Tag: streetzlegend

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How does nitrous work and is it safe?

I explain how it works, what are the parts involved and go over some important safety precautions to allow nitrous to be a long term safe power adder.

How does it make more power?

Nitrous is injected into the engine through the intakes manifold. When nitrous goes into the cylinder and combustion occurs, the heat generated causes the nitrous molecules to split and release oxygen. The additional oxygen plus added fuel produces more powerful combustion pushing the piston down with more force. Nitrous accelerates the rate of combustion and therefore increases torque drastically. If you have not read it already you can go over to a previous article which discusses how an engine works to get a better idea of the internals function: what-is-engine-tuning

Nitrous is liquid when contained in the tank and expands once released. When using nitrous generally the bottle pressure should be in the 950psi to 1000psi range. When filling a bottle with nitrous you want to have the bottle as cold as possible, for example placing it in a freezer before filling. This allows for the nitrous molecules to be closer together and be able to pack in more nitrous into the bottle; another method would be to pump the nitrous but freezing is more common. When you warm up the bottle it expands and increases the pressure ready for use. The pressure can be raised to the target by heating the bottle with a heating blanket.

Benefits of Nitrous

When nitrous is injected into the intake manifold it cools down the air making it denser, this means more oxygen in addition to the oxygen the nitrous provides during combustion. The power and torque obtained from nitrous is instantaneous, unlike a turbo or supercharger.

Wet and Dry Systems

You may have heard of a wet nitrous kit, these are nitrous kits that inject nitrous and fuel into the intake. In a wet system, the nozzle responsible for spraying the intake has two inlets, one for fuel and one for nitrous.

In a dry nitrous system, only nitrous is injected and the additional fuel delivery is handled by the injectors.

Dynotune nitrous and fuel wet nozzle.

DynoTune Wet Nitrous Nozzle
Dynotune nitrous dry nozzle.
DynoTune Dry Nitrous Nozzle

Solenoids and Nozzles

A nitrous system is simple. You start from the bottle, the bottle has an outlet which is usually a 4an fitting size. This connects to a nitrous stainless steel braided line. The line goes into a solenoid then exists the solenoid and goes into a nozzle which is mounted on the intake before the throttle body. When you give the solenoid 12v current, it opens the flow.

With the wet system, you have a T fitting on the existing fuel feed line that’s between the fuel filter and the fuel rail. From this T you then run a hose into a solenoid, and from the solenoid, a braided line goes into the nozzle that is mounted on the intake. When the nitrous is activated, the fuel solenoid also activates and allows flow from the car fuel line into the nozzle. Both nitrous and fuel are pushed into a single nozzle and spray together into the intake.

Here is a diagram by DynoTune Nitrous showing the plumbing for a wet nitrous kit:

Dynotune Nitrous Wet Kit Plumbing
DynoTune Nitrous Wet Kit Plumbing

Jets

Nitrous jets are what regulate how much nitrous is fed into the engine. These jets are placed at the nozzle where you connect the lines coming from the solenoids. You put the nitrous jet then you screw in the lines. In a wet system there is a nitrous jet and a fuel jet, in a dry system there is only a nitrous jet as there is no fuel delivery through the nozzle. To provide the proper mixture of nitrous and fuel you follow a chart that’s provided by the nitrous system you are using.

When you have a dry system you have to be sure that every time you change the nitrous jet you are also adjusting your injectors fuel delivery.

Here is are DynoTune’s recommended jet sizes for the desired horsepower using 43psi fuel pressure:

35 HP: 28 N/ 16 F
50 HP: 34 N/ 18 F
75HP: 42 N/ 24 F
100 HP: 48 N/ 28 F
150 HP: 58 N/ 34 F
N represents the nitrous jet, F represents the fuel jet.
The nitrous jet number is in inches; for example, a 48 jet is .048in.

Bottle Warmer and Pressure

A bottle warmer is a very good investment because it allows you to control the pressure of the tank. You want to have the nitrous between 950psi and 1000psi. It is highly recommended you get a warmer that has an automatic shut off switch to not overheat the bottle and cause the pressure to rise too high; this will result in too much nitrous being sprayed and run a very lean combustion.

Nitrous bottles come equipped with a safety burst disk that will release the nitrous once it excessed certain pressure; like leaving the warmer on without monitoring or leaving the nitrous bottle in the car during a sunny Miami day for example. For track use, you are required to use a blowdown tube that connects to the burst disk and then routes to the outside of the car (usually towards the ground).

Parts

  • Bottle
  • 16 foot braided stainless feed line, blue fittings 
  • Nitrous and Fuel solenoids 
  • 2 foot Braided stainless Nitrous and Fuel feed lines, red and blue fittings 
  • Braided stainless line for Fuel rail test port installation, red fitting 
  • Jets
  • Wet Nozzle or Dry Nozzle
  • Relays, wire, and connectors.

Supporting Modifications

Exhaust

Nitrous produces a lot of exhaust flow, one important change you should make is to have an exhaust system that as least restrictive as possible. On a VQ I would say no less than 3 inch in diameter from the headers merge all the way to the outlet in the back. With nitrous the larger the diameter the better.

Fuel Pump

Since you are going to provide a lot of more oxygen you are going to need more fuel. This means that you most likely will need to upgrade the fuel pump to support the demanded delivery. The common pump one starts off with is usually 255lph.

Intake

On a nitrous car, the intake is not as critical as naturally aspirated because the added air(oxygen) is provided chemically rather than by airflow. However it is always good to have an acceptable intake upgrade that is meant for higher flow than factory.

Tips and Warnings

When you purchase a nitrous system the manufacture includes warnings that you should pay close attention to. For example in the case of DynoTune which we offer in our nitrous shop section, they took the time to explain details regarding tuning, reading spark plugs (I will have an article on this), and more.

Nitrous Backfire

When you have the nitrous bottle open and ready to use, never engage the nitrous while the car is idle or turned off. This will cause the nitrous and fuel to puddle in the intake manifold and valves and cause an explosion. The nitrous is not flammable on its own but when mixed with the fuel, the fuel can ignite and causing the nitrous to react as well. It will be a violent explosion sending your intake manifold, piping, and even hood flying along with a fire. (“Danger to manifold” is a real thing).

Timing and AFR

When it comes to tuning, I treat nitrous like the turbo. I keep the AFR in the low to mid 11:1 and I keep the timing a couple of degrees lower than without nitrous, depending on the amount of course. Like I mentioned before, nitrous adds a lot of torque due to how fast it accelerates combustion so you must retard timing when using nitrous. Consult with your tuner and the nitrous instructions regarding timing, reading your spark plugs is also a good idea to determine how well it’s handling it.

When to Spray

It is advised to engage the nitrous at over 3,000 RPM, this will prevent it from puddling; spraying at a low RPM the intake valves may not be opening fast enough to pull in the content into the cylinder. Spraying nitrous at a low RPM especially in a high gear will produce an enormous amount of torque that your rods may not be ready for (my fellow stock VQ35 block guys, please pay attention to this!).

Automatic Transmission

On an automatic, never engage have the nitrous spray during a downshift, it could easily be the last time the transmission ever downshifts.

Purge

For the best performance, it is a good idea to purge the line. When you first open the bottle the line connecting the bottle to the solenoids is full of air, when you activate the nitrous the initial result will be fuel and air without nitrous, you may feel the car bog due to being too rich at first. To solve this you install a solenoid between the main nitrous solenoid and the bottle and you activate the solenoid before you activate the nitrous (before racing). This will fill the line with nitrous and get it ready to be sprayed as soon as you activate the system.

Where to get a nitrous system

I hope you have enjoyed this article and found it valuable. If you are interested in nitrous you can purchase it from the shop section where I have two kits available, a Dynotune Universal Bundle with purge and a bottle warmer or a Universal Dynotune Wet Kit.

Fastmaximas – Nitrous

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Mr Greenmax Turbo VQ30 550WHP+

Now this is what I am talking about folks. Today we feature this 1999 Nissan Maxima that is making over 500WHP on the VQ30. Nowadays most maxima enthusiasts want to swap a 3.5 (VQ35) in their 4th Gen (95-99) Maxima’s and forget to realize that the VQ30 is well equipped to handle great power in factory and in built form.

An interesting aspect of this build is that despite making such great power it still has the factory 4th Gen intake manifold which is proven to be the most inefficient. This build has a lot more potential and I am looking forward to seeing more.

Overall Details

The turbo is a Precision 62/62 with 3″ piping from the turbo to the throttle body and a 3″ exhaust from the turbo to the back along with a cutout that exists out of the passenger side door.

The fuel system consists of a 6an return line and a 8an feed. Feeding the fuel are 960cc Injectors and a 450 Walbro with a Aeromotive fuel filter.
It also has nitrous using a ZEX Nitrous Wet System, jetted for 65HP.  

The computer handling this monster is a Haltech Platinum Sport 2000. To get the Haltech to work at the time a Ford Mustang trigger wheel needed to be used. The boost is controlled by gear via the Haltech, 1st gear has no boost, 2nd gear gets 15psi, and there after 21psi. 570WHP.

Engine Details:

JWT Cams
VQ30 Built Block with Wiseco pistons 9.1 compression
K1 Rods
ACL bearing
Block Guard

Transmission

05 Maxima 6 speed with SER Spec V gears and limited slip; using Redline Fluid to help with shock.
Holding it the torque is a ClutchMaster twin disk clutch

Worked performed by MPHFabrication and tuned by Autoauthorityct.

I hope you enjoyed this post as much as I did and I will be sure to continue sharing updates of this sweet ride.

Follow Mr.Greenmax on Instagram https://www.instagram.com/mr.greenmax

Thank You

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Streetzlegend Front Mount Turbo Build Part 3

In this part three of the front mount turbo setup I go over the exhaust options. Exhaust exit to the floor, exit out of the hood and cat back exhaust.

Some information about the car:
1997 Maxima
VQ35DE
Automatic
Turbo (initially rear mount turbo)

Floor Exit

To get the car on the street quickly I made the turbo exit aiming down to the floor. This was not fun like when you drive around the block with no cat back installed and you cant feel your own body due to the noise and drone. The pipe used was 3.5inch and the bend was made with pie cuts for a sharper turn to stay away from the radiator.

Driving required some getting used too. As you drive a car for a long time you start to become aware of the sounds it makes. You can hear when its lean, rich, knocking, or piston slapping. When those sounds are overpowered by the exhaust, you are left with no feedback; you feel disconnected. Apart from that the car was now alive. Here are videos with the exhaust to the floor.

Front mount turbo idling with down pipe aiming to the floor.
Front mount turbo untuned test drive with down pipe to the floor.

Cat Back

I started working on a cat back solution. There was enough space between the cross member and the turbo feed pipe. I had to make a reducer from the turbo to a 3 inch 90 degree pipe. To accomplish this I got the flange for the turbo and made v cuts all around the end that welds to the exhaust. I then bent the fins(created with the V cuts) inward and welded them all; this gave me a smooth reducer. I welded the 90 degree pipe to the flange, welded the other end to a new 90 degree pipe that turns under the engine and between the cross member and turbo feed pipe.

Catback exhaust sound clip.
Testing the cat back exhaust at 16psi of boost.

Hood Exit

The hood exist was not my first option, it was not even a thought. With the car not being daily driven I figured I would try something new. I made a 3.5 inch pipe with pie cuts to achieve 90 degrees and pointed it up to the hood. To find where I needed to cut I put grease on the pipe and closed the hood to see where it would mark. After hacking away this is the result.

The hood exit was more quiet than when pointing to the floor. It is still loud but it does not feel like an earthquake anymore.

In Part 4 of this article I will go over the finishing touches, and that is the side exhaust that sounds great.

To be continued…

Thank you for visiting and be sure to subscribe at the top of the page to get the latest from FastMaximas.

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Streetzlegend Front Mount Turbo Build Part 2

In this part two of the front mount turbo build I will go over making the radiator efficient enough to cool the engine in all conditions.

Some information about the car:
1997 Maxima
VQ35DE
Automatic
Turbo (initially rear mount turbo)

DIY Fan Shroud

I used a generic brand radiator from eBay. It is a two core aluminum radiator for a Honda del Sol. The fan used is a Spal 12″ Curved Blade Puller Fan. With a pullIng fan it is important to use a shroud so that the air is pulled from all sections of the radiator. Having no shroud the fan will only pull air through the area where the fan is mounted too; limiting the cooling area to that diameter.

I created the Shroud using two cookie baking trays. I cut both of them in half then I overlaid the ends together so that I can have a specific width to cover the whole area needed. The tray is about a quarter inch to half an inch deep which means this is how far the trays floor will be away from the radiator; you want this distance or greater to help pull air from the corners of the radiator.

I then riveted the trays together to make a sturdy. I cut a hexagonal shape in the center with the same diameter as the fan (12″). To support it all, I used the brackets that came with the fan and bolted them to the radiator; I fastened the shroud to the radiator with through bolts.

Dealing with exhaust Heat

For the radiator hoses I visited a local parts store and asked to get access to all the hoses. The tricky part was the bottom hose, so I found several bends that worked out great. I used a connector to merge the hoses together to make one final piece that would go across the radiator support, to the passenger side, and up like the usual stock hose path. This bottom hose passes directly in front of the feed and down pipes so wrapping them in header wrap was necessary in my opinion to protect the rubber from direct heat.

After driving around it was clear that I needed to wrap the down pipe and feed pipe to keep it from starting to over heat; this is when I thought I should have purchased a three core radiator. With a few modifications I have had success with the two core. I created a shield to block the down pipe from radiating heat directly onto the radiators side which helped a lot.

This video shows the heat shield made to block heat from the downpipe.

As you can see in the video, I had the transmission cooler mounted on the grill in front of the turbo. This was an issue because the heat coming off the turbo and exhaust piping would warm up the cooler in traffic. I had to relocate the cooler and at the same time upgraded to a larger unit; more on this in its own blog post.

The next test was sitting in traffic or in a staging line. The engine would start to warm up after a long while. I realized that the reason for this was because the passenger side of the grill area was opened exposing the turbo and exhaust piping. This means that when the car is at a stop, heat comes out of the front of the grill area then gets pulled back in through the radiator; basically the radiator was pulling air that was already hot. The solution was to make a plate from thin aluminum which blocked the left side of the grill completely. I then cut a triangle on the hood above the turbo so that it could be an escape for the heat. The end result gave me a reliable setup for cooling.

Finally, since the car is now more focused for racing, I created a short exhaust pipe that exits out of the hood. This is used for the track or weekends. Alternately I can attach the catback to the original turbo outlet I created when I want a quiet ride. will go into details in the next post.

In the next post I will go over how I created the rear side exhaust while still keeping a muffler.