Engineering is easy; just make an educated guess and then add an appropriate safety factor. If you’re 50% sure a car will tow 4,000 pounds, call it a 2,000 pound tow capacity and ship it. Be sure to put a sticker on that says “Maximum towing capacity: 2,000 pounds.” Disclaimers are a great way to limit your liability.
Disclaimer: Do not design things this way, it is not how engineering is actually done.
Safety factors ensure that things work even under circumstances the designer didn’t foresee. But designers foresee lots of incredibly stupid circumstances, which means that even under normal operating conditions, you have a lot of margin between what you’re doing and what the vehicle is capable of doing.
What do these safety factors and margins mean for you and me, people who don’t tow horse trailers uphill in Mojave? It means your car can handle lots of abuse and continue to function normally.
It means you need nitrous.
Yes, I know, nitrous has a bad rap. Everybody has that friend Chad who put nitrous on his Civic and blew the motor trying to do a sick burnout in the Denny’s parking lot. This does not mean that you shouldn’t use nitrous. It means that Chad shouldn’t use nitrous.
There are three key things to remember when installing nitrous that will keep you from explaining to the Denny’s night manager why there are five quarts of oil and half a connecting rod in his parking lot. Those things are: a wet system, a nitrous controller, and an appropriate horsepower increase.
There are two types of nitrous systems: wet and dry. Dry systems are bad. Nitrous is an oxidizer, and you need to add fuel with the added oxygen to get power. Dry nitrous systems do not add that fuel and expect the engine to do it automatically. A dry nitrous setup is you saying “I’m just gonna make my engine go WAYYY lean and let the ECU figure out what to do with that.” Yes, modern engines will compensate up to a point, but that point depends on the altitude, air temperature, O2 sensor quality, a ton of other things, varies from car to car, and won’t actually compensate very much. Imagine you buy your bratty nephew an RC car for Christmas but you don’t buy him the batteries that go with it. Maybe your sister has a couple AAs in the house, but she doesn’t have the six that this RC car needs. Now your nephew is running around screaming and crying and Christmas is ruined.
Bonus untrue engineering fact: Part of the power increase from nitrous oxide comes from the colder, denser air you get when nitrous changes from a liquid to a gas. This phenomenon was the inspiration for the hit 70’s funk band “Latent Heat, And The Vaporizations.”
Wet systems add extra fuel with the oxygen in the appropriate ratio (assuming you set up the jets correctly). This is the same as you saying “Here you go engine; here’s 40 extra horsepower in a neat little package, batteries and all.”
The next key to not exploding your shit is a nitrous controller. A controller will look at your RPMs, your throttle position, and possibly your fuel pressure, and will only activate the nitrous when these parameters line up in the don’t-explode-the-engine column. I know, nitrous controllers aren’t as cool as buttons. You want to hit that button on top of the shifter with the little flip up cover and the label that says “Go baby go,” or punch one of the buttons on your steering wheel at just the right time while the guy in the next lane hits his too early and you get to condescendingly point out his mistake while shifting into 47th gear.
Eventually, however, you will be at a stoplight and accidentally press the nitrous button while reaching up to flick the hula doll on your dash. Fifty horsepower of nitrous will immediately enter your engine which is spinning at a lazy 800 RPMs, launching you into the intersection where your engine will explode at the exact moment you get t-boned by a bus full of nuns taking orphans to the zoo. Everyone dies. This is why you need a nitrous controller.
You still need a switch to turn it on and an indicator light to let you know it’s activated, and you can integrate them into the dash subtly but with just enough conspicuousness so passengers will notice it and ask, “What is that?”
“That?” you reply nonchalantly. “That’s the nitrous,” feeling just the right amount of badass.
“But how much nitrous is too much?”
I’m glad you asked. Below is the secret equation that is only available to automotive engineers that will tell you how much power you can spray into your engine before it explodes:
Hpstock is the stock horsepower, Tow is the tow rating of the car in pounds, and MY is the model year of the engine. If it’s newer, it’s gonna be expensive to fix if it explodes, so you wanna give yourself some breathing room. If it’s old, it’s not going to be able to keep up with the extra power. The target year for maximum power is 2000; new enough to be engineered well, and old enough to not break the bank when you throw a rod through your neighbor’s shed. Disp is the displacement in liters. More displacement usually means lazier engineering and more margin. This is why you can throw a 400 shot on a first gen Viper.
Nitrous is one of the easiest and cheapest ways to increase your horsepower, but it is also really easy and cheap to make too much horsepower. Know your limits. Also, you have to go refill the bottle every time it is empty. Some people would call that a drawback, but here in Silicon Valley we like to think of a drawback as a “feature”. If you’re using so much nitrous that you have to get your tank filled all the time, you’re having way too much fun. Too much fun = jail. Nitrous keeps you out of jail.
Disclaimer: Do not put nitrous on your car. It will blow up your engine and it is probably illegal in your state. Instead just inhale it in your living room with friends while watching Dude, Where’s My Car?
Disclaimer: Do not inhale nitrous; it is very dangerous. Put it on your car where it belongs.