Credited to the underground street racing scene in Japan, drifting is exploding onto the import car scene
in the U.S., and it is the fastest growing motorsport in the country. The FC3S has been one of the
top models embraced by drifters, but the Nissan S-chassis (S13 / S14 / S15) is still the pinnacle of
chassis for drifting. We will try and compare the FC3S to other popular drift car models available.
We are talking about competition-level drifting and not the occassional sideways action done on the
weekends. Tips and tricks are to increase the FC3S chassis to try and compete with the Nissan
S13 / S14 that currently dominate the drifting scene; the S15 is not available in the U.S., and we do
not have too much direct experience with the S15 chassis to be comfortable offering comments, so we
will concentrate more on the S13 and S14 models. In the U.S., we were stuck with the 240SX and
limited to S13 and S14 models runs. No turbocharged engines (CA18DET or SR20DET) were available,
and we were stuck with normally-aspirated KA24D and KA24DE 2.4-liter inline 4-cylinder engines derived
from the Nissan trucks. Although power does matter and SR20DET swaps are common, we will not
linger too much on powerplant specifics; the 13BT and SR20DET both offer similar power output and
performance potential.
Steering:
The Nissan S13 / S14 has some obscene steering angle stock from the factory. The FC3S just cannot
compete with the steering angle in stock form. Measuring off turntable bearing plates under the
front wheels, we measure the steering angle as the wheel is turned "out" to max steering lock.
The S13 will have between 40° and 45° of steering angle. The FC3S will only have
35° to 40° of steering angle. The Nissan has at least 5° of extra steering angle
to use. Luckily, we can add that 5° of extra steering angle by shimming tie rods off the
steering rack on the FC3S with spacers. Maximum spacer thickness is 0.30" (thanx to Ho Mastah!),
so 1/4" or 6mm is a safe bet.
To shim the tie rods, you'll need to remove the tie rods. Start by popping the tie rod end on the
front hubs by removing the cotter pin and castle nut. Remove the steering boots on both ends of the
steering rack. The steering boots are plastic and secured by a spring clamp on the outside and twisted
wire on the inside. Undo the twisted wire on the insides and slip the spring clamp off; the boot
should slip to the outside with a little tugging. If you have power steering, be prepare for some power
steering fluid leaks when the boot is loosened. You should be able to see the large swivel joint
underneath after removing the boot. The inside part of the joint has a threaded end that is
screwed into the steering rack itself. You'll need a large wrench to loosen the tie rod off the
steering rack. Once the tie rod is removed, you can insert the spacer in between the steering rack and
the tie rod. You'll need to get the car realigned after you do this mod.
The other, more time-consuming method to get more steering angle on an FC3S is to relocate the tie rod to
hub connection point. This increases steering angle and steering response, as it changes the steering
ratio significantly. We're getting up to 50° and more steering angle with this mod! Here's
some pics that explain this mod...
Special thanx to Wendo for the pics...
Power steering is popular over manual steering for drifting. The faster steering response is more important
over steering feedback.
Wheelbase:
The S13 and S14 both have longer wheelbases versus the FC3S. Longer wheelbase means a more stable chassis,
especially when going sideways.
| Chassis: |
FC3S |
FD3S |
S13 |
S14 |
AE86 |
| Wheelbase: |
95.7" |
95.5" |
97.4" |
99.4" |
2400mm / 95.4" |
Front Suspension:
S13 / S14 front suspension and FC3S both use a MacPherson strut damper design. The S13 / S14 use a tension
rods to keep the front wheel in place, while the FC3S uses a a lower A-arm. Adjustable tension rods are
available for the S13 / S14 and is a popular mod; adjustable tensions rods allow for caster adjustment (which also
changes the wheelbase) on the S13 / S14. The FC3S front A-arm is not adjustable, but caster can be adjusted
via aftermarket front upper camber / caster plates. Front upper camber plates are available for the S13 /
S14 also.
Rear Suspension:
This is where the S13 / S14 outshines the FC3S for drifting. The S13 / S14 rear suspension is a "double
wishbone" design. The FC3S uses a multi-link trailing arm design. Adjustable rear links are popular
for the S13 / S14. There is no real easy way to adjust the rear suspension on an FC3S with the exception
of an aftermarket rear camber adjust bar that has limited adjustability on rear camber. Due to the rear
suspension design, the S13 / S14 is very stable while the rear is sliding. The FC3S is not as lucky
in terms of drifting, but the FC3S is superior in terms of regular grip driving. Once the rear end
starts to slide on an FC3S, an oversteer spin is quickly induced.
Polar Moment:
One of those fancy racing terms, but a very important one when comparing these chassis... "Low polar
moment" means weight in concentrated in the center of the vehicle - this allows the chassis to react to
turns faster. "High polar moment" means weight is moved toward the ends of the vehicle - this causes
the chassis to react slower to steering inputs, but change of direction of the vehicle is more progressive.
For beginners, a slower reacting chassis is much easier to control and learn with. The FC3S spins
very easily due to it's low polar moment; this has a lot to do with the compact 13B engine, and the fact
that the engine is mounted at the very rear of the engine bay behind the front axle line. If you notice
each chassis drift (especially in a left / right transition), the FC3S pivots almost at the center while the
S13 / S14 pivots at the front where the engine is located. For grip driving, you want low polar moment,
as this allows the chassis to turn faster.
LSD:
I'm going to just touch on the subject, as this is very important for drifting. The FC3S Turbo (called
the Turbo II in the U.S.) comes with a clutch-type LSD for Zenki models and viscous LSD for Kouki models.
240SX SE models in the U.S. came with viscous LSD's. Clutch-type LSD's are most desirable for drifting, and
viscous LSD's are frowned upon. Stock Zenki FC3S clutch-type LSD's are usually worn-out by now, so an
aftermarket clutch-type LSD is highly recommended for either vehicle if you don't have one by now.
Brakes:
In terms of sheer braking performance, this is one area the FC3S is an outright winner. The FC3S Turbo
runs 4-pot calipers up front controlling a 10.9" x 22mm vented rotor. The S13 / S14 runs an inferior
single-pot front caliper squeezing a 9.9" x 0.8" vented front rotor.
Weight:
Both chassis are of similar weight, and mild chassis lightening would not present a clear-cut winner.
Tires / Wheels / Rims:
Amazingly, the FC3S and S13 / S14(?) use approximately the same size (maximum width and similar offsets) wheels
and tires. Wheel design is subjective. Lighter wheels are desirable, but if you're a beginner,
stronger (usually heavier) wheels would be best. Tire choice is another subjective area, and it's
dependent on driver's style and choice. It's easier to run stickier tires in the front and cheapie,
harder tires in the rear. This easily induces oversteer on a vehicle. As you get better, start
using better rear tires.
Alignment:
This is one of the most varied areas of suspension tuning, but there are still
some general guidelines. We need to keep the front stable and the rear loose.
We tend to run almost regular grip driving alignment settings on the front.
Front FC3S camber is around -2° to -4°. We tend to set the car
up for high-speed drifting, so we run a slight toe-in (1/16") for stability; others
have run slight toe-out (1/16") for quicker steering response, but you sacrifice
high speed stability. In the rear, we try to run no toe and slight negative
camber (-1° to -1.5°). Some drifters run obscene negative camber
to get really wide rear tires to spin, but I find this a waste of wide rubber.
The rear tire width should be matched to the front tire width and to how much
torque your engine makes. With more engine torque, the easier the engine
can spin a wider rear tire which allows you to step up to a wider rear tire.
When we do kill the rear tires, we inspect them to see if they are wearing even
across the entire width of the tread.
Turbo:
Well, I wasn't planning on talking about engine or power stuffs, but this is kinda important. You want to
select a turbo with quick response and broad torque / power band. This allows instantaneous response from
throttle inputs; turbo lag would kill any smooth drifting when throttling. High power output becomes
secondary to quick turbo response, so size is not that much of a concern. Ball-bearing turbos are it when
it comes to turbo selection for most of the top drifters, as the GT2835 (or variants) are popular with the SR20DET
crowd. As for 13BT applications, a GT3540 (or variants) or the A'PEXI Isamu RX6 kit are good choices for
quick turbo response due to ball-bearing centers.
Questions? Comments? Send mail to:
reted@fc3spro.com
07/20/2004
