Unlocking Power: The Best B58 Downpipes for Street Racing
When it comes to extracting maximum performance from your B58-powered street racing machine, few mods deliver as much bang-for-the-buck as a high-quality downpipe. Whether you’re rocking a Toyota Supra B58, BMW 340i, or other B58-equipped car, upgrading to a B58 downpipe – particularly a catless or high-flow catted version – is the top way to enhance stock sound and power.
Why Upgrade Your B58 Downpipe?
The factory downpipe on B58 engines is designed to meet emissions standards, not performance. Its restrictive catalytic converter creates backpressure that chokes power potential. By applying an no stock B58 downpipe, you’ll face:
- 20-40+ WHP gains (depending on tune and other mods)
- 30-50 lb-ft torque increase
- Faster turbo spool and reduced lag
- More aggressive exhaust tone
- Improved throttle response
Top B58 Downpipe Options for Street Racers
1. VRSF Downpipe B58 (Catless)
The VRSF catless downpipe B58 is a favorite among budget-conscious racers looking for maximum flow. Features include:
- 3.5″ mandrel-bent pipe for maximum muffler velocity
- T304 stainless steel construction
- Direct OEM fitment
- Out performance when tuned
Best for: Racers wanting maximum performance without emissions concerns
2. VRSF Downpipe B58 (Catted)
For those needing to pass emissions or reduce smell, the VRSF catted downpipe offers:
- 200-cell high-flow catalyst
- Near-catless performance
- Reduced exhaust fumes
- O2 sensor bungs for proper tuning
Best for: Street-driven cars needing some emissions compliance
3. Active Autowerke Downpipe B58
The premium Active Autowerke downpipe B58 stands out with:
- Handcrafted T304 stainless steel
- Proprietary high-flow catalyst design
- Perfect OEM fitment
- Dyno-proven power gains
Best for: Enthusiasts wanting top-tier quality and performance
Catless vs. Catted B58 Downpipes: Which is Right for You?
B58 Catless Downpipe Pros:
- Maximum horsepower gains
- Most aggressive exhaust sound
- Lowest cost option
- Best for track/dedicated race cars
B58 Catted Downpipe Pros:
- Passes emissions in most areas
- Reduced exhaust smell
- More socially acceptable for street use
- Still provides significant power gains
Installation and Tuning Considerations
Installing a B58 downpipe is relatively straightforward but does require:
- ECU tune to eliminate CEL (check engine light)
- O2 sensor spacers (for catless options)
- Professional installation recommended for first-timers
For best results, pair your new downpipe with:
- Stage 2 ECU tune (BM3, MHD, or JB4)
- Upgraded intercooler
- High-flow intake
- Exhaust system upgrades
Real-World Performance Gains
Dyno tests show impressive results:
- Catless downpipes: 30-45+ WHP gains
- Catted downpipes: 20-35 WHP gains
- 0-60 MPH improvements of 0.3-0.5 seconds
- Significantly improved mid-range torque
The Street Racer’s Verdict
Whether you choose the raw power of a VRSF catless downpipe B58 or the refined performance of an Active Autowerke catted downpipe, upgrading your B58 downpipe is one of the smartest first mods for any street racer. The combination of immediate power gains, improved throttle response, and intoxicating exhaust note makes this one of the most satisfying upgrades for your B58-powered beast.
For maximum street performance, we recommend:
- VRSF catless downpipe for up to maximum racing made
- Active Autowerke catted downpipe for premium street builds
- VRSF catted downpipe for budget-friendly street builds
Pair your new downpipe with a proper tune, and your B58 will transform into a true street-dominating monster.
