Lately, it seems like a weekly occurrence that someone reads one of our articles and then comments, “That’s a nice sleeper.” And for the life of me, I can’t figure why someone would refer to a Camaro or a ZR1 Corvette as a Sleeper. Yes, in the articles, both of these examples were highly modified and make 400 to 500 horsepower more than stock. However, no matter how much power a ZR1 or ZL1 makes, it’s never going to be a sleeper. Why? Because these cars are expected to be fast in the first place.
Definition of a Sleeper
A Sleeper is an outwardly common-looking vehicle that possesses something special in the way of high-performance modifications. These changes are performed in a subtle way to keep people’s attention off the car, making it unsuspecting while appearing stock.
For this article, we will be taking a look at two different sleepers and looking at the execution of each car. On the left, we have a 1987 Oldsmobile Cutlass know as the Bingo Bomber owned by Lucas Shields. On the right is a 1977 Buick LaSabre called the Church Lady Buick, owned by David Thompson. Both cars are super-stealthy and fast.
Selecting A Car
If you’re going to build a sleeper, the first thing you need to do is find the right candidate. Stay away from Corvettes, Mustangs, Camaros, Chargers, and anything else that is known for performance. You will want to find a car that was never popular, and there are tons to consider from the 1970s, 80s, and 90s. Buicks, Mercurys, Lincolns, and Cutlass’ are all excellent examples. But don’t stop there, you could also build a van, small truck, or maybe even an older import, as well.
Here’s a good test for you: if the car you’re looking at was sitting in a parking lot, would you give it a second glance? If your answer is yes, you have failed. If not, then you’re on the right path.
Nothing says, “This car is not a sleeper” more than a fresh paint job. If you’re willing to spend money on the exterior, odds are you have the cash to build an engine and drivetrain. In the case of a sleeper, the factory paint is good. Normal dents, dings, and oxidation are even better. Remember, the idea is not to draw any attention to the car. It doesn’t need to be repulsive, but if it’s too polished, it might raise a few eyebrows, which is exactly what you don’t want. Oh, and stay away from performance decals…this is a dead giveaway.
In our opinion, the Church Lady Buick is the perfect car. Buick LeSabres were never thought of as being fast, and while the vehicle isn’t sporty-looking, it’s not too mundane either. This car still wears all of the original trim and looks like it belongs in a church parking lot on any given Sunday.
The Bingo Bomber is another great candidate, and G-body’s have fantastic support from the aftermarket. One thing that Shields’ did was replace the ’87 factory front end with an earlier model, making it look even less sporty, in true sleeper fashion.
The interior of a sleeper needs to be stock, and the more original, the better. Column shifters, couch-like seats, and saggy headliners will get you bonus points. If you’re running aftermarket electronics and gauges, do your best to hide them. Just like the body, you want to be as discreet as possible. Unfortunately, this rule goes for safety precautions, as well. Roll cages, five-point seat belts, and racing seats are all off the table. It should be noted that we are not telling you to go and run a 9-second vehicle without the proper safety measures; we are just informing you of the rules. It’s in your best interest to build a car that is safe for the e.t. that the vehicle is capable of running.
Here’s another important tip: You will want to avoid dark window tint, as well. Why? Because it will look like you’re trying to hide something, and everything you have to hide is under the hood, but that’s our little secret. So let them see the faded green bench seat in all it’s glory when they walk by and take a peek. It needs to look like your great aunt Peggy just drove it to church for the first time in a month. We will give you bonus points for that vintage mothball scent and a box of tissues.
Wheels and Tires
Wheels can make or break a car in the looks department. And with the case of a sleeper, you won’t need to worry about it. Nope, you get to run the factory wheels or something of that nature. Billet wheels and beadlocks are completely out of the questions. Steel 15-inch wheels on all four corners are a solid choice, but you might get lucky. Some cars were equipped with aluminum wheels from the factory. Are they cool looking? Not at all. They will be lighter than the steel options and could offer some slight performance gains.
Both of our sample cars have period-correct wheels that give them an innocent look. While the factory 15-inch aluminum wheels on the Olds look sporty, they certainly don’t scream drag-car. The factory hubcaps on the Buick are the perfect accessory for a sleeper. They are low-key, and no one would expect this car to yank the front wheels at the starting line.
Tire selection can be a tricky situation, depending on how fast the car is. This is one of the few areas that is impossible to hide your true intentions. If you decided to run anything but a standard radial, most people would notice pretty quickly. If you’re trying to hook up on a hard radial, there are a few tricks to try. First, you can widen the wheels, if you have room for a wider tire in the rear fenderwells. Secondly, over the years, we have seen some pretty discreet traction bars that would go unnoticed. Third, a good set of adjustable shocks is a must, and get ready to spend a lot of time in “Mexico” testing and tuning your setup. However, if the car is really fast, it will need a sticky tire for added traction and safety, as well.
A Diamond In the Rough
Under the hood is where the magic of a sleeper takes place, and any powerplant is fair game. We’ve seen all types of combinations, from big-blocks, small-blocks, LS’s, turbos, superchargers, and nitrous.
Superchargers and big cubic-inch engines are not the standard selection for a car trying to be sneaky. Monstrous mountain motors, big cams, blowers, and some turbos tend to make lots of noise, giving the unsuspecting a heads-up on the situation. In my opinion, nitrous is king in the realm of sleepers. You can get away with a mild cam, adjust horsepower levels, and activate it when needed, if needed. However, you will want to avoid using a purge. Like the whine of a supercharger, bleeding nitrous from the lines is an unforgettable sound, letting people know what you’re packing. Instead, crack the feed line at the solenoid before making a pass. This act will accomplish the same thing as a purge solenoid by bleeding the air out of the line, but without the “Hey, look at me, I’m running Naws” as you pull up to the line.
If we take a look at the Church Lady Buick in the above video, the car sounds pretty mild. Most could tell that the LT1 powerplant has a cam, but without opening the hood, you would never know it has a nitrous system. The LT engine makes 430 ponies naturally-aspirated, and when the N2O activates, 300 additional horsepower is added instantly, along with gobs of torque to the wheels.
Shields’ Oldsmobile takes a slightly different approach to the engine combination. Everyone knows that junkyard LS engines love boost, and it’s a safe way to add some serious power to the platform. Shields’ started off with a stock-bottom-end 6.0-liter engine with a stage 2 cam, upgraded gaskets, and head bolts. He then added two BorgWarner 366SXE’s with billet wheels. This setup, with an inadequate fuel system and Holley EFI, the Olds makes enough power to crush the dreams of anyone that’s not making north of 900 horsepower.
Shields also took a modern approach with the transmission in the Oldsmobile. Ryan Maguire built a bulletproof 4l80E with a ProTorque torque converter. Shields says, “This car cruises effortlessly at 85 mph going down the highway. In fact, people always look at me funny when they see this old car cruising at speed with all of these modern cars.”
An exhaust system is an essential part of the program. You will want it to be as quiet as possible at all times. If you’re running a turbo, plumb the wastegates back into the exhaust tubing. You will also want to use quiet, high-performance mufflers. While a reserved set of mufflers will cost you some horsepower, you can always turn up the boost or, as they say in the nitrous world, “pill it up.”
We would not recommend running a custom license plate. Plates like, 1SLOSS or 2SLOW4U are not going to trick anyone. If you must run custom tags, get creative. Plates like the Church Lady’s YERLUZIN are sure to fire those egos up as the unsuspecting try to prove you wrong.
You Should Build One
While it might be a little harder to keep a sleeper a secret these days due to social media, don’t let that discourage you from building one. As you can see from both videos, these two cars are a riot on the street as well as the track and are sure to surprise a ton of people. And who doesn’t love a good suprise?