In the classic baseball flick Bull Durham, Tim Robbins’ character – the young pitcher with a “million-dollar arm and a five-cent head” – justifies his insistence on throwing fastballs by simply saying, “I want to announce my presence with authority!”
That philosophy largely sums up the impetus behind SLP’s Loud Mouth lineup of exhaust components, which has been one of the most popular aftermarket systems for the ubiquitous fourth-gen Camaro and Firebird. In fact, the story behind the Loud Mouth’s development and production dates back more than 15 years, while the systems for LS-powered F-cars didn’t actually arrive in the market until after the fourth-gen cars had already gone out of production.
If you’re doing the math in your head, you’ve figured out that it hasn’t been quite 15 years since the fourth-generation F-body production run ended, though. That’s because the Loud Mouth was originally developed – ahem – for the Mustang.
Making Some Noise
SLP had always been about GM vehicles, but we couldn’t ignore the size and strength of the Mustang world. – Kevin Woodruff, SLP
The straight-through, resonator-type design of the Loud Mouth “muffler” was it. It was bold, brash and undeniably loud. The true “authority” of the car might have been up for debate at the drag strip, but when it came to announcing it, the car was audible from a few blocks away.
By the time it was clear the Loud Mouth was a success with Mustang owners, we were looking to change up our lineup for F-bodies. – Kevin Woodruff
“By the time it was clear the Loud Mouth was a success with Mustang owners, we were looking to change up our lineup for F-bodies,” says Woodruff. “We had been doing our ‘two outlets on the left’ systems for years and it was getting a little dated. The trend was definitely toward outlets on the left and right sides of the car and we thought the Loud Mouth would be a good choice for that.”
Interestingly, the first Loud Mouth system for the fourth-gen Camaro didn’t debut on the market until 2003 – about a year after the car had gone out of production. That didn’t dampen demand in the least, as the LS1 cars were still in stride as the affordable performance car of choice for GM enthusiasts.
SLP had also revised the earlier, all-welded design of the exhaust system to a modular design that used strong, leak-preventing torque clamps, but that were easy to remove, allowing the car owner to change the original Loud Mouth resonator with the slightly tamer-sounding Loud Mouth II muffler if so desired. It features a wrap around the perforated pass-through pipe, toning down the exhaust note considerably.
That’s not to say the Loud Mouth II was quiet by any measure, but it was certainly less obtrusive to passengers in the car and wouldn’t necessarily incur the wrath of neighbors during a 6 a.m. start-up on a Sunday morning.
“The modular concept is the true hallmark of the Loud Mouth series,” says Woodruff. “Rather than scrapping the entire system and installing a new one – or even hack-sawing off a welded muffler and replacing it – the Loud Mouth system allows you to simply unbolt the resonator or muffler and bolt in the new one, whether you want it louder or quieter.”
Love Thy Neighbor
For those looking for even a quieter sound, SLP’s PowerFlo system offer a, oh, let’s say more “mature” exhaust note. It incorporates a pair of more conventional mufflers, but still offers the easy clamp-on installation of the Loud Mouth resonator or Loud Mouth II muffler. In fact, the Loud Mouth resonator stays in place and the PowerFlo mufflers simply install downstream in the exhaust system, just ahead the exhaust tips.
Not everybody wants the full-on Loud Mouth experience and that’s why we offer a range of choices. – Kevin Woodruff
One thing all of SLP’s exhaust systems have in common is stainless steel material and in-house construction. It’s been that way from the very beginning.
“Exhaust systems have been a specialty of ours from the company’s early days as an emissions-legal performance parts manufacturer,” says Woodruff. “We’ve got it down to a science.”
Indeed, all of the exhaust components are made of stainless steel and that goes for SLP’s F-body headers, as well. In fact, the company has been making F-car headers just about as long as they’ve made anything.
The headers were originally developed as a compromise-free, racing-inspired equal-length design. They represented a marvel of engineering prowess, but they weren’t exactly street-friendly because, frankly, they hung down too low.
The header design evolved by necessity into a more conventional long-tube design that delivered a performance benefit without ground clearance problems – even on slightly lowered cars. And in true long-tube fashion, they deliver the biggest power gains in the mid-range and upper rpm levels.
SLP, which was acquired by ROUSH Industries in 2013, manufacturers the majority of its exhaust components at its suburban Detroit factory, along with some at a Canadian facility. The fixtures for welding the components have been with the company for years, but the equipment to produce them has been revamped or updated since coming under ROUSH’s umbrella a couple of years ago. That meant moving them from SLP’s former headquarters in New Jersey to the Motor City.
“It’s all good with the changeover,” says Woodruff. “It’s like your favorite pizza maker moved to a new location, but took his seasoned pizza pans and recipe with him. All that’s really changed is the address – the ‘pizza’ is still as good as it ever was.”
They’ve also expanded their menu in the new location, adding components for the fifth-gen Camaro – particularly supercharger systems. With ROUSH’s considerable experience manufacturing supercharger systems, the synergies are natural and mutually beneficial. That’s helped SLP retain the OEM-level of engineering and manufacturing quality on which their reputation was originally built.
Exhaust systems, however – and the Loud Mouth series specifically – continue to constitute SLP’s bread and butter.
“We’ve sold literally thousands of systems for fourth-generation F-bodies alone,” says Woodruff. “I couldn’t even guess right now how many we sold overall, because enthusiasts adapt the resonators to vehicles we don’t even offer kits for. Again, it’s the modularity of the design that makes it stand out. They build the rest of the system around the resonators to get that unmistakable sound.”
As a staple of the F-body performance world, the Loud Mouth series unquestionably announced SLP’s presence with authority. They’ve kept throwing those fastballs ever since.