The two words `tuning’ and ‘Skyline’ go together like ‘eggs’ and ‘bacon’ or `Manchester’ and `rain’. Let’s face it, if you’ve bought yourself an GT-R R33, you’ve either got plans to treat it to some tuning work, it’s already under way, or it’s received some attention by a previous owner. Even a few small and relatively inexpensive mods can net decent power increases, making the big Nissan a real fun car to hoon around in.
That RB26DETT motor has a lot of potential built-in and, as long as your credit card will stand it, you can make all that power accessible and do some serious damage to the opposition on track days and RWYB drag events. The key is knowing how to get that power without compromising reliability, and then to ensure the rest of the car’s systems are upgraded to match the new velocity quotient.
The first thing to think about is how far you want to go with your power mods? Do you want something quite lively but not much more powerful, or do you want to go for a huge increase and double the standard 280bhp-plus output? You need to consider this carefully before you throw your wedge around, otherwise you could be spending money twice on some aspects of the tuning work because certain things work for a mild level of tune but may prove to be inadequate at a higher level.
Another point to consider is how fit is the engine in your car? Skyline motors are tough, but they age like anything else. If there are a few miles on the clock, say 50-60,000, you might want to consider freshening up the lump before you go mad with the tweaks. Doing this means you could also have upgraded items such as a metal head gasket, tougher con-rods or better pistons fitted before they were strictly necessary for the level of tune. So, if the motor is due for a rebuild, it’s certainly worth fitting the right kit if you are planning big power in the future.
And while it is in bits, get the whole of the bottom end properly balanced to help prevent possible problems appearing from sustained high-rpm work. Much above 8000rpm can seriously damage the crank if it’s not running really smoothly. If you want to go for 500-plus bhp, spending something like £3,500 on fettling the motor and making it better than new will save you money later. Honest.
Having said that, the extremely durable GT-R is more than capable of developing a lot more power with just simple bolt-on goodies, assuming that the basic unit is in good order. Job One on the R33 motor is breathing and, more specifically, the way it exhales the smelly stuff once the turbos have pinched the free energy hurtling down the exhaust. Fitting downpipes and fitting a race catalytic converter to keep the Plod happy also helps. While the car would be better off without it, and a de-cat pipe is a much cheaper part, the environment – and your local MOT tester – would be happier with the cat in place.
In most cases this increase in gas flow through the motor would be compensated for by the stock ECU and any extra fuel would be readily available. In the odd cases where the air/fuel ratio was getting too lean, our experts added piggy-back modules to compensate.
To get more air into the engine, swap to either a pair of aftermarket retain the standard airbox treated to some extra ducting from a bonnet vent and with a performance panel filter.
The boost could be tweaked a bit from the standard 0.85 bar, the ceramic turbine wheels on the standard R33 turbos were a bit sensitive to working too hard. Much above 1.0 bar could see turbine wheels shearing off and wrecking anything in their path, so just winding up the boost until it squeaks isn’t an option. Once you’ve reached this point you’re bound to want more power before long, so be prepared to dig deep into your pocket to get a bigger fix of adrenalin. Some form of additional or replacement engine management would be necessary to look after the increased fuelling and ignition requirements, as well as keeping a check on the turbo boost.
To give the increased boost levels without the possibility of turbos literally going pop, a rebuilt pair of original turbos with 360-degree bearings and steel turbines can be yours relatively cheaply. Safe boost levels around 1.2 bar are now on the cards, and that leads us on to sorting out the deficiencies in the standard intercooler and boost piping.
Bigger intercoolers can be had from a lot of companies. If you do decide to upgrade your intercooler, you’ll probably be able to sell your original one to someone who’s modding a Pulsar GTI-R or maybe a GTSt wanting to fit an FMIC, and recoup some cash.
Aftermarket piping alternatives range from a half-pipe kit or you can have the full induction pipe kit at considerably more cost.
Much above 400bhp will require a serious ~ upgrade to the fuelling system, with new injectors and a new pump to supply demand. Again, the size of injectors you need depends on the power level you’re looking for, but bear in mind that they all cost roughly the same, so don’t skimp on their capacity, otherwise you’ll be spending your money twice.
As for upgrading turbos, again it’s down to ultimate power goals as to how far you go. The best combination of drivability and power output is gained from having the smallest turbos you can get away with that flow enough air for the chosen bhp target. This is probably the only area where you don’t want lots of extra tuning capacity in your upgrades. Make sure the turbos you choose are going to achieve your target bhp figure, but not masses more or they will always be running at less-than-peak efficiency levels. That’ll increase lag and spoil drivability and power delivery response.
For most people, this is as far as you’ll need to go with a road car but, if you’re looking for ultimate power for the dragstrip, then it’s arguable whether to go the single turbo route and fit one dirty great big blower that will deliver lots of puff, albeit at the expense of drivability, or to fit two huge blowers with even more of an all-or-nothing power delivery.
During normal motoring, even with lots more power, the Skyline’s transmission copes very well. Go in for a lot of drag racing and the clutch will need some serious uprating to make it hold on. If you go above 400bhp you will have to swap the stock clutch assembly but, if you resist the urge to do 7000rpm launches, an uprated clutch cover will grip a standard Nissan organic spinner to give nice drivability with good grip.
Really high power applications, or lots of abusive starts, will require something much more heavy-duty in the form of a multi-plate unit. Triple-plate clutches can hang on really well, and have reasonable drive characteristics, rather than being on-off switches like some other multi-plate units we’ve heard of.
Apart from that, the gearbox has its fourth/ fifth synchro weakness, but the best solution is to drive a little more sympathetically when gear-changing. Keep ramming that gear home and you’ll chew up the baulk ring double quick.
Like the R34 GT-R that followed on, the R33’s standard set-up does a pretty good job for all-round use. Experts favoured the V-Spec suspension for a car that does some track work, but a non V-Spec car can be slightly lowered and stiffened up with a set of replacement springs and some Nissan V-Spec dampers.
For anyone who wants to get a bit more serious, a Nismo S-Tune kit that gives adjustable damping, or an R-Tune kit for trackday heroes who hardly ever run the car on the rubbish that passes for our roads these days. Of course there is the option of coilovers with all the options they give, plus the in-car gadgetry some now offer.
Being a well-developed car, the Skyline’s brakes are pretty good as standard, and with some performance pads they can bite well and haul the big Nissan to a stop pretty sharply. The problem comes when the standard Brembo rotors need swapping, as they are very costly. It’s probably a better option to take this as an opportunity to swap for a set of bigger front discs and calipers. But before you do this decide if you want to go for bigger rims, because this can open up all sorts of options for even bigger brakes.
WHEELS AND TYRES
With 17-inch rims as standard, the R33 can accommodate 18s or 19s without problem. Having seen a couple of R33s running on R34 rims, I reckon the newer wheel suits the older model better than the car they were originally fitted to. Skylines aren’t particularly tyre-hungry unless there is something out of whack on the suspension geometry.
Handling a car that’s this quick isn’t something that you just fall into. And, even if you are naturally talented behind the wheel, a few lessons from a top-level performance driving instructor will always help you to get the most out of your car on both road and track. If you get one of these cars it’s well worth taking it for a track day because that’s what it was designed for. It’ll cost you a few quid, but it’s probably the most fun you can have with your clothes on.