So if you haven’t seen it yet, or even if you have, my esteemed colleague Gregson has launched a video onto our YouTube Channel. In said video he introduces you to us, and specifically his ride, a 2014 Subaru WRX. Gregson poses the question, “What should I do to my ride?” What mods should he make and what general direction he should take to transform his common daily driver into something more, something better. This raises a more general question and that is, “What should I do to improve or mod my turbocharged car?” The process is simple and it is much easier (and cheaper) to squeeze power out of a turbo car than it is an NA car. See: My Lexus IS300, that is a topic for another day.
So where do you start? You can get lost in a bevy of options, engine, suspension, body work, etc. There is a lot to choose from and frankly it all boils down to your personal preference. Me, personally I’m fascinated by engines and making a car go faster. Body kits look cool but often ad weight, thus slowing the car down. Obviously you want to upgrade the suspension/brakes at some point but with Gregson’s car, the WRX we already have a solid foundation. I have broken it down into 2 stages. Stage 1 is for basic mods, stage 2 for more advanced. Both focused on making more power! (said in the most Clarksonian way possible)
These are the simplest mods to make they offer a great bang for limited budget. These are also mods that you will need later to maximize effectiveness of future upgrades. I will repeat this quite a bit, but this is the time to make a plan for your car. Take the time to plot out what you want to do and what your budget will allow. Do your research. You never know you might be able to swap in a pissed off version of your engine for the fraction of the cost of upgrading the parts yourself.
#1: Turbo Back Exhaust. This is probably the best mod for any turbocharged car. It allows for more power by freeing up exhaust air. More efficient exhaust removal leads to more power. Plus, by freeing up the air behind the turbo you allow the turbo to operate more efficiently.
#2 Front Mount Intercooler (FMIC). If it isn’t abundantly obvious turbos get hot, really hot they’re exhaust driven after-all. In addition to the ludicrously hot compressor the actual act of compressing the air generates heat. Hot air does not do well in engines. Thus an Intercooler is required. Some cars have a FMIC from the factory, however the vast majority do not. Gregson’s WRX for example. By running a FMIC you can run a larger surface area which cools the charge air more efficiently than a top mount or side mount intercoolers. Cooler air means more oxygen, more oxygen means more fuel, more oxygen and more fuel means a bigger bang, bigger bang means more power!
#3 Boost Controller. There are 2 kinds, manual and electronic boost controllers. Either works fine, though I prefer the added control an electronic boost controller offers. Both in similar ways, they work in conjunction with your car’s wastegate to regulate boost pressure. While a manual boost controller will allow you to set a maximum boost level. This is good if you are looking for a good, inexpensive way to increase boost. Electronic boost controllers offer more adjustability. This offers you the ability in conjunction with an aftermarket ECU or flashable ECU to fine tune boost across the rev range. Speaking of tuning…
#4 Professional Tune. Ok, so you’ve gotten the air in and out of your engine more efficiently and you’ve increased boost. Now it is time to think about a tune. Beyond this stage is more advanced mods. For these mods you will definitely need some way of managing your engine. This is done 1 of 2 ways. If your car’s ECU is flashable, meaning a professional tuner can re-map your engine settings to increase things like timing, boost, red-line etc. This is great if all you’re looking to do is round off your mods and make sure they are giving you the added performance you purchased them for. In some cases the factory ECU is limited in its tuning capabilities or you are given no option at all (Thanks Toyota!). This is where an aftermarket standalone ECU comes into play. These aren’t cheap, however many are plug and play and are easy to install and offer a professional tuner the freedom to tune your car without any computing limitations. This is where you can really fine tune your engines performance. Not to mention it gives you the ability to data log. So in the future you can see what is holding your car back from making more power.
#5 Clutch and Flywheel. Now that the engine is making more power you are going to be stressing your clutch’s holding power, better to just upgrade there are a ton of clutch options out there. This is another time where you want to sit down and think of what you want your car to be. No sense buying a clutch that has a harsh engagement if this is where your tuning journey ends. While your in there you might as well replace that beast of a heavy flywheel with a lightweight unit. You would be shocked how heavy factory flywheels can be. I saved 11ish pounds when swapped mine out. Lighter flywheel means less mass to move which means less loss of power through the driveline.
You can replace things like pulleys and such but they don’t really add a ton of power and are more trouble then their worth.
Overall these are the basic mods, in most cases you’re looking at spending about $5000 (using Gregson’s 2014 WRX as a bench mark) on parts. Obviously the costs vary depending on your car. Plus installation and tune, though most are easy to install and can be done in your driveway at home. You may be wondering why I left Cold Air Intakes off this list. More on this a little later, but most factory air induction systems are pretty efficient these days. If your car is a bit older or has an inefficient air induction system, then you should consider a intake.
It is at this point you may want to consider upgrading your suspension, brakes etc. After that you should end up with a very well sorted, well rounded daily driver.
This is where we get into the more expensive options come into play, however this is also where you start to make some big power gains. With more power comes more heat. Heat is the enemy. So it is at this point you want to think about upgrading your engine cooling system. Radiators, pipes, water pumps etc. It is also worth noting at this point you should start checking the various limitations in your driveline. Every engine has a limit on what the stock internals can handle. You NEED to know this. In addition, how much power can your transmission, diff and other components can handle? No sense turning your car into a fire breathing monster if the transmission explodes on your first hit. Lastly, now is also the time to upgrade the intake system.
#1 Fuel System Upgrades. This is a mod you can do either before upgrading your turbo. In fact it could be done at the end of Stage 1 should you believe you are going to be making further upgrades. Obviously by increasing the volume of air you want to equally increase the volume of fuel. This is not only important for making more power, but critical to the health of your engine. Fuel actually acts as a coolant inside your engine. So when you start to lean out, the engine gets hot and you risk the whole thing going kablooie. First step is larger injectors, figure out your fuel demands and purchase injectors accordingly. Things like oost levels, fuel type (E85 requires larger injectors than standard gasoline) will determine the size injectors you need and if you require an upgraded fuel pump. Depending on the age of your car you may want to replace your fuel pump anyway just to be safe. However if you are going to run big boost you may even need to upgrade your pump setup. Once again, to prevent your engine from leaning out and melting.
#2 Turbo Upgrades. Now it is safe to upgrade the turbo. At this stage in your cars development there really isn’t much more power to be had outside of upgrading your turbo (yes there’s NOS but at the risk of going into a long winded rant you do not want NOS for a daily driver. You just don’t). You may also have 2 turbos when a single turbo setup may be beneficial. Again, figure out what exactly you want and upgrade your turbo accordingly. You can send your stock turbo out to have it’s internals upgraded or you can purchase a bigger turbo. Upgrading your turbo’s internals can gain you more boost but won’t be as high as a brand new or bigger turbo. Obviously a bigger turbo means more air being rammed into your cars combustion chambers which means more power. However a more modern turbo, may be able to offer the same increased boost at a smaller turbo size. Smaller turbos spool quicker, thus the problem of lag with big turbos is reduced. Consider what exactly you want before throwing your money at a bigger turbo.
Once you’ve decided on which direction you want to go with your turbo, now it is time to consider wastegate options. There is multiple different options when determining wastegates. Packaging is probably the biggest determining factor. You can either run an internal or external wastegate depending on what your engine bay allows. you may need to modify or replace some of that turbo back exhaust you purchased but sometimes sacrifices need to be made in the pursuit of more power!
#3 Manifolds/Throttle Body. These are really the last things to be replaced before you dive into the engine. In some cases it isn’t even necessary. As cost of a manifold exceeds the cost of something like cams which adds more performance. It really depends on your car. This is why consulting a shop that knows your engine or consulting forums is key. However a high flow turbo manifold will allow air to enter the turbo more efficiently. More efficient airflow once again spools the turbo faster allowing for more boost quicker. Intake manifold/throttle bodies operate on the same principal only in reverse. If you move air more efficiently you can add more. Or simply have a better explosion within the chamber.
Your throttle body/bodies literally determine how much air makes it into your engine. When adding serious boost you may find yours is holding you back. Upgrading to a larger unit may be required. This is where a good tuner is worth his weight in gold. While dyno tuning your car he/she can tell you what is holding you back. this way you don’t go wasting money on upgrades that do not need to be done. Not to mention at this stage of any build you are going to need to tune to get the most out of your parts. This is also where you might want to consider switching to an electronic throttle. This will once again allow for more precise tuning and fail safes to be built into your tune. IE the computer reads something wrong, it can immediately cut power to prevent a catastrophic failure.
#4 Engine Internals. Honestly this could be a stage all to its own. When you start diving into things like pistons, connecting rods, cranks etc you are on a whole different level. For the sake of this post we are going to leave the bottom end alone. We are strictly going to work with the top end of your motor. First You’re going to want to look at new cams. Larger lift and longer duration will allow for the increased levels of air and fuel you are punting into your engine. Power gains can be significant, in some cases you may want to consider replacing these before any other stage 2 upgrade. The downside is they can be a pain to install, in some cases the engine has to be removed from the car. So they can be quite labor intensive thus more expensive to install.
While you have the heads off your car you might as well do 2 additional things. #1, replace the Springs, Retainers and Valves. This will allow you more RPM. In conjunction with everything else, tune etc, more RPM means you can stay on boost longer between shifts, thus losing less time. #2, Have your heads ported and polished. This will allow for maximum airflow/fuel efficiency. Plus it will make sure everything is in good working condition. Shame to spend all this money only to have a valve destroy a piston.
And if you are intent on installing a stroaker kit, or upgrading your pistons etc, this would be the time to consult an engine builder.
The costs here are as high as you want them. It can be done inexpensively or you can shoot for the stars, spend a fortune, and build a monster. This all comes down to what you want your car to be.
I’m not saying we plan to do all of this to Gregson’s car. As much as I would like to turn his car into a street beast this is his daily driver we’re talking about. I’m sure he wants to upgrade the power while also keep it streetable and retain its reliability. This is more of a road map to help you with your tuning goals. Hopefully this is helpful. Agree? Disagree? Comment below.