DPi (Daytona Prototype International) cars are the fastest and most technically advanced sports cars in North America.
Developed specifically for the IMSA’s WeatherTech SportsCar Championship. It’s the top class of car in this racing series.
While DPi cars are specifically designed for the racetrack, they’re not complicated.
They share an albeit modified version of the engine under the hood of road legal cars from mainstream manufacturers like Acura, Cadillac, Mazda and Nissan.
But they look nothing like the street cars from which they’re derived. Take a ride with us as we learn more about DPi cars and how fast they go.
DPi Car Horsepower
Although DPi cars are sports prototype racing cars. The mills powering them come from cars you see every day.
But they range widely. For example, at the Sebring circuit in Florida during the mid-March race weekend in 2022.
Among the DPi cars that kicked off at 10:45 on Saturday morning in the IMSA 12-hours of Sebring were Mazdas and Cadillacs.
Mazda used a 2.0-liter turbo four engine, while Cadillac’s DPi racers used a naturally aspirated 5.5-liter and a 6.2-liter V8 from road going Cadillacs (the displacement was reduced in the Cadillac motors to meet series rules).
Although these engine designs vary, each produces roughly 600 HP, as dictated by IMSA BoP (Balance of Performance).
DPi cars are capable of top speeds of 200 MPH.
Specs of a DPi Car
image source: MotorSportMagazine
DPi cars use homologated parts which means they’re approved by the type of race they’re entering.
In this case, the IMSA’s WeatherTech SportsCar Championship.
For the race at Sebring, four chassis suppliers provided the base for all the entrants: Multimatic to Mazda; Dallara to Cadillac; ORECA to Acura and Ligier to Nissan.
Part of the homologation process means the chassis are built to international specifications.
This involves all the cars getting balanced aerodynamically in the Windshear wind tunnel.
It’s then up to the competing manufacturers to develop their engines and aero kits.
As such, the competing DPi cars also vary in wheelbase and height which reflects their production design.
The maximum legal weight for a DPi car is less than 2100 pounds. Each car is backed by a six-speed sequential gearbox.
In the Sebring race, the cars were allowed to use one of two IMSA-specific, semi-confidential Micheline tires: a hard or medium compound.
And they’re only allowed to run on one spec of Michelin tire all season. All cars raced on E-20 fuel.
Costs Associated with DPi Cars
Racing DPi cars isn’t cheap. When they say that there’s a lot of money that goes into racing. There’s a lot of money that goes into racing.
If you want to throw your hat into this ultra-competitive ring, a prototype will set you back around 6 million to run per car per year.
While an exact figure for a new top tier car is unclear. To give you some idea of how much each individual car costs.
Juncos Racing is selling a lightly used Cadillac DPi car for $549,900. That number doesn’t include the engine.
For that you’ll need a formal engine lease agreement through Cadillac to run their 5.5-liter V8.
What Is IMSA?
All this talk about IMSA and we don’t even know what it is.
So, let’s get into it. Created in 1969, the International Motor Sports Association is a North American sports car sanctioning body based in Daytona Beach, Florida.
It’s currently known as the IMSA WeatherTech SportsCar Championship under sponsorship.
NASCAR has had ties with IMSA since 1969. Although NASCAR has owned IMSA since 2012, the two racing series are actually very different.
In sports car racing, there are usually multiple classes of cars racing on the same track at the same time.
In the United States, the premier series of sports car racing is the WeatherTech SportsCar Championship.
It features two main categories of cars: Prototype and GT (Grand Touring).
From there, they’re split into a total of five classes for any season, one of which is DPi. Keep reading to learn more about these categories.
Are DPI Cars Faster Than LMP2?
The prototype cars are again split into three categories: LMP2, LMP3 and DPi.
Besides the designation at the top of the windshield, there’s not much to differentiate the prototype cars.
Le Mans Prototype 2 cars are about a second and a half slower per lap than DPi cars. LMP2s are the second-highest class of the Prototype category cars.
And although they have the same tire choices and weight cap of less than 2100 pounds, they’re not customized to display any street car features like the DPis.
And unlike the DPi cars, all LMP2 cars use a Gibson Technology 4.2-liter, naturally aspirated flat-plane V8 producing over 560 horsepower.
Is Indy or Formula 1 Faster Than DPi?
While DPi cars can reach a top speed of 200 MPH.
Indianapolis 500 cars use a twin-turbocharged 2.2-liter V6 engines to surge to top speeds of approximately 235 MPH.
F1 cars use a single turbocharged 1.6-liter V6 motor to hit top speeds of 205 MPH. So, both F1 and Indy cars are faster than DPi cars.
Can DPI Cars Race at Le Mans?
Since DPi cars are king of the hill, they’re tuned by IMSA rules to be the fastest.
Le Mans is open to both specialized prototypes and cars based on road-going vehicles.
They just need to meet the requirements of having no more than 670.511 mechanical horsepower (even if a hybrid engine).
And they can’t weigh any more than 2271 pounds. These include LMP1, LMP2, LMP3 and GT cars are allowed to race at Le Mans.
Are DPi Cars the Same as LMP1 Cars?
LMP1 cars are the same as DPi car, which means that DPi cars are allowed to race Le Mans.
As mentioned, the Prototype division of the WeatherTech SportsCar Championship splits again into three classes.
And while they all look the same with a prominent tail fin that runs just behind the cockpit to the end of the car.
One way to tell the difference between which LMP car you’re looking at is by the color of the number plate.
LMP1 cars have a white number on a black background. LMP2 cars have a white number on a blue background.
And LMP3 cars have white numbers on orange background.
Top Speed of the Cars at the Rolex 24
In an episode of The Office, Dwight Schrute used the word perfectenschlag to describe a time in a man’s life when everything comes together perfectly.
During the 2019 Rolex 24 race at Daytona, the Cadillac, Acura and Mazda DPi cars were able to reach a measured top speed of 200.011 MPH.
During practice, driver of the Cadillac, Kamui Kobayashi turned in the fastest lap of 1 minute, 36.389 seconds around the twelve turn, 3.56-mile Daytona International Speedway road course.