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Discussion Starter #1 (Edited)
2016+ Nissan Titan XD Performance Intake R&D, Part 1: Stock System Review

Some exciting things are happening for this new Titan! In addition to the projects already planned, we want to develop a performance intake that will squeeze out a bit more power from this 5.0L V8 Cummins Turbo Diesel. We managed to get an accurate dyno reading with a few adjustments, which we know a few folks have been struggling with on this truck, but more on that later – let’s dive into the stock intake!






Dissection of the Stock System
This turbo inlet is located at the top of the engine. The inside diameter measures right around 3.5 inches; the intake tube has the same inside diameter as well. The airbox grabs its air from inside the fender on the passenger side of the engine bay. Check out the opening in the image below.



That’s a pretty sizeable opening, so we will definitely incorporate that into our prototype design for an airbox. Speaking of which, let us take a closer look at the stock airbox and its components.









As you can see, the stock airbox has two sensors. The one on the top of the inlet is the mass airflow (MAF) sensor, and the one toward the bottom of the box is the intake air temperature (IAT) sensor. Both of these are necessary for this truck to run properly, so we’ll be including these sensors in our design. At this stage, we are unsure of the sensitivity of the MAF sensor. In our experience, the MAF sensor tends to be finicky with some of the newer applications, so we may need to test multiple MAF housings to find the best size.





The two images above show the bottom half of the airbox with the opening for the inlet scoop. Another inlet duct bridges the connection to the air coming from inside the fender to the airbox. It is important that we include this aspect of the stock intake in our prototype design. The intake tube is fairly straightforward as well. On both ends, the diameter measures right at 3.5 inches.




Baseline Dyno Run
We know that this Cummins turbo diesel is factory rated at 390hp and 401ft-lb of torque. That torque figure is high, but we expected this, as trucks generally have higher torque ratings because they are utility vehicles meant to carry and haul heavy loads.



Now back to my original point. Before going into this project, we knew that dyno testing this truck was going to be a challenge. We turned to our Dynapack™ in order to get the most accurate results. It’s important to note that this truck has a torque converter and that when it engages, the torque output spikes. To give you an idea, during our baseline testing, both of our packs nearly started overheating!

Because of this, we had to carefully monitor the temperature of our packs just as closely as we did with the truck’s engine while we ran it on the dyno. Whenever we use the Dynapack™, we run water through it during each run so the packs don’t overheat. Our engineer had to run almost twice as much water for a longer time to keep them cool during and even a little after each of the runs! This was indeed a first for us.



We were spot-on when we said that dyno testing would not be easy. If you get on the gas too slowly, the resulting data would show power outputs similar to those that would be obtained at half-throttle. If you get on the gas too quickly, the transmission would immediately shift into a lower gear and give us all sorts of weird numbers. To dyno this car properly, our awesome engineer figured out that feathering the throttle to steadily match the boost increase with the RPM rise would give us our cleanest runs with the most accurate plots. Much easier said than done! We had to make countless runs to get the good plots. Check out a clip of some dyno runs below!

https://www.youtube.com/watch?v=BkE30UuSiTs

We made right around 300 horsepower and an impressive 499 ft-lbs of torque. It’s not often we see a dyno chart where both data plots are so far apart from each other. This does, however, make sense due to how much torque this truck makes. This big disparity between the power and torque is a first!

What’s Next?

Now that we have a foundation for our design with the stock data, we can move on to the prototyping phase of these Titan XD performance parts. We know that we will want to use a fully enclosed airbox and a big filter, and for this kit to be safe, it needs to run on a stock tune. Of course, seeing some power gains is important as well. Stay tuned for the next update!

Thanks for reading!
 

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the turbo diesel is rated at 310 horsepower and 555 ft. lbs. of torque. According to your numbers (i'm not familiar with Dynapak), you are getting almost no drivetrain loss which would be really impressive but I would have expected somewhere in the range of 15% drive train loss.
 

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Whats the point of a aftermarket air intake system when running a turbo? Pretty sure the turbo provides greater than atmospheric pressure. So how would a new intake affect this?
 

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Less resistance is less lag, and if the intake charge is cooler it will make it denser. Cummins wants no more than 1.5 hg of resistance on the track to the turbo.
 

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Discussion Starter #5
the turbo diesel is rated at 310 horsepower and 555 ft. lbs. of torque. According to your numbers (i'm not familiar with Dynapak), you are getting almost no drivetrain loss which would be really impressive but I would have expected somewhere in the range of 15% drive train loss.
Great point! There are so many ways to dyno this truck and this causes a lot of differences in power output ratings. The power numbers provided here are straight from Nissan's factory ratings so there is a good chance that came from the crank. The way we had tested the car on the dynapack will be different from other results out there, but rest assured that the data we have here is accurate.

There will always be inherent drivetrain loss, and there indeed was some here. We didn't quite hit the 310hp/555ft-lbs mark although we were close. It could be that those are the more realistic numbers that dyno results for this truck should aim to hit, but without more in depth baseline testing, we can't confirm whether that really is the case or not.

Whats the point of a aftermarket air intake system when running a turbo? Pretty sure the turbo provides greater than atmospheric pressure. So how would a new intake affect this?
Our planned design aims to bring more air into the system over stock. More air means more power! A turbocharger already takes care of bringing in more air of course, but in order to further stabilize and thicken the volume of air passing through, upgrading the stock design is necessary. With this increase in air, there will be more air for the turbo to compress and force into the motor, so that is the major advantage to upgrading from the stock intake system. Hope this helps!
 

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Our planned design aims to bring more air into the system over stock. More air means more power! A turbocharger already takes care of bringing in more air of course, but in order to further stabilize and thicken the volume of air passing through, upgrading the stock design is necessary. With this increase in air, there will be more air for the turbo to compress and force into the motor, so that is the major advantage to upgrading from the stock intake system. Hope this helps!
Unless you are physically increasing the diameter of the opening on the turbo, I don't see how this is possible, as thats going to be the limiting factor. Unless you can prove the turbo has been gasping for air.... doesn't seem to be the case.

I would like to see some hard numbers showing how a larger intake system is going to increase power without modifying the turbo... Seems like a waste of money unless you are replacing the entire turbo system.

What would make a **** of a lot more sense to me would be to work on improving / disabling the EGR and the rest of the emissions system.....
 

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There are dyno backed gains for the No Limit stage 2 cai, on the powerstroke forums. But in order to run the stage 2, you have to be custom tuned, or the truck will run ragged or go into limp mode. But not many of the other cai's are producing any notable gains.
 

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Unless you are physically increasing the diameter of the opening on the turbo, I don't see how this is possible, as thats going to be the limiting factor. Unless you can prove the turbo has been gasping for air.... doesn't seem to be the case.

I would like to see some hard numbers showing how a larger intake system is going to increase power without modifying the turbo... Seems like a waste of money unless you are replacing the entire turbo system.

What would make a **** of a lot more sense to me would be to work on improving / disabling the EGR and the rest of the emissions system.....
If you can reduce the amount of pressure drop through the stock intake system by getting more flow through the filter and box, you will have more air available at the turbo. The question is, how much better can it be designed and how much performance gains will be made from it? Hopefully, the future dynos will show us.
 

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I think the interesting factor is that according to the dynapak, 300hp and 499tq sounds like cummins/nissan sandbagged the HP figures. If you take a 10% drivetrain loss for the factory published numbers, your at 279hp and 499.5tq. So being we have arrived at these dyno figures, this engine would be making 333ish at the crank assuming all is equal. Probably add a 5% deficit to account for frictional and rotational losses with the wheels on rollers for say a dynojet roller type. Agreed on the intake, pressure drop is one of the enemies in this system for pumping losses and negative pressure at the inducer of the turbo, (some systems with too much at higher HP levels can over-speed the turbo from no load on the compressor, making for some messy work later) same as any air charged piston engine. But how much is actually present remains to be seen. The exhaust by far will be the biggest hurdle, and no, not even talking the emissions (mainly because the plumbing is plenty sized for the output, it's very close to that of the 6.7's system), it's the manifolds and y-pipe to the turbine inlet that's your major restriction for adding power. Although looking at the inlet of the LP turbo compressor, it looks to be comparable to the intake size on the down leg from top of the engine.

BigRed
2016-nissan-titan-cummins-14.jpg

cummins-v8-engine-assembly-plant-tour-engine-testing.jpg

cummins-v8-engine-assembly-plant-tour-turbo-components.jpg
 

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Our planned design aims to bring more air into the system over stock. More air means more power! A turbocharger already takes care of bringing in more air of course, but in order to further stabilize and thicken the volume of air passing through, upgrading the stock design is necessary. With this increase in air, there will be more air for the turbo to compress and force into the motor, so that is the major advantage to upgrading from the stock intake system. Hope this helps!
Unless you are physically increasing the diameter of the opening on the turbo, I don't see how this is possible, as thats going to be the limiting factor. Unless you can prove the turbo has been gasping for air.... doesn't seem to be the case.

I would like to see some hard numbers showing how a larger intake system is going to increase power without modifying the turbo... Seems like a waste of money unless you are replacing the entire turbo system.

What would make a **** of a lot more sense to me would be to work on improving / disabling the EGR and the rest of the emissions system.....
Do you even know how a turbo works? It doesn't just turn itself on full speed. It requires hot expanding gases from the exhaust to drive the turbine, which spins the compressor on the other side of the shaft. The more resistance from sucking air through an air filter and restrictive ducting, the more resistance the exhaust is going to get to spin the turbine. So with freer flowing intake air, there is less resistance to drive the turbo, and less lag. Then throw in the factor of cooler air, which contains more oxygen per volume, and you get more power that way.
 

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Discussion Starter #11
Unless you are physically increasing the diameter of the opening on the turbo, I don't see how this is possible, as thats going to be the limiting factor. Unless you can prove the turbo has been gasping for air.... doesn't seem to be the case.

I would like to see some hard numbers showing how a larger intake system is going to increase power without modifying the turbo... Seems like a waste of money unless you are replacing the entire turbo system.

What would make a **** of a lot more sense to me would be to work on improving / disabling the EGR and the rest of the emissions system.....
If you have an efficient way of getting air into the system and if you can remove as many restrictions as possible, that can only benefit the turbocharging process! We are definitely going to have dyno results, so we'll be able to break down how our prototype design improved the induction process. So stay tuned for that!
 

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Do you even know how a turbo works? It doesn't just turn itself on full speed. It requires hot expanding gases from the exhaust to drive the turbine, which spins the compressor on the other side of the shaft. The more resistance from sucking air through an air filter and restrictive ducting, the more resistance the exhaust is going to get to spin the turbine. So with freer flowing intake air, there is less resistance to drive the turbo, and less lag. Then throw in the factor of cooler air, which contains more oxygen per volume, and you get more power that way.
I'm very familiar with how turbos work. The fact is, the only way your getting more air to be available to the turbo is increasing the id of the turbo's intake, or dramatically increasing the flow threw the filter system. The only way to increase the flow via the filter system is to either use filters that filter less particulats or are significantly larger in area. There is only so much area avaialbe to increase the size, and I sure dont want to decrease the filtration level.

All said and done trying to improve the filtrations system, is only going to help if the turbo was laking access to air in the first place. I doubt thats the case. I just want to see some cold hard numbers.
 

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I'm very familiar with how turbos work. The fact is, the only way your getting more air to be available to the turbo is increasing the id of the turbo's intake, or dramatically increasing the flow threw the filter system. The only way to increase the flow via the filter system is to either use filters that filter less particulats or are significantly larger in area. There is only so much area avaialbe to increase the size, and I sure dont want to decrease the filtration level.

All said and done trying to improve the filtrations system, is only going to help if the turbo was laking access to air in the first place. I doubt thats the case. I just want to see some cold hard numbers.
You are right, if the flow through the filter and induction system was perfect (matched or exceeded the flow rate of the turbos unimpeded intake), the bottleneck would ultimately be the turbo intake. However, without people like Mishimoto doing the R&D, we don't know if the intake system needs improvement. Also, there are ways to increase the flow rate though the filter without dramatically increasing the physical size of the induction system or reducing the filtration rate. What you need, is to increase the surface area of the filter. The current filter is a rectangle maybe 6"x10" (just a guess). A conical or spherical filter has a much greater surface area. No reason to be critical of Mishimoto or any other developers at this point. Let's see what they come up with, what their claims are and what their evidence is, THEN we can dissect it!
 

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Also, there are ways to increase the flow rate though the filter without dramatically increasing the physical size of the induction system or reducing the filtration rate. What you need, is to increase the surface area of the filter. The current filter is a rectangle maybe 6"x10" (just a guess).
Thats pretty much what I said above. I just want to see some numbers showing that it is lacking as is. As most diesel turbos, don't benefit a heck of a lot from air intake systems unless they are running a tune.... Anyways, your right, lets give them the benefit of doubt, but remember they are here to try to sell you there products, so it shouldn't be too much to see some hard numbers showing how the factory system is lacking first.
 

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You should correct your post. The Cummins diesel is NOT rated at 390hp and 401tq..... Thats the GASOLINE 5.6L V8.

Also, before that you claimed that the intake grabbed air from the passengers side and it's actually the drivers side....
 

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You should correct your post. The Cummins diesel is NOT rated at 390hp and 401tq..... Thats the GASOLINE 5.6L V8.

Also, before that you claimed that the intake grabbed air from the passengers side and it's actually the drivers side....
Those errors in the post will be fixed soon, but great catch! Thanks for reading through the information. For everyone else just tuning in, the diesel Titan is rated at 310hp and 555ft-lbs of torque!
 

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Well if your going to go threw the RnD of this CIA go a step further with it and think outside the box. Literally run your tubing threw the fender to the outside fender Cummins logo open it up and make a ram air for the truck, If you want to get the most out of it HP wise you need cooler air. get forced fresh air it's not going to be any cooler than that.
 
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