Note: It should be understood that these views are
my own opinion, combined with personal
experiences on my 88 Conquest TSI. I am not a professional
auto mechanic, but do have a large amount of mechanical ability due to
my training as an aircraft mechanic.
I will not be held liable for any damage caused
by attempting to duplicate my work or ideas..
Several modifications may violate state and federal laws on cars used
on public roads.
You are expected to be familiar with these
laws, and base your decisions accordingly.
Here we go,
I have found the car to be quite fun, but instantly
got into autocrossing (a form of low
speed racing), and found many weak spots quickly!
KNOWING WHERE YOU STAND:
First to note is the Weight. The StarQuest is severely
overweight up front, causing it to push the nose away from a tight turn.
At 3100 lb., we are easily out cornered by lighter, more agile sports cars
on the race track. In looking at the power to weight ratio, we again
loose by a wide margin to cars like the Supra Turbo (touting a whopping
11 lb. per horsepower, compared to the '89 StarQuests 16.4.) My point
is not to be fooled..... The StarQuest was marketed as a LUXURY SPORT
COUPE. Although it has great potential, you must understand your
beginnings, and work with what you have. From there you will gain
a far better car in the end, and not succumb to unrealistic dreams.
For an Interesting view of our car compared to others, check out these two tables!
Powerplant is good, but has potential to be much more, at a price..
For those of you new to the StarQuest, you will soon find out that our
car has an evil side called "high cost of maintenance"!
(Bet the guy selling you yours didn't tell you that!)
The StarQuests limited production numbers eliminate all but a few aftermarket
performance parts for our car, and seeing that they (the manufactures)
can sell only so many, they go for a very high price to cover R&D.
Also you might find even the most common parts a "Dealer Only" item, flashing
a price tag 4 time that for any other type car.
Watch the StarQuest groups for those enterprising
few willing to manufacture go-fast-goodies in limited numbers (although
again, at a price) as they can be your greatest source for mods.
Brakes on are adequate on later models with the larger 10.5" rotors, except when doing extended high speed stops (like when running a road course..)
As to performance mods, your directions are pretty
easy to start, but you need to look at a
long term goal (be realistic) to make sure you progress in the right
order, and avoid repeating
steps..
I have tried to cover all aspects of the car, as
I am more into road race, than I am quarter mile times. (You build
the car differently for each) So I will address that area, cause its what
I know best. Note that a road race configuration (in my opinion)
creates a far safer car overall, mainly cause the chassis must handle well
in all aspects of motion, not just straight line power.
BALANCE:
Front to rear weight ratio is touted at 53.6%/46.4%,
but if you have ever driven on a scale and check while carrying a 150lb
driver (and an empty tank), the numbers skew slightly further out, showing
a 55.4% /44.6%.
Interesting also to note side to side weights at 52.4% drivers/47.6%
passenger.
In a race car, the ideal is to move as closely to
a 50/50 ratio as possible. This prevents the car from displaying
different characteristics between a left and right turns. The Starquest
needs weight removed from the drivers front, but provides very little real
opportunity.
I have relocated my battery to the passenger trunk
area as one step (a real pain) and have detailed the job for those interested
: CLICK
HERE.
I have often wondered about removing the front bumper,
and using a fiberglass form to replace it behind our rubber nose, but the
task is currently beyond my budget, and perhaps my skills..
In the near future, I plan on removing the bulky ABS system all together.
And I have heard others talk about having a fiberglass hood made, I have
yet to see this happen or a price tag for one.
HANDLING and SUSPENSION:
If you want improvements in overall handling,
first step is to dump the stock springs in
favor of something stiffer, and lower. This effects ride quality
(gets harsher), so you must decide what is more important. I use
the progressive rate Eibachs, which lowered the car (and the body roll)
by about 1.5 inches all around. There are several spring manufacturers,
like H&R and Suspension Techniques, so look around and determine which
is better for your application. The stabilizer (sway) bars and end
bushings are next, to eliminate body roll further.
Suspension Techniques is a popular choice, although no adjustable bars
exist for our cars unless you have a set customized for you..
If your shocks are bad, look into Tokico replacements.
A Warning here as you progress... If you plan on using sticky
tires (I.E. a race compound, like the Yokohama 008R series or Hoosiers)
you should consider a Strut bar to span the shock towers up front..
The car has been known to flex in a hard corner, and pop the windshield
loose (this is not a problem on any normal performance street tire as they
are not near the grip of a race compound.)!
A good 4 wheel alignment will do wonders as
well. If your intent is to remain a daily
driver, stick with factory specs. For cornering, adding extra
negative camber (which will automatically happen if you lower the car)
will let the tires stand more vertically in a hard corner for better grip.
This will have a tendency to wear the tire unevenly during normal street
driving. With a little diligent looking around, you can find custom
made camber plates help return the camber angle to a more streetable use.
Experiment with tire pressures as well.
The listings in our owners manual are not correct,
simply a general guideline. A simplistic method of determining
the approximate pressure for you tires is to use white shoe polish, and
mark the edge of the tread, and a short distance up the sidewall
(towards the center hub). Drive the car through a couple corners
hard, and look at the markings. You will see how far over your tires
are rolling onto the side walls by observing where the polish has been
rubbed off. (Note, an incorrect alignment may give you misleading information,
so have that done first.) Many performance tires come with very small
arrows on the sidewall, pointing to the tread. This is used as a
rollover indicator, and should not be exceeded. The professional way of
checking pressure is with a pyrometer, or tire temperature gauge.
BRAKES
Brakes prove adequate for street use, but can be over
stressed with continuous high speed stops. I have seen my rotors reach
a nice orange cherry glow after an hour on the race track! An often
overlooked part of the car is brake fluid, which should be flushed completely,
and changed at least once a year. This will prevent the fluids from boiling
due to excess water retention. Also consider stepping to a DOT4 fluid
with a higher boiling point. ( As an added note, I change my fluid twice
a year. Also do not use DOT5 fluid, as it is incompatible with the
neoprene seals used in our car. )
Cross drilled rotors are available for our cars,
but I have not research these as of yet. Be leery of OEM units shoved
in a vice and drilled, as they can disintegrate under stress. Better
units will be made of superior materials to prevent cracks from forming
at the holes (some racers prefer slotted rotors over cross drilled
because they have less tendency to crack, but I do not know of any made
for our car..).
In addition, I recommend dumping stock brake pads,
in favor of a racing compound, such as the Carbon Kevlar pads from Porterfield
or other such company. You gain quicker stops, and far less fade
as the temperatures go up. On the down side, they wear faster, cost
more, squeal, and turn your rims black with dust very quickly. I
don't mind the extra cleaning required, to get the overall benefits, but
if you are going towards a show car, these pads may not be for you.
You may consider removal of the ABS, as the
overall racer opinion is that it offers nothing to the experienced driver.
If your car is a daily driver for you and your spouse, then leave it alone,
but most of us on the track disconnect the silly thing as it is not a "true"
ABS system at all.
ENGINE an POWER:
My first warning here comes from experience... Don't
add lots-o-power to an old motor (i.e. high mileage) without expecting
it to come apart in a very expensive way... If your plan is to add
50+ horsepower, then consider at a minimum having the block rebuilt before
your mods are done.
For mods up to 300hp, I know several owners
that rely on the stock lower end (ie. Rods,
pistons, rings.), and it seems to hold up well. Any
attempts at power above 250hp,
should consider having the piston crowns ceramic coated to help prevent
meltdowns.
Before getting to far into performance mods, you may want to
consider getting yourself
a good boost gauge. Turns out the stock unit is a computer generated
approximation, and not
to be trusted. In addition, a good Air/Fuel ratio gauge will
alert you of impending destruction of your engine, should you raise the
boost to high and drive the fuel mixture too lean. Well worth the
$150!
The big obstacle to power is the intake and
exhaust system. It is very restrictive.
At a minimum, the K&N filter changer is an OEM type replacement,
is more free breathing, and reusable. So it is a win-win choice..
There are other choices out there as well, but most are not designed for
the StarQuest, and would require slight modifications to fit. Should
you stick
with OEM type filters, there are light mods you can also do to the
air canister the filter. Consider drilling a couple 2" holes in the sides,
to help air get in. Many remove the pleated
cardboard (a sound deadener), and cross bars that supported it. You
will see these when you have the air filter base (I.E. the Mass airflow
sensor) out of the car. DO NOT attempt to modify the air sensor (the
large plastic unit with honeycomb screen) until you learn much more about
the car electronics, fuel system, and ECU.
This is about as far as most go on the intake,
however, additional steps you might consider
in the future would be:
1.) Mandrel bent air runner (the tube that runs across the top
of the head to the throttle body)
available from Top End performance.
2.) Enlarged throttle body (an extra 5 mm) from Custom Network
Motors and also by Top End.
Head work is something you do after all else
is done, so I'll address it at the end of this
section...
The exhaust system needs all the help it can
get.. with two cats and a muffler on a small 2"
pipe, things are pretty bogged down. This holds back the maximum
possible boost, and spool-up time of your turbo. If you are to remain street
legal, then a "Cat Back" is your only choice. Many chose a ready made system
from HKS, Trust, or other such company. I feel a muffler shop is
as good, with the right choice in mufflers (although you do forfeit bragging
rights to owning a name brand exhaust, you can console yourself that
you paid half the price for the same performance!)
For exhaust systems on a turbo, bigger is always better.. 3"
is as large as I have seen, I personally run 2.5" to a Flowmaster single
in, dual out muffler. I like Flowmaster for their performance, and
the way they are built, but there are other good mufflers out there (maybe
even better) as well.
If your not concerned with emissions testing (like say, your car is
for off road use.) Dump both
the cats, and run 2.5+" from the turbo back. I try to stop people
from punching out the cats, as
you never know when you will need to put them back on, and new ones
cost a lot! Find a person (not a business) parting a car, and try
to buy the cats from it (Technically illegal for street cars)
then punch the worst of the two systems, and keep the better one on
a shelf. My total exhaust
costs was: front cat $50, Flowmaster $65 (sorry, a one time deal!..),
and welded to 2.5" pipe all the way $120... So, for $235, I got a far superior
system than any name brand cat-back, for less
money, PLUS my entire original exhaust system, that I can bolt on in
under 20 minutes..
The stock turbo and head can push 15psi provided
the rest of the system lets it breath.. I'm
unsure if the fuel system on earlier models can keep up without going
lean, but the one on my '88 does just fine..(they are different) If you
plan on exceeding that, then you will have to consider
adding extra injectors, or perhaps simply larger injectors to keep
from frying your pistons. An HKS F-CON, is ideal for controlling fuel delivery
if you have the money.
Boost controllers are everywhere, and vary
from $70 to over $500. I opted for the
manual adjuster from HKS due to my budget at the time, and it seems
to work fine with the stock
turbo, but I have no experience with it on larger units.. Electronic
versions are far superior..
Turbo upgrades are spendy, but a lot of power
is to be had here! As a general rule of thumb, for every pound of
boost, you gain 7 horsepower! Mitsubishi offers a higher output
unit
(about 100cfm over the stock unit) that is a direct bolt on replacement.
Other ($better$) turbos are out there, but some, I understand, require
a different exhaust manifold, and different exhaust mountings to the turbine.
If this is a direction you are thinking about, look into it before doing
any up-front exhaust work, as we all hate redoing something we just did!
Head work is a final stage you may, or may
not look towards... With the head off, you
should match all ports to the runner, just to keep the airflow clean.
Three angle grinds on the
valves (what used to be the normal on production cars in the '60's)
is now touted as "performance oriented work..." What ever...
Just be sure to request it done should your valves need work.
The starQuest has a very poor head design, as it
is known for cracking, regardless of year.
Although this can be repaired by welding, I recommend you follow up
with having the head heat treated to "normalize" the internal stresses,
then get the deck resurfaced to eliminate any warpage. This generally
prevents cracks in the future except when severely over stressing the motor..
Aftermarket heads with thicker castings (and no Jet Valves) are available
for a reasonable price considering the typical cost of repairing a cracked
one, so you may wish to look into that option if you need to..
I have had my head flow benched, and
deck milled .20 (I've been told we can mill as far as
.40, but that figure is a little scary for me) I guess as long
as we are into the big money stuff, I
might as well mention extrude hone, but I feel it is very expensive
for the minimal gains.. Finally, having the MCA jet valve removed
is an little kicker many do.. I still have mine, and see no real need to
have them removed right now. Kits exist to replace the valves (i
have not seen these yet, to see how good they are.) , or you may chose
to have the hole simply welded shut and combustion chamber smoothed back
out (my personal choice of the two).
Cams vary, but the amount of lift is important.
Later model StarQuests used hydraulic
lifters, which limit the amount of lift your cam may have. Earlier
version (pre 85 I think) used
mechanical adjusters, and allow for slightly higher lift. I hear
that a couple 88 racers have
re-installed the older valve train to give them that extra flexibility...
The ignition is fairly solid, but I recommend
you get rid of the stock coil. It is known to be
weak above 5000rpm. I swapped mine with a blaster 2 (cheap, at $39)
and noticed I could then
redline with ease, as well as feel a little extra pep in the throttle
response.. Nice change for only
$40!
Many debates about the ECU used in the StarQuest
have arisen, but one thing seems
consistent. The latest made ECU (after 07/87) has the optimal
timing and fuel curves
programmed into it. Many question if it can be used in an older
version StarQuest. I feel this
could prove to be a major job, worthy of only those who know everything
about all the sensors,
wiring harness, and subsystems used on the car.
If you want to see a listing of ECU's by production dates: CLICK
HERE
Now that you are on your way to a killer car, I'd like to make
one more suggestion... Take the
time to learn how to drive all that power safely. My wife
and I have become actively involved with autocrossing, a low to medium
speed sport, that not only teaches you how to properly handle your
car, but is flat out fun too. It is a one car show, with you in the
driver seat (i.e. not fender to fender racing) and a clear spance of asphalt
in front of you to get wild on. For those of you that already know
about it...great! Those that don't, look into it, as the skills
you will learn may well save your life, as well as others. I challenge
you to ask any autocrosser his/her opinion of their driving skills before
and after becoming involved in the sport. Contact your local
SCCA and find out more..
Hope you all forgive me if I you feel I am talking down to you,
(or possibly over your head), as I really have no idea what mechanical
experience you have.. So I tried to keep it somewhat low keyed..
If you have more specific questions, feel free to write, I'll try to help
as best my time allows.........
Keep it shiny side up!
Vince (believer in the love/hate relationship!)