4 Things You Should Never Do In An All-Wheel Drive Car
1. Failing to tailor your driving technique
This is particularly common for drivers who have switched to a new four-wheel drive machine after years of driving a rear-wheel drive performance car. In RWD cars you can use the throttle to help you turn, using the power to rotate the car mid-corner. So you can release the brake early, carry high corner speed to the apex and if the car starts to push, you can use the power to bring the car back to a neutral stance.
This technique doesn’t work in the majority of AWD vehicles. The reason for this is quite simple: when you get on the throttle mid-corner, the weight moves aft, causing the rear of the car to squat. This makes the front-end lighter, and because power is being sent to the front wheels, the tyres become overwhelmed - inducing understeer.
In recent years, better chassis set-ups, clever transmissions and advanced electronics have given us AWD cars that will happily oversteer at the limit (think Ford Focus RS, Audi R8 V10 Plus, Mitsubishi Lancer Evolution X). However, for most AWD cars - R35 GT-R included - the best way to drive them on track is to brake deep, turn in early, trail brake to the apex, get the car turned and then straighten the wheel as quickly as possible on the exit. This way you minimise time-sapping front-end push, and you can utilise the car’s four-wheel drive traction on the way out.
2. Hard launches
Hard launches take their toll on all transmissions, but all-wheel drive cars fare the worst. This is because AWD cars often have more grip than power. For example, it’s possible to perform full-throttle launches in the current WRX STI with minimal wheel-spin. So unlike a RWD BRZ or M3, the tyres aren’t the weakest link. This leaves the transmission to bare the brunt of a hard launch.
As a result, we don’t recommend full-throttle launches in manual AWD vehicles, but if you’re determined to give one a go, here are some quick tips to minimise the damage to your car. The first thing you should do is make sure that everything is up to temperature (coolant temperature, transmission fluid temp, transfer case temp etc). You should then depress the clutch, bring the revs up to 5000 to 6000rpm (will vary from car to car), slip the clutch, creep forward at around 1mph and then release the clutch quickly and smoothly. By slipping the clutch, first gear is almost engaged, taking slack out of the driveline. So when you release the clutch, the jolt sent through the transmission is lessened.
Granted, this technique will take a toll on your clutch, but think of it this way: you’re sacrificing the clutch to save the drivetrain. And we all know which one costs more to replace.
3. Handbrake turns
This one might come across as commonsensical, but I’ve seen plenty of people yanking their handbrakes at autocross events, ignoring the damage that they’re causing to their transmissions. The reason this is a bad idea is the simple fact that pulling the handbrake causes the rear wheels to slow suddenly, putting a lot of stress on the transfer case, which is a drivetrain component not designed to deal with a sudden and prolonged change in speed between the front and rear wheels. (Also one of the reasons you should only transport your AWD vehicle on a flat-bed.)
The engine will also be under heavy load trying to fight the handbrake to turn the wheels. You probably won’t break anything if you use the handbrake occasionally, but it’s not good for your car. Ultimately, if you want to slide an AWD vehicle, use trail-braking or a Scandinavian flick instead.
4. Don’t assume you have endless levels of grip
‘Go-anywhere ability’, ‘sure-footed handling’ and ‘all-weather grip’ are just some of the terms used by marketing executives to describe AWD vehicles. But in most cases, these claims are completely disingenuous. It doesn’t matter if you’re driving a G63 with an old-school locking diff, or a new Ford Kuga with an ‘intelligent’ torque-vectoring system - if you don’t have the right rubber fitted when going off-road, you’re not going anywhere quickly.
Ultimately, tyres are the only thing between your car and the road; something the majority of drivers overlook. The general public buys a large amount of SUVs in the UK, based on a false notion of infallibility; conquer every mountain ford every stream etc. But these same people would never purchase winter tyres because they’re ‘too expensive’. A deeply flawed logic.
There’s also a solid group of internet experts who maintain that the cars like the Nissan R35 GT-R and Audi RS6 ‘drive themselves’. Granted, complex four-wheel drive systems allow huge amounts of horsepower to be deployed at will, but it still takes skill to drive these cars on the limit. When I recently drove a GT-R Track Edition engineered by Nismo at a wet and windy Silverstone I was amazed at the rear-wheel drive bias of the car. The rear-axle constantly wanted to play, which was a solid reminder that these cars certainly don’t do the driving for you.
Comments
Great post!!
well, press clutch, keep foot on throtlle, yank the handbreak, release handbreak drop the clutch.
Indeed, we covered the correct technique in last week’s article! But it can still cause undue wear to an AWD drivetrain unless you have a system which effectively disconnects the rear axle when pulling the handbrake.
https://www.carthrottle.com/post/5-things-you-should-never-do-in-a-rear-wheel-drive-car/
Because the clutch obviously dis engauges the rear wheels from the front removing any stress on the transfer box of course… NOT. The reason you cant do handbrake turns is because the rear wheels are connected to the front, not the engine.
Its still not a great idea in a rear drive car because you are still shock loading the transmission.
Best thing to do is get a rear diff with a disconnect unit.
Great post! But what did you mean with “no handbrake”? I thought it was still commonly used in WRC, and all WRC vehicles are 4WD as far as I know. Or is there that much of a difference between AWD and 4WD so that 4WD cars are more suited to do it safely?
Clutch.
Rally cars have a hand brake that effectively disconnects the rear axle when the handbrake is pulled. This allows them to stop the rear wheels entirely for hairpins.
as someone who does SCCA and Rally America rallies in my 2002 wrx, you actually lef tfoot brake around hairpins
I would have to disagree with the SUV and winter tires statement. I made it through my first winter in Colorado with a stock Chevy suburban and run of the mill all season tires. Most of the time I drive around in 2 wheel drive, but on occasion, I went 4 wheeling (with open diffs) in 2 ft of fresh powder with no problems. I do realize the weight of the vehicle helps gain traction, but I had some of the worst tires possible and could still do fine. The performance of any car is more about the driver than the vehicle or tires.
All season is Very diffrent then the worst possible tires. My little 2400lb car with no traction control or antilock brakes, open diff, went from unusable in any amount of snow, even light powder, to being able to go though a foot of slushy heavy snow mix by going from bald tires to all seasons.
You could put a professional racing driver in the old set up with the old bald tires, and in the snow, a teenager who has never driven a manual before would be able to beat them using new all seasons. Why? I don’t care how good you are, the wrong tire and you will never be able to move, stop, or steer
I’ll be doing #2 as long as you’re paying for my transfer case :P
To address point n°3 just press the clutch while pulling the handbrake in a AWD (or RWD) car…
No good. Same reason you have to flatbed awd vehicles, the front and rear wheels can’t spin at such a different weight. It has to do with differential and transfer case, not transmission.
Top tip: if you’re buying a second hand Evo or STi, and ask if it’s been launched much - if they say ‘what dyou mean, it hasn’t launch control’ think very hard…
I did a ton of research with handbrake turns with a WRX, people have been tapping the hand brake for years without an issue, just make sure your clutch is in ;). Also never hold your hand break while you are moving, that would also cause issues.
When you have snow tires on your awd
hahahahaha true !!! the papa is confident
made my day
What about the new ford focus rs with launch mode ?/ and drift mode _?