Gadgetory

well first of all before we get to dual-exhaust let's do a quick lesson and exhaust in the first place they served really free functions the first is evacuation or scavenging as it's known in the trade that's the idea of getting the burned charge that's the air and fuel it's been combusted out of the engine it's no good anymore and on its way quickly and rapidly doing it efficiently lets the engine generate more power by breathing more freely it also can improve mpg your second major function and obviously a critical one is emissions your catalytic converters live on your exhaust system in line with the pipes now back in the day before cats you know exhaust systems weren't really part of emissions so much now they're a critical part of your vehicle's compliance with the law and the last function and the one that's the most fun to be honest is towed whether you want a really hush quiet car or one that has shall we say a certain presence as you arrive you get that done in the acoustic design of the exhaust system either by the factory engineers or by the guy down at the muffler shop who's bent a lot of pipes I love muffler shops in an auto world full of repairs that consist of primarily computer dictated part swaps what happens here is handmade and verging on art nowhere more true than at one of the best muffler shops in our San Francisco area Johnny Franklin's in San Rafael California let's take a tour of the exhaust components of in this case we got an older car but it hasn't changed too much now except no catalytic converters exactly Don Johnson is a third generation muffler man good choice to explain how it all works so the first piece coming off the engine is as the exhaust manifold right off the cylinder head itself four cylinders on each side for the v8 when he's still under firing at exhaust yep they've got their own port exactly that exact then it's all merges into a collector into the exhaust pipe so now we're under the pipe for the first point yes bolts up on each side of one over here one over here yep and then the front pipes come down does it cross member here each pipe or otherwise known as the equalizer pipe if that actually breaks the pressure between the right and left sides of the motor so this could be an X also right can be an X yeah that you would just kind of do that yep cross over and now they've changed sides basically exactly it's also helping as you guys in the biz say helping it scavenge absolutely because each side is kind of helping draw the other side's exhaust out exactly okay it's going a venturi effect does this rushes by it sucks some of the other stuff with it yep these X or H pipes also do wonders to give the system a smoother more muscular sound without it you'll get that classic lowrider sound you'll get that right so like a machine gun sound almost you know sixties Impala yeah and now we just have some more pipe until we get to the traditional duals glass packs here they're a straight-through design there's no restriction so the tube actually goes through the center it's a preparatory there's not much there to calm it down and then we'll travel up and over the rear end and then we finish up with one last muffler here the exhaust will come in on both sides and the exhaust would merge together again and then out output saw out the tailpipes on each side okay and then tailpipes or basically keep the exhaust up from pooling under the car yeah without it you'll get fumes obviously inside the car but also without tailpipes and you'll pick up a lot of harmonic Jeron inside the car customers that have us do no tailpipes we all kind of joke around on how many weeks before they're back back right yeah because of the the drone is it just a boom you had the car it's not a pretty sound no it's horrible now a dual exhaust system is nothing more than a system that is to exhaust they're identical on both sides of the car typically running off two sides of the engine that usually is predicated on the engine being a V configuration but why a duel generally speaking like on an older vintage car single exhaust to dual exhaust you're gonna pick up probably about 20 horsepower on a new modern-day car you're only gonna pick up probably about camp still it's a notable difference yeah and what about fuel efficiency does it help get better gas mileage 375 your fuel mileage is usually about 2 miles a gallon better newer cars and trucks really vary from nothing to a mile or two yeah lots of cars have bogus duals today they look like duals or even quads at the rear but there may be only dual from the catalysts on back or even only at the tips for cosmetic reasons a true dual is a parallel system from each of the two cylinder banks all the way back to the end if I see two or four tips on a car today what do I read into that not so much most of the newer cars you know that come through the Calla converters and then they'll split into two and the rear of the car and it's a little bit more of a fake dual if it's a factory muffler system there's not usually a lot of performance gain if the aftermarket performance mufflers got in bulk yes there is a game there and bottom line is using a lower restriction muffler versus a regular stock muffler that's got a little bit more back pressure to it so there are a lot of ways to get a better performing exhaust without this assume of making a dual exhaust yes but a dual is kind of the more ambitious level absolutely letting an engine breathe yeah absolutely I think the bottom line is the consumer wants to see dual pipes on the back of the car is it's adds a little extra something something back there it's a car jewelry but this looks good does it looks great yeah