Body, Suspension, Reinforcement
Mk3 Supra is good handling car from the
factory. It's multi link suspension was considered quite advanced in the second
half of 1980's. If somebody says now that this car handles like shit it's only
because there are too many neglected Supras on the road. Any 20-25 years old car
with 200-300K miles on odometer and original bushings and shocks and bold tires
will be disaster to drive. It's up to the owner to make it handle. There are not so
many aftermarket parts in this department for our cars, here are few hints on
what you can do to improve handling.
1. Tires. It is obvious, buy the best tires you can afford, the most
sophisticated suspension in the world is good for nothing without proper tire
grip. Good tires also reduce braking distance dramatically.
2. Springs and dampers. They keep your tires planted to the ground on bumpy
road, besides stiffer springs help to reduce body roll. There are few makers on
the market producing springs and dampers for mk3, few years ago I used
Suspension Technique springs and Bilstein dampers, ride quality was close to
stock. Far more desirable are adjustable coilovers, this is more expensive
option, generally they cost between 1 and 1.7K dollars. They are far lighter
than stock spring and damper combination and offer ride height and rebound
adjustability. I am not aware of double adjustable coilovers for mk3. I use Tein
Flex coilovers, too bad they don't have camber plates. Ride is very stiff, most
likely this is the result of dropping a lot of weight from my car, Flex
coilovers supposed to give quite comfortable ride quality. Very often even on
slightly bumpy roads I have to slow down because too stiff springs don't allow
tires to comply with road surface. As you all know cars don't brake or steer in
the air, there is no traction there.
3. Anti sway bars or stabilizers. They help to prevent severe body roll similar
to stiffer springs, but difference between stiffer springs and stiffer sway bars
is that latter don't sacrifice ride quality like springs do. As far as I know
there are four makes of sway bars for mk3 - Whiteline, Cusco, Suspension
Technique and Tanabe. I have Suspension Technique bars, they drastically improve cornering
ability of the car. Rear bar has 2 mounting holes for sway links, one is stiffer
position (more oversteer), another less stiff. Bars are solid and weigh a ton,
tubular sway bars would offer substantial weight saving. Here is the link with
some data regarding stiffness of aftermarket sway bars vs. stock
http://www.geocities.com/ma71supraturbo/MK3Tech/swaybar.html . Definitely
hollow chromoly Tanabe sway bars in my future "to buy" list, they are about 10
lb each lighter then ST bars. They are also the most stiff, if you are into
auto-x or drifting stock end links will be too weak for you, I broke my rear
stock end links when switched over from stock to ST bars. I bought pair of stock
links, another solution is to fabricate metal adjustable end links with
spherical bearings
4. Bushings. There are two choices here. First - to buy polyurethane bushings
from Suprasport and second - nylon bushings from Champion Toyota Gulf Freeway,
formerly Jay Marks Toyota. I have set of nylon bushings on my car, bought it
through SOGI group buy organized by Geoff Moeller 4 years ago. Installed this
set only last summer, it is very important to fit them with grease nipples, if
not greased they squeak terribly.
added in December 2006 -
see my bushings related
accident below
5. Wheels. Here the same as tires - buy the best you can afford. Lighter wheels
reduce unsprung weight, make your car accelerate faster and reduce load on
brakes. I have Volks TE37 wheels, they are some of the best - light and strong.
Front wheels 17x8.5, rear 17x9.5, they weigh around 16lb each.
6. Strut tower braces. There are many of them, some better, some not so good. I
use Cusco 40mm CF rear bar and custom front bar. My front strut tower bar
is very low profile, thanks to front facing intake manifold. Aftermarket braces
made to work with stock intake manifold which is very high, hence braces have to
comply. Some of them (don't want to call names here) look more like decoration.
Good three-point front strut tower brace is sold by Suprasport.
7. Rear traction arms. High power mk3 running slicks can bend stock arms, not
good. Easiest thing to do is to weld some reinforcement plates over the stock
arms. Or buy aftermarket traction arms from Carbonfibre FX, Suprasport or A1
Racing. I bought my traction arms from Suprasport, they are made by LIPP.
8. Various reinforcement braces, like targa bar or Do-Luck lower brace. I always
hated my targa and wish my car was hardtop. Targa comes with something like
70-80 lb of weight penalty. With targa off car behaves like jelly, actually I
removed it only 2 or 3 times during many years I own this car. Last year when I
left my Supra in body shop for fitting roll cage I asked to weld it. End of the
story, no more targa leaks ;-)
9. Cage. This is ultimate in body reinforcement if done properly. I have custom
custom 8-point chromoly roll cage.
Autopower
makes bolt on roll cage and full cage for mk3
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Here is my unfortunate experience with nylon bushings. When the set was installed 1.5 years ago bushings were fitted with grease nipples and inner steel bush received spiral groove to spread grease evenly. I was quite happy with car's more precise handling, though loss of comfort was very noticeable. About 2-3 weeks later they began to squeak, it is extremely annoying and embarrassing. I realized it was time to grease them. When I put my car on the lift I found that few bushings were impossible to press through with grease gun. I had to remove few arms and take apart bushings to grease them, whole process took me 4-5 hours. I was not very pleased with perspective to do this every month and felt like shit. This summer bushings became loose because of the lack of grease and excessive wear. I was really pissed, it was time to return back to stock bushings. Then one day rear left transverse arm broke, wheel toed out 10-20° and car became uncontrolable. I hit 2 parked cars, still consider myself lucky because nobody got hurt and speed was only 80 km/h. If it happened on highway damage would be far more severe. I can't blame nylon bushings for what happened, the accident was the result of lack of regular greasing, simply because they were impossible to grease. Dusty and bumpy roads don't make bushings life easier as well.
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In the spring of 2007 my car was taken to
body repair shop after my road accident. Positive outcome of it is that there was
good chance to lighten the front end of the car. A lot of useless things and
fittings were removed, heavy OEM front bumper support was replaced by
lightweight aluminium one from Toyota Majesta. Rear bumper was removed as well
and similar aluminium beam from Majesta was fitted. OEM steel rear bumper
support is incredibly heavy. Majesta beams are very light, 6lb
each.
I also sold my heavy solid ST swaybars and bought Tanabe chromoly hollow bars,
another ~20lb of weight saving.
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Last summer I ordered locally to fabricate fiberglass doors and chromoly front lower arms. My car is '89, OEM doors are without steel reinforcement, in some countries and after ~1991 in Europe Supras were sold with door intrusion beams. Full weight of my OEM door is 32 kg (70 lb). Full weight of fiberglass door is 20 kg (44 lb). I retained only stock glass and central lock. All other door internals gone, including heavy power window mechanism. It is in manual cranking mode now :)
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Chromoly tubular arms weigh 4.2 kg vs. stock 6.2 kg (9.3 lb vs. 13.7 lb). Every little bit helps, especially if it is in the front of the car and partly contributes to unsprung mass reduction. Though when car was already considerably lightened like mine, every other kg becomes more expensive.
In September of last year I purchased Flaming River steering rack for '79-'93 5.0L Mustang, conversion from power steering to manual rack was done by many mk3 owners in States. Most popular are Flaming River rack for Mustang and OEM racks from early RX7. As far as I know RX7 racks fit without major modifications, fitting Mustang rack proved to be more involved than I expected. Rack I bought is quick ratio (15:1, 3.3 turns lock to lock), part # FR1520. Installation requires cutting off OEM rack mounting pads and welding of new ones. On the photo below you can see how it was done.
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I mistakenly offset rack slightly to the
driver side fearing it would hit engine mount, but later realized it could be
fitted without any problems in the centre. This error will cost me more steering
effort :(
End result - I like my power steering much more and miss it despite it's heavy
weight. With my 245 size front tires steering effort on low speed and when
parking the car is unacceptable. Just can't do quick manoeuvre in heavy traffic
and it sucks. Another negative aspect - increased tendency to bump steer. On highway speed
though it's fine and road feel is very good.