TBI exhaust

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Overthedge21

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What's the best exhaust for a 350 TBI. It's git long tube headers with twin 2 1/2 pipes down to two raptor mufflers. I was looking into new mufflers since the raptors not only sound pretty bad but they're kinda shot. What do you guys recommend for a more agressive sound? I would just run staright pipes but every time I do that the truck loses bottom end. I can feel it in how it drives, it seems to me as though the back pressure bolsters the bottom end a noticeable bit. Is that normal? I've read both ways that tbis run better or worse with or without back pressure, but it seems to me it runs better. Anybody know what mufflers would keep some back pressure but get the sound up louder? Or should I change pipe diameter? I'm really at a loss here
 

1987 GMC Jimmy

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I think your setup sounds solid for a mostly stock TBI motor. The Flowtech Raptors are a turbo muffler, right? It sounds like you'd be happier with a glasspack sound. I like other turbo muffler brands myself, but there's no point in keeping them if they're shot. My stance is I want people to know I'm driving a truck, but I don't want to go overboard with it. On the whole backpressure dilemma, I'd say it's mostly a myth. The faster your exhaust can escape, the better net performance you'll have. That being said, there is evidence that having a more restrictive exhaust system will improve your torque and HP right at the low end so the takeoff should feel nicer with something more than an open exhaust. I'll attach an Engine Masters video that you should watch if you have fourteen minutes to spare. Also, @vkh is good at giving detailed explanations on these matters.

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Honky Kong jr

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I think your setup sounds solid for a mostly stock TBI motor. The Flowtech Raptors are a turbo muffler, right? It sounds like you'd be happier with a glasspack sound. I like other turbo muffler brands myself, but there's no point in keeping them if they're shot. My stance is I want people to know I'm driving a truck, but I don't want to go overboard with it. On the whole backpressure dilemma, I'd say it's mostly a myth. The faster your exhaust can escape, the better net performance you'll have. That being said, there is evidence that having a more restrictive exhaust system will improve your torque and HP right at the low end so the takeoff should feel nicer with something more than an open exhaust. I'll attach an Engine Masters video that you should watch if you have fourteen minutes to spare. Also, @vkh is good at giving detailed explanations on these matters.

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No way loud and proud and in their window. Lol
 

Honky Kong jr

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What do you like to run on your stuff?
Well I'm sure you've seen my black trucks set up. I like Flowmasters. I've run 10s,44s and 50s all depends on the vehicle and HP level. Not a glass pack fan and definitely not a straight pipe fan. My European stuff was always Borla.
 

Overthedge21

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Of the three, which do you think sounded the best? I was thinking about getting a set of super 10s since they're pretty cheap and seem to be the most agressive
 

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I don't think back pressure itself helps, the more gas you get out of the chamber the better the the next combustion will be. However if the tune isn't adjusted to take advantage of the change it can have adverse affects. I imagine TBI would be more finciy than a carb. I suggest an aggressive chambered muffler for your purposes, just avoid the cheap brands, they can create a fair bit of restriction. I've just run turbo mufflers so far so I can't suggest much as far as a particular product.
 

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Of the three, which do you think sounded the best? I was thinking about getting a set of super 10s since they're pretty cheap and seem to be the most agressive
10s are loud.....if you don't want to drive your self insane go 44s or 50s they still have a good sound.
 

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