How To BUILD a 900+ Horsepower BMW M4 (STOCK MOTOR)

Added: 2026-05-21

[00:00:00]Today in the shop, I have Miguel's G82 M4. And in this video, I'm going to walk you through everything you need to do to achieve over 900 horsepower to the wheels on a stock motor G8X. Now, from the factory, BMW promotes that the M4 Competition has 503 horsepower and 479 pound- feet of torque. So, instead of taking BMW's word for it, let's put it on our in-house dyno and get a baseline of our own.

[00:00:37]Heat up here.

[00:00:57]All right. If you take a look over here at our dyno screen, you can see that our horsepower is around that 468 horsepower mark. And for the torque, we're closer to like 498 if I do the quick math in my head. Now, you're going to notice that the horsepower is a little bit below what BMW advertises. Yet, the torque is going to be a little bit more. And the reason for that is while this is on 93 octane and while has a bone stock tune, it does have an aftermarket downpipe on it which oftent times will give you a little bit of torque, but without proper tuning can also rob you of horsepower at the same time. Now, in today's video, we are going to be taking this car to 900 plus horsepower. But we know that there's a lot of you that maybe 900 is not your goal. Maybe 600 is, 700, 800.

[00:01:38]So, what we're going to do is we're going to talk about a lot of different things and show you how to achieve most of these milestones while we're building Miguel's car. First things first, let's talk about what needs to happen to get near 600 horsepower. All right, so to hit near 600 horsepower, there's four main things that we recommend. The first thing you're going to need to do is you need to unlock your DME. Now, Miguel's is already unlocked because we took care of that earlier today. And if you're not aware of what that even is, basically BMW locks down the DME, which is the ECU that's responsible for everything related to engine tuning because they don't want you to have fun, but we want you to have fun. So, we now offer a service where we can unlock these here in the United States. For more info on that and everything else we're talking about in today's video, we have links for you detailed down in the description below. Once you have the car unlocked, which we've already done to Miguel's car, you can then apply a tune. For Miguel's car, the tune solution that made the most sense was boot mode, and we're going to be running their OTS stage 2 map. Now, with a stage 2 map, you do need a downpipe. If you want to run stage one, you don't need any other hardware. With this one, it just makes sense because he already has the downpipe. So, now that we have a way to tune the car, we have a way for the exhaust gases to free flow out of the car. The other constriction is going to be the intake, the opposite side of the turbo. So, to combat that, we're going to also be installing a carbon fiber intake. It's going to allow the car to breathe easier to make sure that he can make as much power as possible. And hey, it's carbon fiber. It's going to look freaking awesome. So, let's get started by installing our carbon fiber do88 intake. Then, I'm going to flash the car with boot mode stage 2 93 octane. And then we're going to run the car again right here, right now.

[00:03:37]Heat.

[00:03:43]Heat.

[00:04:00]Heat up here.

[00:04:15]All right, on our boot mode stage 2 map on 93 octane with a downpipe and a DO88 carbon fiber intake, you can see we went really close to that 600 horsepower goal. Now, keep in mind this car is all-wheel drive. If this was a rear wheel drive M4, 600 all day long. So, for the horsepower, you can see we range from about 592 up to 598. Great numbers again on 93 octane. And then for the torque, we're around that 580 pound- feet of torque. We're up roughly 80 or so over there. And with the horsepower, we're up from again that 468, 469 to almost 600. Now that you know how to land yourself near 600 horsepower, let's go back to the shop and we'll talk about how to hit 700.

[00:05:13]All right, so to bump up to that next level, there's two things that you absolutely must do at this point in addition to what's already on the car.

[00:05:20]And then there are a couple other suggestions that would be really good to have, especially for longevity and making sure that everything is as reliable as possible. The first thing you're going to need is you're going to need a flex fuel kit. This is the one from Protuning Freaks. We install these all the time and they work great. What they do is they analyze the fuel in your fuel line to determine if you have E85, if you have 93, or a blend of both. On these cars running a flex fuel sensor and the accompanying boot mode tune, you can easily run E40, which is 40% E85.

[00:05:49]Just by going to that number alone, you're going to be very close to, if not hit, 700 horsepower to the wheels. We see it time and time again. Now, one thing to keep in mind is that this car came with under 500 horsepower to the wheels, and we're going to take it to 700 horsepower roughly on the dyno to the wheel. That being said, since we're jumping up about 200 horsepower, you really need to start thinking about your spark plugs, and you want to go to a colder plug. For these cars, we typically run these guys. These are the NGK Aridiums. This is the 96206, and we recommend gapping these to 022. I run the same exact setup on my 1000 horsepower G80 M3, and it works flawlessly. The reason for this specific plug and also the specific gap is to reduce the chance of misfires because especially when you're pushing your car, you do not want to misfire because that could cause serious issues. So, that being said, the flex fuel kit and also the spark plugs in addition to everything on the car is going to get you really close, if not past that 700 horsepower mark. But, while this is everything that is required, we do have a couple suggestions on what you should be doing to make sure that your car has a long, strong, and healthy life. The first thing we recommend is a transmission cooler. This one here is from DO88. It has a 71% larger cooler than the factory. Where this comes in handy is that especially in the summer months when everything is hot. When you're running your car at the track, one thing that is very common is that you can get an alert on your dash that says your transmission is overheating.

[00:07:12]You never ever want to see that at all because the more heat you have in your transmission, the more wear and tear you're going to see on your clutches and it's basically going to lead to an early death to your transmission. You do not want this to happen. I have a transmission on the other side of this wall that experienced a very similar failure and it blew all of the clutches in the transmission on an X5M. You do not want that to happen at all. Now, after you figure out the cooling for your transmission fluid, the next fluid that I recommend cooling is going to be your engine oil. This is an engine oil cooler from DO88. It sits underneath the car and this one here specifically has a 57% larger core to make sure that your engine oil is staying as cool as possible. Keep in mind when you're adding several hundred horsepower to your engine, you have a lot more heat that's being generated. So having something like this DO88 engine cooler is going to help preserve and protect your stock engine. Next up at this power level, we recommend changing out the charge cooler. This one is from DO88. It does come black. This one was powder coated just to match the turbo and some other things that are going onto the car. What's great about this is it has a 62% larger core. It's going to make sure that all of that air off that hot turbo is properly cooled to make sure that you have the best power possible. Another huge benefit of this is that, as you can see, it is all aluminum. The factory one has this metal cooler that's crimped onto these plastic parts. And what we've seen is once you start to go above this power level, some of them can separate and cause boost leaks and other issues.

[00:08:34]Another thing that comes in very handy, especially as you bump up the power or if you want to run full E85, it has these additional spots over here. This is for secondary fueling, which we are going to utilize. And then underneath there's these 8 in NPT ports. You can use water methanol injection or something like nitrous if you so desire.

[00:08:51]All right, next up on our recommended parts list for hitting 700 plus horsepower is going to be a charge pipe.

[00:08:56]This one also is from DO88. And as you can see, it is a giant piece of aluminum. The one on the car from the factory is plastic. And over time, especially when exposed to a lot of heat because it's bolted to the engine, you could easily experience cracks and boost leaks over time. But besides that, one thing that we're seeing right now on the factory charge pipe system is with the rubber hoses when you start to turn up the boost. A lot of times what we're seeing is inconsistencies in tuning as they start to expand and contract, making it a little bit difficult to fine-tune some of these cars. By adding this, all of those problems are solved.

[00:09:28]And you also have two additional 8 in MPT ports if you want to run something like methanol injection right into the charge pipe. The next thing that we recommend doing is an XHP transmission flash. These are absolute game changers.

[00:09:40]It is instead of an engine flash, it is for your transmission. It's going to get rid of a lot of the torque limitations, which is going to limit the power potential of your car. It's going to make your car shift faster, and most importantly, it's going to prolong the life of your transmission by increasing the clamping forces on your actual clutches. Without this, what's going to happen is you're going to experience a lot more wear and tear on your transmission. Additionally, this was my secret weapon when I first broke into the 9 back when I had 700 horsepower on my G80. I was stuck at 100. I flashed it with XHP and with that additional clamping force, the speed of the transmission, and all of the other great features, I was finally able to break into nines for the first time.

[00:10:17]>> We got a 98. Yes.

[00:10:20]>> Now, speaking of racing, he's got Continentals. Great tires.

[00:10:25]>> Na.

[00:10:25]>> As you can see, these are the Nysa. I like to call them NISA cuz they're so nice.

[00:10:31]>> Nice.

[00:10:32]>> 3 2 >> All right. Now, toe. All right. Speaking of racing, there's one more thing that we recommend at this power level, and it is tires. Because while he has great allseasons on the car, he's never ever going to hook at the track. And that's why we have a set of Mickey Thompson ET Street SS's wrapped around some Apex VS5RS lightweight racing wheels. With this combination, he shouldn't have any traction issues at all. All right, so once again, in addition to what's on the car, to get to that 700 horsepower level, you need an ethanol analyzer kit with the appropriate tune and these spark plugs. Everything else here is also great to do because it's going to make sure that your car is as reliable and fast as possible. Now, while 700 is a great number and will easily put you in that 9sec 1/4 mile range, let's talk about 800. Now, the bare minimum at this point to achieve 800 wheel horsepower is going to be take everything we talked about and add a set of hybrid turbos.

[00:11:24]Now, I want to reiterate, we are talking about a stock motor S58. At this point, if you guys watch the channel, I have a set of pure hybrids on my G80, which does have a built motor. We do 1019 to the tire. I do not recommend doing that on a stock motor car. That being said, hybrid turbos are a very cost-effective, great way to get additional power. And I've run them on tons of my cars. Now, while this is the basic necessity on what you need to do to hit this power, I do recommend at this point that you do full cooling. As you can imagine, we have more DO88 coolers. We have the OX coolers. These two coolers sit on the corner of your front bumper and make sure that everything is staying nice and cool. And we also have a DO88 heat exchanger. Now, we've talked about a lot of DO88 parts. The reason that we're using on this car is they're very effective, and they're also one of the most affordable options on the market, and they also make a package where you can basically get every cooler that you need in addition to the charge pipe and intake at a low price. It's just a great deal, especially if you're going to be chasing these high numbers. Now, as you start to reach low 800s, what's going to start to happen if you're still running on E40, your fuel system is basically tapped the heck out. And what you need to do from there is start to look at fuel system upgrades on these cars, especially when we're running a charge cooler with secondary injections. What we will typically do is run something like a Precision Raceworks AFS kit. This is the 460. Basically, what it does is it leaves your stock pump to power your factory injectors. We don't touch any of that. We leave the stock high-pressure fuel pump and stock injectors with the stock fuel pump. And then in addition to that, we have a secondary fuel pump. and its only job is to power the six new injectors we're going to be installing.

[00:12:58]For the actual fuel injector, we use these guys over here. These are from fuel injector clinic. These are 1000cc and it's going to give Miguel all the fuel he needs for his port injection.

[00:13:06]But as you can see, there's nothing from the factory that plugs into these aftermarket injectors, which is where something like the Rev 2 comes in. Now, what I love to do is when there's a software solution and they make a hardware component, it just makes the most sense to use them because they're going to work handinand together. By using a Rev 2. This is essentially acting like a secondary DME that's fully integrated with the factory DME to do things like control your port injection, control your flex fuel, and also has a ton of other safeties to make sure that your motor and you stay safe out on the track. Now, speaking of safeties, while we do recommend things like an XHP transmission flash, what starts to happen is regardless of what software, your transmission will start to slip.

[00:13:45]So, at this point around that 800 horsepower mark, if not even a little bit sooner, we do recommend having an upgraded transmission, which has already been taken care of off camera. Now, one last thing. If you start to run things like full E85, the turbos definitely have capability to take the car over 1,000 horsepower. One of the things that you have to talk about with your tuner is what power level they feel safe with hybrid turbos at. The problem and also benefit of hybrid turbos is they come on super fast and super aggressive. They are super responsive. The problem with that is that if it's not properly tuned for a stock motor situation, you can bend your rods and have a very bad day.

[00:14:22]Which is why for Miguel's car, we're going to be running a slightly different turbo as we chase 900 plus. For his car, we have a Doc Race single turbo kit and we're going to be running a precision 7275, which is capable of well over 1,000 horsepower. So, achieving 900 plus on his stock motor is going to be no problem. Now, the reason that it's a lot safer to run a big single turbo with these high horsepower numbers is because while they're not as responsive as hybrids, it's going to move your power band down. Your torque is going to come in later, which is going to be much safer for your rods. Then after that, the last piece of the puzzle is really to fill it up with E85 and get a custom tune so that we can dial all of this in.

[00:15:00]Now, while there are other things you can do, you can do a drive shaft, you can do axles, you can do a diff brace, you can do a built transfer case, there are endless things that you can do, this video is meant to be just a general baseline. If you guys have questions about your specific build, whether it's a G8X car, it's a Supra, it's a Porsche.

[00:15:17]You can always reach out to our team and we can walk you through exactly what we recommend for your specific power goals.

[00:15:23]We tried to make this video as general as possible for stock motor. And like I said, there's a thousand different configurations, but I hope you guys are finding this helpful. So, now it's time for me to get all of this installed.

[00:15:33]Then we'll take it back to the dyno and do a full custom tune.

[00:15:50]Anyone else's shoe wet? Just asking for a friend. Why is it clear?

[00:16:23]>> Well, it's not right. All right. So, it's a little concerning. All of your coolant is not green.

[00:16:30]And you didn't have very much of it.

[00:16:57]Heat up here.

[00:17:30]That was like a stud a stud snapper right there.

[00:17:51]Heat up here.

[00:18:05]Heat.

[00:18:22]Heat.

[00:18:29]Heat.

[00:18:43]Heat.

[00:19:07]Heat. Heat.

[00:19:25]We are about to put in what Brian says is my biggest fan.

[00:19:30]>> They ask you how you are, you just have to say that you're fine when you're not really fine.

[00:19:39]Heat. Heat.

[00:20:15]Heat.

[00:20:19]Heat.

[00:20:40]Heat. Heat.

[00:21:12]All right. And just like that, a couple days later, everything is done with a couple bonus mods. So, before we hit the dyno, let's do a quick walk around and I'll show you exactly what we did. All right, let's start under the hood. Being that we're trying to hit 900 horsepower, the first thing we did was we ordered a Dock Race Precision NextG 7275 turbo.

[00:21:29]The cool thing about this turbo is that it's great for street use, it's not too laggy, although all these big turbos do have some lag and it's also going to be an absolute monster at the track. I will say this dock race kit is one of the best fitting kits that I've ever installed and it looks absolutely incredible. Now, as you can see, the turbo is now over here, which is where the coolant tank was. So, one of the things that we had to do, and they include all the lines to do this, we had to reroute it over there. And it's funny because it's very natural looking unless somebody said, "Hey, we moved the reservoir from here to over here." A lot of people wouldn't even notice. One of the other things that people might not notice is that we had this painted man green to match the car. Just a little subtle thing that 99% of people aren't going to notice, but I think it looks super cool. It was actually on my car before this. So, another thing that I forgot to mention because it fits so good is that the Dock Racing kit includes a catch can. It sits over here.

[00:22:20]They have this really cool bracket and it fits absolutely perfect. What also fits perfect is everything behind this bumper. Not only did we do a DO88 cooler up top, we did the ox cooler. So, we have the one on the driver's side, the passenger side, we had the heat exchanger, the transmission cooler, and also the oil cooler. Everything fit absolutely perfect and I didn't have to modify a single thing. Over here you can see we have our Keys carbon executive line brace. One of the cool things about these is that with most of these turbos on the market, they do clear. Some of the braces that you'll find will hit the turbo and you can't use it. For most of these from the KLMs, the Dock Race, and so many others, our brace does provide the clearance that you will need for these turbo kits. And since we had carbon with the brace, we had to go with a matching carbon fiber engine cover.

[00:23:04]But under the cover is hiding a DO88 intake manifold which you guys saw earlier in the video. One of the cool things that I absolutely love about this kit is we do have the PI rail on and it fits comfortably under the engine cover.

[00:23:17]I'm not sure about other brands, but DO88 makes an effort to make sure that everything looks OEM. If you didn't know this had a fuel rail on it, you would absolutely never know. Speaking of the fuel rail, we have those thousandcc fuel injector clinic injectors, which are powered by a Precision Raceworks AFS kit. What I love about the kit and why I run it on my personal G80 is that it sends out two feed lines. The first feed line is going to power all of your stock DI system and the second one is dedicated to your port injection system to make sure that you have plenty of fuel for everything. Now, for the tuning, our friend HCP from Denmark is going to remote in to tune the car on boot mode. And of course with that rev 2 which is going to control all of the port injectors and a ton of additional safeties to make sure that we make a lot of power as safe as possible. And then because Miguel is going to be tracking this car quite a bit. Wheels are going to be coming on and off. We did a Motorsport hardware stud conversion.

[00:24:08]Then in the interior, we did something for weight savings and also a little bit of style. Because as you guys know, the rule of thumb is for every 100 lb you save, you're going to save roughly a tenth of a second off your 1/4 mile. And by removing the rear seat, you're going to save over 40 lb, which is crazy. So, not only did we do that, and we didn't want to leave it all ugly and bare. So, we had our friends over at SeatX make us a Keys exclusive seat delete. As you can see, this is made of genuine Alcantara and carbon. And it looks incredible with any color interior. So, as you can see, even something like this, which looks relatively simple, there is a ton that goes into it. And a big trick of this is knowing what parts work well together.

[00:24:45]And if that's something that you guys need help with, you can always reach out to our team at [email protected] and we can help you customize a build that's specific to you and your goal. So with that, let's hit the dyno and see what it makes. All right, so right now I'm heading over to the Dino Cell. And I was really curious to see what kind of lag this thing has. But if you're driving light load, I mean, besides the whistling sound from the turbo, it feels great. Even on its base map, it definitely has some boost lag, but it feels great.

[00:25:15]And it sounds incredible. I love the way this thing sounds. He also has a mad single midpipe on here with a stock exhaust actually. So, it's relatively quiet. It's not outrageously loud or anything like that.

[00:25:30]It sounds I love the way this thing sounds. This is crazy. I might need to do this to my car.

[00:25:39]The way the boost kicks in these big turbos is so different.

[00:25:47]So, the overall driving impressions for 93 octane, this thing is so streetable, it's not even funny. It drives so smooth. I was really concerned about massive boost lag. It's really not that bad, especially for just daily normal driving.

[00:26:07]Heat up here.

[00:26:47]Heat.

[00:26:52]Heat.

[00:27:14]All right, we just got done our custom tuning session with HCP, who remoted in all the way from Denmark to dial this car in, and the results did not disappoint. on 93 octane, he was looking for a very calm daily driving map, which makes sense because you don't want to have this car an absolute race car all the time. But when it came to E85, he wanted to go all the way up to that 900 horsepower range. Now, as you guys may know, with a 7275 in the fuel system that is currently on the car, it's very similar to mine, and we do about 1040 to the tire. So, it has all of the air and also all the fuel that it needs for over 1,000. But while it's possible, you got to remember this is a stock motor car and it's not going to live long if we do push it all the way to 8,000. However, if we keep this car in that 900 horsepower range, this car is going to be a ton of fun and it's also going to be very safe. So, after a couple hours of revisions, let me show you where we landed. Now, before we got started with everything, we did a baseline run on Miguel's car. He landed at 468 horsepower to the wheels, and for the torque, he did 495 lb feet of torque.

[00:28:16]The only modification he had on the car at the time was a catless downpipe, which a lot of times is going to rob you of a couple horsepower, but it will typically bump up your torque just a little bit. From there, since he had a downpipe, we went to a stage 2 OTS map from boot mode, and that bumped him up to 594 horsepower. The only other thing we had besides that downpipe was we did install a carbon fiber intake from DO88 to make sure we got as much air flow as possible. And for the torque, we landed at 579 lb feet of torque. After that, we went nuts with a big single turbo fueling, cooling, and everything under the sun. On 93 octane, his new number is 557 horsepower to the wheels and his torque is over here at 515 lb feet. Now, again, with 93, Miguel wanted Calm Cooling Collective for the street for daily use. He didn't want these giant torque spikes, which is exactly what we gave him. If you take a look over here, here's the horsepower. You can see it comes in super smooth and it's very linear. Same with the torque. You don't have any crazy boost spikes. But on E85, it is quite a different story. If you take a look over here, our power jumps up to 910 horsepower to the wheels and our torque lands us at 782 lb feet. If you take a look at these graphs, you can see that around what is this? 3600. This thing takes you straight to the moon.

[00:29:37]Again, stock motor, 900 horsepower. A couple years ago, I never would have thought this was possible. And today, this is actually pretty tame. Absolutely nuts to see this. Now, earlier in the video, we talked about a crossroads where if you're trying to make big power, you can either go with hybrids or you can go with a big single. Now, the benefit to a big single is you don't have to build your motor if you're going for this power range. Where with hybrids, the power comes in so much stronger and so much more aggressive that if you don't build your motor and you try to hit some of these numbers, you can have an issue where you bend your rod. So, let's compare Miguel's single turbo G82 versus my hybrid turbo G80. So, on the graph, Miguel is on the top over here and I am on the bottom. If you take a look over here, we're going to start by comparing the hybrids. My hybrid turbos come in and this is the torque curve and it goes straight to the moon and we have a ton of torque all before,000 RPM. This is best if you have a built motor because it's very aggressive and it's very hard on the motor. If you take a look at Miguel's torque curve, you can see that it comes in significantly later. I mean, check out this giant gap between where the hybrids are spooling up and where the big single is getting all of its power.

[00:30:47]Because your power is coming in so much later, it gives you the ability to get way more out of a stock engine car because this is much safer on stock rods. Anyway, I hope that you guys found today's video helpful. If you did, make sure to give us a like, make sure to subscribe, and if you're looking to go fast, check us out at keys.com. We have links to everything that we did in today's video down in the description.

[00:31:08]Thanks so much for watching, and I'll see you in the next video.