The exhaust system is a crucial aspect of making the Subaru WRX or STI perform better. DarkLight Fabrication specializes in making high-quality turbo exhaust manifolds, downpipes, and custom exhaust systems that cater to the specific needs of these cars. In this blog post, we cover the basic, essential things that need to be considered when making an exhaust system for a WRX or STI. We focus on three main aspects: exhaust system clearance, exhaust system routing, and exhaust system sound.
Understanding Your WRX/STI Exhaust Needs
The rally-bred performance and turbocharged engines of the Subaru WRX and STI are known for their explosive power. Yet, to truly make these cars sing, an aftermarket exhaust is practically a necessity. The 2022 price tag for the exhaust options isn't a hard number to swallow, especially since the cheapest option doesn't sound anything close to the Subie rumble.
1. Clearance: The space you have in your engine bay and undercarriage is very important. An exhaust system that is designed well should have enough clearance so that it doesn't touch other components of the vehicle, even under aggressive driving or off-road conditions.
2. Routing: The way your exhaust goes from the turbocharger to the rear of the vehicle impacts back pressure and overall performance. Good routing can mean better efficiency and power output and fewer headaches over unwanted noise. Routing is mostly short, but there are some things you should really avoid doing.
3. Sound: Your WRX or STI may not be as quiet as a luxury car, but the auditory experience is part of the performance package. Different exhaust configurations produce different sound profiles: some cars have a fairly subtle growl at the rear when you throttle down; some have a bigger bang and a wilder sound; some are really loud, and some are a bit obnoxious.
Clearance Considerations
1. Underbody Clearance
When upgrading your exhaust system, it is imperative to first think about underbody clearance. Many aftermarket exhaust systems tend to hang lower than their stock counterparts, which can lead to us—unfortunate mortals who insist on driving our vehicles over bumps and uneven surfaces—scraping them or damaging them in some way. Here at DarkLight Fabrication, we promise that our custom exhaust systems will maintain the kind of clearance one expects of a high-performance exhaust system. Our systems have the clearance you need, the power you want, and the right look under your vehicle.
2. Heat Shielding
Turbocharged engines produce a considerable amount of heat, and their exhaust parts can get very hot. Ample clearance not only keeps the parts from touching each other but also lets heat dissipate effectively. We suggest that you use heat shielding in the vicinity of the exhaust when it runs close to anything that could be adversely affected by excessive heat.
That could anything up to and including the ecu. But in the area of concern to us, the exhaust is running close to the fuel lines and quite a bit of the engine wiring.
Routing Recommendations
1. Turbo Manifold Design
The exhaust system of your vehicle has many vital parts, and the turbo manifold is one of them. A good manifold is essential if you want to reduce turbo lag and improve throttle response. Your manifold needs to be very well designed and built to funnel the exhaust gas from the engine out to the turbo with minimum back pressure and turbulence.
2. Downpipe Configuration
Another critical area where routing plays a significant role is the downpipe. An unobstructed straight path from the turbo to the exhaust can reduce back pressure and improve turbo efficiency. For most WRX and STI applications, we recommend a 3-inch diameter downpipe to ensure that optimal flow.
3. Cat-Back System
The section of the exhaust that runs from the catalytic converter to the rear of the vehicle is known as the cat-back exhaust system. A cat-back system that is properly routed should have few bends and restrictions, and it should have enough clearance that it can never touch the driveshaft, even during off-road operations. Our custom cat-back systems are made to hang like an art piece and work like a Rube Goldberg device. They flow exhaust gas smoothly, with no turbulence, right to the end of the tailpipe.
Sound Considerations
1. Exhaust Tone
The noise your WRX or STI makes is an essential part of the experience. Different exhaust setups yield different tones. A straight pipe does not only look the part (hello, horsepower), but it also practically guarantees the loudest, most aggressive tone. By contrast, if you want bigger, badder sound while still retaining a modicum of civility, we would recommend going with an exhaust that has suitable resonators and/or the kind of mufflers that sound better than the kinds of straight pipes that come with off-road kits.
2. Drone Reduction
A frequent problem with aftermarket exhaust systems is drone, which is a bothersome resonance that takes place at certain RPMs. To avoid this, we suggest using resonators or specific muffler designs that can reduce drone while still maintaining a sporty sound. We can help you choose the suitable components to achieve the ideal sound.
Issue: What happens when you don't use the right components?
Conclusion
Enhancing the performance and driving enjoyment of your WRX or STI can be best achieved by upgrading the exhaust system. At DarkLight Fabrication, we understand that clearance, routing, and sound are the big three when it comes to making your custom exhaust system. Our turbo exhaust manifold, downpipe, and cat-back system designs ensure that what you receive is not only well made and performing at the level of your goals but also is aligned with your personal preferences. We make the products that the other guys don't.
If you are prepared to elevate your Subaru WRX or STI to the next echelon, reach out to us today to confer about your exhaust specifications. Allow DarkLight Fabrication to liberate the latent power of your automobile!