How fast is The Flash when he's outside the Speed Force?

Question

Obviously The Flash is known to be faster than light but I was just reading another source that compares him with The Silver Surfer who happens to be exactly 99% faster than light. this source gave the victory to The Silver Surfer because supposedly he is able to surpass the speed of light on his own without any special assistants while Flash in the other hand needs to be inside the Speed Force to reach this speed.

Now this is where my confusion comes in. I really thought The Flash was faster than light on his own while the Speed Force just gives him a little extra boost. He also beat his Marvel counterpart Quicksilver in a DC/Marvel crossover where Marvel characters somehow end up in the DC universe, I believe in this crossover he was able to beat Quicksilver by using the Speed Force. However in another Crossover where the DC characters end up in the Marvel universe Quicksilver was able to get the victory for the fact that The Flash cant use the Speed Force in the Marvel universe.

So anyways exactly how fast is The Flash when he's not in the Speed Force?

Answer 1

When cut off from the Speed Force, speedsters who utilize the Speed Force are incapable of using their super-speed.

This has been shown in the Arrowverse TV series, as well as in the numerous DC/Marvel crossovers (as you indicated in the question) and in DC comics as well.

The Speed Force gives a speedster his speed. It is always present in their bodies, and they can tap into it at will. It allows them to hyperaccelerate their senses and thought processes, as well as their bodies, and it permits them to move at superhuman (and super-sonic, and occasionally super-luminal) speeds.

If a Speed Force Speedster is cut off from the Speed Force, they lose all associated abilities (including their accelerated metabolism and healing). This has been seen in DC comics, as well as the current TV series.

In the crossovers you mention, Flash was able to easily defeat Quicksilver because Flash had access to the Speed Force, and could move at speeds that made Quicksilver (who has trouble breaking the speed of sound) look like he was standing still.

When cut off from the Speed Force (because they were in Marvel, which lacks it), he was just a normal human being in a silly costume. Of course, this couldn't stand. I believe in the mentioned crossover, they returned to the DC Universe for a time and constructed a Speed Force Battery or something similar that let Flash store some of the Speed Force and bring it with him, giving him limited ability to access his full powers.

No, it didn't make sense then, either.

In short: Without access to the Speed Force, the Flash (and similar speedsters) are no longer speedsters at all.

Answer 2

The Speed Force is a phenomenon unique to the DC Universe. It is a result of the energy of the Godwave which empowers metahumans in the DC Universe. It is unique to the DC Multiverse. A speedster dependent upon the speed force cannot utilize their superspeed at all without technological support.

One does not have to utilize the Speed Force to have superspeed. But the benefit of having the Speed Force protects the environment from the effects of a speedsters superhuman capacity and allows speedsters to perform a variety of metahuman feats, often unique to speedsters.

• Speedsters in the DC Universe who utilize the Speed Force each do so at differing capacities.

• The more significant their connection, the faster the speedster. Sometimes this is a psychological connection, other times it's just a limit to the speedster's connection.

• The heroic speedsters with the best connection have been Barry Allen, Wally West and Jay Garrick.

• There have been other speedsters whose connection wasn't quite as good and they were slower than the top tier speedsters. This includes Max Mercury, Jesse Quick and Johnny Quick.

• For a time right after Crisis on Infinite Earths (1986) Wally West (who previously was shown to be as fast as Barry Allen) was limited to the speed of sound.

• Wally believed he needed to consume significant calories in order to utilize his powers. Once freed from his psychological limits, his connection to the Speed Force strengthened and he became one of the most facile and capable speedsters in DC history.

In the Marvel Universe

It had been decided by DC and Marvel that the Speed Force as we have understood it is not available in the Marvel Universe.

• Though this limitation had not been established when Fast Forward (Buried Alien) was running a race in the Marvel Universe. He appeared to be capable of running as fast as any of the other speedsters of the Marvel Universe. See: Quasar #17.

• When DC and Marvel had the Flash crossing over to the Marvel Universe, he had to use a battery which stored the Speed Force energy to allow him to compete with Quicksilver, since there is no Speed Force in the Marvel Universe. Note the backpack the Flash is wearing.

In the Marvel Universe, there was, at least for a time, a degree of physical possibility written into the characters capable of moving at superspeed. As such this limited them to a maximum speed equivalent to the speed of sound or a bit faster because their bodies were augmented either through technology or mutation. See: Speed Demon, The Whizzer.

The Official Handbook of the Marvel Universe listed the Speed Demon, a known speedster-style villain listed his capacities as such:

• Speed Demon possesses superhuman motion, running abilities, and reflexes. These abilities are the result of body-wide mutagenic changes induced by the ingestion of chemical compounds of a technically advanced formula.

• His altered body has greater efficiency in his central nervous system, including the brain, stronger and more efficient musculature structure, and stronger bones. As a result OF These mutagenic changes, Speed Demon can run at a maximum speed of about 160 miles per hour.

• He can run at his maximum speed for about three hours before fatigue significantly impairs his performance. Speed Demon's superhumanly fast thought processes and reflexes (about six times faster than the average human being's) enable him to perceive his surroundings while moving at high speeds, and to pick up objects and execute complex acrobatic maneuvers at these high speeds as well.

Similar writeups for other speedsters including the Whizzer (a Golden Age speedster) and Quicksilver (a mutant biologically enhanced for speed) existed for the longest time until the Marvel Universe began improving the capacity of their speedsters.

Since then, the limitations on speedsters in the Marvel Universe have fallen away with Marvel's speedsters getting significantly faster than they had ever been but no mention of the Speed Force is referenced, but something like it must exist for speedsters to be able to move at the speed of light in atmosphere and not bursting into flame due to thermonuclear forces.

See: Relativistic Baseball.