Having had over 60 Nissan GTR R35s and their owners through the door at Millbrook Proving Ground on training days in 2009-10, Colin Hoad, CAT Driver Training’s Chief Instructor, thought he would share his training notes with you. Pedalling an R35 around a circuit is not as easy as some may think. Contrary to popular belief the car does need a driver. And if you want to get the best out of an R35 you need a sound technique.
Car Club days
Our club driving days continue to be popular with members. An opportunity to put a face to a forum name and enjoy an adrenalin-fuelled day with like-minded car enthusiasts at Millbrook. Our association with the GTROC and Nissansportz has been strong from the beginning and our relationships continue to grow positively year on year. 2010 has been no exception. CAT Driver Training has hosted 4 car club days with 8 cars on each day and a further 31 individual owners taking performance driver and road and track training courses. A total of 63 GTR R35 owners and their cars through the gates of Millbrook through 2009-10. So what have I learnt about Nissan’s long-awaited supercar?
You could wallpaper a large room with what has been written about the R35, the motoring press all agreed it was the “Car of the Year” when launched into Europe – the general feeling being it exceeded expectation in all departments. I won’t waste words covering the ground they have all covered before, my aim is to give you an overview of the R35s dynamic characteristics, the minutia of driving Nissans road-going rocket ship at grip limit. It will give you a flavour of what we cover on club days and 1 to 1 training sessions.
Do the brakes really fade when pushing On?
The brakes are more than adequate for spirited road use and those drivers that use their GTR for their daily commute all seem to be happy with them. Some track day users, however, can report fading from high speed and inconsistency in pedal pressures. On a training day, we will regularly see 140mph on the speedo, before braking at the threshold of adhesion down to zero. The brakes are very happy to carry out this task three or four times without any detectable fade. In summary, if you are really pushing on, you may want to consider a fluid and pad upgrade for track days.
The brakes give adequate feedback, not too sharp on the initial press and are easy to modulate as the car retards from speed. The GTR tracks in a straight line under braking on smooth surfaces, but can be nudged off course on an undulating surface. It’s not enough to be alarming but can require an input from the driver to remain on course. In this area, the GTR is also sensitive to tyre pressure change. Although filled with nitrogen at the factory, you will still find an appreciable change in pressures on a hot summers track day – don’t let them get too high.
Low-Speed understeer outside Tesco’s!
Drivers often complain to me that the GTR understeers when driving at low speed, when a large steering input is applied – especially on a low grip surface. Their local Tesco’s roundabout is often sighted as the offending corner. With any vehicle there has to be a compromise between ride quality and handling – the GTR is no exception. Read the telemetry and you will see spikes of 1.5g and consistent 1.3g levels of lateral acceleration through a corner at grip limit on a dry surface. In order to support such high cornering forces, spring rates and dampers are tuned accordingly.
They offer limited compliance at low speed, and therefore the tyre struggles to follow the surface of the road when only lightly loaded with a cornering speed relative to a low-speed roundabout, hence the understeer. We can consider two additional features to explain away the unwanted understeer: steering angle; and a rear LSD.
Four-wheel drive assistance on a GTR only begins to intervene when the steering wheel is in the straight ahead position or just a few degrees away from it. In reality, when you are driving around a tight roundabout with a large steering angle applied, you have rear wheel drive only.
The rear LSD aggravates the problem. It enhances the drive to both rear wheels and pushes the nose of the car off-line. Think of your GTR as having 2 ends. It will understeer or oversteer depending on driver input. Once you have induced understeer, if you keep your foot on the gas pedal you will have understeer for the duration of the roundabout. You must reduce the rate of acceleration to allow the front wheels to find grip and then reapply the gas a little more conservatively to ensure you remain within the threshold of grip. It’s no different to driving around a tight track day circuit on a wet day.
It is potentially dangerous to push through the understeer in order to achieve an oversteering exit. If you think of the logic behind that comment all becomes clear. If I am understeering I have little grip left. I have overwhelmed the available grip the tyre can offer at the front of the vehicle. By taking a foot full of gas to power the rear around what happens? I now have no grip left at the front and the rear, and I might spin. Why have I highlighted this particular GTR characteristic? Because it has happened to 2 of my clients!!
Straighten the steering as quickly as you can
I have mentioned that four-wheel drive activates as you exit a turn and unwind the steering. Therefore, the quicker you get the steering wheel pointing in the straight ahead position, the quicker you exit the corner. This is an area most drivers have to spend some time working on irrespective of the vehicle you drive. Untrained track drivers have a tendency to hold the steering angle on for a little longer than they need. In order to achieve the optimum exit speed from a corner, you need to be actively unwinding the steering wheel as quickly as possible as you exit the corner.
Earlier versions of the GTR had a noticeable dynamic vague feel when the vehicle proportioned the available drive around each corner of the car. In the R32’s it lasted a portion of a second and translated back to the driver as a momentary loss of feedback, which resulted in a slight loss of confidence for the driver in the attitude the vehicle would take through a corner. Each version improved as the response time and execution of the four-wheel drive distribution improved. In the R35 the operation of the four-wheel drive is seamless, you know where the wheels are pointing throughout a corner at grip limit. The transition from rear wheel drive to four-wheel drive virtually imperceptible.
Directional change Can be a problem
It is easy to forget when driving an R35 that its kerb weight is 1740kg. In fact, it is not just easy to forget – it is one of the astonishing features of the GTR. In most driving scenarios it feels significantly lighter. If you are driving a series of long sweeping compound curves the GTR feels at home, moving and fidgeting underneath you, but never making you feel as if it will let go on you. Fast sweepers are rewarding and exciting. The steering in these long high G turns can be lacking in feedback, perhaps a little benign, but you always know where the wheels are pointing. But I have discovered a chink in the warrior’s armour.
Ask the GTR to drive through a series of tight sweepers at mid to low speed but at grip limit, and the weight leaps out and gives you a “dig in the ribs”. The same is true if you get too brave in the braking zone. If you do not separate out your braking and steering you can find the rear of the car following you into the corner faster than you want. Trail braking will help the nose of the GTR to turn in, but you cannot take liberties. There is a lot of weight already sitting over the front wheels, so you can only tease the front end in with the brake pedal. Percentage steer versus brake is a sensitive issue if you are looking to hustle a little extra speed out of a lap. Be careful!
Keep it simple – keep it safe
Although the dynamic capability of the GTR chassis can leave you feeling as if you can defy physics, the basic rules of performance driving still apply. The car can achieve high G loadings consistently and safely through corners. The drawback of all of that lateral acceleration is, if you go off, you are travelling very quickly. My advice to new owners who want to enjoy a track day in their GTR or perhaps want to drive out for a session on the “Ring” is to keep it simple.
Stick to the golden rules. If you are aggressive and not linear with your control inputs you simply give the vehicle more work to do than it needs. All of that 1740kgs has to be braked, cornered and accelerated – so keep it smooth. The electronic wizardry is best employed helping you to go faster – not correcting poor driving technique. I will emphasize straight line braking as one of our golden rules as it is the safest option with such a heavy car. If you wish to improve your technique and explore threshold braking for example, then come for some training and practice in a controlled and safe environment.
Should I turn the stability programme off?
The stability programmes job is to optimise the available grip between the tyre and the road. If you go into a corner a little too fast, the system will intervene to assist you in maintaining your steered route around the corner. It does this by reducing power to the over speeding wheels and braking each wheel individually to help maintain your course. In road mode, the system works a few percentage points under the limit of adhesion. Put the Stability Programme in R mode and it will give you the freedom to drive your GTR over its limit of adhesion before the electronic insurance policy jumps in to help you – it is now working a few percentage points over grip limit.
Why is this significant for track users? As you grow in skill and confidence to the point you are driving through the corners close to, or at the limit of adhesion, in road mode the system will be working through every corner and your brakes will get very hot very quickly. If you select R Mode, the system will allow you to circulate the track with freedom to understeer and oversteer without the system working continually and overheating your brakes. Your silent partner is still there waiting to help, it just lets you have a little more fun before it intervenes.
Would I turn the system off? Personally only if I wanted to “go for a lap time”, drift, or power slide through a corner. In summary, safety first. Leave the system on unless you have a very good reason to turn it off.
The R35 GTR has impeccable road manners and a user-friendly personality on circuit. It is so good it is easy to forget that just like any other car it has 4 tyre contact patches – each one just a little bigger than a CD case. What an amazing machine!
Engine: Twin turbo V6
Horsepower: 480BHP @ 6,400 RPM
Torque: 430 Ft Lbs @ 3200RPM
Transmission: 6 speed DSG
0-60MPH: 3.3 Secs