The BMW S58 engine is surely powerful, but enthusiasts never seem to be satisfied. This is where catless downpipes come into the picture. If you’ve been hearing more turbine noises while driving, I assure you, it’s not just you. Upgrading to BMW S58 catless downpipes also enhances the exhaust sound, delivering a more aggressive and sporty tone.
Let’s analyze the 5 most important reasons why BMW S58 catless downpipes are moving quickly to the top of the priority list of all drivers.
1. Boost in Horsepower and Torque
As expected, S58 engines come with their twin-turbo power and their tuning capabilities. However, they are constricted from achieving their true potential due to OEM catalytic converters. Catless downpipes free these constraints, allowing for improved airflow.
Before we go any further, take a look at the numbers.
- Stock BMW M3/M4 (S58): Approximately 473-503 HP, depending on the trim
- With Catless Downpipes + Tune: Estimated gains of 60-100+ hp, 80-120 lb-ft torque
With the help of leading tuners such as Bootmod3 and MHD, these gains are not merely theoretical. The power boost is very real, particularly at mid to upper RPMs, with dyno tests revealing strong torque increases.
You will start to notice improvements in acceleration, particularly in Sport and Sport+ driving modes.
2. Faster Turbo Spool
With regards to turbochargers, turbo lag is the wait you experience until the boost begins to work. The addition of a catless downpipe helps turbo lag by removing the restrictive catalytic converter. With less backpressure, the turbochargers spool up quicker, particularly with bypassed catalytic converters.
Here are the ways you can benefit from turbochargers:
- Improved acceleration off the line
- Cornering throttle response is much sharper, thanks to improved transfer efficiency
- Underload, the shifts become more pronounced, sharper, and smoother, resulting from the improvements in transfer responsiveness
Most drives claim that spool time is reduced between 10% to 15%, which leads to heightened torque availability sooner with every push on the gas pedal.
Irrespective of driving style, feeling responsive with a catless downpipe will become a common phenomenon.
3. Aggressive Sound Output
If the B58 performs like a beast, it should also sound like a beast, right? The boldest quality that stands out for switching over is also one of the boldest features. A catless downpipe brings an exhaust note that is both aggressive and raw.
You can expect the following:
- Enhanced the severity of the tone produced while idling alongside revving
- Amplified pops, bangs, and burbles
- Turbo whistle, as well as spool noise, becomes much clearer
With a missing catalytic converter, these sounds get highly enhanced. Such an upgrade not only feels but rather makes it so that every single drive is race-like in nature.
Just remember that the exhaust has become louder. This noise will no longer be muffled, and the neighbors will hear your car from afar.
4. Reduced Exhaust Gas Temperature
A cooler exhaust gas temperature (EGT) allows an engine to operate at lower temperatures. It is beneficial for the lifespan of the turbocharger, manifold, and even the downpipes.
Some key points:
- Catless setups can lower EGTs by 100-200°F.
- Lower degrees of heat soak during traffic or on longer drives.
- Decreased risk of engine knock during aggressive driving.
Lower temperatures of exhaust mean better for the engine, which translates to better lifespan for performance parts.
5. Easy Maintenance
You might be surprised, but yes, it is really easy to maintain a catless downpipe. While some fret over the catalytic converter, going catless saves you from worries, with performance benefits.
Here’s how:
- No catalyst means no (clogging, melting) restrictions, which helps in the movement of exhaust gases.
- Less clogging means easier inspections or swap-outs.
- Lighter when compared to stock systems.
You also avoid failures caused by broken ceramic cores or blocked airflow with OEM cats, especially with tuned setups.
Overall, fewer restraining parts mean less weight, which is better for spirited driving.
What Should You Know Before Going Catless?
Before you dive right in, there are a few things you should think about. Catless is not always plug-and-play.
These are the primary issues:
- Check Engine Light (CEL): Most likely, you will trigger an engine check light. This can be fixed with a tune or CEL delete.
- Emissions Testing: In certain states or countries, catless downpipes are illegal due to excessive emissions.
- Warranty Impact: Changing the exhaust may void some portions of your manufacturer's warranty.
- Smell: The absence of a catalytic converter may lead to a stronger exhaust smell.
To straddle the line of legality and performance, many owners use high-flow catted downpipes.
Conclusion: Is Catless Worth It for Your S58?
If it's the power, faster response, and raw sound you are after, then yes, it is indeed worth it. Catless downpipes add immense value to the already potent BMW S58 engine. Just make sure you understand the trade-offs, though. A catless donpipe, along with a proper tune, will level up the car’s performance and feel instantly.