TRUE DUALS

[00gmc_country_boy]

Hey anybody here have a sierra 1500 with the 4.8 L V-8 with TRUE dual exhaust? If so, I am thinking about putting true dual exhaust (leaving the cats) with 12-18" glasspacks. I had this setup on my 98 z71 w/ the 5.7 L. It sounded awesome and ran great. I recently went to one exhaust shop to have this done to my 00 GMC sierra 1500 4X4 but the muffler man wouldn't do it becasue he said my check engine light come on and it would run like crap and so on..... So I left. I was just wondering if this was really true or if he just didn't want to do it because of emission laws or whatever?? Any help would be greatly appreciated!!!

[SS Crew]

On a stock engine you will gain nothing or maybe lose some low end power. Unless you're putting some serious power out of your engine, you're just wasting your money.

 

Just put on a Corsa system and be happy.

[PELICAN]

you lose some low end power when you convert to true duals? I have a 4.8L V8 and I'm planning on doing this the first part of next year. It will run me around $500 installed. I am not looking for any performance gain but would like the truck to be louder then what it is. I figure if I am sitting lower then a ford or a dodge then I want to be heard.

[Mark_in_Tulsa]

you lose some low end power when you convert to true duals? I have a 4.8L V8 and I'm planning on doing this the first part of next year. It will run me around $500 installed. I am not looking for any performance gain but would like the truck to be louder then what it is. I figure if I am sitting lower then a ford or a dodge then I want to be heard.

 

<{POST_SNAPBACK}>

 

 

 

 

 

Yep a larger single exhaust is better, unless your pushing a lot of HP. Of course a larger one, wouldn't exactly be an improvement on a stock motor. The stock one is pretty tuned well to these motors nowadays. Just a better muff, and mandrel bent pipes would make a better improvement than true duals.

 

I'm not going to get into the science of why one larger one is better for low end torque, (which we need to get these giant bricks moving) than true duals. Someone else can do that.

[lerbud]

I have true duals on mine and no glasspacks. I love the sound!! I have had them on a 2000, 2002 & 2004. No codes or problems ever.

[00gmc_country_boy]

you lose some low end power when you convert to true duals? I have a 4.8L V8 and I'm planning on doing this the first part of next year. It will run me around $500 installed. I am not looking for any performance gain but would like the truck to be louder then what it is. I figure if I am sitting lower then a ford or a dodge then I want to be heard.

 

<{POST_SNAPBACK}>

 

 

 

 

 

Yep a larger single exhaust is better, unless your pushing a lot of HP. Of course a larger one, wouldn't exactly be an improvement on a stock motor. The stock one is pretty tuned well to these motors nowadays. Just a better muff, and mandrel bent pipes would make a better improvement than true duals.

 

I'm not going to get into the science of why one larger one is better for low end torque, (which we need to get these giant bricks moving) than true duals. Someone else can do that.

 

<{POST_SNAPBACK}>

 

 

 

[00gmc_country_boy]

I have true duals on mine and no glasspacks.  I love the sound!!  I have had them on a 2000, 2002 & 2004.  No codes or problems ever.

 

<{POST_SNAPBACK}>

 

 

THANK YOU lerbud04, THATS WHAT I WANTED TO HEAR!!

[mcreyaufmiller]

Just run the siongle in and dual out. This configuration will do well for you and give you the look of duals with out the problems of true duals. The stock cat is a high flow unit, so you do not need to replace it. If you do go true duals, make sure there is a cross over somewhere around the tranny to balance the system. the right wat to do this is run the truck and find the hottest spot in the line, that is where yoiu put the cross over.

 

We are talking about true duals; 2 cats, 2 mufflers, 2 tail pipes, right? connecting a new muffler to your existing system with 2 outputs is not considered true duals.

[lerbud]

Mine has a pipe from each cat and they are joined together under the cab for balance and seperate to the rear. I run mine out behind the wheels so I can hear it better. lol No mufflers or glasspacks. Its really not loud unless you get on it hard. All my trucks have this and I have never had a problem. My buddies have it on their trucks too and no problems for them either. You either like the noise or you dont.........

[michaelrayce]

most trucks have the pipes ran to the passenger side , so if you ran a duel pipe system , one side would be longer than the other , and one pipe would sound different than the other , and you get that neasty rasp you hear so often . a nice single pipe system balances the sound out and provides a little back pressure for low end torque , something you need on a street driven truck . most aftermarket systems run this way and they know what there doing , theyve tested this stuff , there not stupid . sound is a prefrence , i would never run without a muffler or run a glasspack or no muffler at all , you dont see nice performance cars in magazines running glasspacks or no muffler . they all sound good when there sitting there rumbling , but when you get on it , it would sound like ass , but hey , like i said , sound is a preference .

[dannyukonxl]

on the 8.1 its got w 2.75 inch pipes into the can, im doing true dual magnaflows 2.5 inch cases with duals straight out the back with 2.5 inch tubing. I also have a cross over right after hte last cat, also on the 4.8 true duals will lose hp unless you do 2 inch piping, i think a 3 inch pipe has an area of 7 inches or something and 2 2.5 inch pipes have 10 combined. Do the math before you put on true duals, generally you will lose power until 2400 rpms and 2500 rpms will start building power and taking advantage of the flow. The H pipe allows gas from one bank to compensate for the vacuum in the other pipe giving more bottom end power and reducing sound

 

bottom line you will need some small pipes and diameter cans to take advantage of a true dual system on the 4.8