Intro
If you've seen my previous thread: [How-To]: 3.8 Performance Upgrade Path Then you know I've been trying to get more from this engine for a long time. I've had so many people contact me over the forums, Facebook, and in person at events, telling me they based their build on my work and I usually hear, "I've done everything on your list except A, B, C but I'm doing those next!". I appreciate all of the feedback and comments too!
I've learned so much more since I wrote that last guide and now it's time for a serious update! This is the 3.8 Performance Upgrade Path V2. I will include both BK2 and BK1 relevant items and will include more drivability mods as well. There will be some new stuff, some old stuff, and some changes in opinion from the last write-up. I'll also include info on mods that people ask about and provide info on whether you should consider them or not.
So, here is my latest dyno result. 346HP / 292TQ
![Image]()
Preface
I've spent the last 3 years working on different things to try out. I've spent countless hours on the dyno, under the car, in the engine, in books, talking with tuners, etc to get ideas and test them out. My goal has always been to help the average 3.8 owners build a fun, well-rounded car and get the most from it with the budget they have. I've been hassled about not just doing a turbo build and that's the common response when someone asks how to get more from their build. Sure, if you're looking for the maximum power possible, a turbo is the way to get there.
I see a lot of guys spending money in the wrong places and buying incorrect parts. There is a lot of misinformation and a lack of understanding about how things work and I always try to improve that with facts and data and prove it all using my own vehicles.**
Goals
Not everyone is looking for a 700whp monster and to be honest, most Genesis owners couldn't handle it anyway. Some people like canyon runs, autocross, or road courses. Not everyone wants to do freeway pulls or 1/4-mile runs. So there is really no one correct answer to building a car because it's all personal and based on your goals and budget. Build the car based on what is important to you.*
As stated, my goal is to give the information needed to build a fun, well-rounded car with max gains without breaking the bank and for the most part, that will be good enough for most. I'll have Turbo build information down below as well as info on other power adders.
Setting Expectations
I want to clear up some things that are not well understood. If you are following someone else's build, there is no way you will make more power than they did unless you go above and beyond what they did. I bring this up because it's getting far more common to hear people claiming numbers because they feel good to say. You are welcome to say whatever you want, but you will need to have definitive data to back up your claims. Please don't make statements without proof because it leads to newer guys getting their hopes up and then getting disappointed.*
I do believe there is far more to get out of these 3.8s, but FBO + custom tune builds will always net around the same power levels. So, if no one has made 400whp with FBO, then you shouldn't expect yours to do so either. There is a great thread with all sorts of dynos and mods here 2013+ V6 Dynos*so you can see realistically what to expect. It's also a fun thread to see the progression of the power levels over the years.
The Sad Truth
Ever hear, "your car was made on a Friday"? I have. I've had a tuner tell me that I must have bought a Friday car when his tune was sh*t and I proved it to him with data logs (previous car, not the gen). Well, if you're not familiar with this, it means that you got a car that was assembled on a Friday when no one cares because they're thinking about the weekend so basically they produced sh*t.
This applies to the Gen Coupe 100%. The inconsistency in these motors is just amazing. Take two 2014 3.8s and one might make 10-15 more than the other with the exact same mods and tuning. Some 3.8s don't last long under abuse (Friday car) and others take the abuse and ask for more (Monday car). A Monday car, meaning everyone is refreshed after their weekend so they assemble the car with extra care, is what you want to have.
It's the sad truth, but the absolute garbage QC that Hyundai does is scary and makes these cars vary wildly. You could have a Friday car while your buddy has a Monday car so don't be surprised if he makes more than you or is faster with the same mods. You can see what I mean with this thread here: http://www.gencoupe.com/3-8-v6-discussion-2013-up/651265-free-power-look-hyundai-s-sh-t-qc.html. Taking care of these issues can go a long way.
Mod Stacking
Mod stacking is a very misunderstood concept. If you took a 100hp stock engine and added 5 mods that each claim to add 10hp, you would not end up with 150hp in the end. You'll most likely end up with 120-130. Why? Because those numbers you see advertised are all taken against a stock setup when it's most sensitive to change (least efficient). The more mods you add, the fewer gains you'll get from each mod because the efficiency of the engine is increasing with each previous mod, so you have diminishing returns.
Not only that, even if it was dyno proven that a mod showed a gain of 10hp, it doesn't mean your setup will also see that same 10hp gain. Remember, companies selling products work hard to get the conditions absolutely perfect to get the best results because it means more sales.
Comparing Dyno Sheets
Dynos are tools. They should be used only to test before/after changes for your particular car and the same dyno should be used always. Comparing your dyno to someone else's dyno is a fun game, but it's little more than penis-wagging and the data is meaningless. The type of dyno used and how that dyno is set up plays the most important part in the numbers reached so you might make 300whp on one dyno and 500whp on a different dyno.
Peak Power vs The Curve
Too much emphasis is placed on peak power. The overall curve is what you should really be concerned about. There are plenty of 500whp cars that are slow as hell because they are peaky and have almost no curve. So just because your friend has 350whp and you only have 330whp doesn't necessarily mean he'll beat you in a race.
Which curve do you think would be the best curve for street use and which do you think would be best for advertising?
![Image]()
If you've seen my previous thread: [How-To]: 3.8 Performance Upgrade Path Then you know I've been trying to get more from this engine for a long time. I've had so many people contact me over the forums, Facebook, and in person at events, telling me they based their build on my work and I usually hear, "I've done everything on your list except A, B, C but I'm doing those next!". I appreciate all of the feedback and comments too!
I've learned so much more since I wrote that last guide and now it's time for a serious update! This is the 3.8 Performance Upgrade Path V2. I will include both BK2 and BK1 relevant items and will include more drivability mods as well. There will be some new stuff, some old stuff, and some changes in opinion from the last write-up. I'll also include info on mods that people ask about and provide info on whether you should consider them or not.
So, here is my latest dyno result. 346HP / 292TQ
Preface
I've spent the last 3 years working on different things to try out. I've spent countless hours on the dyno, under the car, in the engine, in books, talking with tuners, etc to get ideas and test them out. My goal has always been to help the average 3.8 owners build a fun, well-rounded car and get the most from it with the budget they have. I've been hassled about not just doing a turbo build and that's the common response when someone asks how to get more from their build. Sure, if you're looking for the maximum power possible, a turbo is the way to get there.
I see a lot of guys spending money in the wrong places and buying incorrect parts. There is a lot of misinformation and a lack of understanding about how things work and I always try to improve that with facts and data and prove it all using my own vehicles.**
Goals
Not everyone is looking for a 700whp monster and to be honest, most Genesis owners couldn't handle it anyway. Some people like canyon runs, autocross, or road courses. Not everyone wants to do freeway pulls or 1/4-mile runs. So there is really no one correct answer to building a car because it's all personal and based on your goals and budget. Build the car based on what is important to you.*
As stated, my goal is to give the information needed to build a fun, well-rounded car with max gains without breaking the bank and for the most part, that will be good enough for most. I'll have Turbo build information down below as well as info on other power adders.
Setting Expectations
I want to clear up some things that are not well understood. If you are following someone else's build, there is no way you will make more power than they did unless you go above and beyond what they did. I bring this up because it's getting far more common to hear people claiming numbers because they feel good to say. You are welcome to say whatever you want, but you will need to have definitive data to back up your claims. Please don't make statements without proof because it leads to newer guys getting their hopes up and then getting disappointed.*
I do believe there is far more to get out of these 3.8s, but FBO + custom tune builds will always net around the same power levels. So, if no one has made 400whp with FBO, then you shouldn't expect yours to do so either. There is a great thread with all sorts of dynos and mods here 2013+ V6 Dynos*so you can see realistically what to expect. It's also a fun thread to see the progression of the power levels over the years.
The Sad Truth
Ever hear, "your car was made on a Friday"? I have. I've had a tuner tell me that I must have bought a Friday car when his tune was sh*t and I proved it to him with data logs (previous car, not the gen). Well, if you're not familiar with this, it means that you got a car that was assembled on a Friday when no one cares because they're thinking about the weekend so basically they produced sh*t.
This applies to the Gen Coupe 100%. The inconsistency in these motors is just amazing. Take two 2014 3.8s and one might make 10-15 more than the other with the exact same mods and tuning. Some 3.8s don't last long under abuse (Friday car) and others take the abuse and ask for more (Monday car). A Monday car, meaning everyone is refreshed after their weekend so they assemble the car with extra care, is what you want to have.
It's the sad truth, but the absolute garbage QC that Hyundai does is scary and makes these cars vary wildly. You could have a Friday car while your buddy has a Monday car so don't be surprised if he makes more than you or is faster with the same mods. You can see what I mean with this thread here: http://www.gencoupe.com/3-8-v6-discussion-2013-up/651265-free-power-look-hyundai-s-sh-t-qc.html. Taking care of these issues can go a long way.
Mod Stacking
Mod stacking is a very misunderstood concept. If you took a 100hp stock engine and added 5 mods that each claim to add 10hp, you would not end up with 150hp in the end. You'll most likely end up with 120-130. Why? Because those numbers you see advertised are all taken against a stock setup when it's most sensitive to change (least efficient). The more mods you add, the fewer gains you'll get from each mod because the efficiency of the engine is increasing with each previous mod, so you have diminishing returns.
Not only that, even if it was dyno proven that a mod showed a gain of 10hp, it doesn't mean your setup will also see that same 10hp gain. Remember, companies selling products work hard to get the conditions absolutely perfect to get the best results because it means more sales.
Comparing Dyno Sheets
Dynos are tools. They should be used only to test before/after changes for your particular car and the same dyno should be used always. Comparing your dyno to someone else's dyno is a fun game, but it's little more than penis-wagging and the data is meaningless. The type of dyno used and how that dyno is set up plays the most important part in the numbers reached so you might make 300whp on one dyno and 500whp on a different dyno.
Peak Power vs The Curve
Too much emphasis is placed on peak power. The overall curve is what you should really be concerned about. There are plenty of 500whp cars that are slow as hell because they are peaky and have almost no curve. So just because your friend has 350whp and you only have 330whp doesn't necessarily mean he'll beat you in a race.
Which curve do you think would be the best curve for street use and which do you think would be best for advertising?
. My friend is looking for something similar fun quick reliable DD he can have fun messing around with other quick cars on and off track. And something he can have fun building making it better than stock. However he isnt quite as dedicated or savy mechanically or with electronics. Hence why im the one researching this XD because I understand it. Im not sure if he started with this platform how excited he would be after we start with a few bolt ons and its not that noticeable a difference between stock. 
