Powering mutiple Infrared LEDs through a single Arduino Uno pin?

I'm doing this project where I control an RC Car using infrared. Everything is perfect with 1 IR LED, connected to a 220ohm resistor. I'm worried about the range of the signal so I'm thinking of using multiple IR LEDs (let's say 4 to 6 LEDs) to emit the signal.

My problem is how do I achieve this while controlling them through a single pin?

For testing I tried connecting 2 normal red LED serially through a 220ohm resistor and both of them became dimmer. The LEDs needs to be bright.

On hand now I have the IRF520 transistor. Will it work?

I bought my IR LEDs online, while it doesn't say it's part number it comes with this description:

IR Transmitter
Emitted color:infrared
Lens:5mm, water clear
940nm wavelength
Forward current:50mA
Forward voltage: 1-1.4V

Answer

Typical Collector Follower setup.

^{simulate this circuit – Schematic created using CircuitLab}

Size the R1-R3 for your leds and current, choose a transistor that can handle that current. A common 2N3904 or 2n2222 type transistor would do for a few leds no problem.

Edit:

The IRF520 N Channel Power Mosfet is overkill for this but as the saying goes, there's no kill like overkill (Yes).

Based on the LED specs you provided, you can skip multiple resistors per 3 leds. (Sized for 40 mA instead of 50mA). Add more in parallel as the other circuit.

^{simulate this circuit}