Written By:
Jamie Harvey



In Part 2 of this project we covered the appearance aspect of this sleeper.  
Now we'll cover some performance upgrades we can perform that can go
virtually undetected by the naked eye.


Sucked or Blown?
There are many ways one can go about upgrading their 420a to squeeze
some extra ponies out of it.  Some prefer to go the 'naturally aspirated' route
while others dabble into the world of 'forced induction'.  Its no secret that the
420a has a bit of trouble waking up that extra potential when going down the
'N/A' path.  Granted, there are a few people currently running low 15 to mid 14
second passes, such as Mark Bullett who currently runs a 14.33 second
quarter mile pass at 95.77mph with his 1997 Mitsubishi Eclipse RS  without
the aid of forced induction but for most people the results haven't been nearly
as successful.

In this project we have decided to go with forced induction as our power adder
of choice.  Since the stock internal components of the 420a have been proven
time and again to handle up to 300hp when properly tuned and maintained,
while still having long term reliability, we have opted to build a turbo system
which can bolt on to a completely stock engine without the need of upgrading
any internal engine parts.  Once we have reached the 300hp mark and
squeezed every ounce of excitement from the engine, we'll pull the engine and
start our upgrade for higher boost and power using the existing system.  This
will give everyone an idea what to expect when running a stock engine versus
an engine built for higher boost.



Shake, Rattle and Body Roll
Since we're keeping the stock ride height with this sleeper, we looked into
simple "hidden" upgrades that could be performed to aid in handling.  There's
a lot of room for improvement in this category and plenty of inexpensive parts
to help us corner far better than we probably have the need for.  Adding a front
and rear, upper strut tower brace bar along with a rear, lower tie bar is
probably the most common inexpensive upgrade.  This helps stiffen the body
and reduce body flex dramatically during hard corning.  You'll notice the
difference with all three braces installed on the very next off ramp you take
without a doubt.
Next would be to upgrade the front anti-sway bar with a larger diameter
replacement.  You can even purchase an aftermarket, beefed up rear
anti-sway bar to greatly improve the rear of the cars stability.  These, coupled
with an upgraded urethane bushing kit for the suspension components will
make you car respond far better than it did the day it was built.  

Speaking of urethane bushing upgrades, another option is a set of motor
mount inserts.  These slide inside the factory motor mounts to help stiffen
them up, resulting in less absorption of power transfer from the engine to the
wheels.   Though this helps put the power to the pavement, it does however
cause quite a bit of engine vibration in the car when all 3 mounts are
reinforced.  If the front motor mount is left untouched and only the side and
rear mount are upgraded it should reduce the added vibration, making the ride
a bit more tolerable.  

Lastly, we'll address the struts.  Though the stock struts do a rather fair job of
keeping things in check, they have their limitations.  Adding a set of quality,
adjustable, stock replacement struts also can help with cornering and
acceleration.  By having the ability to adjust the firmness of the front and rear
struts you will be able to tailor the 'feel' of your ride to accommodate your
driving tastes.  For instance, on track day most people will adjust the rear
struts to their firmest rating to help reduce 'inertial drop' in the rear of the car.  
This is when a car is launched forward so quickly that the rear of the car
seems to squat down towards the ground.  The transfer of weight which
occurs has an adverse effect on the cars ability to apply all of its power in a
forward motion.  Which explains why you see wheelie bars front-wheel drive
race cars.  Having the firmer suspension in the rear also aids in acceleration
in a car already in motion as well.  If you were to quickly accelerate from
40mph, the same inertial drop factor applies. Less squat, more go.



Five Gears or Four?
Our project car came with an automatic transmission which wasn't our first
choice.  This isn't because it lacks potential, (though it does have lower
horsepower limitations than the manual transmission) more so because we
enjoy the fun of shifting through the gears of a 5 speed manual transmission.  
We were lucky enough to find a parts car for $300 with a fully functioning 5
speed drivetrain that can be swapped into our project car at a later date.  If you
are content with your automatic transmission and just want to give it a little
extra oomph, there are a few things that can help.  

The biggest killer of these automatic transmissions is heat.  On the bottom of
the radiator is a small section delegated to cooling the transmission fluid in a
rather poor fashion.  Adding a small transmission radiator, also known as a
tranny cooler, that is separate from the coolant radiator will extend the life of
your drivetrain and give you far more consistent results when you push it really
hard.  These transmission radiators are rather inexpensive and can be had for
around $35.  

Shift kits for the auto tranny is another well known upgrade.  The stock
transmission is meant to slip a bit between shifts for a smoother ride.  
Actually, this is really bad for your transmission and is only done for customer
comfort and convenience.  Adding the shift kit will give you firmer shifts which
will help with the response time between gears.  Be warned that it will be a
noticeable transition when it shifts, though most people are willing to sacrifice
the smooth shifts for the performance gain they have received.

A well known modification is to take the final drive gears from the '99 Dodge
Stratus with the 2.0L engines . The final drive gear ratio in these cars is more
suited for the powerband of the 2G.  This mod has been done many times
with happy results by all who have done it.  We probably will upgrade the
project cars tranny cooler for now but I dont see the need to go any further with
modding the auto tranny when we will be swapping in the 5 speed later on.  
For specific info on this mod, simply use an internet search engine such as
Google for the proper transmission swap information.

The 5 speed manual transmissions are quite capable of handling high
horsepower levels while still being daily driven and very reliable.  Bill Hahn Jr.
of Hahn Racecraft currently has the worlds fastest 2G 420a powered car and
he uses the stock manual transmission.  The factory clutch is capable of
handling at least 200-220hp without the need of upgrading.  Anything past that
level and your going to need a better clutch.  There are a few companies who
offer different levels of clutches for this transmission such as SPEC and
CLUTCH MASTERS so at least you have some choices.  Unfortunately, the
manual transmission  doesn't come with a limit-slip differential so you are
burdened by the "one wheeled" power transfer.  Phantom-Grip makes an item
which somewhat converts the drivetrain to LSD, though it is not a 'true' LSD
setup.  If you are interested in going with a L.S.D. setup to improve handling
and traction during launches, look into a true L.S.D. conversion if you can.



Stop Talking and Start Showing
Curious what is going in the Project car yet?  I bet you are.  Don't lie, you are
and we're gonna tell you!  Next time.  
Strut tower Braces help with
chassis rigidity and reduces
body flex during hard corning
Anti-sway bars reduce body roll
and keep the wheels planted
on good ol' mother earth
Urethane motor mount inserts
aid in getting the power from
the engine to wheels
Adjustable struts like those
offered by Tokico can help firm
up the rear end for faster
launches
A tranny cooler can increase
your automatic transmission
reliability and help give you
consistent performance
Automatic transmission shift
kits like this one offered by
TransGo can give your tranny
faster acceleration capabilities
Changing the auto transmissions
FINAL DRIVE gears can improve
acceleration and performance
Once you are pushing over
220hp in your car, upgrading
your manual transmissions
clutch is a must!
Phantom Grip makes an L.S.D.
Conversion kit which can aid in
getting power down to both
wheels which improves
launching.
Hahn Racecraft and Star
Performance are a few
companies who offer a full
bolt-on turbo kit for the 420A
engines