How fast would NASCAR go without restrictor plates?

On Daytona and Talladega today, a modern NASCAR Cup car with no horsepower-limiting device (no restrictor plate or tapered spacer) would likely average about 220–230 mph on a solo qualifying lap, touch 230+ mph on the straights, and in a tight multi-car draft could nudge into the mid‑230s—potentially flirting with 240 mph—speeds NASCAR considers beyond safe racing limits. The question surfaces often because NASCAR has long managed speed for safety; here’s what evidence, engineering, and history tell us about the upper limits.

What restrictor plates are—and what NASCAR uses now

Restrictor plates were introduced in 1988 at Daytona and Talladega after Bobby Allison’s 1987 Talladega crash tore down catch fencing at over 200 mph. Plates physically limited airflow into the engine to curb horsepower and keep pack speeds under roughly 200 mph. In 2019, NASCAR replaced plates with tapered spacers, which achieve the same aim with more predictable engine response. With the Next Gen car (since 2022), superspeedway engines run roughly 510 hp with high-drag aero, yielding pack racing around 190–200 mph; at most other tracks the engines run about 670 hp.

What the record book and tests already show

The best clues about “how fast” come from history and controlled tests in eras without plates—or when teams were allowed to run without them briefly.

• 1987, no plates: Bill Elliott set Talladega’s all-time qualifying record at 212.809 mph and set Daytona’s record at 210.364 mph—benchmarks achieved before NASCAR began limiting superspeedway horsepower.
• 2004, no plate test: Rusty Wallace privately tested a modern Cup car at Talladega, reporting an average lap around 221 mph with a top near 228 mph. He called it “too fast to race.”
• 2014, high power/low drag at a 2‑mile oval: Jeff Gordon’s 206.558 mph pole at Michigan became the fastest Cup qualifying lap since 1987, underscoring how quickly speeds climb when power rises and drag falls—even on a non-superspeedway.
• Today, with limits: Superspeedway pack laps typically average 190–200 mph, with peak draft trap speeds around 200–205 mph—numbers managed by the 510 hp package and draggy aero.

Taken together, those datapoints strongly suggest that removing today’s horsepower restriction would push solo superspeedway laps into the low‑to‑mid‑220s immediately, with straight-line peaks above 230 mph, and even higher momentary speeds in a strong draft.

Physics and engineering: why 220–230+ mph is realistic

Top speed on a big oval is mostly a tug-of-war between engine output and aerodynamic drag. Modern Cup engines without a spacer can produce on the order of 850–900+ hp, enough to overcome the Next Gen car’s sizable drag at well over 220 mph on 2.5‑ to 2.66‑mile, high-banked tracks where drivers run nearly flat-out. The draft further reduces effective drag, letting a trailing car momentarily exceed a solo car’s top speed by several mph—sometimes many.

Key variables that set the ultimate number

Several controllable and uncontrollable factors would determine the exact top speed if NASCAR removed horsepower limits today.

• Horsepower: Removing the tapered spacer unlocks hundreds of horsepower, which directly raises top speed where drag is the main resistive force.
• Aerodynamics: The Next Gen body and superspeedway spoilers produce high drag; a lower-drag trim would add multiple mph on the same power.
• Gearing and RPM: Teams would select taller gear ratios to keep engines in the power band at higher speeds, trading acceleration for top end.
• Drafting: Multi-car lines reduce drag for trailing cars, allowing short bursts several mph faster than a solo run—potentially mid‑230s.
• Track specifics and weather: Talladega’s length and banking, cool dense air, and tailwinds can all add speed; heat and headwinds reduce it.
• Tires and grip: Tires must survive sustained high loads; if grip forces lift cornering speed limits, lap averages climb with them.

Given these variables, the most defensible estimate for today’s machinery is low‑220s average laps solo, with best-case peaks surpassing 230 mph and draft-aided bursts higher still.

Why NASCAR keeps the lid on

Blowovers and catch-fence impacts become more likely and more violent as speeds rise, especially when cars are yawed or backward. Roof flaps (introduced in 1994), tethers, and better fences mitigate but don’t erase those risks. At 220–230+ mph, kinetic energy and liftoff forces scale dangerously; the sport’s safety systems—and the venues themselves—are not designed to race side-by-side for hours at those velocities. That’s why NASCAR balances entertainment with safety by capping power and adding drag at its fastest tracks.

Would other tracks see similar gains?

Not to the same extent. Intermediate ovals (1.5–2.0 miles) and short tracks limit speed primarily with cornering grip, not just power. Uncorking horsepower helps on the straights, but drivers must still lift for the turns, so lap averages won’t explode the way they would at Daytona or Talladega. That’s why the eye-popping figures are mostly a superspeedway story.

Bottom line

Remove today’s horsepower restrictions at Daytona and Talladega, and NASCAR Cup cars would likely average 220–230 mph on solo qualifying laps, hit 230+ mph on the straights, and see draft spikes into the mid‑230s—approaching 240 mph in perfect circumstances. Those numbers align with historical no-plate records and modern tests, and they explain why NASCAR continues to manage superspeedway speed for safety.

Summary

Evidence from the 1987 no-plate era, a 2004 unrestricted test, and modern power/drag trends indicates that current Cup cars, freed of restrictors/tapered spacers, would run in the low‑220s to potentially mid‑230s at Daytona and Talladega, with draft-aided peaks higher still. That’s fast enough to raise unacceptable safety risks—hence NASCAR’s enduring speed limits on its biggest tracks.

Will NASCAR stop using restrictor plates?

There is another one on tap Sunday: The Daytona 500 will be the final NASCAR race for restrictor plates, the horsepower-sapping devices reduce speed and were intended to improve safety at the nation’s fastest tracks. Don’t expect a big send-off for the oft-maligned part, which has been in use since 1988.

How fast can a NASCAR go without a restrictor plate?

Rusty Wallace tested a car at Talladega Superspeedway without a restrictor plate in 2004, reaching a top speed of 240 mph (390 km/h) in the backstretch and a one-lap average of 221 mph (356 km/h).

What does NASCAR use instead of restrictor plates?

NASCAR’s tapered spacers are thicker than restrictor plates, being roughly 1 inch (2.5 cm) thick, with conical walls that allow for more consistent airflow. Restrictor plates were thinner, measuring 1/8 inch (0.32 cm). Both restrict a NASCAR car’s speed, but tapered spacers create less turbulence.

What is the highest speed in NASCAR history?

The highest official speed in NASCAR was set by Bill Elliott, who achieved a qualifying speed of 212.809 mph at Talladega Superspeedway in 1987. This record-setting speed, achieved with a streamlined Ford Thunderbird, has stood the test of time and is unlikely to be broken due to safety regulations implemented after the race that limit speeds on NASCAR tracks.
 
Details of the Record 

• Driver: Bill Elliott
• Track: Talladega Superspeedway
• Date: 1987
• Speed: 212.809 mph
• Vehicle: Ford Thunderbird

Why the Record Will Not Be Broken
Following this record-setting performance, NASCAR introduced safety measures, such as the use of restrictor plates, which have significantly reduced car speeds in an effort to prevent accidents. Without these regulations, a 2004 test session with Rusty Wallace showed that without restrictor plates, cars could reach speeds well over 220 mph. 
You can watch this video to see Bill Elliott’s record-breaking lap at Talladega: 43sDaily Sports History Podcast YouTube · Apr 30, 2025