REAL HANDLING FOR YOUR SILVIA / 180SX
Hot4s Magazine - Jan/Feb edition 2000

The S13 (precursor to the 200SX) is brought in as a low-volume import by a huge number of compliance plate-holders. As there is plenty of competition at work, compliance is relatively cheap and the cars are also quite cheap and plentiful at auction in Japan. The good news for buyers here is that you can now buy an S13 very cheaply and they are really a great performance package for the money. The S13 started in 1988 with an 1809cc CA18 twin cam in turbo and naturally aspirated form. A mild facelift in 1991 also brought the 1995cc SR20 engines.

Apart from needing a different-shaped front swaybar, the suspension system remained the same for the whole S13 series.

The only major variation is that some are equipped with HICAS four-wheel-steer. Now like the 200SX, the S13 has a 'passive rear steer' design built into the multi-link rear suspension, which uses soft bushes that deflect under load to change steering angle. The HICAS system supplements this by actively deflecting the suspension using hydraulic rams.

While the HICAS system is of some benefit for the larger part of the handling envelope, when you're driving at the limit, its interference can be downright scary, as it shifts your geometry when you really don't want it to. This makes the car even less predictable when driving hard, which is never a good thing. So, what are your options?

As the HICAS system was optional, it's not hard to find a car without it. That's the easiest option. You can also install a hydraulic loop in the system so that the rams do nothing. The third is to live with it, but fit very stiff urethane bushes so that it has minimal effect. More on this later.

In standard form, the S13 is quite well balanced on a constant throttle, though many arrive with poor front alignment, which is the cause of understeer. Lift off oversteer is fairly mild, but power oversteer can get very wayward, especially as the rear gets less grip when it squats, due to camber change. In all, quite a similar handling package to the local 200SX. The only real maintenance issues are front control-arm bushes and rear trailing arm bushes.

A large number of imports have very low, very stiff, Japanese aftermarket springs already fitted. Unfortunately, this makes the car's shortcomings even more obvious. If the shocks aren't up to the task of controlling the spring, then the car will simply 'pogo' over bumps. If they are, then you'll simply have a bone-jarring ride. Depending on what other modifications have already been made to the car, you may need to pick and choose from the parts listed at the end of this article to get the ideal handling result.

If you have a standard car and simply want to improve the handling, here's what you need to do:

The 'handling pack'
First you need to sort out the wheel alignment, especially as it is usually wrong. Nissan have a surprising 4.0 degrees of positive caster, which was quite good for 1988. A caster conversion urethane bush kit (KCA331) bumps this up to 4.5 degrees, but, more significantly, improves dynamic caster, as the firmer bush won't distort as much as the rubber original. This change helps give crisper turn-in response and better overall steering precision. For an even greater improvement, the S81260 camber bolt kit allows 1.5 degrees of negative camber to be dialed in.

Rear camber is particularly important, due to the sensitivity to oversteer. Nissan has built in some adjustment but, unfortunately, you can't dial any less than 1-1.75 degrees negative. That means you can't have positive or neutral camber - even at standard ride height. Some cars have a problem with the left rear, which prevents any less than 2.0 degrees of negative camber on this side. Whiteline have a workshop remedy, so call them if you have this problem.

The car in the shots had inconsistent toe settings (which is typical). It was toeing out slightly at the front and toeing in by 2mm each side at the rear, making it very sluggish on turn in. Whiteline recommend neutral toe front and rear for the S13. As we mentioned when talking about the HICAS system, the rear suspension is intentionally set up with very soft bushes and with multi-link there are a lot of them, which means an awful lot on compliance. The car is much more predictable when this is minimised, so Whiteline replace almost all of these bushes with their own spec urethane bushes. There are a number of kits involved to do this, all of which can be purchased separately.

Urethane bushes are also used on the swaybars used in the handling pack. A 27mm front bar is used, part number BNF20 for the 1.8 or BNF21 for the two-litre. 'Blade' adjustable versions are also available, so that the handling can be fine-tuned. As this car had a lot of rear-wheel horsepower, the bar was set to its stiffest setting to help offset the power oversteer.

The rear doesn't really need adjustment, so a normal 20mm bar is used on both models, part number BNR20. All of these upgrades combined, create a much more responsive and predictable chassis, starting from $760 plus $300 for fitting. The fitting cost is, usually, due to the labour involved with changing the bushes. If your only concern is lowering the car, however, you may simply want the sports pack.

The 'sports pack'
You have to be careful how much you lower the S13. The rear-end is designed to move through a predetermined arc for rear steer effect, hence, lowering the mean ride point changes the static alignment settings and the available range of travel. This car had excessively low springs fitted originally, which looked good but really screwed the ride and handling. The shift from understeer to oversteer was very dramatic and the car often hit its bumpstops. It also had adjustable Konis, which had been wound up to near maximum adjustment. Contrary to popular belief, harder shocks don't necessarily equate to better handling. In this case, it made matters even worse.

When first measured, the car had heights of 335mm front and rear (measured from the center of the wheel to the guard lip). This looked great, but when measured at the sill there was a pronounced downward slope towards the front. This is a common trap, as people forget that cars often aren't supposed to have equal tyre-to-guard clearance front and rear. This is also true of the 200SX. In restoring the sill rake balance and some of the suspension travel, Whiteline's spring package gave heights of 335mm at the front and 340mm at the rear. This is still considerably lower than a standard car, which will usually measure around 390mm front and 380mm rear. The Konis were then revalved to match Whiteline's specs for bump and the rebound adjustment was set to only a quarter turn above full soft.

The shocks are all gas, with an insert for the front and a full leg for the rear, with spring seat height adjustment via a circlip groove. Fronts are 1302302 and rears 1101102 in the Whiteline recipe book. Price for this kit is about $695.50 plus fitting.

'The works'
In the unlikely event that you have a completely standard car, you can buy the full handling and lowering package, which will set you pack a total of $2100 in parts, plus $400 for fitting. Bear in mind that the alignment specs are slightly different when you do the full Works package. An optional extra for the S13 is Whiteline's polished alloy front strut brace (KSB594), which fits all S13s.

Parts list
As mentioned before, packages will vary depending on what your car already has, so here is a list of everything that is available for the S13 series: