Dual Exhausts on a Burb - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**Already Gone** · 11-09-2012, 12:49 AM

I have developed a small hole in my muffler so its time to go to the muffler shop. Now my Burb is a 1994 with the 5.7 TBI and my question is will I gain anything (besides a nice sound and rumble) if I go to dual exhausts. Can I put a true dual exhaust system with the catalytic convertor that is on the Burb now, or do I have go through the convertor then go duals and if I have to do that I'm thinking I might as well stay with the single exhaust. We don't have any emissions stuff here and can cut the convertor off if need be. Does removing the convertor screw up the way the truck runs?

96k1500ecsb · 11-09-2012, 08:21 PM

To stay legal you'll have to go through the convertor then go duals or stay with a signal exhaust after the cat. There are plenty of bolt on kits to choose from for either configuration after the cat.
My shop truck is a '94 K3500 5.7L TBI that has dual pipes after the cat with no mufflers.
It has a nice growl and it's not as loud as I thought it would be.
Removing the cat will not effect engine performance on your OBD1 truck. However, do not remove the O2 sensor(s) before the cat.
I doubt a muffler shop will cut the cat off for you in order for them to install true duals. It's a liability thing for them. If you personally cut the cat off, then take the truck to a muffler shop, they may refuse to install true duals without a cat or dual cats ($).
True duals without a cat is usually a custom bent exhaust by the muffler shop so it will cost more than a bolt on kit after the cat.
I hope I made sense.
Laters

**Already Gone** · 11-09-2012, 09:04 PM

Quote:

Originally Posted by 96k1500ecsb

To stay legal you'll have to go through the convertor then go duals or stay with a signal exhaust after the cat. There are plenty of bolt on kits to choose from for either configuration after the cat.
My shop truck is a '94 K3500 5.7L TBI that has dual pipes after the cat with no mufflers.
It has a nice growl and it's not as loud as I thought it would be.
Removing the cat will not effect engine performance on your OBD1 truck. However, do not remove the O2 sensor(s) before the cat.
I doubt a muffler shop will cut the cat off for you in order for them to install true duals. It's a liability thing for them. If you personally cut the cat off, then take the truck to a muffler shop, they may refuse to install true duals without a cat or dual cats ($).
True duals without a cat is usually a custom bent exhaust by the muffler shop so it will cost more than a bolt on kit after the cat.
I hope I made sense.
Laters

Thanks for the info. We do not have any emission tests in Saskatchewan so I dont think its a problem to remove the cat. I don't see the point in running duals to the cat, then going duals again. I just wanted to make sure if I removed the cat that the truck would run okay. I just picked up a K& N fresh air system for my Burb ands was hoping if I went to duals with the K&N I might gain some gas mileage.
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red94chev · 11-09-2012, 11:26 PM

I say turn the headers upside down and run dual stacks straight out of the hood.

96k1500ecsb · 11-10-2012, 12:53 PM

Cut the cat off yourself (unless a shop has no problem with it) and have a muffler shop bend true duals. You will have to run mufflers and the type would be your preference.
I personally like Flowmaster 40 or 50 series mufflers. I have a friend in Wyoming (no emissions state) that has a '95 K1500 Sierra extra cab 5.7L TBI with the cat removed , true 2.5" duals, a set of Flowmaster 50 series mufflers, with the tail pipes exiting under the rear bumper. The thing sounds real nice.
My daily driver is a '96 K1500 Sierra extra cab with a 5.7L vortec. It came factory with dual cats and dual pipes to the factory dual inlet muffler. I just cut the muffler off and installed a dual in/ dual out Flowmaster 50 series muffler. Then I had a muffler shop install dual tail pipes that exit under the rear bumper.
It also sounds real nice. It's not quite as loud as my friends '95 but that's because the dual cats muffle the sound.
If you went to duals with the K&N you will gain some gas mileage but it won't be as dramatic as you might think. You may gain a mile or two per gallon and the engine will feel a little more responsive.
The biggest effect will be what your ears hear. You'll want to hear the exhaust tone more often so you'll lean into the engine a little harder. Of course, your gas mileage will go down.
Good luck.

11-09-2012, 12:49 AM	#1
Already Gone 70+ ( Old Skool Club ) Join Date: Nov 2003 Location: Saskatoon, Saskatchewan ,Canada Posts: 9,231	Dual Exhausts on a Burb I have developed a small hole in my muffler so its time to go to the muffler shop. Now my Burb is a 1994 with the 5.7 TBI and my question is will I gain anything (besides a nice sound and rumble) if I go to dual exhausts. Can I put a true dual exhaust system with the catalytic convertor that is on the Burb now, or do I have go through the convertor then go duals and if I have to do that I'm thinking I might as well stay with the single exhaust. We don't have any emissions stuff here and can cut the convertor off if need be. Does removing the convertor screw up the way the truck runs? __________________ 1972 C10 Custom/Deluxe 613 Highlander 406/700R4 1999 White Tahoe LS 4x2 with Z56 Police Package 1992 K1500 GMC Suburban Members I have personally met: MusicMan70 - HeavyD - ChewyChevy67 - StingRay -71SWB4x4 - 67 Burb - DeadheadNM - too much stuff - bc65 - das601 " In the end, we only regret the chances we didnt take " " Time is the only currency we spend without knowing the balance, use it wisely ." ..

11-09-2012, 08:21 PM	#2
96k1500ecsb Registered User Join Date: Oct 2012 Location: Greeley,Colorado Posts: 2	Re: Dual Exhausts on a Burb To stay legal you'll have to go through the convertor then go duals or stay with a signal exhaust after the cat. There are plenty of bolt on kits to choose from for either configuration after the cat. My shop truck is a '94 K3500 5.7L TBI that has dual pipes after the cat with no mufflers. It has a nice growl and it's not as loud as I thought it would be. Removing the cat will not effect engine performance on your OBD1 truck. However, do not remove the O2 sensor(s) before the cat. I doubt a muffler shop will cut the cat off for you in order for them to install true duals. It's a liability thing for them. If you personally cut the cat off, then take the truck to a muffler shop, they may refuse to install true duals without a cat or dual cats ($). True duals without a cat is usually a custom bent exhaust by the muffler shop so it will cost more than a bolt on kit after the cat. I hope I made sense. Laters

11-09-2012, 11:26 PM	#4
red94chev Registered User Join Date: Jun 2010 Location: Conowingo, MD Posts: 341	Re: Dual Exhausts on a Burb I say turn the headers upside down and run dual stacks straight out of the hood.

11-10-2012, 12:53 PM	#5
96k1500ecsb Registered User Join Date: Oct 2012 Location: Greeley,Colorado Posts: 2	Re: Dual Exhausts on a Burb Cut the cat off yourself (unless a shop has no problem with it) and have a muffler shop bend true duals. You will have to run mufflers and the type would be your preference. I personally like Flowmaster 40 or 50 series mufflers. I have a friend in Wyoming (no emissions state) that has a '95 K1500 Sierra extra cab 5.7L TBI with the cat removed , true 2.5" duals, a set of Flowmaster 50 series mufflers, with the tail pipes exiting under the rear bumper. The thing sounds real nice. My daily driver is a '96 K1500 Sierra extra cab with a 5.7L vortec. It came factory with dual cats and dual pipes to the factory dual inlet muffler. I just cut the muffler off and installed a dual in/ dual out Flowmaster 50 series muffler. Then I had a muffler shop install dual tail pipes that exit under the rear bumper. It also sounds real nice. It's not quite as loud as my friends '95 but that's because the dual cats muffle the sound. If you went to duals with the K&N you will gain some gas mileage but it won't be as dramatic as you might think. You may gain a mile or two per gallon and the engine will feel a little more responsive. The biggest effect will be what your ears hear. You'll want to hear the exhaust tone more often so you'll lean into the engine a little harder. Of course, your gas mileage will go down. Good luck.



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