My hat goes off to Keith Barry for tackling this interesting subject. It’s been my long-held belief that hybrids and electrics can make excellent race vehicles. The sheer raw torque of an electric motor is frightening. You want it to go and it goes, unlike gas engines that need to rev up into higher RPMs to really get going. It’s a distinct advantage. And hybrids like the Toyota Prius that basically have no gears in the transmission might not do as well as they could for gas mileage on high speed turnpike driving, but for low speed acceleration, there’s never any time spent changing gears, giving it another interesting advantage in races like autocross.
Further, the braking force of a hybrid is not like a normal car. The majority of the braking is done through “regenerative braking”. Which basically means turning those electric motors that speed up your car into brakes that also slow down your car. They act as generators, producing electricity (instead of consuming it) by creating a drag right on the hybrid transmission. It’s a very wonderful feeling, because when the regenerative braking is working, the braking force is centered right down the transmission. It’s like downshifting or engine braking. It’s remarkably smooth and centered, a stability that really can’t be beat. Unlike the normal wheel brakes, especially when they’re antilock brakes.
So hybrids should make excellent autocross racers.
So, yeah, racing a Prius …
Been there. Wanted to do it. The perks sounded good. And mostly, it’d just be really great to prove that hybrid cars aren’t slow. They don’t have to be just for sensible drivers.
But the reality is not something that Toyota made worth while.
As I said, the electric motor’s torque (or in the case of the Prius, the two electric motors’ torque) can give the car great acceleration off the line, especially combined with a low or no gear hybrid’s transmission. But at least with the Toyota Prius, there are flaws. The first flaw comes in the form of the traction control (trac). At the slightest hint of a loss of traction, the trac on the Toyota Prius instantly kicks in by automatically doing two things: It drops the electric side of the Hybrid Synergy Drive (HSD), and it drops you to about 20% power. What does this mean? Well, for starters, your car will suddenly and quite literally crawl. Imagine trying to power-steer through a turn, your tires chirp, and suddenly your car practically stops regardless of how far down on the gas pedal your foot is. It’s dangerous in driving, and it’s practically a race killer. With sticky enough tires you might get lucky enough to not trip that trigger, but it’s a constant threat hanging over your head.
But that’s not all that trac threatens to screw you over with. Let’s examine it a step deeper while we’re at it. Whenever you even so much as start to slip, trac does two things, remember? What was the first one? That’s right, it drops the electric side of the HSD. What is the predominant brake force of the Toyota Prius, being a hybrid? That’s right, the regenerative braking. What does that mean? That means that the majority of your braking force, the super-stable braking advantage of a hybrid, suddenly vanishes at the slightest sign of a skid. It’s incredibly dangerous in winter and other bad weather. The actual wheel brakes on a Toyota Prius are incredibly tiny. They don’t need to be larger. They’re hardly ever used. … Except when you need them the most! So you skid and you go from the best brakes you’ll ever experience to the worst brakes that you’ll ever see on a car, all in the single beat of a heart. Oops. Bad bad bad!
Now, this is all done to protect the vehicle. As said, the raw torque of the electric motor(s) is phenomenal. Enough so that, rumor has said, left unchecked it can literally rip the teeth right off of the gears. So drop the electric side and you make sure your transmission doesn’t suddenly turn into lots of little pieces of metal exploding out of the casing. That’s a good thing, I guess. But the extreme response, from all to nothing in a heartbeat, is an incredible danger to the driver: in every day driving and in racing. Surely there must be a better way to protect the car without putting the life of the driver in danger.
Toyota, apparently, doesn’t seem to think so however. Because for as many years as the Toyota Prius has been out (even if you just count the “newer” version based on the Matrix body) this design “choice” (read “extreme flaw”) has not changed.
And so, the Toyota Prius is nothing like it’s hot Matrix cousin. This dog don’t run. If you try to race a Toyota Prius, you’re practically running through a minefield, just praying that you don’t misstep. The trac brings out the worst in the Prius. And the risks to the car are so great that I really couldn’t condone disabling the trac.
So what can you do to race in a Prius?
Well, for starters, there’s about a hundred stiffening devices to add to the car with more roll than a bakery. Surprisingly, the engine in a Toyota Prius is already equipped with a cold air intake to improve gas mileage. However, the stock air filter sucks. Or, I guess, doesn’t suck, it chokes. A lot of people driving a Prius have noticed that the car “hesitates” when you floor it. I used to think this hesitation was just the computer trying to decide how to best accelerate, gas/electric/both. Nope. Tired of having to go to Toyota for an air filter, I installed a K&N performance air filter. The hesitation completely went away. Just like that. (Which means, as little air as the Toyota Prius uses, the stock air filter somehow manages to not even provide it with that much.)
That’s just to make the Prius drivable. Now to counter (as best as possible at least) the bad effects of trac. First, don’t lose traction. So the best tires that money can buy are in order. And second, prepare for the wrath of trac + HSD. Get yourself better brakes. With the braking system of the Prius as goofy as it is (you’ll definitely need a dealer or major Toyota shop to help you as a special tool is needed to work on the brakes because of a highly complex valve system that needs a computer to operate) I’m really not sure if you can put better calipers in play or not. But there are at least better performing brake pads that you can get. Anything is better than nothing.
And if any driver needs to know their vehicle, a Toyota Prius autocross racer especially needs to really know their car. Because you’re going to have to push – but never cross – that very fine line of traction to keep trac from kicking in. Because once it does, you’re losing pretty much your whole engine and your braking force. You’re losing time at the very least, and possibly going out of the cones (or even out of control if you’re in the middle of a tricky maneuver) when the trac hits the fan.
And if you can afford it, you’ll be much happier to race your Prius if you turn it into a plug-in hybrid. You know, that costly mod where you fill the storage space under the trunk with batteries to jump the capacity of the high voltage battery? Yeah. Because nothing says pep in a Prius like green bars. Not only do you increase your HV capacity, but you also give yourself the ability to top it up at will. Which will do wonders for you, more so than anything you can try to do to increase engine performance. (Not that you shouldn’t try, but hybrids have priorities, and for once the gas engine isn’t the priority in a race car.)
All-in-all, for a car as heavily related to the Toyota Matrix as the Toyota Prius is, it’s a very different animal. Which is a real shame. Toyota could have just gone the other way and made one truly excellent car. Maybe one year…
My sincere hope is that other hybrids don’t suffer the racing ignominy that the Toyota Prius does. Besides making for some unsafe driving from the day-to-day commute, it makes for a lousy race. But the performance potentials of hybrids just blow pure gas engines away. Electric motors really offer a lot, in acceleration, and in braking. We’re still on the dawn of the Day of the Hybrid, and one day soon we’ll see just how sexy hybrid can be.