Tech talk: Formula 1 VS IndyCar turbo boost pressure comparisons

[theriusDR3]

Formula 1 hybrid turbocharger


IndyCar BorgWarner EFR7163 turbocharger

Formula 1 current engine hybrid turbo boost pressure: Up to 5 bar but varies by engine manufacturers - single-turbo hybrid
IndyCar Series current engine turbo boost pressure: 1.3 bar (superspeedways (ovals length 1.5-mile and beyond); 1.5 bar (short ovals, Road/Street Courses and Indianapolis 500 qualifying); 1.65 bar (with Push-To-Pass) - twin-turbos

So why IndyCar turbo boost pressure is more smaller than Formula 1?

[FW17]

https://i.ytimg.com/vi/l2_eTLCz_3I/maxresdefault.jpg
Formula 1 hybrid turbocharger

https://cdn11.bigcommerce.com/s-e0b3c/i ... 83.jpg?c=2
IndyCar BorgWarner EFR7163 turbocharger

Formula 1 current engine hybrid turbo boost pressure: Up to 5 bar but varies by engine manufacturers - single-turbo hybrid
IndyCar Series current engine turbo boost pressure: 1.3 bar (superspeedways (ovals length 1.5-mile and beyond); 1.5 bar (short ovals, Road/Street Courses and Indianapolis 500 qualifying); 1.65 bar (with Push-To-Pass) - twin-turbos

So why IndyCar turbo boost pressure is more smaller than Formula 1?

No intercooler

[wuzak]

https://i.ytimg.com/vi/l2_eTLCz_3I/maxresdefault.jpg
Formula 1 hybrid turbocharger

https://cdn11.bigcommerce.com/s-e0b3c/i ... 83.jpg?c=2
IndyCar BorgWarner EFR7163 turbocharger

Formula 1 current engine hybrid turbo boost pressure: Up to 5 bar but varies by engine manufacturers - single-turbo hybrid
IndyCar Series current engine turbo boost pressure: 1.3 bar (superspeedways (ovals length 1.5-mile and beyond); 1.5 bar (short ovals, Road/Street Courses and Indianapolis 500 qualifying); 1.65 bar (with Push-To-Pass) - twin-turbos

So why IndyCar turbo boost pressure is more smaller than Formula 1?

The boost pressure reflects the power level desired.

F1 currently doesn't restrict boost, but will be capped at 4.8 bar MAP (3.8 bar boost) for the 2026 regulations.

F1 engines are also fuel restrcited, so run very lean.

[Tommy Cookers]

https://i.ytimg.com/vi/l2_eTLCz_3I/maxresdefault.jpg
Formula 1 hybrid turbocharger
https://cdn11.bigcommerce.com/s-e0b3c/i ... 83.jpg?c=2
IndyCar BorgWarner EFR7163 turbocharger
Formula 1 current engine hybrid turbo boost pressure: Up to 5 bar but varies by engine manufacturers - single-turbo hybrid
IndyCar Series current engine turbo boost pressure: 1.3 bar (superspeedways (ovals length 1.5-mile and beyond); 1.5 bar (short ovals, Road/Street Courses and Indianapolis 500 qualifying); 1.65 bar (with Push-To-Pass) - twin-turbos

So why IndyCar turbo boost pressure is more smaller than Formula 1?

No intercooler

well ....
primarily .... because hybrid F1 is Miller cycle

plus ....
this OP's info may be WRONG
official info says boost is 1300 mb pressure in plenum (apparently meaning 0.3 bar boost + 1 atmosphere)
https://www.indycar.com/news/2015/05/5- ... ram-primer
but in their glossary say boost is pressure above atmospheric
(ie 1.3 bar boost is 1.3 bar + 1 atmosphere - but quoted powers are far too low for 1.3 bar + 1 atmosphere)

[Hoffman900]

1) rules differences

Outside that…
• F1 is Miller Cycle, this reduces cylinder temperature which allows them to survive, while not giving up any of the power stroke. This concept has been around since the 1970s, mostly in high boost diesel applications, which the current F1 PU’s are kind of like (HCCI). The Audi LMP diesel cars were also this. The Miller Cycle needs large boost / air flow to work.

Indy Car engines are traditional DI gasoline engine platforms.

• F1’s lean burn concepts require a lot of air flow. Boost is a measure of resistance. If you looked at CFM of the turbo, you’d see the F1 PU’s are moving a lot more air.


But really, at the end of the day, the difference is rules. Even with spec chassis’s and current PU’s, they’re already hitting nearly 240mph at Indy. You would kill a lot of drivers and fans at ovals if they opened the rules up.