Nitrous Oxide Tutorial for Nissan Sentra, 200SX, Infiniti G20

Everyone loves a good old fashioned Nissan B13 and B14 chassis 200sx or Sentra SE-R and Infiniti G20 P10 and P11. In this article I'm going to use the SR20DE normally aspirated to make power with nitrous oxide. Now, most uneducated hot rod guys and week end warriors will tell you that nitrous will blow up your motor. Which this can be true if your trying to use too much nitrous oxide or you have an engine other than an SR20DE. Why wouldn't an SR20DE blow up like the rest of them? Because it's stout and I don't just mean sturdy, it's practically built and designed for nitrous oxide. The displacement id good compared to other non SR20DE motors and the static compression is super nitrous friendly at 9.5.1.

The horsepower and torque on the SR20DE from the factory make it ideal for nitrous oxide measuring in at 140hp and 135tq. Unlike Honda motor with no torque the Nissan SR20DE makes gobs of torque which make it great for use with nitrous oxide because the motor stay in it's power band the whole time from low rpm to high rpm and the SR20DE doesn't rev over about 7000rpm which makes using nitrous oxide fun without any lag time. You don't need to build an SR20DE to handle nitrous oxide either unless you're going to be spraying more than a 125hp shot and do you really need more than 265 horsepower instantly on tap when you spray nitrous? I think not. Using this much nitrous on an SR20DE can yield mid 12 second time slips and mid to low 8's in the 1/8 mile.

So what do you need when spraying nitrous on a SR20DE? Not too much, but there is some optional equipment that helps.

Things you will need:
SR20DE nitrous part--Single fogger (wet) or direct port nitrous kit
SR20DE nitrous part--BKR7E NGK spark plugs (cold heat range plugs)
SR20DE nitrous part--A good header such as HotShot (or even an Ebay header made by SS Autochrome)
SR20DE nitrous part--A test pipe replacing the catalytic converter
SR20DE naturally aspirated part--A 2 ½ to 3 inch cat back exhaust
SR20DE naturally aspirated part--Magnacore spark plug wires
SR20DE naturally aspirated part--4 puck competition clutch kit stage 3
SR20DE naturally aspirated part--Nice new distributor cap and rotor bug
SR20DE naturally aspirated part--Warm air intake with filter and maf (mass air flow) sensor adapter
SR20DE nitrous part--Walboro 255lph fuel pump
Optional SR20DE Nitrous parts or materials:
SR20DE naturally aspirated part--Lightweight flywheel
SR20DE naturally aspirated part--Lightweight underdrive pulleys
SR20DE naturally aspirated part--MSD 6AL ignition box
SR20DE nitrous part--Nitrous bottle warmer and blanket
SR20DE nitrous part--Electric nitrous bottle opener
SR20DE naturally aspirated part--JWT S4 or S5 camshafts
SR20DE nitrous part--Race gas (your friend)
SR20DE nitrous part--Nitrous jetting kit
SR20DE nitrous part--Innovative air/fuel ratio meter

Now that you have the parts and accessories to make a nitrous breathing monster it's time to get to it. Some things you should know...

**You want a good header and exhaust system because of the amount of gas volume a SR20DE creates when huffing nitrous, you don't want that exhaust gas heat and energy backing up in the combustion chamber and burning your SR20DE's valves.

**A good ignition system is always recommended, we don't want to have a misfire on one cylinder when all of the other ones are under tremendous cylinder pressures. The pressure inside the SR20DE combustion chamber is so much so on nitrous that there is an extreme amount of heat and energy created so you want a good ignition box so the spark can jump from the electrode to the prong on the spark plug under this amount of great pressure.

**Because there is so much pressure in the SR20DE's combustion chamber on large quantities of nitrous you want to close the gap on your spark plugs to ensure that the electricity (or fire) happens with the plug under these conditions.

**We want to use NGK BKR7E spark plugs because they are a colder plug and great for nitrous usage. So much heat is generated during the power stroke that if you have a plug with a stock heat range it's likely to continue glowing red which means the next instant that air and fuel are in the chamber they will ignite before the correct timing of the event. This is called detonation or preignition and it is very harmful to your motor, we don't want to blow the ring lands off our pistons or sling a rod through the block do we?

**Using the stock air box is just a no-no; so, I won't really get into that, but the principle is that we want as much air other than nitrous entering the engine.

**A lightweight flywheel and pulley system will have less rotational weight and mass allowing your engine to rev quicker with more momentum, just free horsepower when driving around without nitrous on your SR20DE powered car.

**A good clutch, you want a good 4 puck clutch that doesn't have an overly strong clamping pressure plate such as ACT or Competition Clutch. If you get a pressure plate that holds way more torque capacity than what your needing it will have a tendency to stretch your clutch cable or possible break it, so beware when buying a clutch.

**Always use an arming switch and a wide open throttle micro switch. It's all about safety. Although the SR20DE is strong and more than capable it will still blow up in your face if you use a push button on your shifter and miss a gear on accident. I know that push button Hurst shift knobs look cool, but they are impractical unless you have an automatic or an RPM activated cutoff switch, which is a good idea to have anyway.

**Dial down your ignition timing, you need to have it at about 12 degrees at idle for a 120-125hp nitrous shot.

**Use good gas, while many times I have sprayed a 120hp shot of nitrous on pump gas and not had a problem this is not to say that you won't so for shot's over 100hp I suggest using 104 unleaded fuel, do not use leaded fuel because it will kill your o2 sensor; contrary to popular myth nitrous will not harm your o2 sensor either.

**Always keep your bottle pressure above 850psi, if you don't than you will be slow from shooting more fuel than nitrous into your motor causing a rich condition and a loss of power.

**Use a bottle warmer and a nitrous bottle blanket when it's cold in the winter months. Nitrous bottle pressures go way down when it's cold outside so you need to keep that bottle warm to keep pressures up.

**Do not put your nitrous bottle behind your passenger seat because it's easy to reach and turn on. Nitrous is still a compressed gas so you want it as far away from you as possible in the trunk, this is where a switch automatic nitrous bottle opener comes in handy.

**When assembling your nitrous kit use teflon paste for the nitrous and fuel fittings not teflon tape, teflon tape can clog up the tiny filters in your solenoids and cause you to either run lean or to rich; both situations can be bad.

**Make sure to use a relay going to your micro switch and solenoids. I don't know how many solenoids I have rebuilt for people from not using a relay and frying their solenoids. Solenoids are expensive to rebuild and even more expensive to replace so make sure to follow your nitrous kit instructions carefully.

**Do not start off your first time with a 125hp nitrous shot, you need to slightly break in the motor with lower nitrous shots first. Begin with a 50 or at most a 75hp nitrous shot and get used to the way it feels first before going bigger.

**When first using nitrous on a low shot you need to either use an air/fuel ratio gauge (a real one, not the one with little flashing lights-a wide band gauge) to make sure you are within safe air/fuel/nitrous ratio limits or take your car and do a full throttle pass on a deserted road, go through first, second, and a little bit of third and immediately turn the key to your ignition off. Pull over (best to do this in the sunlight) and inspect your spark plugs to see what your SR20DE engine is doing. Use a magnifying glass to look at them and the back of a Chilton's manual for color photos of spark plugs under rich or lean conditions.

**Camshafts will help your power off nitrous, but will considerably assist you on nitrous by leaving the valves open longer to get more nitrous in your SR20DE combustion chamber and by getting all of the hot pressurized gasses out of your SR20DE. By installing JWT (Jim Wolf Technology) S4 and S5 camshafts you will keep all the drivability you had before without all the work of removing your cylinder head (which is a headache on a SR20DE) to install new valve springs and retainers for more radical cams, they are not really needed on the SR20DE for nitrous and will kill your drivability.
**Fuel pump, only use either a 300zx twin turbo or high pressure Walboro 255lph fuel pump. You need as much fuel for nitrous going to that fuel solenoid for your SR20DE as you can get, to stay safe. It's also a good idea to replace your current fuel filter to a larger capacity 300zx (90-96) one.

**Tires...Last, but not least good tires. With a high dose of nitrous on your SR20DE you're going to need some sticky tires to catch traction. BF Goodrich drag radials, Nitto drag radials, or a slightly high tread wear like Falken Azenis if you do a lot of driving. So be safe out there and now you have the bare necessities to go fast. But, remember for all the power your nitrous eating SR20DE will have you need to consider brakes and suspension also just for safety.