Nitrous Oxide Systems & Components

Nitrous is the simplest power adder to bolt on and the easiest to get wrong on paper - the difference is almost always delivery, jetting and bottle pressure, not the badge on the bottle. This page pulls together 24 in-stock products from Nitrous Express, NOS, ZEX and Allstar Performance, from $38.99 to $1,862.95: complete wet systems for EFI and carburetted cars (plate, throttle-body plate and fogger delivery), two plates sold on their own for builds and upgrades, and the components that make a system consistent - solenoids, nozzles, a purge kit, progressive controllers, bottle heaters, bottles, a jet pack, a fuel-pressure safety switch and a wide-open-throttle switch bracket. Every horsepower figure on this page is the jetting range the kit’s own listing states - a range to tune within, never a promise for your engine. Every order over $200 ships free.

OUR NITROUS PICKS

Product	What it is (as stated in the product listing)	Spec (from the product listing)	Price	Why it is here
4150 Pro-Power Plate Only (100-500HP)	Plate only - no bottle or solenoids (per listing)	Pro-Power plate, 100-500 HP, aluminum, black anodized, square bore (per listing)	$171.97	The build-your-own entry: a 4150 square-bore plate rated 100-500 HP in its listing, for racers who already own a bottle and solenoids and want the delivery end of the system only.
Main Line Nitrous Kit 50-150HP	Complete kit, 10 lb bottle (per listing)	Main-Line EFI, wet, single stage, 50-150 HP, universal EFI (per listing)	$524.91	The complete-kit value pick: Nitrous Express’s Main Line is a wet single-stage EFI system with its 10 lb bottle in the box and jetting steps its listing states at 50-150 HP.
Hitman Nitrous System Holley 4150	Complete kit, 10 lb bottle (per listing)	Wet, single stage, 100-200 HP, square bore (per listing)	$676.51	The carb pick: the Hitman is the 4150 square-bore version of the same idea - a wet single-stage plate system, 100-200 HP as listed, bottle included.
EFI Plate Nitrous Kit - GM LS 4-Bolt Plate 102mm	Complete kit, 10 lb bottle (per listing)	LS 102 mm plate system, wet, single stage, 50-400 HP, built for GM LS-Series (per listing)	$945.66	The late-model pick: an LS-specific throttle-body plate system - its listing states built for GM LS-Series and a 50-400 HP range, the widest jetting spread of any complete kit here.
Pro Fogger System	Complete fogger system (listing states no jetting range)	NOS Pro Fogger System, MPN 02462NOS; its listing states no further spec	$1,862.95	The ceiling pick: NOS’s Pro Fogger is the per-cylinder fogger end of the ladder - the delivery style built for large, evenly distributed shots. Its own listing is terse, and this page will not dress it up with numbers it does not state.

DELIVERY FIRST: PLATE, NOZZLE OR FOGGER

Shop delivery before horsepower. A plate system sandwiches a spray plate under the carburettor or throttle body - the flange is the fitment gate: the carb kits here are 4150 square bore (Hitman, Sniper, Power Shot at 125 HP as its listing states), the Pro Power Dominator kit is Dominator flange, and the LS kit is a 102 mm 4-bolt throttle-body plate whose listing states built for GM LS-Series. A nozzle system sprays through a fogger nozzle in the intake tract - the Proton EFI systems are that style, wet and single stage at 35-75 HP as listed. A fogger (direct-port) system puts a nozzle per cylinder for the largest, most even distribution - the Pro Shot Fogger kit and the Pro Fogger System close this page, and that style is the one that asks the most of the install. Wet versus dry is the second split: a wet system adds fuel with the nitrous at the plate or nozzle, while a dry system sprays nitrous only and leans on the engine’s own fuel system for the extra fuel. The complete kits gathered here state wet in their listings; if your build needs dry, say so before ordering rather than converting a wet kit on the bench. Questions before you order? Call 213-549-4279 (Mon-Fri, 9am-5pm PT) and we will read the listing with you.

JETTING IS THE TUNE - AND THE NUMBERS ARE THE MAKER’S

Every HP range on this page - 35-75 on the Proton, 50-150 on the Main Line, 100-200 on the Hitman, 50-400 on the LS plate, 100-500 on the Pro-Power plate and Dominator kit - is the range of jetting steps the manufacturer lists for that kit. It is not a dyno result and it is not transferable between engines: the same jets make different power on different combinations, and the fuel and tune around them decide whether the power is safe. The kit makers’ own instructions are consistent on the method, and this page repeats them as instructions, not advice of ours: start at the lowest jetting step and work up, use the premium or racing fuel the instructions require, and do not combine a kit with a chip or device that advances timing. The one tuning component on this page makes the point in hardware: the Big Shot Jet Pak is sold as four stated steps - 225, 275, 325 and 350 HP - because moving up a system is a jet change and a re-check, not a guess. Our listings mark these systems professional installation recommended, and that line is on the page because it is in the listings.

THE COMPONENTS THAT MAKE IT CONSISTENT

A nitrous system is only as repeatable as its bottle pressure and its switching. Purge: Nitrous Express’s own purge instructions state the purpose - release trapped air and gaseous nitrous from the feed line so liquid nitrous is waiting at the solenoid; the Mainline purge kit here is the 4 AN version, button, fittings and solenoid as listed. Bottle heat: bottle pressure falls as the bottle cools and empties, and heaters exist to hold it - the fully automatic heater here is listed as pressure controlled, 12V, for 10 and 15 lb bottles, with gauge and sensor. Read pressure targets from your own kit’s instructions, not from another brand’s page: the targets differ by brand, and a number that is right for one system is rich or lean for another. Control: progressive controllers meter the shot in over time instead of all at once - the EZ Maximizer is the entry controller, NOS’s 2-Stage Mini and the Maximizer 6 step up from there - and a wide-open-throttle switch (the Allstar bracket here is for Holley 4150 carburettors) keeps activation where its name says. Safety switching: the fuel-pressure safety switch is listed as adjustable with a 3 psi minimum - the component whose job is to keep nitrous from flowing when fuel pressure is not there. Solenoids close the list: the Lightning Stage 6 nitrous solenoid is listed with a .093 in orifice and 1/8 in NPT inlet and outlet, and NOS’s Power Shot solenoid listing states a PTFE plunger puck and stainless base - read orifice and thread per listing when you are replacing, not upgrading by eye.

AN HONEST NOTE ON WHAT IS NOT ON THIS PAGE

The wider range linked below carries well over a hundred individual jet listings - single NOS stainless flare jets and Nitrous Express replacement jets, size by size. They are deliberately not padded into this page: a jet is a tuning part you order by the exact size your tune calls for, from the wider range, not a pick we can make for you. Dry systems are likewise not gathered here, because the complete kits in stock state wet in their listings. And a legality note that belongs on the page rather than in fine print: NOS’s own kit instructions state that NOS has not pursued California CARB exemptions for its kits and they are not legal for use on pollution-controlled vehicles in California - check your own sanctioning body and state rules before a bottle goes in a street car.

QUESTIONS RACERS ASK US

Wet or dry - which do I need? Wet adds the extra fuel at the plate or nozzle with the nitrous; dry sprays nitrous only and relies on your fuel system to add it. The complete kits on this page state wet in their listings, so if your combination was planned around a dry system, that is a conversation to have before ordering, not a conversion to improvise after.

Is the horsepower on the box what my engine will make? No. The ranges here are the jetting steps the manufacturer lists for each kit - the tuning window, not a result. What a given step makes depends on your engine, fuel and tune, which is why the makers’ instructions say to start at the lowest step and work up.

Do I need a purge kit and a bottle heater, or are they upsells? They are consistency parts, and whether you need them depends on how repeatable you need the car to be. The purge clears gaseous nitrous from the feed line so the hit is liquid from the solenoid; the heater holds bottle pressure as the bottle cools. A first system on a test-and-tune car can run without both; a bracket car chasing hundredths usually ends up with both.

Can I run nitrous on the street in California? For NOS kits, the manufacturer’s own instructions answer it: no CARB exemption has been pursued, so the kits are not legal for use on pollution-controlled vehicles in California. Track and competition use is what these systems are built and listed for - confirm your sanctioning body’s rules for your class.

Shopping the wider range? Browse the full Nitrous Oxide Systems and Components collection, read our guides on the News & Builds blog, or see the page that came before this one: Racing Fire Safety (suits, gloves, suppression).

× Close