The order of these mods is recommended, though everyone decides to go down their own path.
1. Maintenance before modding- This include changing fluids, spark plugs, filters, timing belt,
making sure your brakes work etcs… Some cars may need more maintenance than others, but
it’s never a good idea to start modding a car that has not been properly maintained.
2. Catch Can- A catch can is a great preventative mod that will reduce the amount of carbon build
up in your engine. Our PCV systems are a known problem, and carbon buildup becomes a big
issue that reduces power in our cars. Although a catch can will not completely fix the issue, it
will definitely help. Pairing one with the occasional sea-foaming will help keep your valves clean
and carbon free.
3. Downpipe (DP) and ecu tune- The reasons I put these two categories together is because they
go hand in hand. I will explain each individually later on. The stock DP on the mkiv 1.8t is very
restrictive and sucks a lot of potential from the engine. Adding a larger downpipe (usually 2.5-
3inchs) will allow your engine to breathe like never before. But since the engine is tuned to use
a small restrictive DP, adding a DP alone will not add much gains; it actually could cause your car
to run badly. An ECU tune will allow the engine to properly use its new DP and give you the most
power gains for your buck.
4. ECU tune (more detailed)- Every car has an ECU (engine control unit) which is basically a
computer that controls many different aspects of the engine. VW engines have a tendency
to be underpowered from the factory, and the easiest way to fix it is to tune the car. There
are 5 major tuning companies: APR, UNItronic, REVO, GIAC, and Gonzo. Most people choose
whichever is closest to them, and there is a lot of debate as to which is best. APR has the
reputation of having a good balance between power and reliability, whereas UNI and GIAC
are more aggressive. REVO has mixed reviews, some love it, some hate it. Some REVO tuned
cars run lean which causes engine problems. Gonzo is a new tuner that has recently come out
and for the most part has had great reviews, but being a new tuner, his tunes have not been
time tested for reliability yet.
Each tuner has different stages of tuning. Stg 1 is just an ECU tune, no other modding is
required. Stg 2 requires a downpipe, and an intake is recommended. Stg 3 is a big turbo(BT) file,
which involves changing the turbo and requires a lot of engine work.
5. Exhaust- As previously mentioned, the stock DP is restricting, and changing it yields big gains.
The downpipe is the part of the exhaust that bolts up directly to the turbo. A stock downpipe
will have a Catalytic Converter (Cat) on it. An aftermarket DP will either come with a high flow
cat, or catless. Most people make their decision on going catless or not based on state laws and
being able to pass emissions/inspections. Performance wise, there is almost no difference. The
part of the exhaust that attaches to the DP is called the catback. It is not necessary to change
unless you go BT. That being said, a lot of people enjoy upgrading the stock catback so that their
car produces a nicer/louder sound.
6. Intake- People have different views on how helpful an intake is for the engine, but general
census seems to agree that it’s not very useful. It adds a nice noise, but does not do much for
performance. There are plenty of intakes out there, but essentially they are filters on a stick.
Buying a 300$ intake vs buying a 40$ pod filter and sticking it to the end of your MAF will
produce more or less the same results.
7. DV/BOV- After getting a tune, it is recommended to upgrade the factory Diverter Valve (DV).
The diverter valve allows the excess pressure caused by the turbo to be released or recirculated
in order to prevent unnecessary damage to the turbo/engine. Another option is a Blow Of Valve
(BOV) which causes excess pressure to be vented to the atmosphere and adds a Pshh sound
every time you take your foot off the throttle (some love it, some hate it). Some BOV can be
problematic for the MKIV, so if you decide to buy one, you have to make sure it closes at idle.
The HKS SSQV BOV has been proven to work well with our cars.
8. Intercooler- Our stock intercooler is small, and may not be efficient enough to cool the air
of a tuned car. If you are stock, then upgrading the intercooler might actually make you lose
performance. Since aftermarket intercoolers have a larger core than stock, it takes more boost
pressure to fill it up, resulting in possible turbo lag if the car is not tuned. But if you have a tune,
it will be helpful in reducing heat soak. These intercoolers are also known to heat soak on an untuned
vehicle as well.
9. Water/Meth kit (W/M)- Cools down your engine so it can run more efficiently. It can also help
clean the valves that are notorious for caking on carbon. W/M kits allow you to run more
aggressive timing, which gives you more power. But if your car is tuned to run a W/M kit, then
you have to be certain that the W/M tank never runs out. It could cause major damage to the
engine if a car tuned for W/M does not use it.
10. Suspension- The stock suspension on our cars is mediocre at best, and upgrading the suspension
is usually one of the first mods that is recommended. There are multiple ways to do this. If
you’re looking for a slight drop with improved handling and close to stock ride comfort, then
a shock and strut combo would probably be your best choice. The problem with this is that
you cannot raise or lower your car how you like, it is a set drop, and if you ever want to go
lower in the future (which 99% of people always do) then you will have to buy another type of
suspension. The most used suspension upgrade is coilovers. Coilovers allow you to raise and
lower your car to the height you desire. They have a large price range, starting from around
400$ to being over 2K$. The difference will be ride comfort, adjustability, reliability, and
performance. The last option is airbags. These will allow you to go subframe to the ground LOW,
and with the push of a button be back at stock height. People who have bags are usually more
about form than function, so if you plan on auto-Xing or tracking your car often, coilovers are
probably a better choice. That being said, Bags do improve handling over stock.
Misc Suspension parts- The shock and struts are only part of the suspension, but there are
many more things you can do to improve handling and grip. Getting a thicker front and rear
swaybar will reduce understeer and allow your car to stick to the ground more. Most people
who are performance oriented upgrade the swaybars. On the other hand, many who have
Bags remove them completely because it prevents them from going as low as they want to be.
Another upgrade is the dogbone mount. This will cause slightly more vibrations in the cabin,
but will allow you to have much better grip and much less wheelhop. Upgrading the Suspension
bushings will also improve handling, but will cause more vibrations in the cabin.
I'm gonna add to this weekly if not daily, but this will be a good starting spot for most new members