This is my recommended list for your first 10 modifications to
your stock car. It is a little difficult to know exactly what to do first and if this
affects that, what does this do, does this mod work, what's the best thing to spend my money on etc...
Please bear in mind that opinions vary and that as I see things
these are the first 10 mods I would do to my car if I was to start again on a stock car.
What is the aim of these mods?
The aim of these small 10 modifications are to be low cost, quick and "mostly easy",
to provide a small foundation on which to build and to release a bit more power from the
engine. They will also guide you around
the car looking at engine bay, suspension and other bits and pieces. These mods tend to focus on the key weak areas, as well as being the cheaper ones!
One of the golden rules for modification is intake, exhaust, fuel and
ignition. Something that is always worth bearing in mind.
Okey dokey, what is your list of first 10 mods?
1. Maintenance Before you start modding away the car needs to run well
beforehand. If it's misfiring belching out smoke and generally misbehaving then
get these things sorted first. If you don't it may well cost you dearly later.
Things to address:
Change engine oil and filter
Check all fluid levels and rectify any leaks - brakes, clutch,
engine coolant, IC coolant, gearbox oil, rear diff oil
Change spark plugs
Change rotor arm and dizzy cap
Change the fuel filter
Ensure the cambelt, power steering belt and alternator drive
belts have all recently been changed
Service or overhaul the brakes
Cost - depends on the state of your motor...
2. Replacement panel air filter
Get the K & N as they are relatively cheap, reliable and you'll
probably never need to buy another filter! To clean it wash it through with
soapy water, dry it and then re-oil it. You'll save money in the long term.
Don't get a foam one cos they tend to disintegrate and if it does then foam will
be drawn into the engine and turbo. The K & N is a cloth filter sandwiched
between metal gauzes - much safer. Drawback - if you want a straight intake
later then this will be redundant. There are induction kits available but they
are expensive i.e. >£150.
3. Boost gauge
You really need to now what is going on in the intake manifold,
and if you are going to do further mods then you definitely need a boost
gauge or it may go horribly wrong. TIM manufacture cheap and cheerful gauges,
whilst not particularly good looking or highly accurate it is certainly a step
in the right direction...More expensive gauges are electronic, can be linked
together, have warning functions, replay functions etc etc expect to pay >£150
per gauge for these shiny bits!
Cost ~£30 (low quality and reasonable accuracy)
4. Intercooler mods - these will depend on the
type of GT4 you own...
The turbo heats up air as it compresses it. To cool this air
down and reclaim some of the "lost" power the intake air charge needs to be cooled.
For WTAIC GT4s, insulate the underneath and sides of the
IC to prevent it from heating up due to
the engine and exhaust manifold temperatures and close proximity. Demon Tweeks and Fensport sell insulating material and tapes, see the
links section for more shops.
Modify the IC pump so that it runs continuously on the 165s and 185s - I
wouldn't bother on the 205 as the control system appears to be better.
For ATA IC Wash the core, ensure
the fins are undamaged and aren't clogged with dead flies etc.
For all ICs - wash out the IC with petrol to clean the
interior to ensure it transfers heat efficiently. Maybe worth a few bhp, and should help to keep your engine safer...
Cost - heat reflective tape ~£5. If your adventurous, heat shield ~£5 for
aluminium and some of your time.
5. Fit a Dump Valve
This will help to prolong your turbo life and help to keep the
turbo spinning between gear changes improving driveability. Also makes you grin
a little and feel like a boy racer...A popular choice is the Bailey DV26. The
GT4OC offers a very competitive price for the valve and fitting kit! (only
available to GT4OC members). Other more "fancy" dump valves are louder,
different sounds, sequential etc. Expect to pay >£150 for some of these shiny
bits. Drawback - the car will over fuel on gear changes. Not really required on
the 205 as this comes with a DV
Cost - ~£90 for the DV
and the fitting kit from the GT4OC
6. Replacement exhaust
Your stock exhaust is probably rusty and blowing, go get a new
stainless one. At this stage just get the cat back exhaust to keep the spending
in check. Performance exhaust probably good for ~15bhp. This also frees up the exhaust gas
path for later power increases and helps to prevent this from becoming a
big restriction later on. Get the largest diameter possible 3" is a good size.
You might want to look at an
as these are right up there with the best and are 3" systems... Watch out that
the exhaust you get covers all three sections, (the Scorpion does), i.e. flexi
section, mid pipe and back box.
7. Gut the catalytic converter
Gutting the cat will release approx 5hp and help the turbo to spin up
earlier. If you can afford it then replacing the cat with a down pipe is much
better. The 3" Aussie is considered to be the best ~£250, available from Fensport.
Cost - nothing if gutting the cat, just time.
8. Relief Valve & TVSV
Firstly disable the TVSV so that you
can run the same amount of boost in all gears, thereby establishing a common
level, and taking away the ECUs input... Note - this will reduce boost in 3rd+
gears by approx 2psi...which isn't a problem cos you are going to raise the
overall boost level with the
To increase power the boost needs to be turned up. To do this cheaply fit an
alternatively called a Dawes Device.
To obtain one contact Martin Farrell via e-mail or visit
his website. For
much better/more controllable/repeatable results fit an SBC ~£350 (ouch).
On your stock setup you need to watch what boost you run, or you will hit
fuel cut, (a safety feature to help prevent damage). Guide levels for fuel cut
Note - the exact fuel cut level varies from car to car.
Cost - ~£20 for RV, a little bit of rubber hose that you might need to buy ~£2, and use a couple of old bolts that are lying around to block off the TVSV pipe work.
9. Fit Polyurethane suspension bushes
You have increased power by doing the above, now you need to
make the car a little safer and also to sort out that bloody awful handling,
Fitting PU bushes will stiffen up the car. Don't forget to get the anti-rollbar
bushes as these made a noticeable difference, as well as the front and rear
suspension bushes. Click here
for an article on how to replace the rear suspension bushes.
Cost - ~£180
10. The list continues...
After that cheap lot it starts to get expensive, items you might want to
Fuel Cut Defencer - allows you to raise the fuel cut level in order to run
more boost pressure
Colder grade spark plugs
Straight air intake
Engine Management System
Suspension - strut braces, shocks, springs
Brakes - the stock brakes are awful...(165 and early 185s)
Front Mount Intercooler
~£700 will set you on the right path and provide, (~40bhp - 165), and a lot more fun!
Blimey! Got any more info on that lot?
Have a look through the modifications section...
On the shopping list really should be a bigger turbo and some way of
controlling all this lot i.e. a replacement o ECU.
How much is the car worth? How much do you plan on spending on
mods? Would you be better off putting that modding money towards a faster car?!?
i.e. a 205? Bear in mind that the 205 already comes with 239bhp, better
intercooler, different cams, larger injectors, metal head gasket, better
pistons, different turbo, better fuel maps, much better engine management, bigger throttle body, revised intake
manifold, revised oil filter location, better gearbox, better rear diff, mild head porting, massive brakes, much better
suspension and is not so prone to rust! But it's not the original GT4!