AC Schnitzer
Well-Known Member
I thought I do a break down on Rallies in simplified terms since there is so much talk about Circuits.
Rallies are an entirely different style of driving compared to circuit but the end-goal and built are identical in principles to circuit. It is one that fascinates me.
Brief History and WRC Car
WRC has come a long way from the 70s to the late 80s where we saw the death of Group B cars with all out insane horsepower output and no restrictions on weight, to the safer Group A and now WRC.
Group B cars in the 80s has and always will be my all time favourite. It was an era where WRC cars had very little restrictions and engineers were permitted to make the car go as fast as technology allows. For a start, the minimum cars required for Homologation was 200. This was considered to be a "Small figure" compared to Group A's requirement of 5000 cars per year, which was later reduced to 2500 per year.
Simple English: This means a car manufacturer only had to manufacture 200 cars in order for it to be permitted for use in WRC. Homologation is generally imposed to prevent car manufacturer from producing a "One-Off" purpose built rally spec car and call it a production car and sanction them for use in Rallies. Therefore, this keeps cost down so that other car manufacturers/Teams with lower budget are able to enter.
In Group B, there was no restriction on Boost Pressure for Forced Induction cars or minimum weight limits. Because of this, it was common to see cars of that era flirting with about 400 horsepower with the exception of the Audi Quattro S1 firing up to 600 horsepower.
Not a lot you say ?
Well, these cars are hovering in the region of 1000kg. To put things in perspective,
Power to Weight Ratio (Hp/Ton)
Ferrari 458 (562hp): 378.45hp/ton
Lamborghini Aventador (690hp): 438.09 hp/ton
Nissan R35 GTR (520hp): 300.57hp/ton
BMW E92 M3 (414hp): 246.42 hp/ton
Audi Quattro S1 (600hp): 600hp/ton
Audi Quattro S1 (Source: Audi Sport quattro S1 1985)
And of course, we should not neglect to mention that Walter Röhrl and Michèle Mouton are just one of the few drivers who drove the S1 who went on to win the San Remo Rally and Pikes Peak Intl Hill Climb in 85' respectively.
(Source: rallymemory / Best of Rally Live | All the news about IRC and WRC in Live! Le meilleur du Rallye en direct)
Death of Group B
Henri Toivonen & Sergio Cresto (Source: File:Henri Toivonen.jpg - Wikipedia, the free encyclopedia / ForoCompeticion - Portada)
In 1986, the demise of Group B was inevitable when Henri Toivonen and his Co-Driver Sergio Cresto passed away in a crash. Group B cars were deemed too fast too dangerous and offers little protection to both drivers and spectators when crashes occur.
Fast Moving Object vs Spectators standing on track is a cocktail for disaster.
[ame=http://www.youtube.com/watch?v=vH4z5OI5aNY]WRC Classics - Rallye Monte Carlo 1993 with pure engine sounds - YouTube[/ame]
Think standing at the Apex of a corner is safe ? Put down the weed and think again.
[ame=http://www.youtube.com/watch?v=N4ulS8GvTM0]Old Geezer Rally Near Miss - YouTube[/ame]
Group A eventually took over Group B. Because Group A required 5000 vehicles per year (later changed to 2500) for homologation purposes, this meant the end of the era where car manufacturers could build all out purpose built rally cars that were not suitable for public roads. Therefore Group A cars look somewhat similar to road going cars as a result.
In addition, Group A cars were limited in speed due to the mandatory 34mm restrictors which is placed at the inlet side of the turbo. This means you may install a massive turbo like the T88 but at the end of the day, all that air has to go through that tiny 34mm diameter. In addition cars are also regulated to a minimum weight of 1230kg.
Simple English: To make this easier to understand, I am going to ignore that Air is compressible.
Imagine 2 guys drinking a cup of water. Both guys and cups are identical in all aspects. Guy A drinks the cup of water through the mouth while Guy B drinks water via a straw.
Naturally the guy who drinks the cup of water by the mouth is going to finish 1st. Guy B drinking via a straw can drink as fast as he could but at the end of the day all that water has to go through that tiny straw.
This is somewhat the same concept as a restrictor being imposed on the turbo inlet. You may install the largest turbocharger but in the end all that air has to go through a 34mm diameter tube. However some teams have gone around this problem by designing the restrictors in such a way that accumulates/stores a mass of air at the restrictor's inlet area . This high pressure area then provides all the air that the turbocharger can draw, through the 34mm restrictor thereby maximising efficiency.
Due to restrictors being imposed, pre-2011 WRC cars are very limited in Horsepower. However what they lack in horsepower, they make up in torque and 600nm is easily achievable. Because of restrictors, Rally drivers seldom rev past the 5000-5500rpm mark even though the redline is about 7000rpm or so. This is because boost pressure is tapered off and therefore if you notice on TV, in a straightline, Rally drivers upshift very early to get the best out of the powerband.
2011 rules dictate 33mm Restrictors and limited boost pressure to 2.5 bar absolute. Minimum weight 1350kg.
This is a Group N 33mm Restrictor.
(Source: www.rallyandracingparts.com|Motec ECUs for Rally, Racing, Motorbikes, PWC Plug-In ECUs|Haltech ECU|www.rallyandracingparts.de -Home)
Today, WRC cars are 4 cylinders boasting only 1600cc turbocharged, 4WD. Safety has been drastically improved by making the car slower with strict regulations on FIA approved full welded roll cage made of T45 Steel Grade. Entry level Rally cars uses the more expensive Chromoly, which fairs very well in the strength to weight ratio department.
Ford Focus RS WRC. Rolled 12 times 200 metres downhill.
(Source: Ford Focus RS WRC passes severe crash test | AutoNewscast.com)
Boost Pressure - Boom Boom Bang Bang Antilag
"My Evo 9 4G63 is faster than your GTRtoyotabanana because I run 2 bar which wakes up by 19,000rpm"
Well pre-2011 WRC cars are running close to 4 bar. Of which, about 3 bar is available at about 2500rpm through the use of Antilag System. Your Defi Boost gauge be it genuine or fake only reads up to 2 Bar...
That is nearly 60 psi which is about 2x the amount of pressure you pump in your road tyres. With Antilag System (ALS), depending on which map (ALS Mode 1-4), about 200hp is readily available on tap at a mere 2000rpm.
Depending on the ALS mode (aggressiveness), the ignition timing is retarded or delayed, the butterfly valve kept slightly opened and fuel mixture ratio is richer. Because ignition timing is delayed, the spark plugs fire just when the exhaust valve opens and with all the unburnt fuel being sent into the exhaust manifold, the explosion takes place, the explosion increases the velocity of the exhaust flow which then spins the hotside of the turbo and therefore keep boost pressures up even without throttle input.
Simple English: When ALS is turned on, the ECU then tries to keep the turbo spinning even when your foot is off the throttle and therefore 1 bar (eg) of boost pressure is readily available for you once you step on the throttle.
This is considerably different as compared to road cars where you step on the accelerator, wait for the revs/boost pressure to build up before you feel that surge of power. The Boom boom bang bang sound you hear in a WRC car is fuel still in its liquid or fume state that comes in contact with very hot exhaust. Fuel + high temperature = explosion and that's what you hear.
"I have a turbocharged car, how do I make my car boom boom bang bang ?"
Given the technology we have today, most reputable standalone ECU or Opensource ECU have ALS options.
But this does not mean you should hurry off to your tuner and ask for boom boom bang bang because ALS makes your turbo work over time which means very high wear and tear as it is exposed to high temperatures. The turbochargers used in WRC cars are rebuilt after every race. If you feel you have the budget to rebuild your turbocharger every month depending on usage, feel free to install. With ALS on, depending for how long and how aggressive, Exhaust Gas Temperature can surpass the 1000 deg mark and that kills a lot of things in your car, amongst which, your catalytic converter if you have one, exhaust manifold, etc.
==========================================================================
The Drive
If you know someone who says he drives around Sepang International Circuit in the 2 minute using a Hyundai Getz, enrol him into a Rally School.
I promise you a 3 hour session is more than sufficient to bring him back down to Earth.
Here's a great video compilation which I thought it contains some interesting things worthy of noting in Rallies.
Video Compilation
[ame=http://www.youtube.com/watch?v=pqx4E-QluHI&feature=relmfu]Best of Rally 2009 - Trailer Rallymedia Jaaroverzicht 2009 - YouTube[/ame]
While it may look like Drivers are driving as rough, jerky and violent, this does not mean you should do the same at Sepang because by logic, "if I do what race car drivers do therefore I shall be just as quick." No
Earlier in 2011 I was watching the in car footage on youtube of someone driving at Sepang. I believe it was maybe turn 6 or turn 7 where the driver spun and he was still on the track. In Rallies on gravel, mud even tarmac, the corner will have no problem spitting you out of the track and into something hard.
The thing with Rallies is that you can never run out of topographical objects to hit. If you bring along a mindset of, "I am the fastest d̶r̶i̶v̶e̶r̶ /car, of Sepang" you will get hurt in Rallies and possibly die.
The Basics of Gravel
Driving in Gravel surface is a little different to circuit racing but the aim is essentially the same. Be as smooth as you can.
First time you drive on gravel surface, it will feel like Disney on Ice. At moderate speed, turn the wheel and the car will continue to go straight until you hit something hard.
During my time, I've seen someone hit a lamp post. Driver had to pay $6000aud to replace that lamp post. I've seen someone who understeered off the cliff and thankfully stopped by a tree. But mostly it is always the concrete barriers.
Think of driving on Gravel surface the same as digging a shell scrape in NS. Apologies to those who were PES Cs and below. Find a back yard and start digging and those without a backyard....
anyway, as I was saying, if you ever dug a shell scrape, you should find the upper layers of the surface is generally soft and easy to remove. As you dig deeper, you find more resistance and requires more effort than before to go deeper. Generally speaking, a Rally driver is looking to remove the top layer of loose surface and firm more traction beneath it.
Apart from paying attention to your Navigator yelling out pace notes, a Rally driver also has to analyse and predict the road surface ahead of him.
Generally speaking, sliding the car, getting on the throttle and using the deep grooves in gravel tyres to chew into the upper surface of the gravel and dig deep for traction.
Had you driven the car like you did at a circuit and backing off the throttle each time you felt understeer or oversteer, it would have been possible for an average human being to run through the corner faster than you driving through it.
It takes a lot of courage to overcome your intuition of braking or backing off the throttle whenever you feel the car sliding or losing traction. To make the difference, you really need to get on the throttle and find grip and power out of the corner. The best part is when you have mastered this, the seasoned rally drivers walk up to you and say, I can find another 5-10 kph in corner speed. So then its best you put your P plates back on and keep trying.
Note: 0:24(Referring to Video Compilation) is a prime example of a very soft muddy surface.
(Source: www.crash.net.com)
In essence, surface condition is always changing, unlike a circuit where traction is more or less consistent, in Gravel and Tarmac stages, traction levels varies wildly. It can be very slippery one moment and very grippy the next. Imagine your mindset throughout the rally stage adjusting your driving style every few seconds. Its mind boggling.
You have to take into account the drivers ahead of you who may or may not have dug deep, the drivers who clipped the apex and threw a ton of stones on the tarmac or the 5 cars ahead of you who drove through a preceding pond of water and carried most of that water onto the next corner.
These are external factors that are beyond your control and as a Driver, you can either spend time to sit and complain or do mental preparations, visualisations and account for these factors and ask yourself how do you intend in going about to tackling this problem if this or that happens.
There are no yellow flags, safety cars or "hey lets stop and clean up that oil spill".
Generally speaking, strategy wise, it is sometimes in the Team's interest to plan and allocate their drivers sequence well. Sometimes it is better to let the first few cars dig deep into the gravel and remove the upper slippy surface so that later drivers will have more traction and therefore translate to better laptimes.
The Team also has to take into account the type of soil and surface condition, level of precipitation and wear rate on the soil because if the gravel is too soft and 20 cars had dug deep, this may result in a bottoming out and this is something that race engineers have to take into account when setting up ride height. The Key is a find a balance.
Driving Techniques
(Note: 0:42 of Video Compilation)
On Rally cars, Hydraulic handbrakes are used as it locks up the rear wheels quickly. In circuit racing, we always talk about achieving the highest corner speed possible. In Rallies around hairpin corners where surface conditions are slippery, Rally drivers trade off corner speed for higher rate in change of direction.
(Note 2:41 of video Compilation)
This S turn is executed via a combination of weight transfer by unloading the rear tyres using brakes followed by locking up the rear using hydraulic handbrakes.
Note 1:04 (Referring to Video Compilation)
For the most part in snow driving, drivers may use snow to slow them down by clipping the inside surface. As such, less is demanded from the tyres where stability around the corner is key and that given the slip angle, drag caused by clipping the inside surface of the snow helps pivots the car more around the corner. This does not mean you can go charging into a corner and use snow as your primary means of slowing the car down.
[ame=http://www.youtube.com/watch?v=Cq3A6ADqVzY]Tommi Makinen Rally di Sanremo 2000 camera car - YouTube[/ame]
(Note: 1:31 above video) In circuit racing we cut the Apex as much as permitted to find the straightest line. In Rally the inside wheel is used to slingshot the car where lateral load is high. Generally you risk damaging your suspension.
(Note: 1:34 and 1:44 of the video compilation)
When jumping over crest, the pitch angle can be controlled through driver input. From a very basic point of view, braking just before the jump transfer weight to the front and therefore the the car will pitch down first. Accelerating before the jump transfer weight to the rear and therefore the car will pitch up and land rear first. As technology progresses, aerodynamics plays a big role in today's WRC cars to help stablise the car's pitch angle in mid air.
Just like circuit racing, corner speed is very important. This often means using up every inch of the track as much as you can be it to find an extra 1-2 kph in corner speed or gain 1-2kph at the end of the straights.
Some say, "well 1-2kph is not a lot".
That's 1-2kph for just the 1 corner. Total up the number of corners in a circuit or stage and it will quickly add up. This can translate into 1-2 tenth savings in lap times depending on track.
This does not mean you should starting getting as close to the wall as possible without making sense to relevant racing lines. Using up every inch of the track takes a lot of practice, experience and adding a wall into that equation certainly does not help.
Using up every inch of the track at Sepang will never be the same as using up every inch of the track at Singapore's F1 circuit or a track with walls or concrete barriers.
Note 2:51 of the video compilation - This is a prime example of using up every inch of the road. This is the same with F1 in a street circuit like Singapore. If you are having difficulties getting comfortable with walls after considerable amount of seat time, perhaps Rally isn't your cup of tea. Hero or Zero is measured in inches and centimeters.
Note 0:19 and see how Alonso uses up every inch of the track.
[ame=http://www.youtube.com/watch?v=yTGUecYTGp0&feature=related]Fernando Alonso Onboard Singapore 2011 - YouTube[/ame]
Here's a clip of Colin McRae at the X Games. Note: 1:27
[ame=http://www.youtube.com/watch?v=L5YXE7J9U58]Colin Mcrae X Games (Entire Run) - YouTube[/ame]
Notice just how finely Colin McRae is driving and clipping the barrier.
In addition, notice how he chooses not to slide the car excessively and minimising air time on every jumps. Its interesting how he chose to trade off momentum carried in air for more time spent on ground. This is because when all 4 wheels are in the air, there is nothing you can do to propel the car forward as compared to more time spent with tyres in contact with the ground. This style isn't always the best option and it depends on track layout.
This clip is one of my all time favourite and is one of the smoothest driving I've seen from external view. Even after the roll over at 2:11, you can see Colin McRae's relentless, "Never give up" attitude and takes the limping car through the finish line. Truly indicative of an experienced WRC driver
Had we rolled the car, some of us would have sat in the car, dazed and disoriented as to which direction the car is facing.
Here's another favourite clip which is more inline of some of the events I did only mine had more obstacles to hit.
[ame=http://www.youtube.com/watch?v=rZ_0WU5P1GQ]Testday Niederrhein 2011 - Pre Tank S Rally Test - YouTube[/ame]
Note 0:38 of the above video and see just close the driver is cutting it to the cone. Mindset wise, the risk involved is taking a time penalty if you knocked a cone, nothing life threatening. Had the cone been a concrete wall or a metal pole, the driver's mindset would have been different as risk is higher.
Center of Gravity
Rally cars are built around some fundamentals. Without going into too much detail, the CG of a Rally car is kept as low as possible. This is to reduce body roll in corners and also to prevent the car from actually rolling upside down. This is predominately done by reducing weight at the top or bringing weight from the top to the lowest point of the car as possible but not lower than roll center of the car.
Note how much lower Mikko Hirvonen's Navigator is sitting. Because a Navigator's forward vision is less of a priority, the Navigator's seat is lowered further to improve the CG of the car.
(Source: http://static-jpeg.action-tuning.fr...ssai-Finlande-Ford-Focus-Action-Tuning-1.jpg])
In addition, the weight is further centralised as much as possible to improve yaw rate. This is done by repositioning the seats to the center of the car. Modifications will have to be made to extend the steering column, customised clutch, brake, throttle pedals and seat brackets.
Note 4:50 of the video Compilation
[ame=http://www.youtube.com/watch?v=pqx4E-QluHI&feature=relmfu]Best of Rally 2009 - Trailer Rallymedia Jaaroverzicht 2009 - YouTube[/ame]
Notice the side mirrors are located further behind the original factory location. Indicative the driver's position has been shifted rearwards.
Here is another example of a ALMS GT2 M3. Note the pedals, steering, gear levers are shifted rearwards.
(Source: BIMMERPOST | BMW Forum, BMW News and BMW Blog)
As the Navigator is also moved rearwards, part of the safety regulation is to ensure that Navigators have footrest that are positioned close enough to ensure that their knees are bent when resting.
Note the bottom right corner of the photo and you'll notice the foot rest.
(Source: Speed Arena | Motorsport and Racing News, Galleries, Forums, Calendar.)
The consequences of having the Navigator's legs straightened in a locked position means that if a frontal impact is strong enough to move the firewall backwards, the Navigator's knee caps will shatter. Having the knees bent will allow a lot of that energy from a frontal impact to be absorbed.
Earlier in 2011, an ARC driver supported by the same workshop I use had a crash. While at the top of 5th gear traveling at about 200kph in a series of flat out corners, the Driver clipped something on the left. The car unsettled and sent him and his navigator into a tree.
In Car Video Footage
[ame]http://www.youtube.com/watch?v=dIZLfMWzYFs[/ame]
I have personally seen the video footage and the remains of the wreckage myself at least 6 months before it was broadcasted on TV. I watched the video footage over and over again and was surprised his injuries were minor.
Imagine a mass of about 1.4 tons decelerating from 200kph to 0kph in less than 1 second.
According to X-Ray, the Driver's knee cap was shattered in 3 pieces. The amazing thing is that everything from the firewall and rearwards looks immaculate. No signs of ripples. Everything in front looks quite "Second hand"
I'm not crash expert nor do I intend to assume to be one. Having watched the video footage many times and having a chat with the mechanics and chief engineer, we somewhat speculated that if the Driver's leg was not locked in a straighten position (not possible even if throttle/ clutch fully depressed), neither the firewall nor the dashboard intrude into the cabin, Driver was using 6 point harness (no slide under effect) and seat mountings intact, imagine how much energy was involved to shatter the Driver's knee cap in 3 places.
Driver still lives but 2011 season was over for him. Hopefully he'll be back for 2012 ARC.
As a result, I have since placed an even higher value on the functions of rollcage. Its interesting how some people today install cheap and poorly designed/install rollcage for the sake of being seen as "cool" or "hardcore driver" but don't realise the inherent value of a rollcage.
It certainly does give you a whole new perspective on rollcages, 1Kg fire extinguishers and battery kill switches.
That is all.
I hope this write up provides a very shallow insight into Rallies and offers a different perspective compared to circuit racing.
In the words of the late Colin McRae who passed away in a helicopter crash.
"...give me 300 brake horsepower, a winding road — and no brakes, and then you’ve got my attention" - Colin McRae
Rallies are an entirely different style of driving compared to circuit but the end-goal and built are identical in principles to circuit. It is one that fascinates me.
Brief History and WRC Car
WRC has come a long way from the 70s to the late 80s where we saw the death of Group B cars with all out insane horsepower output and no restrictions on weight, to the safer Group A and now WRC.
Group B cars in the 80s has and always will be my all time favourite. It was an era where WRC cars had very little restrictions and engineers were permitted to make the car go as fast as technology allows. For a start, the minimum cars required for Homologation was 200. This was considered to be a "Small figure" compared to Group A's requirement of 5000 cars per year, which was later reduced to 2500 per year.
Simple English: This means a car manufacturer only had to manufacture 200 cars in order for it to be permitted for use in WRC. Homologation is generally imposed to prevent car manufacturer from producing a "One-Off" purpose built rally spec car and call it a production car and sanction them for use in Rallies. Therefore, this keeps cost down so that other car manufacturers/Teams with lower budget are able to enter.
In Group B, there was no restriction on Boost Pressure for Forced Induction cars or minimum weight limits. Because of this, it was common to see cars of that era flirting with about 400 horsepower with the exception of the Audi Quattro S1 firing up to 600 horsepower.
Not a lot you say ?
Well, these cars are hovering in the region of 1000kg. To put things in perspective,
Power to Weight Ratio (Hp/Ton)
Ferrari 458 (562hp): 378.45hp/ton
Lamborghini Aventador (690hp): 438.09 hp/ton
Nissan R35 GTR (520hp): 300.57hp/ton
BMW E92 M3 (414hp): 246.42 hp/ton
Audi Quattro S1 (600hp): 600hp/ton
Audi Quattro S1 (Source: Audi Sport quattro S1 1985)
And of course, we should not neglect to mention that Walter Röhrl and Michèle Mouton are just one of the few drivers who drove the S1 who went on to win the San Remo Rally and Pikes Peak Intl Hill Climb in 85' respectively.
(Source: rallymemory / Best of Rally Live | All the news about IRC and WRC in Live! Le meilleur du Rallye en direct)
Death of Group B
Henri Toivonen & Sergio Cresto (Source: File:Henri Toivonen.jpg - Wikipedia, the free encyclopedia / ForoCompeticion - Portada)
In 1986, the demise of Group B was inevitable when Henri Toivonen and his Co-Driver Sergio Cresto passed away in a crash. Group B cars were deemed too fast too dangerous and offers little protection to both drivers and spectators when crashes occur.
Fast Moving Object vs Spectators standing on track is a cocktail for disaster.
[ame=http://www.youtube.com/watch?v=vH4z5OI5aNY]WRC Classics - Rallye Monte Carlo 1993 with pure engine sounds - YouTube[/ame]
Think standing at the Apex of a corner is safe ? Put down the weed and think again.
[ame=http://www.youtube.com/watch?v=N4ulS8GvTM0]Old Geezer Rally Near Miss - YouTube[/ame]
Group A eventually took over Group B. Because Group A required 5000 vehicles per year (later changed to 2500) for homologation purposes, this meant the end of the era where car manufacturers could build all out purpose built rally cars that were not suitable for public roads. Therefore Group A cars look somewhat similar to road going cars as a result.
In addition, Group A cars were limited in speed due to the mandatory 34mm restrictors which is placed at the inlet side of the turbo. This means you may install a massive turbo like the T88 but at the end of the day, all that air has to go through that tiny 34mm diameter. In addition cars are also regulated to a minimum weight of 1230kg.
Simple English: To make this easier to understand, I am going to ignore that Air is compressible.
Imagine 2 guys drinking a cup of water. Both guys and cups are identical in all aspects. Guy A drinks the cup of water through the mouth while Guy B drinks water via a straw.
Naturally the guy who drinks the cup of water by the mouth is going to finish 1st. Guy B drinking via a straw can drink as fast as he could but at the end of the day all that water has to go through that tiny straw.
This is somewhat the same concept as a restrictor being imposed on the turbo inlet. You may install the largest turbocharger but in the end all that air has to go through a 34mm diameter tube. However some teams have gone around this problem by designing the restrictors in such a way that accumulates/stores a mass of air at the restrictor's inlet area . This high pressure area then provides all the air that the turbocharger can draw, through the 34mm restrictor thereby maximising efficiency.
Due to restrictors being imposed, pre-2011 WRC cars are very limited in Horsepower. However what they lack in horsepower, they make up in torque and 600nm is easily achievable. Because of restrictors, Rally drivers seldom rev past the 5000-5500rpm mark even though the redline is about 7000rpm or so. This is because boost pressure is tapered off and therefore if you notice on TV, in a straightline, Rally drivers upshift very early to get the best out of the powerband.
2011 rules dictate 33mm Restrictors and limited boost pressure to 2.5 bar absolute. Minimum weight 1350kg.
This is a Group N 33mm Restrictor.
(Source: www.rallyandracingparts.com|Motec ECUs for Rally, Racing, Motorbikes, PWC Plug-In ECUs|Haltech ECU|www.rallyandracingparts.de -Home)
Today, WRC cars are 4 cylinders boasting only 1600cc turbocharged, 4WD. Safety has been drastically improved by making the car slower with strict regulations on FIA approved full welded roll cage made of T45 Steel Grade. Entry level Rally cars uses the more expensive Chromoly, which fairs very well in the strength to weight ratio department.
Ford Focus RS WRC. Rolled 12 times 200 metres downhill.
(Source: Ford Focus RS WRC passes severe crash test | AutoNewscast.com)
Boost Pressure - Boom Boom Bang Bang Antilag
"My Evo 9 4G63 is faster than your GTRtoyotabanana because I run 2 bar which wakes up by 19,000rpm"
Well pre-2011 WRC cars are running close to 4 bar. Of which, about 3 bar is available at about 2500rpm through the use of Antilag System. Your Defi Boost gauge be it genuine or fake only reads up to 2 Bar...
That is nearly 60 psi which is about 2x the amount of pressure you pump in your road tyres. With Antilag System (ALS), depending on which map (ALS Mode 1-4), about 200hp is readily available on tap at a mere 2000rpm.
- Anti Lag System
Depending on the ALS mode (aggressiveness), the ignition timing is retarded or delayed, the butterfly valve kept slightly opened and fuel mixture ratio is richer. Because ignition timing is delayed, the spark plugs fire just when the exhaust valve opens and with all the unburnt fuel being sent into the exhaust manifold, the explosion takes place, the explosion increases the velocity of the exhaust flow which then spins the hotside of the turbo and therefore keep boost pressures up even without throttle input.
Simple English: When ALS is turned on, the ECU then tries to keep the turbo spinning even when your foot is off the throttle and therefore 1 bar (eg) of boost pressure is readily available for you once you step on the throttle.
This is considerably different as compared to road cars where you step on the accelerator, wait for the revs/boost pressure to build up before you feel that surge of power. The Boom boom bang bang sound you hear in a WRC car is fuel still in its liquid or fume state that comes in contact with very hot exhaust. Fuel + high temperature = explosion and that's what you hear.
"I have a turbocharged car, how do I make my car boom boom bang bang ?"
Given the technology we have today, most reputable standalone ECU or Opensource ECU have ALS options.
But this does not mean you should hurry off to your tuner and ask for boom boom bang bang because ALS makes your turbo work over time which means very high wear and tear as it is exposed to high temperatures. The turbochargers used in WRC cars are rebuilt after every race. If you feel you have the budget to rebuild your turbocharger every month depending on usage, feel free to install. With ALS on, depending for how long and how aggressive, Exhaust Gas Temperature can surpass the 1000 deg mark and that kills a lot of things in your car, amongst which, your catalytic converter if you have one, exhaust manifold, etc.
==========================================================================
The Drive
If you know someone who says he drives around Sepang International Circuit in the 2 minute using a Hyundai Getz, enrol him into a Rally School.
I promise you a 3 hour session is more than sufficient to bring him back down to Earth.
Here's a great video compilation which I thought it contains some interesting things worthy of noting in Rallies.
Video Compilation
[ame=http://www.youtube.com/watch?v=pqx4E-QluHI&feature=relmfu]Best of Rally 2009 - Trailer Rallymedia Jaaroverzicht 2009 - YouTube[/ame]
While it may look like Drivers are driving as rough, jerky and violent, this does not mean you should do the same at Sepang because by logic, "if I do what race car drivers do therefore I shall be just as quick." No
Earlier in 2011 I was watching the in car footage on youtube of someone driving at Sepang. I believe it was maybe turn 6 or turn 7 where the driver spun and he was still on the track. In Rallies on gravel, mud even tarmac, the corner will have no problem spitting you out of the track and into something hard.
The thing with Rallies is that you can never run out of topographical objects to hit. If you bring along a mindset of, "I am the fastest d̶r̶i̶v̶e̶r̶ /car, of Sepang" you will get hurt in Rallies and possibly die.
The Basics of Gravel
Driving in Gravel surface is a little different to circuit racing but the aim is essentially the same. Be as smooth as you can.
First time you drive on gravel surface, it will feel like Disney on Ice. At moderate speed, turn the wheel and the car will continue to go straight until you hit something hard.
During my time, I've seen someone hit a lamp post. Driver had to pay $6000aud to replace that lamp post. I've seen someone who understeered off the cliff and thankfully stopped by a tree. But mostly it is always the concrete barriers.
- Where do I find Traction ?
Think of driving on Gravel surface the same as digging a shell scrape in NS. Apologies to those who were PES Cs and below. Find a back yard and start digging and those without a backyard....
anyway, as I was saying, if you ever dug a shell scrape, you should find the upper layers of the surface is generally soft and easy to remove. As you dig deeper, you find more resistance and requires more effort than before to go deeper. Generally speaking, a Rally driver is looking to remove the top layer of loose surface and firm more traction beneath it.
Apart from paying attention to your Navigator yelling out pace notes, a Rally driver also has to analyse and predict the road surface ahead of him.
Generally speaking, sliding the car, getting on the throttle and using the deep grooves in gravel tyres to chew into the upper surface of the gravel and dig deep for traction.
Had you driven the car like you did at a circuit and backing off the throttle each time you felt understeer or oversteer, it would have been possible for an average human being to run through the corner faster than you driving through it.
It takes a lot of courage to overcome your intuition of braking or backing off the throttle whenever you feel the car sliding or losing traction. To make the difference, you really need to get on the throttle and find grip and power out of the corner. The best part is when you have mastered this, the seasoned rally drivers walk up to you and say, I can find another 5-10 kph in corner speed. So then its best you put your P plates back on and keep trying.
Note: 0:24(Referring to Video Compilation) is a prime example of a very soft muddy surface.
(Source: www.crash.net.com)
- Why do Rally Drivers appear to be very aggressive behind the wheel ?
In essence, surface condition is always changing, unlike a circuit where traction is more or less consistent, in Gravel and Tarmac stages, traction levels varies wildly. It can be very slippery one moment and very grippy the next. Imagine your mindset throughout the rally stage adjusting your driving style every few seconds. Its mind boggling.
You have to take into account the drivers ahead of you who may or may not have dug deep, the drivers who clipped the apex and threw a ton of stones on the tarmac or the 5 cars ahead of you who drove through a preceding pond of water and carried most of that water onto the next corner.
These are external factors that are beyond your control and as a Driver, you can either spend time to sit and complain or do mental preparations, visualisations and account for these factors and ask yourself how do you intend in going about to tackling this problem if this or that happens.
There are no yellow flags, safety cars or "hey lets stop and clean up that oil spill".
Generally speaking, strategy wise, it is sometimes in the Team's interest to plan and allocate their drivers sequence well. Sometimes it is better to let the first few cars dig deep into the gravel and remove the upper slippy surface so that later drivers will have more traction and therefore translate to better laptimes.
The Team also has to take into account the type of soil and surface condition, level of precipitation and wear rate on the soil because if the gravel is too soft and 20 cars had dug deep, this may result in a bottoming out and this is something that race engineers have to take into account when setting up ride height. The Key is a find a balance.
Driving Techniques
- Hand Brake Turns
(Note: 0:42 of Video Compilation)
On Rally cars, Hydraulic handbrakes are used as it locks up the rear wheels quickly. In circuit racing, we always talk about achieving the highest corner speed possible. In Rallies around hairpin corners where surface conditions are slippery, Rally drivers trade off corner speed for higher rate in change of direction.
(Note 2:41 of video Compilation)
This S turn is executed via a combination of weight transfer by unloading the rear tyres using brakes followed by locking up the rear using hydraulic handbrakes.
- Using Terrain
Note 1:04 (Referring to Video Compilation)
For the most part in snow driving, drivers may use snow to slow them down by clipping the inside surface. As such, less is demanded from the tyres where stability around the corner is key and that given the slip angle, drag caused by clipping the inside surface of the snow helps pivots the car more around the corner. This does not mean you can go charging into a corner and use snow as your primary means of slowing the car down.
[ame=http://www.youtube.com/watch?v=Cq3A6ADqVzY]Tommi Makinen Rally di Sanremo 2000 camera car - YouTube[/ame]
(Note: 1:31 above video) In circuit racing we cut the Apex as much as permitted to find the straightest line. In Rally the inside wheel is used to slingshot the car where lateral load is high. Generally you risk damaging your suspension.
(Note: 1:34 and 1:44 of the video compilation)
When jumping over crest, the pitch angle can be controlled through driver input. From a very basic point of view, braking just before the jump transfer weight to the front and therefore the the car will pitch down first. Accelerating before the jump transfer weight to the rear and therefore the car will pitch up and land rear first. As technology progresses, aerodynamics plays a big role in today's WRC cars to help stablise the car's pitch angle in mid air.
- Being Comfortable with Walls and such
Just like circuit racing, corner speed is very important. This often means using up every inch of the track as much as you can be it to find an extra 1-2 kph in corner speed or gain 1-2kph at the end of the straights.
Some say, "well 1-2kph is not a lot".
That's 1-2kph for just the 1 corner. Total up the number of corners in a circuit or stage and it will quickly add up. This can translate into 1-2 tenth savings in lap times depending on track.
This does not mean you should starting getting as close to the wall as possible without making sense to relevant racing lines. Using up every inch of the track takes a lot of practice, experience and adding a wall into that equation certainly does not help.
Using up every inch of the track at Sepang will never be the same as using up every inch of the track at Singapore's F1 circuit or a track with walls or concrete barriers.
Note 2:51 of the video compilation - This is a prime example of using up every inch of the road. This is the same with F1 in a street circuit like Singapore. If you are having difficulties getting comfortable with walls after considerable amount of seat time, perhaps Rally isn't your cup of tea. Hero or Zero is measured in inches and centimeters.
Note 0:19 and see how Alonso uses up every inch of the track.
[ame=http://www.youtube.com/watch?v=yTGUecYTGp0&feature=related]Fernando Alonso Onboard Singapore 2011 - YouTube[/ame]
Here's a clip of Colin McRae at the X Games. Note: 1:27
[ame=http://www.youtube.com/watch?v=L5YXE7J9U58]Colin Mcrae X Games (Entire Run) - YouTube[/ame]
Notice just how finely Colin McRae is driving and clipping the barrier.
In addition, notice how he chooses not to slide the car excessively and minimising air time on every jumps. Its interesting how he chose to trade off momentum carried in air for more time spent on ground. This is because when all 4 wheels are in the air, there is nothing you can do to propel the car forward as compared to more time spent with tyres in contact with the ground. This style isn't always the best option and it depends on track layout.
This clip is one of my all time favourite and is one of the smoothest driving I've seen from external view. Even after the roll over at 2:11, you can see Colin McRae's relentless, "Never give up" attitude and takes the limping car through the finish line. Truly indicative of an experienced WRC driver
Had we rolled the car, some of us would have sat in the car, dazed and disoriented as to which direction the car is facing.
Here's another favourite clip which is more inline of some of the events I did only mine had more obstacles to hit.
[ame=http://www.youtube.com/watch?v=rZ_0WU5P1GQ]Testday Niederrhein 2011 - Pre Tank S Rally Test - YouTube[/ame]
Note 0:38 of the above video and see just close the driver is cutting it to the cone. Mindset wise, the risk involved is taking a time penalty if you knocked a cone, nothing life threatening. Had the cone been a concrete wall or a metal pole, the driver's mindset would have been different as risk is higher.
- Fundamentals of a Rally Car
Center of Gravity
Rally cars are built around some fundamentals. Without going into too much detail, the CG of a Rally car is kept as low as possible. This is to reduce body roll in corners and also to prevent the car from actually rolling upside down. This is predominately done by reducing weight at the top or bringing weight from the top to the lowest point of the car as possible but not lower than roll center of the car.
Note how much lower Mikko Hirvonen's Navigator is sitting. Because a Navigator's forward vision is less of a priority, the Navigator's seat is lowered further to improve the CG of the car.
(Source: http://static-jpeg.action-tuning.fr...ssai-Finlande-Ford-Focus-Action-Tuning-1.jpg])
In addition, the weight is further centralised as much as possible to improve yaw rate. This is done by repositioning the seats to the center of the car. Modifications will have to be made to extend the steering column, customised clutch, brake, throttle pedals and seat brackets.
Note 4:50 of the video Compilation
[ame=http://www.youtube.com/watch?v=pqx4E-QluHI&feature=relmfu]Best of Rally 2009 - Trailer Rallymedia Jaaroverzicht 2009 - YouTube[/ame]
Notice the side mirrors are located further behind the original factory location. Indicative the driver's position has been shifted rearwards.
Here is another example of a ALMS GT2 M3. Note the pedals, steering, gear levers are shifted rearwards.
(Source: BIMMERPOST | BMW Forum, BMW News and BMW Blog)
As the Navigator is also moved rearwards, part of the safety regulation is to ensure that Navigators have footrest that are positioned close enough to ensure that their knees are bent when resting.
Note the bottom right corner of the photo and you'll notice the foot rest.
(Source: Speed Arena | Motorsport and Racing News, Galleries, Forums, Calendar.)
The consequences of having the Navigator's legs straightened in a locked position means that if a frontal impact is strong enough to move the firewall backwards, the Navigator's knee caps will shatter. Having the knees bent will allow a lot of that energy from a frontal impact to be absorbed.
Earlier in 2011, an ARC driver supported by the same workshop I use had a crash. While at the top of 5th gear traveling at about 200kph in a series of flat out corners, the Driver clipped something on the left. The car unsettled and sent him and his navigator into a tree.
In Car Video Footage
[ame]http://www.youtube.com/watch?v=dIZLfMWzYFs[/ame]
I have personally seen the video footage and the remains of the wreckage myself at least 6 months before it was broadcasted on TV. I watched the video footage over and over again and was surprised his injuries were minor.
Imagine a mass of about 1.4 tons decelerating from 200kph to 0kph in less than 1 second.
According to X-Ray, the Driver's knee cap was shattered in 3 pieces. The amazing thing is that everything from the firewall and rearwards looks immaculate. No signs of ripples. Everything in front looks quite "Second hand"
I'm not crash expert nor do I intend to assume to be one. Having watched the video footage many times and having a chat with the mechanics and chief engineer, we somewhat speculated that if the Driver's leg was not locked in a straighten position (not possible even if throttle/ clutch fully depressed), neither the firewall nor the dashboard intrude into the cabin, Driver was using 6 point harness (no slide under effect) and seat mountings intact, imagine how much energy was involved to shatter the Driver's knee cap in 3 places.
Driver still lives but 2011 season was over for him. Hopefully he'll be back for 2012 ARC.
As a result, I have since placed an even higher value on the functions of rollcage. Its interesting how some people today install cheap and poorly designed/install rollcage for the sake of being seen as "cool" or "hardcore driver" but don't realise the inherent value of a rollcage.
It certainly does give you a whole new perspective on rollcages, 1Kg fire extinguishers and battery kill switches.
That is all.
I hope this write up provides a very shallow insight into Rallies and offers a different perspective compared to circuit racing.
In the words of the late Colin McRae who passed away in a helicopter crash.
"...give me 300 brake horsepower, a winding road — and no brakes, and then you’ve got my attention" - Colin McRae
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