CA18DET
Power
129kw (85 to 95rwkw)
The CA18DET is a good engine but it is starting to age, lacks the capacity
and strength of the SR20DET. The CA featured technology ahead of its
time a twin cam, 16 valve head, and a intercooled turbo. With a few
minor modifications the potential of the CA can be realized.
Engine
Tuning Stage 1
Exhaust (around 105rwkw)
As with most factory turbo cars the exhaust causes a huge restriction.
A good free flowing exhaust will have your CA18DET performing much better,
turbo lag will be reduced, and power gained throughout the rev range.
The new exhaust should start from the turbo with a dump/front pipe,
either a 3" open bell mouth or better still a split dump to separate
the gases from the turbine and waste-gate can be used. From here use
a high quality 3" high flow cat, then a 3" system all the
way to the back of the car with high flow mufflers.
10-15rwkw is achievable with this mod
Intake (around
110 rwkw)
Now we have the exhaust side of the CA18DET breathing the next step
is to get more air into the engine. Either use a high performance air
filter in the stock airbox, or replace the air box with a POD style
air filter. If you choose to go the POD filter route I recommend you
fabricate some type of shield to keep hot air from the engine bay away
from your intake. A cold air intake to the filter from the front of
your car will also give you a performance advantage.
5-10rwkw is achievable with this mod
Intercooler
Upgrade (about 115rwkw)
The standard CA18DET intercooler is tiny and before a boost increase
I recommend installing a better one, if you don’t you risk detonation
on warm days. Second hand intercoolers can be used, a popular choice
is the intercooler found on the 7MGTE Toyota Soarer or Supra, this intercooler
fits with very little modification.
The price of Hybrid
and Hybrid copy intercooler kits has dropped dramatically over the past
few years and many people have had good results with these. I think
this is a good option as all the piping and clamps come with the kit
so there is less hasle when it comes to fitting. Aftermarket japanese
intercooler kits perform a little better but they are more expensive,
if you dont plan on a radical turbo upgrade the hybrid kit will be fine.
The last option you have is to go for a custom made intercooler, if
money is not an issue this is the best option.
With most intercooler
upgrades you will end up with extra piping and a larger intercooler
core, as a result you may notice a small decrease in throttle response.
A small increase in power may be noticable without increasing boost
as airflow will increase and the air will be denser. But it’s the ability
to run more boost that makes this mod a good one.
5rwkw is achievable with this mod
Boost increase
(120 to 125rwkw)
The T25 turbo is tiny and struggles to hold more than 10psi to redline,
12psi seems to be the maximum boost recommended. It may not hold this
boost level to redline but midrange power will be greatly improved.
You have a few options when choosing to increase the boost, a manual
boost controller, electronic boost controller, or a new waste-gate actuator,
the differences are explained bellow.
A manual controller
is very basic in its operation it bleeds off air causing the waste-gate
actuator to open later. The amount of boost run depends on the amount
of air bled form the system. It is critical to install an after market
boost gauge before carrying out this modification as the stock gauge
is not accurate enough. Manual boost controllers are cheep and easy
to install but they do have there disadvantages some can cause boost
spikes and boost creep, I have also found boost tends to tail off high
in the rev range.
Electronic boost
controllers on the other hand use stepper motors and monitor boost about
every 10th of a second because of this boost spikes and boost creep
are kept to a minimum, and the desired boost level is held to redline.
Electronic boost controllers are expensive and for this level of modification
a manual controller in conjunction with the free boost mod will probably
be good enough.
A 3rd option is
to install a different waste-gate actuator, I have not looked into this
option for a silvia but I know for a fact that HKS make after market
ones for Skylines and would not be surprised if there is one availible
for the silvia. The Skyline HKS actuator has an adjustable arm to help
set your desired boost level. I think this would be a good option for
this level of modification as boost spikes and boost creep are eliminated.
After this modification
your car will probably be running very rich this is typical of nissan
ECU's basically once the ECU sees extra airflow it richens the mixtures
up for safty. This hearts power and may result in flat spots throughout
the rev range, many people find re-gaping the spark plugs to a smaller
gap can reduce or fix this problem.
5-10rwkw is achievable with this mod
Cam Upgrade
(125 to 135rwkw)
A good cheep upgrade for the CA18DET is to install a CA16DE
intake cam. This cam has more Lift and duration, which means mid to
top end power is increased but a slight decrease in bottom end power
may be noticed.
The exhaust cam is identical so there is no need to change it.
Inlet cam specs
CA16DE Inlet cam: 248° - 8.5mm valve lift
CA18DET Inlet cam: 242° - 7.8mm valve lift
5-10rwkw is achievable with this mod
ECU Upgrade or retune(130 to 140rwkw)
Many Performance shops are able to edit the standard ECU's settings
this is good news If you are a CA18DET owner as you don’t have to be
a new one. Timing, air fuel ratios and all other aspects of your stock
ECU can be edited. In my opinion this is the best, most cost effective
option.
You can however choose an aftermarket ECU. One popular option is the
Apexi SAFC (Super air flow computer), the SAFC is a piggy back to the
standard ECU and works by tricking the ECU into thinking your engine
is getting more or less air than it actually is. Tuning should be done
be a professional, on a dyno, this modification will trim your air fuel
ratios at different RPM points, which will result in a smoother power
delivery and improved power throughout the rev range.
If you planning
to modify your car further at a later date a better but more expensive
option is the Apexi Power FC which replaces the standard ECU. All parameters
of your car can be tuned with a Power FC but once again it should be
dyno tuned by a professional. Other options are available but the Power
FC if familiar to many tuners, is easy to install as it plugs directly
into your wiring loom, and has been proven itself many times over.
* Please note the power FC cannot be used an automatic transmission.
10-15rwkw
is achievable with this mod
Fuel System
These cars are starting to age and even in standard form the
fuel pump may not be flowing well enough so for peace of mind its probably
a good idea to upgrade the stocker. Popular choices include the bosche
040, or 044 these are probably your cheapest new option, Nismo, Tomei
and HKS also make aftermarket direct fit pumps. A second hand S15 or
Skyline GTR pump can also be used but I would suggest buying a new pump.
To
get a little extra out of your standard injectors can buy a fuel
pressure regulator to increase the fuel pressure. This may get
you out of trouble and save you the expense of upgrading your
injectors but upgraded injectors would be a better option. |
 |
 |
| |
Clutch
and Flywheel
At this level of modification the clutch may start to slip due to the
extra power if so it will need to be replaced with a heavy duty item.
Many people choose to upgrade the flywheel at the same time, this increases
acceleration but you may loose a little torque.
Conclusion
This completes stage 1 engine tuning for the CA18DET. Basically at this
stage we are at the limits of the standard turbo and fuel systems but
in terms of car modification this level of tuning is offers great value
for money. The next stage of tuning is expensive as power above 160rwkw
stars to test the limits of the standard internals.
Continue to Engine Tuning Stage 2 (comming soon)
Please
use this as a guide only I recommend consulting a professonal before
carrying out any of these modifications. Nissansilvia.biz takes no responsiblity
for any problems you may encounter from following this guide.
© COPYRIGHT 2006 ALL RIGHTS RESERVED NISSANSILVIA.BIZ
