There's a 455-hp Civic on our cover. Let's take it for a drive.
Step 1: Drive to the gas station. Four hundred fifty-five hp uses a lot of gas.
Step 1.1: Oops, pump gas won't work. Detour to the local sandrail shop for a tankful of C16 leaded race juice instead.
Step 1.2: Not so fast. Pumping C16 into a street car is illegal. Even if they would look the other way, the large-diameter leaded pump nozzle won't fit in a Civic's skinny filler neck.
Step 1.3: Drive to the auto parts store for a gas can-slowly, so you don't run out of gas. Naturally, all they have is a 2.5-gallon can.
Step 1.4: Fill the can. Fill the car. Fill the can. Fill the car. Fill the can. Fill the car. Fill the can... oops, car is full. Put the full can of gas in the hatch and drive carefully.
Step 1.5: Pay $85 for 10 gallons of gas.
Step 2: Prowl the stoplights for a victim. An STi would be funny. Or maybe a Z06. Better yet, a Viper. Power-to-weight, remember? Fate inevitably lines you up with a cheerleader in a Cavalier. Oh, well, gotta warm up on something.
The light goes green. Polly prissy pants finishes dialing her phone, looks up and tries to remember which pedal makes it go.
Gas, clutch, finesse. The Civic is so light that even off boost, the front tires scramble for traction and you pull even with her driver's door before the turbo finally comes alive. Wham! The engine is bouncing off the rev limiter in a blink. Grab second and ... wait. There's hissing. The turbo is doing something. Wait for it ... wham, rev limiter! Damn, she's pulling away! Grab third. Nail it, hiss ... whoa, actual acceleration. The engine strains, the tires pound over every crack in the pavement, ready to snap an axle with all the strain. The steering wheel yanks left, then right-don't run into rear bumper as you pull even again! Wham! The tires break loose again and the rev limiter hits. Grab fourth, hiss, wait ... oops, red light.
The cheerleader gets there first.
Skid to a stop next to her, engine idling with tense impatience, rear hatch rattling in sympathy, a faint whiff of smoke wafting around the edges of the hood. Your victim-to-be looks over quizzically, faintly wondering what all the noise and smoke is for, then rolls up her window so she can hear her boyfriend on the phone.
Step 3: Drive home and think about balance.
A 455-hp Civic is a dick-swinging achievement of engineering, and a fully justified exercise if you have a business plan, but before you start building your own, consider the consequences. Even though you can switch to low-boost mode and run pump gas, the quest for a big number introduces compromises that ruin the drive. The injectors and turbo still have to be sized for your dyno conquests. That means a rich idle-since the huge injectors can't meter out small doses of fuel accurately enough-and the lag of a monster turbo. The occasional tankfuls of leaded gas poison your expensive wideband O2 sensor and cat (if you have one), not to mention the air. And then there's the fact that after one 455-hp dyno pull and one 117-mph quarter-mile pass, this particular Civic barfed its guts all over the ground. Oh, sure, with more prep time and a lot more money you could make it live longer, but you can't make more than 225 hp per liter truly reliable.
So why do you really want a 455-hp Civic? Are you just trying to be an Internet hero? Photoshop and an active imagination work just as well. Wanna be on the cover of Sport Compact Car? Too late, we just did the 455-hp Civic thing. Fact is, unless it's a purpose-built racecar, a 455-hp Civic is just automotive self-service.
Nobody will worship you if you build a 250-hp Civic, but your car will actually be much better. Little things like boost response, part-throttle driveability and traction are useless for Internet one-upmanship, but they're everything behind the wheel. This is why my own Silvia makes a lowly 280-ish hp at the wheels while any self-respecting 'Net maven makes twice as much. I don't want to be your hero, I just want to enjoy my car.
Start thinking this way and you start coming up with some very different plans. I was recently daydreaming about a real-world MR2 Spyder. Our long lost project car managed to pull more than 1.0 g with perfect balance and a comfortable ride. It was only lacking power. This is where most project daydreams would go wrong. You dream up a turbo, but then the rods go shooting out the side of the block, so you dream up a built bottom end. You have to dream up an intercooler, but with no airflow back there, it has to be air-to-water. That means a pump, a reservoir full of water, and a big cooler in front of the radiator. Oops, now cooling is compromised.
Suddenly you've dreamt up 300 hp, but now that perfectly balanced car is a terror to drive. Touch the throttle and you're backwards in a ditch. Now you need big rear tires, but that means a widebody kit. Looks like you're in for paint and bodywork, too. In the end, you might as well park it on some mirrors and pillow stuffing; you just built yourself a show car.
Here's what happens when you aren't trying to impress anybody: First you realize the car is really good as is, so you shouldn't change much. An extra 50 to 70 hp would be plenty to make it fast. Remember, this thing only weighs 2,200 pounds. Then you start thinking supercharger. You'd get linear throttle response and TRD already makes one.
But wait. Why are we willing to accept a 6-psi supercharger with no intercooler, but not a non-intercooled, 6-psi turbo? At the same boost level, a properly sized turbo is more efficient, so it should work better without an intercooler. Even better, a non-intercooled turbo could be bolted on without removing the engine, which you have to do to bolt anything on the intake side of an MR2 engine.
We tested a 6-psi, non-intercooled G20 built by Jim Wolf many years ago and boost response was so quick, you honestly couldn't tell it was turbocharged. It just felt big and powerful. All the hardware you need is a manifold, a turbo and a pipe. You don't even need a blow-off valve at 6 psi. This is cheap!
That G20 only made 170 hp, but it made lots of torque all the time. Flexible, responsive power would be perfect for the MR2's nimble chassis, but it would probably roast the inside tire on any corner. Order up a nice, smooth, helical limited slip and call it a day. Your car is done. No widebodies, thanks.
Now the clencher: A turbo is a pretty effective muffler, so you could just run the downpipe into a catalytic converter, then a short resonator, and out the back. Eliminating that big, stock muffler opens up a big hole in the back of the car. Maybe, with a little clever fiberglass work, you could add a trunk!
Of course, I'm not going to do any of this, so I guess this is just punching my automotive clown. Hey, everybody does it.