Audi B5 A4 S4 RS4 front tubular subframe

After extensive CAD development based on a 3D scan of the OEM subframe, tested with CAD FEA (Finite Element Method) and road testing, you can now buy a brand new, rust-free subframe for the front of your Audi B5 A4 S4 RS4.

Here you will find the subframe for B6/B7 cars.

Utilizing the same T45 tubing found in WRC cars, our subframes provide increased stiffness and reduced weight . This additional design allows for improved access to the car's underbody. All factory parts are bolted to this unit, so no modifications are necessary.

Some cars that use a subframe are shown below.

Characteristics:
- 8.5 kg, that's a 7.5 kg (16 lb) savings over the OEM subframe
- T45 tubes (BS4T45 to BS4T100) imported from Great Britain and S355 sheets
- all elements welded using the TIG method
- delivered painted (powder coated) in black or on special order (50 euros) in any RAL color
- solid body mounts for increased stiffness and additional weight reduction
- can be used with OEM control arms
- Attaches to OEM bodywork and no other modifications are needed to fit the subframe

What's included:
- front subframe painted black
- printed installation instructions

Used in:
- Audi A4 B5
- Audi S4 B5
- Audi RS4 B5
- Audi A6 C5 2.7t manual (will not work with V8 4.2L cars)

T45 is a very unique seamless carbon based steel tube used in many applications across various industries. It is stronger than the Co-Mo 4130 inner tube also used in motorsport. It is widely used in the aerospace sector in equipment such as pilot and crew seats due to the materials ability to withstand high G-forces without cracking or breaking. This material is carbon manganese based and complies with full aerospace specifications set by British Standards.

Properties
Tensile strength: 700 – 900 MPa,
Efficiency 0.2% Minimum 620 MPa
Hardness test: 201 min – 262 max HB or 210 min – 275 max HV.

Replaces:
- 8D0399313BT
- 4B0399313DE
- 4B0399313BL
- 8D0399313BH

Note: Sold for off-road, track and racing applications only. We strongly recommend that the subframe be installed by a qualified and experienced workshop that knows what they are doing.








1,200 HP RS4 limousine from the Hanover Hardkor team





Audi S4 with 1,300 HP from TTD





Audi S4 with 1100 hp