Ni pa fajn preveč na enkrat. Za 6h boš potreboval še kaj za pojest (vsaj jaz bi) 

Uredil February 19, 2016 - urhpi

[B_U_R_I 3 290]

Če je kriza, si kateter naštimaš. Al pa plenico oblečeš. 3 ure je muka. 6 ure je brutalno. Bolj kot fizično neudobje in praznenje mehurja, je problem koncentracija, da ti sploh rata dokončat dirko.

[mancSLO 1 945]

Jaz sem imel krigel vode pa je kar šlo. Na stolu se že malo poravnaš, koncentracija je pa zgodba zase. Odvisno od dneva. Zadnjih 30 krogov mi je res kar dol teklo zaradi tega, ker sta fasDash for iRacing in podatki v iracingu kazala različne podatke o porabi goriva. Tu bi pri kalkuliranju lahko naredil kakšno napako. Sicer se nekaj malega (jaz z moim znanjem angleščine dobesedno) zamotiš z čvekom, ki je v iRacingu part of that. 

V bistvu bi jaz raje videl, da bi nas razdelili v manj skupin po 50 in več na startu. Očitno so nas dali v 8 skupin po caa. 30 na štartu.

@silicijeva dolina, za tisto 6 ur sta dva ali trije verjetno ali kako.

Uredil February 19, 2016 - mancSLO

[markop 702]

@silicijeva dolina: BES

 serija, Blancpain Endurance series, ki traja 3 ure se vozi v teamu kjer se vozniki izmenjujejo. Sploh se večurne zadeve vozijo v teamu. Ne predstavljam si da bi road varianto vozil sam več ur. Rit še zdrži, glava pa ne. Dejte z licencami gor prit pa gremo en bes.

Uredil February 19, 2016 - MarkoP

[urhpi 5]

Jz sem za Sebring 12h,12. marec ob 14h.

Licenca D4.0, avti GT3+Corvette DP, enako kot 24h Daytone.

[ingange 379]

Nehajte mi lušte delat !

Dirke na ovalih in večurne dirke ... nehajte ker res nimam časa še da si iracing nabavim .

Drugače pa ja tudi jaz imam pri daljših dirkah bidon za vodo . Kozarec ni praktičen ker lahko vse poliješ če pride do česa med pitjem " gužva na cesti " Bidon pa ne rabiš čuvat je plastičen pa če hočeš polit tut  moreš bit mojster .

Pogrešam SRW . Tam je bilo veliko ovalov in sem jih kr vzljubil . Enkrat  je bil event 500 milj daytone in se nas je našlo 5 razmetanih iz celega sveta ,smo se menli po sqypu in poizkušali in vadli celi teden . Ko pa nam je ratalo smo .................

Nehajte mi lušte delat !

[markop 702]

12 urni Sebring bo pa potekal istočasno s pravim eventom, kajne ? Kaj to se v 4ih loti te zadeve?

[urhpi 5]

Teden pred pravo dirko. 2 ali več voznikov na ekipo.

[silicijeva dolina 1 254]

Hvala vsem za nasvete.Sam si bom za pitje vode nabavil Camel Back . Je zelo priročna zadeva in si ga bom zmontiral ob simulatorju,potem pa samo cev pripnem na majico in že lahko med dirko kadarkoli pijem,ne,da bi se polil.

Glede več urnih eventov se ve,da ne bom sam odvozil ampak mora biti ekipa. Glede licence se ni za bati,saj sem danes osvojil "C" licenco. Postavil sem tudi svoj osebni rekord na Panorami (2:8:098),dalo pa bi se še izboljšati na 2:7:xxx ampak,ker sem vozil na Time Trial sem moral biti pazljiv.

Tudi sam sem razmišljal o Blancpain Endurance seriji in najbolj verjetna udeležba bi bila trenutno na Laguna Seca, Watkins Glen, Panorama, Nurburgring kajti ta dirkališča trenutno posedujem. 

Glede ekipe pa bi se morali zmeniti,če bi kdo bil zainterisiran. Jaz sem takoj za. Zmeniti bi se morali tudi kateri avto bi vozili. Jaz sem trenutno najbolj zagret za BMW Z4,ampak,ker GT3 dirkalnika še nimam,bi vzel tudi Mclarna. Ruf pa mi ne diši ravno,sploh pa zaradi tega,ker ga itak mislijo umakniti iz GT3 serije.

Torej napišite,če bi bili pripravljeni sodelovati in z kakšnim dirkalnikom. Če bomo našli skupen jezik,predlagam,da napravimo novo temo in se tam dalje dogovarjamo,usklajujemo itd.

Uredil February 19, 2016 - silicijeva dolina

[urhpi 5]

Jaz imam Rufa, ne vem pa, če bo sploh še možno z njim vozit to dirko. Bom nabavil, kar se bomo zmenli  

[silicijeva dolina 1 254]

Kako pa je tebi ime,da te dodam na iR? 

[urhpi 5]

Uros Pinter - sej sva 'kolega'