LEGAMAX Premium CIVIC Explanation of the product Application chart

Code No. 31021-AH004

Full Straight Structure & Low Exhaust Pressure!
Full straight structure with no restriction achieves a 50% reduction in the exhaust pressure compared to the stock exhaust system.
Unpleasant Exhaust Resonance is Eliminated
Without uncomfortable exhaust resonance, the sporty exhaust sound and comfortable interior space are created.

Cert. No. JQR30183047 L15Ct

Vehicle CIVIC
Model FK7
Engine L15C
Model Year 17/09 - 
Shape of muffler Ti (Dual)
(LEGAMAX Premium)
Main material S304(*2)
Diameter of tip 97
Diameter of center pipe 60x2(*3)
Close noise level Stock 84
HKS 91
About road clearance(*4) Clearance 140mm
Portion of the kit Mid Pipe Silencer
Product Weight


※This product was previously released as 31021-BH002 Since fitment to JDM model was confirmed, the part number was changed to 31021-AH004. Also, this product is designed based on JDM and USDM models. Please confirm the model available in your country before purchase.


About HKS muffler

*1: About silencer shell type of Silent Hi-Power
TYPE-S/Oval silencer for noise reduction.
TYPE-H/Round silencer for performance.

*2: Main material in the component figure.

: SUS304/High quality stainless steel.
: SUH409/Stainless steel commonly used for stock exhaust.

*3: About center pipe
Diameter of center pipe is the portion that has the largest diameter. (Excluding silencer and tip.) It is the condition with stock suspension.

*4: Minimum road clearance between HKS muffler (Any parts included in the kit) and road surface. Therefore, it may be different from actual road clearance of the vehicle.
The data is basically the condition with stock suspension. However, please understand that some items have data with low down spring or ride height adjustable suspension kit.

Caution: Hook, bracket, stay may be changed without prior notice.

★ Exhaust noise level at idle.