Chevy Caprice Nitrous Kit - Killer Whale, Part 3

Police Action--Adding A Zex Nitrous System Catapults Our Cop Car Into The Mid-13s

Vinnie The Hitman May 1, 2008 0 Comment(s)
Sucp_0805_01_z Chevy_caprice Nitrous_kit_installation 2/14

Want to put some beef into your pig? Then add a Zex nitrous system to your car and get up to 125 additional horsepower. We did, and as a result, we now have a Caprice that runs 13.50s.

It's been three months since we took delivery of the Killer Whale, and we're just smitten with its performance, all-around capability, and off-the-charts fun factor. Not only has it proven to be stone reliable, but it's also incredibly comfortable for the daily grind and has shown its merits both on the dragstrip and on the streets. Better yet, we've averaged about 20 mpg in combined city and highway driving, proving that LT1 performance comes with little sacrifice at the pump. With well over 115,000 miles on the clock, those 5.7 liters of American willpower are still firin' on all eight and have readily accepted all the mods we've thrown at it without a single hiccup.

Thanks to the Level 10 transmission and torque converter, as well as the slew of new and used bolt-ons, we've whittled our elapsed times from a baseline of 15.251 at 91.11 to a rather impressive 14.405 at 92.81 mph. But at this point, we're pretty much done with the bolt-on mods, and our quest for quicker quarter-mile times has redirected our performance focus toward more substantial modifications. It's a natural progression, really. Question is, which way do we go?

Sucp_0805_02_z Chevy_caprice Zex_nitrous_kit 3/14

Included in the LT1-specific nitrous kit by Zex (PN 82018) is a self-contained management unit that houses all the solenoids, electronics, and plumbing systems; a 10-pound aluminum bottle powdercoated in Zex's signature gloss purple; an inline fuel pump; and all the wiring and hardware necessary for a complete installation. New spark plugs are recommended with any nitrous installation, so we went with Zex's own line of Power Tune performance spark plugs (PN 82070-8) for a more assured spark.

Good Cop, Bad Cop
So there we were, racking that gray matter for the best way to step up our game to increase power. After weighing our options, we decided that a power adder would be a good way to start, as opposed to a full-on naturally aspirated engine buildup. We then had to choose which power adder, and the choices only complicated things some more (in case you weren't aware, our brains aren't exactly the swiftest of machines).

At first, we looked at supercharging, but the subsequent commitment to precise PCM tuning and the added weight was unappealing in the long run. This would also hold true for a turbocharger system that would throw increased underhood temps into the equation. In the end, nitrous oxide made the most sense because of its simplicity and affordability. There is nothing as effective, dollar for dollar, as a good nitrous system.

When looking for a nitrous system, there will be many questions surrounding the topic. Do you want a dry or wet system? How much power do you want to add? How much time do you want to spend on installation? Once you get your answers, you'll have a clearer picture as to what you want so you can make a more educated choice. For our application, we found the Zex system to our liking the most. Let us explain why.

Sucp_0805_03_z Chevy_caprice Nitrous_kit_installation 4/14

First up, we found a spot for the nitrous nozzle that was close to the throttle body. We then drilled a hole into the air inlet tube and mounted the brass fitting that the nozzle itself threads into. The dimple in the hex part lets you know which direction the nozzle will discharge while you're tightening it down.

Although there are no less than seven nitrous oxide companies out there offering systems for fuel-injected V-8s, we turned our short attention spans to the manufacturers of dry kits. By injecting the nitrous oxide directly into the air induction system and allowing the existing fuel injectors to provide the requisite additional fuel, this clean and effective setup reduces the chances of massive backfires. On an older car like ours, using a wet nitrous system that injects both gasoline and nitrous simultaneously into the intake manifold can prove to be dicey. This is because all the fuel being injected can sit in the manifold and cylinder head's ports and get absorbed into the oil sludge and carbon buildup like a sponge, making it a bomb in the event of a slight backfire. All that fuel wants to combust, and it will rip apart expensive hard parts in the process. Therefore, a dry kit is the safer, more preferred choice for our Killer Whale.

There are only a few LT1-specific dry manifold nitrous kits on the market, but by far the easiest one to install and maintain is produced by Zex. It offers a kit that's adjustable from 75 to 125 additional horsepower. Some people may get greedy and feel the need for more power and shun kits that are maxed out at 125, but those who are in the know understand that with a stock engine, this is the safe mechanical limit. Besides, we'd rather keep our rods and pistons inside our block rather than out of it. And yes, because it's designed for LT1 GM cars, it comes ready to install specifically for our application.




Connect With Us

Get Latest News and Articles. Newsletter Sign Up

subscribe to the magazine

get digital get print