If you’re on this FAQ, you’re probably pretty deep into considering whether or not you want to convert your 3.8L Genesis Coupe to Forced Induction (FI) with a big-ass turbo. We understand that this is a big expense and a complex project! This FAQ was built to answer all of your common question, bust myths and misinformation in the Gen community, and collect the wisdom of 70+ Remnant Performance customers into one home.
Before installation
DURING INSTALLATION
AFTER INSTALLATION
BEFORE INSTALLATION
MYTH: Higher PSI is always better?
The author of this FAQ wanted to address this topic upfront, because it deals with one of the most widespread misconceptions circulating about turbocharged cars. One user will claim they run 20 PSI. Another driver will claim they run 5 PSI. Who has the faster car? Most laypeople would immediately think it’s the 20 PSI car, but that is almost certainly not true. Let’s dig into why!
PSI is a measurement of pressure exerted on a certain volume of air. Think about the amount of air that fits into a drinking straw, then think about the amount of air that can fit in a pipe that’s 12 inches in diameter and six feet long. Big difference, right? You can pressurize both the straw and the pipe to 6 PSI, but that 12-inch pipe is going to hold a whole lot more air. And it’s going to be a whole lot more difficult to pressurize that 12-inch pipe, too. In fact, using the volume formula for a cylinder, we can measure exactly how much air volume there is to act upon:
- Drinking Straw: 0.38 cubic inches of air (8.5 inches long, 0.24 inch diameter)
- Pipe: 8143 cubic inches of air (72 inches long, 12 inch diameter)
The pipe holds 21,428 times more air than the straw. Turbos behave the same way and operate on the same principle: they pressurize a certain volume of air to a PSI rating dictated by a wastegate or boost controller. A smaller turbo can pressurize a smaller volume of air than a bigger turbo. And though they could both pressurize air to the same PSI, the volume of air delivered by the smaller turbo may be insufficient to meet the peak efficiency demands of the engine. Now we can apply this thinking to real cars:
- Hyundai Genesis Coupe 2.0T: ~14 PSI stock for 274 HP
- Subaru WRX STI: ~17.5 PSI stock for for 310 HP
- Hyundai Genesis Coupe 3.8 Turbo: 6 PSI for ~525 HP
Why is the 3.8 Turbo generating so much more power for so much less boost? VOLUME OF AIR. Air volume wins the day because cars are glorified air pumps. The greater the volume of air you can pack into the motor, the better the performance will be on the other side.
This plastic hose has been pressurized to 18 PSI with a simple hand pump. This certainly won't make a car faster, though. The 18 PSI is being exerted on a tiny amount of oxygen. This demonstrates that PSI is not an informative metric without knowing other variables like: cylinder volume, piston compression ratio, or the turbo compressor map.
As another useful thought experiment: you can use a hand-squeezed pump to pressurize a simple rubber tube to 30 PSI just by blocking the exit with your thumb. Will that amount of air contained in a small rubber tube do anything for your motor’s performance? No. It will not. That’s why nobody attaches a hand pump to the car--30 PSI be damned.
Calculating the true value of a turbo's PSI must include discussion of the following:
- Turbo area over radius (A/R)
- Turbo flow rate versus engine needs
- Compressor wheel design (P/S/Q trim)
- Engine displacement
- Turbo compressor housing design
- ...and many more!
For example: you can run a too-small turbo at high PSI and not get much out of it, because it can't pack enough air into the engine to build power. Is that better because you have higher PSI? No. Sadly, you rarely (never?) see anyone come to the table prepared to discuss these complicated factors when arguing about PSI on the internet, so don't bother diving in. Just keep this in mind: boost PSI means diddly squat if you're not looking at all the variables.
Why not a supercharger?
Superchargers are easier to install, but significantly less efficient than a turbo. The reduced efficiency has serious drawbacks for you:
- A supercharger will provide less performance than a turbo for the same PSI.
- The 3.8 engine suffers from heatsoak. Because the supercharger is less efficient than a turbo, it must be run at a higher PSI than a turbo to achieve the same performance. This increases the thermal burden on the engine, as more boost = more heat.
- Because the supercharger must be run at higher boost to meet or beat a turbo, the engine is subjected to more stress from the higher PSI. This reduces reliability of the pistons, rings, and rods.
- For approximately the same selection of parts (essentials + better turbo/supercharger + oil cooler + catch can + windshield reservoir), the supercharger kit is nearly $2000 more expensive than a turbo before gauges and tune.
- A supercharger is a parasitic drain on the engine, because it is driven by the crank and belt that drives other accessories. Belt tension is much tighter with a supercharger, however. This will prematurely wear the aluminum main journal bearings
- Alterations to the rotating assembly of the 3.8 Genesis Coupe, such as a lightweight crank pulley, have been responsible for inducing stress fractures on the crank discovered with microscopy. A supercharger also alters the wear and load experienced by the crank, and is believed to have the same wear and reliability effects at a much faster rate.
- The supercharger will sacrifice your windshield wiper reservoir and passenger fog light. You can pay extra to get the reservoir back. You don't have to sacrifice either one on the Remnant Performance kit.
- Many supercharger kits have come and gone for the Genesis Coupe, but turbo kits have a proven and consistent track record. It is worth asking why the history of the Genesis Coupe is littered with failed and forgotten supercharger kits, but not so for turbo kits. When you want help or need tips, who is going to help you? Boosting a car is a big decision, and it's important to think beyond the project to the community, the knowledge, and the support around the project.
Altogether, you can see that a supercharger costs more money, yields less performance, and offers less reliability than a turbo setup. Boosting the Genesis Coupe 3.8 with a turbo is clearly the most efficient, economical, and safe path forward for anyone who wants to boost their Gen.
Is the Remnant Performance kit reliable?
The test vehicle for the Remnant Performance turbo kit now has over 40,000 miles and three years of service with turbo—in addition to its original mileage. This turbo kit was specifically designed for reliable daily operation on a stock engine block with no additional modifications.
This “safety first” philosophy is what guided Remnant Performance to include many safety and preventative components in the kit: an external oil cooler, a 6 PSI wastegate, and a custom billet oil sandwich plate to name a few.
Remnant Performance was the first turbo kit to offer many of these safety features because we were unhappy with the in-market alternatives and/or did not feel it would be appropriate to sell you a kit without these reliability enhancements.
Remember: this kit is designed for long life on a stock block. HOWEVER: Converting to turbo makes the penalties for missed maintenance, unsafe driving, engine abuse, and hooning much more severe. If you have a habit of flooring it on a cold engine, rapidly changing throttle positions, going more than 3000 miles between oil changes, or driving without being 100% certain that your new parts are installed right… You will probably blow your engine. Be smart. Be safe.
What is the all-in cost of this turbo kit?
- $3395 - $4290 + tax (depends on BK1 vs BK2 and turbo selection)
- $545 + tax for PnP gauge kit (includes BK2 gauge pods)
- $850 for an AlphaSpeed custom big turbo tune
- Total: $4790 - $5615
Additional costs you should price out and/or may incur:
7 quarts of Amsoil European MS 5W40 oil
7 quarts of conventional 5W30 for turbo break-in
$125 for an external automatic transmission cooler
2Q of transmission fluid (if moving to an external AT cooler)
$80 + tax for a BK1 dashboard gauge pod
What turbo do I pick?
As of April, 2021, the Remnant Performance (RP) turbo kit has switched from turbochargers supplied by On3Performance, to a pair of new designs customized by RP specifically for this turbo kit and the Hyundai Lambda II 3.8L engine. Those options are:
- GTX3582R Gen 2:
- 65.7mm compressor wheel inducer and 62.3mm turbine wheel exducer (6662)
- Spools at ~2800 RPM, max boost at ~3600 RPM with cast compressor wheel and journal bearings
- This replaces the 70mm On3 Performance turbo that originally launched with the kit in 2019
- 70 OMEGΛ:
- 70mm compressor wheel inducer and 64.2mm turbine wheel exducer (7064)
- Spools at ~1900 RPM, max boost at ~2600 RPM thanks to dual ceramic ball bearings and lightweight point-milled billet compressor wheel
- This replaces both the 72mm and 76mm On3 Performance turbos that originally launched with the kit in 2019
Both the GTX3582R and 70 Omega solutions are perfectly-sized for great performance and fast spool on the Genesis Coupe 3.8L—you simply can’t go wrong. But the 70 Omega turbo holds a definite edge for performance, as it is upgraded with a billet compressor wheel and ceramic ball bearings. These changes allow the 70 Omega turbo to spool sooner, build boost faster, and flow more air. A prized combination when building a turbo car!
As a result of these two changes alone, the 70 Omega turbo can start building boost as early as ~1900 RPM and provides ~30 HP more performance to your build than the GTX3582R option. Considering Gen owners spend upwards of $1000 for catback exhausts that provide a lousy 12HP (max), $595 for a bonafide 30HP upgrade (and earlier boost) is a total steal.
Better yet, the 70 Omega uses state-of-the-art turbo housing and compressor wheel design methodologies including, but not limited to:
- Shape, orientation, and density of blades on the compressor wheel
- Hyper-precise point-milling process for fine tuning airflow across the compressor wheel
- Compressor inlet size/depth/chamfering
- Exhaustive optimization of the compressor housing interior for precise turbulence and airflow control
These advanced geometry and aerodynamics techniques allow this mid-frame turbo to support up to ~1200HP on engine sizes from 2.0L to 5.5L... Perfect for the 3.8L Genesis Coupe!
These wheel and housing design techniques are so effective that they also form the basis of the all-new Garrett G35-1050 launched at SEMA 2019. The older design techniques used in the aging Precision 6266 and 6766 designs just cannot compete with the spool time, flow rate, and performance for you of the 70 Omega.
The author of this FAQ is running the original On3 72mm turbo option, which the 70 Omega replaces this year. Both turbos have similar spool characteristics and power output on the 6 PSI tune for the Genesis Coupe 3.8, though the 70 Omega is a far better and newer design. So let me just say: my On3 72mm upgrade was worth every penny to me, and I'd definitely get the 70 Omega if I had to do it all over again!
The 72mm On3 (my turbo) and 70 Omega (2021 option) units spool so phenomenally fast and early that the car feels like it has a supercharger. Turbo lag is negligible. I can readily hit full boost in the low 2000 RPMs, and the car is hungry to hit max boost. It is unbelievably thrilling to drive and I would always recommend to other 3.8T customers to save pennies for the faster spool—it's so worth it.
Here's the takeaway: A Genesis Coupe with carbon fiber hood/trunk, spare tire delete, and a 70 Omega turbo is comparable power/weight to a Dodge Challenger Hellcat and V10 Audi R8. You ever wanted to throw down versus $70K+ cars? Now’s your chance.
What kind of power will I make?
Our present best estimate is approximately 525 crank horsepower for a BK2, with somewhere between 415-450 wheel horsepower (depending on drivetrain losses). This assumes a 70 Omega turbo and a stock motor with intact headers. Overall, 20-22 horsepower per PSI on top of the stock engine performance is typical. Folks are working to secure updated dyno figures based on th7e latest tuning advancements and the new turbo options in 2021.
To put it in perspective: this is a power/weight ratio that’s competitive with the Dodge Challenger Hellcat, Audi R8 V10 Gen 1, and Mustang 5.0. Your performance will be seriously underestimated by most.
What PSI does this turbo kit use?
In a turbo configuration, the wastegate opens to relieve pressure from the exhaust piping to control how fast the turbo spins and much boost pressure is being generated. The Remnant Performance wastegate will automatically open at 6 pounds of boost. As of August, 2021: Remnant Performance has phased out the On3 Performance wastegate offered with early versions of the kit; the On3 wastegate used a 0.4 BAR (5.8 PSI) spring by default. New kits are now shipping with a semicustom wastegate design built for Remnant Performance, which uses a 6 PSI spring by default.
You will also be provided 3.0 PSI and 4.5 PSI springs. As with any wastegate spring: All springs may be combined in a wastegate, or combined with a boost controller to run up to 2.5X spring pressure.
Why does this kit use 6 PSI?
Some context is needed before addressing this question.
All pistons in cars are surrounded by a series of rings. These rings are retained in slots on the piston called the ringlands. The rings keep things (fuel, air, oil vapor, particulates) where they belong inside the cylinder for proper compression and detonation. So far so good!
As you probably know, metal expands and contracts under hot or cold. The Genesis Coupe rings and ringlands are designed and spaced to accommodate for thermal expansion/contraction with the range of temperatures experienced on a stock(ish) motor.
But a turbo raises pressure. It raises temperatures, too. The addition of a turbo narrows the spacing between these rings due to thermal expansion. With enough pressure and heat, the new force exerted by the rings can overpower the strength of the ringlands and touch--or even slide past one another. When this happens, the powder-pressed metal piston can explode and/or irreversibly damage the cylinder walls due to scoring. That's an expensive repair bill, if not a dead motor.
Years of trial and error have indicated that the OEM rings and pistons have enough thermal margin to tolerate boost in the range of 6-8 PSI on turbos of the size provided with the Remnant Performance kit. Some Gens have proven to handle even more, and there are certainly Remnant Performance customers carefully pushing towards 10 PSI today.
But safety comes first! That is why the Remnant Performance kit ships with a trusted 6 PSI boost configuration, and why you're encouraged to proceed very cautiously beyond this point, or seek outside engine building assistance from MT Motorsports if you want more.
Okay, so do I need to build my motor?
In short: absolutely not.
But a more thorough answer is warranted, as there’s lots of bad advice out there and this is perhaps the biggest question. First, it’s important to understand that the community of 3.8T owners is relatively small, and they usually talk amongst themselves. Much of the knowledge carried by the wider Genesis Coupe community is based on the experience of 3.8T owners from years ago, many of whom have since moved on to other platforms. Oftentimes, people commenting on this platform haven't updated their knowledge in 3-5 years.
In the early days of 3.8T, the community’s understanding of the Genesis Coupe’s onboard computer (ECU) was primitive. Cars being converted to 3.8T were receiving tunes with inappropriate air/fuel ratios (AFR), internal safety limiters disabled, knock sensors disabled, and many other decisions that could easily prove fatal to an engine with or without turbo—and those decisions were fatal to the motors. Even until 2021, the car was unable to compute its own air/fuel ratios under boost, which required that drivers carefully manage their throttle use.
Many people in the Genesis Coupe community have interpreted these failures to mean that the motors could not handle boost. Instead, the truth is that these pioneers were running tunes that were fundamentally dangerous to any motor. Many in the Genesis Coupe community are not experienced enough with engine modification to know the difference and have not updated their knowledge in light of all the advancements made over the last three years.
Today, our understanding of the Hyundai Lambda II motor is significantly improved, as is our understanding of the ECU. We have levels of control and safety that seemed inconceivable even three years ago. Nevertheless, you will still encounter people who will “bro, u gotta build ur motor or ur gonna blow it” you. You may hear this often, and it’s unfortunate that these individuals have not kept up with the current state of tuning and engine management.
Remember this: Remnant Performance played a pivotal role in the creation and proliferation of the AlphaSpeed tuning network. That network grew as a result of tuning the very first Remnant Performance 70mm turbo kit, and that network now dominates the tuning scene for the Genesis Coupe. While there is still work to be done to decode more secrets in the ECU, the complete and rapid takeover of the AlphaSpeed tuner network makes it clear that they have the best understanding of the platform and that is what you will receive.
Buying a Remnant Performance turbo kit isn’t just a turbo kit. You are also buying into a knowledgeable network of people who are passionate about collaborating to make the Genesis Coupe a better platform. You will have on-demand access to a community that can answer practically any question about this platform and are invested in future R&D to grow the platform.
How do I install this kit?
Visit the step-by-step video series!
How does all of this piping fit together?
Turbos are divided into a “cold side” and “hot side.” The cold side is the vehicle’s air intake, which smashes boost into your puny motor. The hot side collects exhaust gases to spin the turbo faster, which makes the cold side spin faster--thus sucking in more air (boost). See “How does a turbo work?” to learn more.
The Cold Side
The flow of air starts behind your passenger side headlight and fog light, where the turbo’s impeller wheel sucks air into the system through a conical filter connected to the turbo with a silicone coupler. Once the air is in the cold side of the turbo (the “housing”), air quickly exits and heads downwards to the intercooler at the front of your car. Once the air is chilled by the intercooler, it then heads back upwards again on the driver side. Once the air has come up to the top of the driver side engine bay, it crosses back over to the passenger side of your engine bay and then towards the firewall, where it connects to the throttle body and intake manifold.
The Hot Side
Rather than just putting the exhaust of your car through your catback, a turbo collects those exhaust gases to spool the turbine wheel, thus sucking more air into the system. That generates boost. So you will see piping that collects exhaust from the engine, then merges it into a pipe that feeds the turbo. As the exhaust gas spools the turbo, it passes through the turbo’s hot side and exits out the rear where it is removed from the vehicle like normal exhaust.
Do I need a boost controller?
No boost controller is required to run the Remnant Performance turbo kit. The included wastegate will automatically open at 6 pounds (PSI) of boost.
But if you intend to build your motor and want a controller: the Grimmspeed manual boost controllers are your go-to option.
Do I need an aftermarket ECU?
You do not need an aftermarket ECU to run this kit. Tuning from AlphaSpeed was originally developed in support of the Remnant Performance Turbo Kit for the Genesis Coupe 3.8, and is a fine choice.
However, users looking to build their motor beyond the scope of the Remnant Performance kit do have some options.
BK1 Genesis Coupe: Owners can use the Haltech Platinum Pro or Elite 2500, and costs range from $1400-3500 depending on the needs.
BK2 Genesis Coupe: Owners can use the MoTeC M142 ECU, which is the only unit capable of controlling GDI on V6 or V8. Later in 2021, AlphaSpeed will be adapting their new "AlphaX" ECU for use as a piggyback alongside the stock BK2 ECU. OEM+AlphaX will enable all the benefits of Haltech on the BK1, including: flex fueling, multiple maps, supplemental fueling (e.g. piggyback MPI), progressive meth control, etc.
Do I need gauges?
Yes. Gauges are absolutely required for any engine running a forced induction setup, turbo or otherwise. Remnant Performance recommends the Plug & Play Turbo Gauge Kit, which was specifically designed for the Genesis Coupe running the Remnant Performance turbo kit. This kit is easy to install, and will provide you the important information: Boost PSI, air/fuel ratio (AFR), oil temperature, and oil pressure.
These gauges can be configured with red, white, green, or blue backlighting. You can also set warning thresholds for oil pressure and oil temperature. It is, by far, the easiest kit you can choose for your turbo conversion.
What oil should I use?
It is strongly recommended that you use AMSOIL SAE 5W-40 FS Synthetic European Motor Oil. 5W40 oil is slightly thicker than 5W30, making it more resistant to thinning out at higher temperatures or when exposed to inevitable fuel contamination. This will help protect your engine as you raise the thermal load on the engine with a turbo. Vehicles without diesel or gasoline particulate filters (DPF and GPF) can safely run the full SAPS ("FS") additive package to optimize detergent, wear, and antioxidance strength.
Recent 3rd party testsing suggests that Quaker State Full Synthetic 5W30 ("QSFS") is also an excellent choice if you need something from the store and/or cannot wait for shipping times.
NOTE: This oil advice assumes you’re running a stock Hyundai engine block. Customers with a built block will want to discuss the appropriate oil with their builder, as tolerances between metal components are different on a built block vs. stock block. This may necessitate a more viscous oil.
Lastly, there is ongoing work to assess whether or not Motorkote is a worthwhile additive for our heavy-duty uses. It had very favorable results in independent bearing wear testing via Project Farm.
What spark plugs do I use?
Your kit will come with 6x NGK 93819 (1-step colder) spark plugs. They should be manually gapped to 0.028" using a gap feeler gauge. Do not assume the spark plug is gapped correctly from the NGK factory, despite what their marketing tells you.
Are there any steps I can take to protect my engine?
Yes, there are FIVE new habits you should adopt as a 3.8T driver.
IDLE BEFORE SHUTDOWN
When you are done driving your car, sit at idle for 30-60 seconds before turning the vehicle off. Just check Facebook or respond to messages for a minute before turning the car off. This will help prevent “oil coking,” or burnt oil. This will ensure a long service life for your turbo and healthy oil.
NO TCS
Immediately after starting the car, get in the habit of disabling Traction Control System (TCS) by pressing the button below and to the left of your steering wheel once. Failure to do this could lead to a condition where your engine runs lean, leading to catastrophic engine damage. NEVER drive with TCS enabled. Please note that pressing the button once will leave Electronic Stability Control (ESC) enabled on the Genesis Coupe.
OIL EVERY 3K
Change your oil every 3 months or 3000 miles. Do not miss an oil change. 3mo/3K oil changes are your new religion.
WARM YOUR MOTOR
Do not try to go to full throttle+boost until the oil is warmed up to 150F or greater. Ideally, you will wait until it’s at operating temp of ~190F.
GET A MAP-ENABLED TUNE
Before completing your 3.8T install and tuning the vehicle, buy the components for a MAP Sensor-enabled tune. This will dramatically improve reliability and safety for your car.
What tools do I need to install this kit?
Customers are able to install this kit with nothing more than a set of metric socket wrenches, screwdrivers, wire cutters, a channel lock, a Dremel for cutting, and jackstands. But there are some additional tools that can make your life significantly easier.
A serious impact gun, e.g. Milwaukee 2763-20 Impact Gun (1/2" Drive)
A Dremel 3000 rotary tool with a large selection of cutting wheels
GearWrech Standard and GearWrench Deep Well metric sockets sets (1/2" drive)
Do you have any tips for me?
Converting a naturally-aspirated vehicle to forced induction (FI) is laborious and complicated. You should expect to spend 20-60 hours, depending on your mechanical skill, performing the conversion. In spite of the best-laid plans, it is certain you will run into trivial unforeseen issues. You must approach this project with a willingness to improvise, and an expectation that you will have to. Planning for the inevitable will help you overcome these challenges more quickly, saving time you would’ve spent on worrying!
Things to consider:
IMPROVISE: There will be brackets, mounting points, hoses, tubes, and other OEM engine components that you will need to move out of the way. Every Genesis Coupe is a little different in terms of fitment, so you should be prepared to stand back, take a deep breath, and think critically about how to free up the space you need.
If it's a hose: bend it a bit or ziptie it somewhere else.
If it's a bracket: unscrew it, move it, use zipties.
If it's a metal tab or mounting point: trim it down or cut it off.
If it's plastic: Trim it or remove it.
Just remember this section of the FAQ when you find that a pipe or hose won't fit where it needs to go. Stand back, chill, and think about what you can cut/bend/move in that area. Your car will be okay!
PREP WORK: There are several tools/fluids/adhesives that can make your life easier if you just buy them in advance so you don't have to run to the autoparts store every couple hours. Consider buying all of these:
O2 sensor socket, both shallow and long
A tub of Permatex copper anti-seize
Vibra-Tite Blue Gel threadlocker (much easier than Loctite)
An extra roll of PTFE thread sealing tape
1-2 cans of Pentosin CHF 202 to refill power steering
7 quarts of cheap 5W40 oil for break-in; you'll use this for ~300 miles and then change it
2-3 plastic paint scrapers to clean the oil pan of silicone
A box of assorted t-bolt clamps sized 7mm to 18mm
A box of assorted worm gear clamps sized 8mm to 44mm
Two rolls of Tesa 51036 tape
A roll of quality 3M electrical tape
An assortment of zipties with several lengths and widths
Permatex assembly lubricant (red)
Two adjustable AN fitting wrenches
An extra roll of DEI Reflect-A-Gold thermal tape
Two jugs of Asian blue formulation coolant
At least three cans of Brakleen
A 50-pack of shop rags
A few rolls of shop paper towels (e.g. Wypall X80)
An extendable 3/8" drive socket wrench with flexible head
Aerokroil thread penetrating fluid
If automatic: 2-4 liters of the right ATF
A 24" (or larger) prybar for shifting the motor
Brake caliper hangers
2x 50' rolls of exhaust wrap
A real Milwaukee impact driver, not a crappy cheap-o Makita/Ryobi model
- ENGINES MOVE: Some Genesis Coupes have a shifted front subframe. This will inhibit running hot side piping from the rear of the turbo to the undercarriage. A 24-36” prybar can shift the motor just enough to move the pipe past the headers.
- 2014+ A/C LINE: Cold side piping on a 2013 BK2 fit perfectly, but the air conditioning line on 2014+ will likely interfere with the cold side piping. You will need to buy and install a UAC HA112532C A/C line from Amazon or Rockauto and have your AC recharged when your car is up and running. Please take caution when working on A/C refrigerants.
CHECK TORQUE:
Confirm that the hex bolts securing the black tophats of your blowoff valve and wastegate are snug. These can sometimes loosen due to NVH, introducing a vacuum leak to your system.
All NPT fittings should be sealed with Loctite 243/Vibra-Tite Blue or Loctite 567. Tighten to finger tight, then rotate the fitting an additional 2.5 revolutions with a wrench.
All Dash AN fittings do not use tape or sealant. Tighten to finger tight, then rotate the fitting 90 degrees more with a wrench.
All V-band clamps should be tightened to around 31 INCH pounds, tapped with a rubber mallet to remove uneven tension, then tightened to a final torque of 45-55 inch pounds. NOT FOOT POUNDS. Tap with a mallet again and confirm 45-55 inch pounds.
Straight metric threads, such as your BOV and wastegate banjo bolts, should be sealed with Loctite 243/Vibra-Tite Blue, and tighten ed to ~35 ft-lbs. This is equivalent to "tight but not Hulk Strength" with a hand wrench.
- SAFETY FIRST: Once you’re installed, check your gauges and numbers!
- CLAMP BETTER: Consider using T-bolt clamps on the fittings for your power steering lines. The smaller hose is ~16mm OD and the larger hose is ~21mm OD. You will need 2x 20-22mm clamps and 2x 15-17mm clamps.
THE RIGHT RUBBER: If you plan to run an external transmission cooler assembled from your own parts, ensure you're using CPE or PTFE hose. Heater hose from your auto parts store is made with a different kind of rubber called EPDM. EPDM rubber is not rated for transmission fluid, and the fluid will weep through the lining. Bad news!
NEW NOISES: New things will rattle and make noise. Some well-placed exhaust wrap can fix these issues. Ziptie it in place on things that stay cold, metal ziptie it on things that get hot.
When in doubt: the Remnant Performance community is here to help you. The kit creators and/or installed customers have almost certainly encountered your hiccup before, and can easily help you overcome the challenge to continue your install.
DURING INSTALLATION
How do I install my catch can?
To start, it's a good idea to understand how an oil catch can is installed on a stock Gen; this lays the foundation for a better understanding of what to change for a turbo.
As you can see on a non-turbo 3.8, the outlet of the catch can is connected directly to the intake plenum. On a naturally aspirated vehicle, this will keep the crankcase under vacuum and/or no positive pressure. That’s the goal! This setup uses the vacuum from air sucking into the intake manifold to pull gases from the crankcase, separate the atomized oil, and circulate the clean air back into the motor. No more, no less.
Once you add a turbo to your vehicle, however, the turbo will raise the pressure of the intake manifold above atmospheric pressure (aka boost). This can cause boost pressure to travel through the catch can setup and into the crankcase. Positively pressurizing the crankcase with boost can--on some vehicles--cause oil to bypass the ringlands and enter the combustion chamber. This leads to ugly blue smoke, nasty smells, oil consumption, and carbon deposits on the pistons/cylinder. Not every vehicle experiences this phenomenon, but it can happen under hard driving and it’s better to be safe than sorry.
That’s why, on a turbo car, the outlet of the catch can should be connected IN FRONT of the turbo. As the turbo sucks air into the engine, the suction effect also pulls clean air from the catch can and provides the negative pressure (vacuum) expected by the crankcase and PCV system. The entire crank vent system returns to experiencing only vacuum or atmospheric pressure, which is the designed behavior.
How do I install my wastegate correctly?
UPDATE: There is now a video install you can watch, if you would prefer.
How do I assemble the oil filter adapter?
You should watch the "Everything Oil" video for detailed instructions on assembling the oil filter adapter and housing. This is one of the most crucial stages of the installation, and you should be very familiar with the process before proceeding.
However, some of the adapter fittings in the kit are not immediately obvious. The below diagram will assist in final assembly.
Where do I run my vacuum lines?
You can follow this instructional video to route your vacuum lines. The basic architecture is: vacuum block to intake manifold. Wastegate, blow-off valve, boost gauge sender to vacuum block. At no time should you run vacuum lines to other devices or locations, except to add boost-actuated exhaust cutouts or a boost controller. When it doubt, ask the Remnant Performance community.
How much oil will I need, and how do I prime my turbo?
When initially filling the vehicle after installing the turbo, you will need to add the usual (approx.) 5 quarts into the motor, then fill up the oil cooler and attach the lines. Now you will need to take new and special steps to account for the larger oil capacity added with the turbo and oil lines. Start by removing the fuel pump relay and ignition coil (IGN coil) from the fuse boxes in the engine bay (see diagram below).
With these removed, you can crank the motor and run the oil pump without starting the car. This process is known as "priming the turbo." Priming is absolutely essential to turbo health, as it ensures the turbo is full of fresh oil before starting the vehicle and running the turbo for the first time.
To prime: crank the car 4-6 times, each time until the car automatically stops cranking. Once you have completed the first round of priming, check your oil level again. If the oil level is not at the full marker on the dipstick, add more until full.
Repeat priming and checking until the oil level remains at the full line after priming. You are now ready to reinstall the pump relay and ignition coil fuse, reinsert the dipstick, and start the car. Ultimately, you will add 6.0-6.5 quarts of oil to the vehicle.
Oil Changes: You should drain the oil cooler and oil pan when performing oil changes. Fill both with fresh oil. It is advised that you repeat the turbo priming process to ensure fresh oil makes it into the turbo before starting the car again. Oil changes will require ~6qt capacity to hit the full mark, but you should buy 7 quarts with your first real oil change to make sure you have enough. After that, you'll get a sense for what your engine really needs, and you can likely buy less oil for a change.
AFTER INSTALLATION
I installed my kit. Can I drive my car, now? (Spoiler: NO)
Absolutely not! Upon completion of your turbo install, your car must not be driven until you have contacted an AlphaSpeed tuner and had your ECU reprogrammed with a basic turbo-ready file. The Remnant Performance community can assist you with this step. You can, however, start your vehicle in park/neutral and confirm proper installation with the Vacuum, AFR, and Fluids steps outlined in the next question.
Driving your car before you are tuned will almost certainly cause you to catastrophically damage your engine. Below is an example. This is what could happen to your engine if you attempt to drive the vehicle BEFORE your vehicle has been tuned with the turbo. Seriously. Don’t drive your turbo’d car until you’ve contacted a tuner and get the all-clear.
How does tuning for 3.8T work?
Tuning operates in a few simple stages:
A “base map” will be flashed to your car’s ECU. The base map contains generic parameters for running a turbo, but will not be highly optimized for your particular engine. It will not account for any mods that you have beyond the turbo. It’s a conservative/safe “one size fits all” solution for the purposes of driving the vehicle to create a better tune.
You or your tuner will conduct a few high-speed pulls in 3rd gear or 4th gear. Pulls are five seconds in duration at wide-open throttle (WOT) from a 20MPH rolling start. During this time, video will be taken of your gauges, and a computer will be logging data from the engine.
This video and engine data will be sent to AlphaSpeed HQ where another tune file is generated for your car. It will be customized for your engine, in your car, with your fuel and your mods.
This new tune is flashed to your ECU, overwriting your base map.
You will once again conduct the pulls described in Step 2, which may or may not result in another round of tune customization to dial in the performance and safety. If no further customization is required, you’re tuned! The final custom tune is more aggressive than the base map, but remains relatively conservative to factor in unknown variables like: old oil, hot days, lower quality fuel, etc.
It is also possible (in rare cases) that the base map is sufficient for your vehicle, as the base map has become increasingly sophisticated and dialed-in over the last 18 months. Don’t be alarmed if this happens.
You should arrange for tuning with your local AlphaSpeed dealer after completing your installation. You may have to tow your vehicle to the location. Some tuners will make house calls if they live nearby. Some tune dealers can send you a remote tuning kit in exchange for a monetary deposit; the kit will help you perform steps 1-5 on your own wherever you are. The Remnant Performance turbo kit chat can help you identify your closest AlphaSpeed tune dealer.
If all else fails: you can drive your 3.8T to the tune dealer ONLY IF YOU NEVER TAKE THE CAR INTO BOOST UNDER ANY CIRCUMSTANCES. This means you are driving like the gentlest, most saintly driver that has ever lived. Your foot is a feather on the pedal. You don’t even know what racing is. You’ve forgotten how to go fast. You annoy everyone behind you with how slowly you leave the stop light. You never do anything that takes your boost gauge above the 0 PSI mark. Failure to follow these instructions could kill your motor.
Note A: The custom tuning process will last 30-60 minutes, and you better make damn sure your car has no leaks before undertaking a tune. Any exhaust leaks, vacuum leaks, or fluid leaks will compromise the quality of the tune and deliver substandard results. Worst case: the errors in your installation may actually risk the health and safety of your motor.
Note B: The custom tuning process differs from a “canned tune,” which is an optimized tune that’s generally safe for any Genesis. A canned tune will enable better performance than stock, but leaves considerable performance on the table that might be harvested from your particular vehicle configuration. It’s also not an appropriate solution for a turbo conversion, where more attention to detail is required.
Note C: This tune is nothing like a tune for a naturally-aspirated (NA) Genesis Coupe. If you are already tuned, this tune will be replaced entirely with a new set of turbo-optimized parameters.
Note D: If you have a Remnant Performance MAP sensor adapter and a 2.0T MAP sensor, do not install them until you are at the tuner. Your car will not be drivable with these components installed until the tune is complete.
How do I verify my kit is installed correctly?
There are four ways to functionally confirm proper installation.
FLUIDS
There should be no indicator of fluid leak anywhere on the vehicle. You will be relocating many reservoirs and lines in your engine bay, and it’s vital that these are clamped tight and leak-free. Oil is the most important and complicated of all the fluids, and great care is required to ensure a smooth install. The Remnant Performance community can help you troubleshoot leaks. Pay extra special attention to:
- Your oil filter housing, and the sensor ports in the housing.
- Your power steering lines.
- Your transmission lines (if AT with a cooler).
- The oil feed and return lines to the turbo.
- Your oil pan.
VACUUM
At idle with a warm motor, your boost gauge should read -17 to -20 inches of mercury (in. Hg) in vacuum. All engines are air pumps, so they create negative pressure until you spool the turbo and achieve boost. If your car is reading closer to 0 than -17 in. Hg, you have a vacuum leak that will inhibit performance and/or prove dangerous to your car. This typically indicates that the silicone hoses you installed to/from your vacuum block are not secured tightly enough, or your catch can is not clamped tightly enough. The Remnant Performance community can help you troubleshoot this.
Additionally: make sure your air conditioning isn't running when you do this vacuum test. It will raise your vacuum closer to 0 and can cause you to think there's a problem.
BOOST
After an AlphaSpeed tuner flashes the base map (basic turbo programming) to your ECU, your car should be able to rapidly hit and hold 6 PSI. Flashing a base map is the first step in the custom tuning process, and you should not drive your car until this step is complete.
It should not fall short of 6 PSI, taper off, or struggle to reach 6 PSI. In fact: it should peak slightly above 6 PSI at max boost and level off at 6.0. If your car is not rapidly building 6 PSI and holding it, you have a boost leak.
Struggling to hit boost typically indicates that your piping is not secured properly: loose clamps, flanges not flush or tight, piping not snug in the coupling sleeves, etc. The Remnant Performance community can help you troubleshoot this.
AFR
As an additional troubleshooting step, you should also be holding 14.3-15.0 AFR when parked at idle. This will confirm you have no exhaust leaks. ANY VALUE OUTSIDE OF THIS RANGE MEANS YOU HAVE AN EXHAUST LEAK THAT MUST BE FIXED BEFORE YOU TUNE THE CAR. DO NOT OVERLOOK THIS.
When tuned, you should also be holding ~14.7 AFR when cruising. Values around 16 indicate you have an exhaust leak, and the car is taking in more air than it should from another source beyond the throttle body.
During a WOT pull, the car should run ~11.5 AFR. Values equal to or greater than 12.4 under WOT indicate an issue.
What are the expected oil pressures during use of this kit?
During breakin on 5W30 conventional, you should expect to see oil pressures of:
- ~70 PSI on a cold start if the weather is colder than 50°F/10°C, falling to…
- ~45 PSI on a cold idling engine
- ~20 PSI on a warm idling engine
- 90+ PSI for hard throttle
- NOTE: Add around +10 PSI to these values for 5W40 full synthetic.
These values will fluctuate based on the original quality control (QC) of your engine, oil age, oil viscosity, and a few other variables.
TIP: You should set the oil pressure warning PSI to 16 PSI, which will sound an alarm if you have an oil leak that has compromised your oil levels. This advice only applies if you are using the plug’n’play gauge kit that is offered on the Remnant Performance store.
My oil temperatures increased! Is this normal?
Yes, perfectly normal. A stock 3.8L Genesis Coupe typically runs oil temperatures circa 170°F/77°C. Adding a turbo will increase the thermal load on the engine, further warming the oil. It will not be uncommon to encounter cruising oil temperature of 190°F/88°C and oil temperatures of ~210°F/99°C. If doing multiple hard pulls, you should give the oil the opportunity to cool down.
What fuel should I use?
Remnant Performance recommends U.S. 93 Octane (or local equivalent) for best performance. Once you are tuned, you should always use that specific fuel in your vehicle. For example: do not get tuned with U.S. 93 octane in the gas tank, then fill up later with 91 octane.
It’s worth noting that “93 octane” is not the same in every country. To learn more, please read about MON, RON, and AKI ratings. Your 101 or 104 octane might not be as good as you think.