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      02-23-2010, 06:10 PM   #1
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Drives: 4 Wheels
Join Date: Aug 2007
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Nitrous Express EFI Nitrous Kit / Progressive Controller / Acces. **FULL REVIEW/DIY**

Before I begin this review, I would ask for an open mind and nothing more. Quite a bit of data will be presented in this review, so I hope we can draw conclusions on the information presented and not urban legend.

About a year ago, I heard of someone running a 50 shot of nitrous on an N54 and immediately something inside me said “NAWS doesn’t belong on a BMW”. It is almost like we are programmed for this type of a response. Then I heard about OldBooster running a nitrous shot, then Brian355i, then AR Design running a 50 shot of nitrous. OldBooster had made tons of drag strip runs with nitrous and never had a single problem. I then consulted AR Design to find out a little more about what kind of shot he was running. AR Design said they ran a dry shot and Andrew was very fast to share that he thought the N54 responded superbly to nitrous. I spoke the STETT Performance to get their thoughts on nitrous and they believed the N54 would respond very well to a dry shot. I started to really question myself and this whole “Nitrous doesn’t belong on a BMW” concept. Is this idea based on fact or was this idea based on old fashion urban legend? Ultimately, I found myself wondering if nitrous can be run safely on an N54?

The question of “Can nitrous can be run safely on an N54” led me to a search of our E46 M3 brothers. I found tons of posts about guys running NO2 (nitrous) on E46 M3s for years without trouble. I saw the response from the community was the same as I have seen here… “nitrous and BMWs don’t mix”. I read a transformation over the years among the community. Some started to believe it was viable, while there were always the stubborn group that hung tight to the urban legend. It was very clear that safety cutoffs are critical, but they are also critical in methanol, boost, etc. I was starting to realize that nitrous isn’t taboo and I am sure people said the same thing about methanol years ago. I spoke with a number of friends that have run nitrous for years and they all said the same thing… if you do nitrous correctly, then it is just as safe as any other power mod. For me, I kept coming back to safety. I think the truth finally burned its way through the years of taboo that had clogged up my mind. Nitrous is as safe as the safety cutoffs you have in place.

If I was to try a nitrous shot, I had a decision to make… wet shot or dry shot?

A wet shot of nitrous is a precise amount of nitrous injected with a precise amount of fuel through one nozzle.
A dry shot of nitrous is a precise amount of nitrous injected through a nozzle.
Why would you need a wet or dry shot? Well NO2 breaks down into nitrogen and oxygen in your combustion chamber which essentially gives you more oxygen to create more power. Now, you must get more fuel into the combustion chamber with the nitrous or you will run lean. Now, I was debating a wet or dry shot? Traditionally for larger nitrous shots, like 100-200 shots, wet shots are exclusively used, but I had no desire for a large shot of nitrous. Turbod cars are notorious for huge gains on small shots of nitrous. Oldbooster, Brian335i, AR Design, and every other N54 I have spoke with ran a dry shot. The most informed people on the N54 will tell you that the N54 intake manifold and charge appears to be very susceptible to pooling (fuel puddling). Pooling can lead to nitrous backfires and they are not good. I knew AR Design had done some logging on his 50 dry shot and said the A/F ratios never went remotely lean on their testing. There was still one piece of the puzzle here that I needed to look at… I have a Snow Performance water/methanol kit. Basically, if I ran a dry shot with my methanol injection then I would always be adding 116 octane fuel to make for a very safe dry shot in my opinion. Testing would be needed to verify this and I could see where this was going. It was at this point that I decided I would try a dry shot, because I sincerely believed the HP addition would be large for a small shot. I knew I would need data to prove to myself if a dry shot could be safe on the N54 and this was one of the reasons I bought the FJO wideband which was used extensively during this testing.

With this my search began. I looked at a lot of the nitrous companies on the market, but kept coming back to Nitrous Express. Everyone I spoke with said they are simply the best bar none. This was not just from a few, but the overwhelming response. “I won’t use anyone but Nitrous Express” over and over. That made a strong impression on me, so I went to the website of Nitrous Express and began to look around.

Deciding on the dry shot is the beginning but how can I keep this safe? This is when the light went on! Nitrous Express has a progressive nitrous controller called the Octane Series Progressive Nitrous Controller. To say this piece is an extraordinary item would be an understatement. Here are some features of Octane Series Progressive Nitrous Controller:

1. Allows you to set a nitrous window (the nitrous will only come on in these
rpms if ALL conditions are met)
2. TPS activation (only activating when you floor the car)
3. Time delay (once all conditions are met, it will delay)
4. Time ramping (the nitrous comes on slowly over a user defined time)
5. Rpm ramping (the nitrous comes on slowly over a user defined RPM range)
6. A/F ratio lean fuel cutoff (if the car goes to lean, then nitrous immediately
shuts off)
7. Rich cutoff (if the car goes to rich, then the nitrous immediately shuts off)
8. Low bottle pressure cutoff (shuts the nitrous down if the pressure in the
nitrous bottle drops)
9. Controls the automatic bottle heater (it turns the bottle heater on and off
to make sure it is at the correct pressure)
10. Displays rpm with a shift light
11. Displays A/F ratios by digital high speed databus
12. Displays TPS (whether the car is floored or not)
13. Displays percentage maximum of nitrous you are injecting
14. Displays whether the system is triggered or not
15. displays bottle pressure

The list goes on and on. The Octane Series Progressive Nitrous Controller to me was the key to this entire project and was the final item that sold me on the Nitrous Express purchase. Some of the benefits on Nitrous Express kits are:

1. Nitrous Express Lightning Solenoids are widely accepted as the best on the
market. They have few bends and incredible longevity.
2. The new Nitrous Express Lightning 45 bottles are the best flowing period.
They have fewer bends to interrupt flow. They even allow pressure
reading on a closed bottle valve.
3. The Octane Series Progressive nitrous Controller offers the ultimate control
and safety.

I felt like it is Nitrous Express, then everyone else, so I decided to purchase. Since this was going to be a test, I purchased a wet kit in case with the plan to run a dry shot first and if I felt it was unsafe, then I would move onto testing a wet kit. My purchase included:

- A Custom EFI Nitrous System with 10 lb. Bottle
- The GenX-2 Accessory kit (bottle heater, purge, blow down tube, etc.)
- Octane Series Progressive Nitrous Controller
- Electric Gauge Transducer (so the controller can read the bottle pressure)

With this the review begins.

Experience with Nitrous Express

I called Nitrous Express to make my order with Mike Abney. The purchase process was very easy and I got a purchase order shortly after from Nitrous Express. Within a few days I had the kit in my hands. I have to say along the way Mike Abney in particular has been nothing less than an absolute wealth of information. When I had questions, he always had the answer. He spent a lot of time with me and even took multiple calls per day on many occasions. I cannot say enough positive things about him.

When the kit arrived at my door, I immediately knew Nitrous Express was the real deal. Their packaging was top tier, the organization was superior, and their protection of the items during the shipment process is as good as I have ever seen.

You can see how well organized the Nitrous Custom EFI system is.

Here are the mounting brackets and Lightning Series Solenoids.

Look at the carbon fiber Lightning Series Solenoids!!! Beautiful!

These are the nitrous fittings and NO2/Fuel lines.

The N02 fuel line is superb quality braided steel line.

Nitrous Express takes the liberty to include a very good hardware kit, wiring, and instructions.

Here you can see the bottle mounting hardware and the relay.

The new Nitrous Express Lightning 45 bottles are absolutely beautiful!

The Gex-X 2 accessory kit. Again, NX really focuses well on the presentation.

Here is a close-up of the automatic bottle heater.

Relays, bottle pressure gauge, fittings, etc.

Since I wanted to test a dry setup first, I ordered the dry nozzle.

This is the pressure transducer so the NX Octane Series Progressive Controller can automatically control your bottle warming functions.

Finally, the Nitrous Express Octane Series Progressive Nitrous Controller. In my opinion, this is the crown jewel of the entire project.

The Nitrous Express Octane Series Progressive Nitrous Controller has a superb manual that is very easy to follow.

The Nitrous Express Octane Series Progressive Nitrous Controller itself.

The ordering process was very easy with Nitrous Express. The second you get the items, you cannot question the quality of what you bought. Nitrous Express may be the best packaged/presented items I have ever ordered.



When you begin the install, it may be a little intimidating. I will tell you first off that this install is easier than methanol injection in my opinion. I think you can really knock this out in a day or weekend if you want to be really patient.

I always like to start at the back of the car and move forward. That means I started by mounting the bottle first. It is important to note that the NX Lightning Series 45 bottle neck needs to face the front of the car and second the neck needs to be higher than the base of the bottle. I chose a simple location near the rear that would allow easy access to the valve when I wanted to open it. First place the bottle mounts on, and place it where you want to mount it. You will then simply trace the holes and drill the rear trunk deck. Use the included hardware to mount the NX Lightning Series 45 bottle temporarily.

The blue arrows show the drill locations. You can see these are easily covered if you need to remove this quickly.

Now, it is time to take the bottle back out of the car and assemble it. The NX Lightning Series 45 valve has superb features that mean less hardware is needed. You can hook up the bottle pressure gauge and NX 1600 psi Pressure Transducer to the NX Lightning Series 45 valve and it will read even if the bottle valve is closed. This is a big difference from the old way of doing things and very convenient. Now you don’t need to have the bottle valve open to read pressure! First you will screw in the pressure gauge on the gauge port side of the NX Lightning Series 45 valve. Always use the included thread lock (red tube) to secure threads from leaking.

Second, you install the NX pressure transducer to the push port and secure using included thread lock.

Finally, let’s finish the bottle work by installing the NX bottle heater. Simply place it over the bottle and secure it using the velcro straps. You can mount it so that it will blend nicely with the label on the NX bottle.

*Note: You will notice, I didn’t use a blow-down tube for now since the bottle is mounted in the trunk. Many NHRA tracks don’t require them as long as the bottle is in an enclosed compartment like the trunk*

Great, the bottle is ready to install, but we should drill the holes for the wiring first to keep things clean. Test fit the bottle, and mark the locations to drill for the NX NO2 fuel line, NX pressure transducer, and NX bottle heater. *One note here, cover the openings of the NX NO2 fuel line with painters tape to assure that no debris will get in.* Notice the blue arrows showing where you will drill and pull the wire/NO2 fuel line/wiring harness for pressure transducer through the trunk floor.

With all the wire run, it is time to wire up the bottle heater and run the wires to the front of the car. First, let’s get the bottle heater and relay wired up. In case you do not know, the battery is on the passenger side of the car behind the trap to the far right of the trunk. Here is how to expose it.

I found a perfect spot to mount the NX bottle heater relay. Wire up the relay according to the instructions and you are a go! I used a 25 amp fuse to the relay to protect the system from a surge. *Note, follow the instructions closely because red on the relay is NOT power.*

Now you are ready to run the wires under your interior to the driver’s side footwell. Since the interior removal has been covered well, I will defer there. I would not install the bottle now because you will need to fill it later and you still have to run the NX NO2 fuel line, but this is a good time to secure the bottle mounting brackets to the trunk floor.

Speaking of the NX NO2 fuel line, let’s get this run to the front of the car. If you chose to mount the NX bottle where I did, then you should follow the NO2 fuel line run path I suggest because the length is perfect. First you will drill a small hole on the exact location I am showing you in the plastic trunk bottom. Start with a small drill bit so it won’t walk on you.

Now drill the hole up to ¾”. If you don’t have a step bit, get one! They are $10 at Harbor Freight and will save you so much time in future installations. You can “step” up the hole to any size necessary without changing the bit.

The final result should look like this.

Run, the fuel hose through the hole and pull out all the slack. I always protect fuel line from impact or cutting surfaces, so I wrapped the NX NO2 fuel line in ½” hose that you can get at any auto store. This is what the final truck product will look like.

Now it is time to run the NX NO2 fuel line under the car to the engine compartment. I always chose the driver’s side of the car because it keeps you away from the transmission and exhaust at all times. You will notice that I follow the white tubing all the way up to the engine compartment where the blue arrows highlight the run. You will need to pull a 2 under car belly panels, but this is very easy work. Remember to secure the NX NO2 fuel line with the included zip ties.

Notice the NX NO2 fuel line in the engine compartment as noted by the blue arrow.

And here is close-up of the NX NO2 fuel line routed into the engine compartment.

At this point, we move toward the NX Lightning Series Solenoid install. The first thing to do here is assemble the fittings on the solenoid and purge solenoid. Always remember to use the included thread lock to secure the fittings.

One awesome features of the NX Lightning Series Solenoid is that it attaches directly to the purge solenoid. Attach the NX Lightning Series Solenoid to the purge solenoid and install the shorter NX NO2 fuel line to the bottom of the NX Lightning Series Solenoid. Remember to cover the open end of the NX NO2 fuel line with painter’s tape to protect it from debris.

Then you will want to bend the mounting bracket as I am showing here and install it on the top screw of the NX solenoid.

Let’s get this mounted in the engine bay. I found fantastic location to mount the NX Lightning Series Solenoid that works beautifully with the NO2 fuel line run. It is the location where the AC refill line/bracket is located!

There are two ways to do this. You can attempt to mount it in front of the bracket or simple shave part of the AC refill bracket off using your dremmel. I personally cut off the back of the AC refill bracket that faces the firewall to make sure the mount was secure. Regardless, this location is absolutely ideal!

After you have mounted the solenoids, screw in the NX NO2 fuel line from the bottle and secure it using the included thread locks if you did not in the earlier step.

Finally, let’s mount the nozzle and jet. I used the STETT Performance Nitrous/Methanol Elbow which includes a 1/8” NPT port for the nitrous nozzle. This is the perfect spot for the nitrous shot and very PNP. I am using a .31 jet which is rated for 35 crank horsepower. The jet will be inserted into the nozzle with the tapered end facing away from the nozzle.

Secure the fuel line to the nozzle using the supplied thread lock.

For the time being, I didn’t finish the purge install yet in the interest of getting this review done, but I will include instructions on this as soon as I finish it.

This really finishes the hardware installation, so let’s move onto the wiring under the hood and in the cabin. Let’s stay under the hood because we are still there. The first item to address is mounting the relay for the solenoid. Again, I found a perfect spot for this relay that keeps it away from heat. Right behind the driver’s side headlight there is a nice spot that you can see below.

For the constant power, you don’t want to run a wire all the way to the trunk obviously, so I used the battery post under the hood. You can see it in the picture below. Simply pull the plastic cover and secure the wire under the rear bolt. I used a 30 amp fuse to protect the system for a surge.

Wire up the solenoid and purge valve according to the instructions and route the needed wires into the cabin. I routed my wires through the steering wheel grommet shown below with a blue arrow. It is an easy, easy run.

At this point you will wire up the NX Octane Series Progressive Nitrous Controller according to the instructions. The instructions are very thorough to say the least. If you want to view them prior to install, here is a link.

Other than the obvious, I do want to cover a few items:

1. Grounding the (2) controller grounds that require locations that are not shared grounds.
2. Key-on power.
3. RPM… where to get it?
4. TPS… where to get it?

The first thing I will cover is the ground locations. I searched for a while and ended up deciding just to drill 2 small pilot holes in the sheet metal below the trunk “pop” lever and mount the grounds there. This location is completely covered by carpet and takes 5 minutes total. You can see the mount points marked by blue arrows.

How do I get key-on power? Well since you ask. I used a Tap-A-Fuse which is such an easy solution. You can tap either fuse location 5 (blue arrow in picture below) if it is open or you can “jumper” fuse location 7 in the fuse box for key-on power.

The NX Octane Series Progressive Nitrous Controller has a driver that will tell the solenoids to turn on. Just find any easy spot under the dash to mount it. I actually put it on under the dash above the hood “pop” lever.

So how do you get the RPM signal? The RPM output is pin 21 on the small grey slider in the ecu box. That is off the driver's side ecu plug. If you are not sure where to find the grey slider, just watch this video and look at 4:23 to see it:

Now you will need to intercept the black wire in pin 21.

What is the easiest way to intercept it? I actually used a wire to create a simple and clean PNP style solution. I simply removed the PNP wire from my JB3 harness and stripped off a small section.

Then I added a black jumper wire.

Soldered it and used shrink wrap.

Then re-insert that back into pin 21 on your PNP harness and you have an RPM signal!!!

This is a standard 6 cylinder tach signal and you will use multiplier of /3 to get any controller to recognize this rpm signal.

Use the same technique to intercept the TPS wire. Where is the TPS wire? It is also on the grey subconnector and pin 7 (yellow/white wire). I intercepted it in the PNP harness using the technique above.

Then run the wire out of the ecu through the middle rubber grommet. I ran the wire across the slider above the engine to the driver’s side of the car to keep things clean.

Route all the wires into the cabin through the rubber steering wheel grommet shown above.

Follow the rest of the instructions to finish the wiring and then tuck all the wires under the footwell carpet to keep things clean.

The final item to cover is the trigger switches for NX EFI kit, NX purge kit, and Purge fire button. I chose to go to Autozone and buy some blue led trigger switches so I could color coat my items. Red is methanol and blue is nitrous. Then, I had to decide where to put everything and I chose the armrest area. Just simply remove the rubber bottom to the armrest location that makes a perfect trigger switch panel. You can even use the rubber bottom to trace out the dimensions for the trigger panel. To remove the rubber insert, just lift it up using a little pressure to create friction. I decided again to use Lexan plastic to create the mounting plate because it is so easy to cut and form with dremmel. I placed the rubber insert on the Lexan to trace the pattern.

Then cut out and sand down the Lexan using your dremmel to create the mounting plate. After it is cut, trace the mounting locations for the trigger switches and purge fire button. Use a small drill to create a pilot hole, then use your step drill bit to open the hole to the correct mounting diameter.

I love carbon fiber fabric and used it to cover the mounting plate. Spray adhesive works beautifully here and follow normal wrapping procedures.

Time to mount the switches and purge button on the plate.

Wire things up and insert the panel into your armrest area.

At this point, your kit is ready to go but you still need to set up your Octane Series Progressive Nitrous Controller. Since the controller is such an advanced piece, I would like to cover that in the next section.

Octane Series Progressive Nitrous Controller

I wanted to look at the Octane Series Progressive Nitrous Controller separately because it is brings so much to the table. If you have a moment, please read through the instruction manual on the Octane Series Progressive Nitrous Controller:

Nitrous safety needs to be a strong consideration as it is with things like methanol or boost. Basically the Nitrous Express Octane Series Progressive Nitrous Controller does everything. I am not sure I could state it better than Nitrous Express, so have a look.

Basic Features:

• RPM window switch
• Wide-Open-Throttle detection when used with factory TPS or WOT switch.
(Supports Fly-by-wire TPS)
• Progressive controller (time or RPM based) with a 5 section programmable

• Progressive Controller Monitor Gauge which graphically displays all configured
• AIR/FUEL Gauge that supports all O2 widebands with a programmable analog
output or the FJO Digital Data Bus.)
• Nitrous Pressure Gauge with programmable safety set points.
• Boost Gauge with programmable safety set points.
• Fuel Pressure Gauge with programmable safety set points.
• Oil Pressure Gauge with programmable safety set points.
• Automatic Bottle Heater Control with safety shut-off
• Shift Light

Advanced Programming Features:
• Lean and Rich Cut-Off
• Remote ARMing
• First Gear Lockout
• Ramp delay
• Default Power Up display mode
• Automatic Armed display mode
• User defined color ranges for each configured option
• Expandable progressive driver that allows the main unit to drive an unlimited
number of solenoids
To me, the Octane Series Progressive Nitrous Controller offers an unbelievable feature set. It is a boost gauge, fuel pressure gauge, nitrous pressure gauge, tach, shift light, bottle heater controller, visual data logger, nitrous window switch, nitrous WOT/TPS switch, progressive nitrous controller, etc. The Octane Series Progressive Nitrous Controller is safety. Safety has been critically important to me through this whole process, so let me define a few things.

What is a window switch? A window switch defines an rpm range where the nitrous can spray if all other conditions are met. An example would be 3500 – 6300 rpms. This means you can never hit redline under nitrous and you can stop it from spraying too low in the rpm range.

What is a TPS (WOT) switch? The TPS switching means the nitrous cannot spray unless you are under wide open throttle (WOT). This assures you will get full fueling when the nitrous system sprays

What is an air fuel ratio cutoff. A lean/rich air fuel ratio cutout means the controller will shutdown the nitrous system in the event that the air fuel ratio goes to rich or too lean. It means it will stop the nitrous system before any damage could occur.

The Nitrous Express Octane Series Progressive Nitrous Controller also allows the FJO digital data bus input which is gigantic. This is a very high speed input for the wideband allowing multiple O2 sensors to be used. This is the fastest possible input ensuring the A/F data the controller uses for the A/F ratio shutdown is extraordinarily fast.

Finally, the Octane Series Progressive Nitrous Controller can obviously progressively control the nitrous. This will allow a time delay from the point all spray conditions are met and a time ramp for the nitrous to come on. It also allows rpm based progressive nitrous spraying. Everything is customizable and user defined.

Have a look at just some of the displays.

And of course, HD videos.

The bottom line is the Octane Series Progressive Nitrous Controller does everything I wanted in a compact color display!

Configuration Settings

Without going through every configuration setting, I wanted to post some of the more important.

TPS maximum voltage or WOT for our car can differ from vehicle to vehicle. For my vehicle 2.03 is highest TPS will go, but sometimes at WOT the TPS can be as low as 1.95v. I set it to 1.80v to ensure the varying TPS at WOT will not kick me out of nitrous spraying.

I set the RPM window to 3000 rpms to 6300 rpms. This means if all the other conditions are met, that nitrous can only spray between these rpms.

I chose to use a time delay of 1 second. This means once I hit TPS voltage of 1.8v or higher (WOT) and I am within the RPM window, then the controller will delay once second before spraying the nitrous. This was to ensure I will be spraying methanol before the nitrous ever hits the engine. I then chose a time ramp of 3 seconds, meaning the nitrous will ramp the nitrous from 0% to 100% linearly over 3 seconds. This ramp gives the car ample time to react to the nitrous through the post turbo wideband O2 sensors. The data shows this worked beautifully.

Next, A/F ratio cutoff is critically important. In my testing, I have found the N54 direct injection to be remarkably flexible. In fact, what you would consider lean on a traditional port fuel injection car is VASTLY different on the N54 DI motor. 13.5:1 air/fuel ratios are not uncommon at all under full boost on the N54. With that said, I wanted it to be richer than what the stock JB3 provides to give me more head room for safety purposes. Terry Burger from BMS was remarkably helpful through the process. Through Terry’s help, I was able to modify my JB3 board from the stock 5.5k ohm fuel resistor ultimately to a 2.2k ohm fuel resistor. Below you can see the difference from 5.5k ohm, to 3.3k ohm, to 2.2k ohm resistor.

The 2.2k ohm fuel resistor gave me a lot of headroom of 12.5:1 at WOT to 11.5:1 at redline.

This allowed me to go with an A/F ratio cutoff on the NX Octane Series Progressive Nitrous Controller of 12.8:1 with a delay of 2/10 seconds. This means if the A/F ratio goes leaner than 12.8:1 for more than 0.2 seconds the system will automatically shutoff.

I set the bottle safety cutoff to 950 to 1075 psi guaranteeing the nitrous system cannot spray without having an acceptable bottle pressure. This prevents the setup from going rich or lean due to high or low bottle pressure.


Once I felt I had effectively addressed safety, it was time to hit the dyno. I knew going in that there was a strong possibility that I would smoke the clutch and unfortunately I did. With that said, I still feel it was worth it because the data is superb.

It should be emphasized that despite the fact that many N54 guys run MS109 during their dyno runs, I wanted to establish real world gains on pump gas.

This data was all obtained on a Mustang Dyno using JB3 2.0 Gen. 3 board with 2.2k ohm fuel resistors. It is also easy to note the massive clutch slip from 4200 to 4800 rpms on the nitrous run. Keep in mind the Mustang Dyno is a load bearing dyno, so it simulates road conditions incredibly well and it is the standard for dyno tuning cars. Let’s begin by examining the A/F ratio data. First, let’s look at the A/F ratios off nitrous.

Now, the A/F ratios on the NX EFI nitrous kit.

On both plots, you can see an A/F ratio of around 12.5:1 at WOT and near 11.5:1 at redline. Notice on the nitrous run, the A/F ratios actually dips slightly richer in the middle rpms and nearly identical at redline. Clearly the car is reacting extremely well and quickly detecting the nitrous then adding the appropriate fuel instaneously. I think these plots speak more than anything I could say.

Next, let’s examine the timing during a street pull I did prior to the dyno session. I wasn’t sure if we would lose the clutch on the dyno and didn’t want to miss a logging opportunity. You can see a clear timing rise through the entire run without any KR (knock retard) events whatsoever.

Again, this data strongly speaks for itself.

Finally, let’s look at the power and torque the N54 made on the Nitrous Express EFI kit with a 35 hp jet. This was the most surprising part of the testing. First, I want to post the run without nitrous running about 16-16.5 psi with approximately 700 ml/min of methanol (66/33) using pump gas.

You can see I made 402 rwhp and 423 rwtq.

Now, the dyno on the Nitrous Express EFI kit with a 35 hp jet. This run averaged about 15 psi with approximately 700 ml/min of methanol (85/15) running pump gas. It should be noted, I ran lower boost on this run than the basline run.

This run produced 487 rwhp and 478 rwtq outside of the clutch slip. It should be noted that the torque was still rising when the slip occurred, so we do not know the full torque the car would have produced. The difference is a gain of 85 rwhp and 55 rwtq! It should also be noted that the increase in horsepower was made at 1 – 1.5 psi less than the baseline run. These are not spot gains, but gains over almost the entire dyno adding enormous area under the curve. We also can see the dyno on the Nitrous Express EFI run was considerably smoother, but I think most of that should be attributed to the JB3 2.0 boost control.

**It should also be noted again, that these runs were done on a Mustang Dyno which traditionally read 8-12% lower than Dynojets. I made 252 rwhp stock and many of the dynojet numbers average around 272 rwhp stock. To compare these Mustang Dyno numbers to a dynojet, we should apply an 8% correction factor. This is an accepted technique by most if not all. The 8% correction factor results in the following results:

526 rwhp on Nitrous Express EFI kit.
516 rwtq on Nitrous Express EFI kit.
Increase of 92 rwhp over baseline dyno.
Increase of 59 rwtq over baseline dyno.


Nitrous Express is clearly in the upper echelon of nitrous systems. Their packaging was superior, their customer service superior, their technical expertise was superior, and the NX EFI nitrous kit is absolutely top quality. The Nitrous Express Octane Series Progressive Nitrous Controller is the crown jewel in this setup. It provides an unmatched feature set allowing a very high level of safety, control, and all in a 52 mm gauge foot print. There is a reason that people say Nitrous Express is the best in the business and now I know.

If I was to order now knowing all the information I have now, I would order:

- Nitrous Express EFI Dry Kit with 10 lb bottle
- Bottle Heater
- Purge Valve Setup (optional)
- Pressure Transducer (1600 psi) & Harness
- Nitrous Express Octane Series Progressive Nitrous Controller

The reality is I ordered a bit too much.

I personally feel comfortable concluding the A/F ratios appear very safe under nitrous. The timing appears to be superb on all the nitrous runs with a stock like rise across the rpm range and similar to everything I have logged. The NX 35 hp shot was worth a dynojet corrected 92 rwhp and at least 59 rwtq on pump gas.

To tell the truth, this began as a curiosity for me. I wanted to know, based on data, whether nitrous would work well on the N54. This exploration lead into a long project that began with the FJO Wideband O2 kit with Data Logging, moved onto the STETT Nitrous/Methanol Elbow, and culminated with the Nitrous Express EFI kit with Octane Series Progressive Controller. I always knew I was going to run a smaller shot, but I never expected such remarkable gains. The N54 seems to respond incredibly well to nitrous. I really feel the safety mechanisms in place on the Nitrous Express Octane Series Progressive Nitrous Controller along with the Snow Performance water/methanol injection make for a very comfortable setup. We are using a small 35 hp dry shot with the addition of 116 octane fuel to create a pseudo-wet shot producing superb gains. I know some people will react like I once did and say “NAWS doesn’t belong on a BMW”, but I hope after objectively looking at the data that many will respond by questioning the real roots of that urban legend.