|Series||Fully Cowled Mini 4WD|
|Release Date||September 12, 2015|
|In fictional media|
|First Appearance||Bakusou Kyoudai Let's & Go! Return Racers!|
|Owner|| Retsu Seiba|
Chiiko Mikuni (Borrowed)
|“|| What's wrong Sonic? Just come out, the race is not over yet! I'm not giving up, because I'm believing in you!|
The fastest is ours, the number 1 is ours!
— The young Retsu Seiba
Great BlastSonic (Japanese: グレート ブラストソニック, Gurēto Burasuto Sonikku), also known as G-BlastSonic (Japanese: Gブラストソニック, Jī Burasuto Sonikku), is the Fully Cowled Mini 4WD car that was released on September 12th, 2015.
It was featured in the on-going manga Bakusou Kyoudai Let's & Go! Return Racers! as Retsu Seiba's 5th Sonic series after Buster-Sonic and before Blitzer-Sonic. (despite being the 7th Sonic series to be released after RodeoSonic in real-life) Chiiko Mikuni temporally borrowed the car at one point of the manga.
The Great BlastSonic is the sharper and refined version of its predecessor. Like most of Retsu's Sonic machines, it has white bodyshell, with red and green stripes mixes onto it.
Much like Z Wing Magnum, with modification (by removing part of the D3 parts of the bodyshell and remove its rear wing), its alternative form, that was presented in the manga, can be replicated. Unlike Z Wing Magnum, however, it doesn't requires add-on stickers from other sources since the kit itself comes with the stickers required for this.
The car was equipped with the yellow small-diameter 5-spoke Saber-type low-profile wheels wheels with low-profile tires.
In the manga
This section of the article may contains details concerning the progression of the plot. If you do not want it to be spoiled for you, skip this section!
Near the end of the race, Go initiates Beat-Magnum's Magnum Tornado, however the strong wind creates from it blows the fire to the tree vines and accidentally torched them and are falling on the race course. The blazing vines blocks the road for Retsu's Blast Sonic, setting it on fire.
Despite the situation, Retsu doesn't give up, and the car finally break through the obstacle and as the flame is extinguished, it is reveal that it transformed into its alternative form. (Missing some of its movable fins and the rear wing) Using the reduced weight of the car to his advantage, Retsu's G-BlastSonic overtakes Go's Beat Magnum and crossed the finish line.
In the middle-schooler arc, Chiiko had once borrowed Retsu's G-BlastSonic (which had restored to the BlastSonic form) to race against Go, Jun and their Cyclone Magnum, but ended up losing the race.
Retsu once again used his BlastSonic to race against Lydia (who borrowed Go's Great Magnum R), but as Lydia noticed, his car's age had finally caught up, and ended up losing the race. This motivate him to modified his BlastSonic into another front motor machine that can matches the Great Magnum R.
It was later restored to the G-BlastSonic form and stored in the Seiba household until the grown up Retsu, who returns from oversea after his space probe project team had loss contact to the space probe (named after his Mini 4WD car), found it while cleaning the room. After the flashback to the last race, and meeting Go and Tsubasa who are standing outside of the household, he decided to race with his car once more.
Length: 155 mm
Width: 97 mm
Height: 44 mm
Chassis: AR Chassis
Gear Set(s): 3.5:1
- To celebrate the creation and release of Beak Stinger G, CoroCoro Channel (Official CoroCoro Youtube Channel) held a race that has MC Guts's Great BlastSonic race against Tetsuhiro Koshita's Beak Stinger G, with MC Guts's car comes out as a winner. 
- ↑ Chapter 10 and 11 of Bakusou Kyoudai Let's & Go! Return Racers!
- ↑ Chapter 14 of Bakusou Kyoudai Let's & Go! Return Racers!
- ↑ Chapter 2 of Bakusou Kyoudai Let's & Go! Return Racers!
- ↑ https://www.youtube.com/watch?v=MtVdGNQ4Qds
|Fully Cowled Mini 4WD series|
|Super-1||Magnum Saber* · Sonic Saber* · Tridagger X* · Black Saber · Spin-Axe · Proto-Saber JB · Victory Magnum* · Vanguard Sonic* · Beak Spider* · Neo-Tridagger ZMC · Fighter Magnum VFX* · Ray Stinger* · Shining Scorpion* · Bergkaiser*|
|Super-FM||Brocken Gigant · Gun Bluster XTO*|
|Super TZ||Cyclone Magnum* · Hurricane Sonic* · Cyclone Magnum TRF · Diospada* · Beat-Magnum* · Buster-Sonic* · Beat-Magnum TRF · Fire Stinger|
|VS||Spin-Viper† · Diomars-Nero†|
|AR||Z Wing Magnum · Great BlastSonic · Beak Stinger G · Proto-Saber Evolution† · Tridagger WX|
|FM-A||Great Magnum R · Cosmosonic|
|* denotes Premium version available; † denotes racing chassis re-release of a Mechanical Mini 4WD car|