Rumble without the grumble
Performance pipes on a Pontiac G8 GT
Tommy Lee Byrd - March 14, 2013 10:00 AM
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Jimmy’s Pro Muffler & Brakes
1 The G8 has a very restrictive exhaust system. Note the single muffler located in the center of the chassis.
2 The two huge resonators in the back seem to offer the perfect location for a pair of high performance mufflers, but that approach has proven to have negative results.
3 Jimmy begins disassembling the exhaust system at the rear, unbolting the big resonators. If you’re doing this at home, be sure to spray all of the original hardware with penetrating oil before getting started.
4 This small steel crossmember must be removed before the original exhaust can be loosened and removed.
5 The oxygen sensors require a 7/8-inch wrench, and they generally need a bit of persuasion to break loose. Jimmy threads both sensors out carefully, as they will be reused in the Solo exhaust system.
6 We’re retaining the stock “cats”, but Solo Performance also offers high-flow versions that have proven to make great gains in power.
7 A couple sprays of penetrating oil on the rubber exhaust hangers help the disassembly process. The main portion of the exhaust comes out in one piece.
8 It’s easy to see where some big time power is being eaten up. In addition, the Solo kit offers a weight reduction, which is always a good thing!
9 The exhaust kit features a polished stainless steel muffler, while a small balance pipe tones down the exhaust note without sacrificing horsepower.
10 Although it looks strange to most folks, this additional “chamber” is what sets the Solo kit apart from the competition.
11 Jig-built using stainless steel tubing, the new exhaust is dead-on with the stock flanges.
12 Jimmy applied anti-seize to the oxygen sensors before threading them into the bungs.
13 The next pieces of the puzzle are the two pipes that fit between the muffler and Solo’s J-pipes. These need to be installed loose, until the entire kit is together.
14 The piping is all 2½-inch mandrel bent T409 stainless steel.
15 Every car is different, so tweak the tailpipe alignment to your liking before fully tightening the clamps.
16 You might ask a friend to hold the exhaust while you tighten the hardware to keep it from moving.
17 Solo Performance builds its kits to work with the original rubber exhaust hangers, and they slid into place easily.
18 It’s so clean and simple — we just hate that it’s tucked away under the car!
19 The rear portion of the exhaust is also very tidy, as the J-pipes are tucked out of the way in the same location as the original resonators.
20 With the new exhaust, we gained nearly two tenths, knocking down the elapsed time to 8.68 at 82 mph! That’s a real world power increase with a great muscle car sound.
When Pontiac introduced the G8 product line for the 2008 model year, it certainly had performance in mind.
The GT and GXP models had healthy V-8 powerplants, and the rear-wheel drive platform gave car guys an excuse to go out and buy a four-door sedan.
Cars need to meet certain requirements for interior noise and all that corporate stuff, so the G8 GT has catalytic converters, a single muffler, and two giant resonators in the stock exhaust system. We wanted to keep the catalytic converters, but free up some power with a new cat-back exhaust kit. And so the search was on.
Our research led us directly to Solo Performance. Their exhaust system for the G8 GT has all the requirements of an aftermarket performance exhaust, good sound and build quality. There’s also no dreaded drone that is so common with modern performance cars, especially the G8 GT. This car is a daily driver and its primary driver happens to be a female, so the idea of drone at low rpm didn’t sound very appealing.
We listened to about a million exhaust audio clips and continued to ask around on the various G8 forums online. Solo offers four kits for the GT and GXP models, so we carefully read the descriptions of each system. Each kit had a different sound level, and we actually chose the quietest kit, which is called the Mach Balanced system.
The Mach Balanced system is made up of 2½-inch T409 stainless steel tubing, which is mandrel-bent. It features one of Solo’s Mach series mufflers, which is a polished stainless steel 14-inch muffler. The coolest aspects of the Solo’s exhaust kits are the J-pipes, which is essentially a J bend that is capped off to create an additional chamber in the exhaust. The J-pipes are the secret to this exhaust system’s lack of drone. The “balanced” aspect of the Mach Balanced exhaust system is a simple crossover pipe just before the muffler, which helps soften the exhaust note. This also softens the transition between four-cylinder and eight-cylinder modes on the L76 engine, which has GM’s Displacement on Demand feature.
With intentions to keep the Displacement on Demand, we wanted a kit that would muffle the transition but still give us an increase in power and overall sound quality. The Solo Mach Balanced kit did the trick, and it was incredibly simple to install. We took the car to Jimmy’s Pro Muffler & Brakes in Dayton, Tennessee, for the install, but it could easily be a great do-it-yourself project, even if you don’t have a lift.
The sound quality during regular driving is excellent, with a deep rumble that isn’t overpowering but really sounds great when the throttle is wide open! For our application, the Mach Balanced proved to be the perfect choice, and it even shaved a few pounds off of our 4,000-pound sedan, and helped it pick up nearly two tenths of a second in the eighth mile!