Dual Exhaust/2 mufflers

[Peter]

I have an I6 03 envoy xl, i want to do the dual exhaust for looks and performance, but many car mechanics and technicians have told me, due to back pressure, you may loose hp with the dual exhaust, is that true with the I6 envoy xl? Yet, i see all these tb's an envoy's with dual exhaust, and im pretty sure they aint all V8s. Well if anyone has done it on their I6 let me know if you came across any troubles with the dual exhaust, and also what brand exhaust system it is

[Envoy Fan]

I have the Borla cat back system on my I-6 Envoy. I noticed minimal increase in performance. I do like the dual look. The Borla system was very easy for my local muffler shop to install, took exactly one hour for the installation. The shop commented it was rare to see a kit fit as well as this one fit. The down side was the increase in drone or resonance at 1500 to 2000 rpm. I remedied that problem with the installation of about 160 sq. ft. of sound deadener in floor and doors.

[IceN]

by removing the stock exhaust and putting in a more free flowing exhaust will actually increase hp. A GM tech in one of the articles said it will gain of up to 30hp, and i beleive it. The difference is night and day on the I6, and is well worth for a lil more sound. Just choose the right setup if really care for sound that much. My setup is really loud, change in my cup hold actually rattles around 2k. Im runnin a bullet muffler dumped at the rear axle.

[em_hova1]

im looking for a dual exhaust fro my 02 envoy as well. i want it for the look(chrome tips) and for the preformance if anyone knows a place online or in the midwest area (illinois preferrably) cheap or can get a discount let me know im very interested

[djcaseanova]

by removing the stock exhaust and putting in a more free flowing exhaust will actually increase hp. A GM tech in one of the articles said it will gain of up to 30hp, and i beleive it. The difference is night and day on the I6, and is well worth for a lil more sound. Just choose the right setup if really care for sound that much. My setup is really loud, change in my cup hold actually rattles around 2k. Im runnin a bullet muffler dumped at the rear axle.


I have a dynomax race bullet sitting in the garage not being used. I am thinking of putting it on my TB, but had been waiting to find someone who had one installed to find out if it was worth it. I had one on a vortec 4.8l V8 one before and it was loud, but any idea on what it sounds like on the I-6 compared to a V8? About the same?

[02EnvoySLE Guy]

I have a dynomax race bullet sitting in the garage not being used. I am thinking of putting it on my TB, but had been waiting to find someone who had one installed to find out if it was worth it. I had one on a vortec 4.8l V8 one before and it was loud, but any idea on what it sounds like on the I-6 compared to a V8? About the same?

I would be careful using something not "engineered for" the TB/I6. The I6, from what I've heard, is very picky about backpressure to run optimally. If you don't custom-fab an entire system around what you're wanting to use, you may see considerable performance decreases.

[kaycee42]

I have a dynomax race bullet sitting in the garage not being used. I am thinking of putting it on my TB, but had been waiting to find someone who had one installed to find out if it was worth it. I had one on a vortec 4.8l V8 one before and it was loud, but any idea on what it sounds like on the I-6 compared to a V8? About the same?

A I-6 will never sound like a V-8. My muffler guy told me the same thing about back pressure and noise. We installed a Flowmaster Big Block 70 series 3 inch inlet/outlet and backed it up with a Megnaflow XL 2.5 inlet/outlet to increase back pressure and curve the noise. Also added K&N Air Intake System. Noticed increase in POWER and GAS milage. Nice muffler sound and low inside cab noise. This is single exhaust maybe your installer can do duals for you.
Check Out TRENDS best muffler and see what others had to say. :cool:


kaycee42
02 TB
CALI

[IceN]

the only downfall of my setup is my low-end sucks balls, to put it simply. My top end is fudgen crazy though. I can get from 65 to 90 like no other. All in all i would say anything that would replace the factory exhaust will be beneficial.

[XTREEME]

A I-6 will never sound like a V-8.

Agreed. IMO, an 'amplified' 6 sounds only marginally better than a fartcan on a 4. :rolleyes:

Adding an exhaust to help increase power or mileage to a 6 is fine, but when guys start putting straight pipes or the like on it, I just have to wonder why. :confused: It just does not sound good. Leave the pipes for the V8's.

[02EnvoySLE Guy]

Agreed. IMO, an 'amplified' 6 sounds only marginally better than a fartcan on a 4. :rolleyes:

Adding an exhaust to help increase power or mileage to a 6 is fine, but when guys start putting straight pipes or the like on it, I just have to wonder why. :confused: It just does not sound good. Leave the pipes for the V8's.

I have to mention there is one exception to that. A 4.3L Vortec V6 is basically an iron SBC with two cylinders chopped off the end. The exhaust, to me, sounds damn close to as lopey as a V8. I've heard those with flowmasters and such on them, and they are actually pretty good. :D

[02EnvoySLE Guy]

A I-6 will never sound like a V-8. My muffler guy told me the same thing about back pressure and noise. We installed a Flowmaster Big Block 70 series 3 inch inlet/outlet and backed it up with a Megnaflow XL 2.5 inlet/outlet to increase back pressure and curve the noise. Also added K&N Air Intake System. Noticed increase in POWER and GAS milage. Nice muffler sound and low inside cab noise. This is single exhaust maybe your installer can do duals for you.
Check Out TRENDS best muffler and see what others had to say. :cool:


kaycee42
02 TB
CALI

do you have pics and/or part numbers for this stuff? I'd love to see how that looks comming out the back of your truck :cool:

[kaycee42]

do you have pics and/or part numbers for this stuff? I'd love to see how that looks comming out the back of your truck :cool:

Check Out kaycee42 in gallery for pics

Flowmaster Big Block II 70 series muffler
part # FLOG53072 (3in center/offset)

Megnaflow 4x9 oval XL muffler (used as resnator)
part # 13215 (2.25 center/offset)

Chrome Tip (what the shop had in stock)
3in diameter, cut the length to fit your look and welded to XL muffler
:cool:

[02EnvoySLE Guy]

excellent, thanks!

[Black Ice]

For you guys with the dual exhaust. is there a real gain or is it just for looks and a little more rumble in the pipes.

[Toolman]

Anyone who says you need back pressure to make power needs reducation. Aftermarket exhaust systems help on some vehicles and make "0" HP on others.

[goldbergv95]

A I-6 will never sound like a V-8. My muffler guy told me the same thing about back pressure and noise. We installed a Flowmaster Big Block 70 series 3 inch inlet/outlet and backed it up with a Megnaflow XL 2.5 inlet/outlet to increase back pressure and curve the noise. Also added K&N Air Intake System. Noticed increase in POWER and GAS milage. Nice muffler sound and low inside cab noise. This is single exhaust maybe your installer can do duals for you.
Check Out TRENDS best muffler and see what others had to say. :cool:


kaycee42
02 TB
CALI

where can u get the Flowmaster Big Block 70 series 3 inch inlet/outlet and backed it up with a Megnaflow XL 2.5 inlet/outlet because mopst web sites dont have one for a trailblazer and does it help save gas, and does it increase hp and does it make real loud noise??Thanks

[kaycee42]

where can u get the Flowmaster Big Block 70 series 3 inch inlet/outlet and backed it up with a Megnaflow XL 2.5 inlet/outlet because mopst web sites dont have one for a trailblazer and does it help save gas, and does it increase hp and does it make real loud noise??Thanks

Check out quote #12 in this trend and get the part #'s go to your local muffler shop and they should have these parts. If not go to web sites.
www.JustFlowmaster.com & www.Magnaflow.com and order mufflers. Your local shop should be able to install. I believe the 70series also come in a dual muffler click on the part # for the picture to see muffler and you can run 2 magnaflows resnator or you can install the single 70 series and install a magnaflow xl dual for dual tips on the same side.Yes my horsepower increased and it has a nice sound inside & out.Any help I, can be let me know. :cool:

[goldbergv95]

Check out quote #12 in this trend and get the part #'s go to your local muffler shop and they should have these parts. If not go to web sites.
www.JustFlowmaster.com & www.Magnaflow.com and order mufflers. Your local shop should be able to install. I believe the 70series also come in a dual muffler click on the part # for the picture to see muffler and you can run 2 magnaflows resnator or you can install the single 70 series and install a magnaflow xl dual for dual tips on the same side.Yes my horsepower increased and it has a nice sound inside & out.Any help I, can be let me know. :cool:

Thanks for the info, but im also currius, does the exhaust lose gas fast or does it save gas, thanks

[kaycee42]

Thanks for the info, but im also currius, does the exhaust lose gas fast or does it save gas, thanks

It's seams like my gas mileage has improved, performance really has improved. I also have a K&N Air Intake System to go with the exhaust/muffler mod. :cool:
goldberg, What type of TrailBlazer do you have and what part of the country are you from ? :cool:

[goldbergv95]

A I-6 will never sound like a V-8. My muffler guy told me the same thing about back pressure and noise. We installed a Flowmaster Big Block 70 series 3 inch inlet/outlet and backed it up with a Megnaflow XL 2.5 inlet/outlet to increase back pressure and curve the noise. Also added K&N Air Intake System. Noticed increase in POWER and GAS milage. Nice muffler sound and low inside cab noise. This is single exhaust maybe your installer can do duals for you.
Check Out TRENDS best muffler and see what others had to say. :cool:


kaycee42
02 TB
CALI

Thanks but i dont quiet get it when u said u installed a Flowmaster Big Block 70 series 3 inch inlet/outlet and backed it up with a Megnaflow XL 2.5 inlet/outlet, are they both mufflers, why do u have to buy two of them and wut do uy mean u use Megnaflow XL as a resonator, it just that im not use to this kinf of stuff. THanks

[goldbergv95]

It's seams like my gas mileage has improved, performance really has improved. I also have a K&N Air Intake System to go with the exhaust/muffler mod. :cool:
goldberg, What type of TrailBlazer do you have and what part of the country are you from ? :cool:

2002 Trailblazer, and I from Northern VA

[kaycee42]

2002 Trailblazer, and I from Northern VA
I also have a 02 TB checkout the gallery kaycee42 :cool:

[kaycee42]

Thanks but i dont quiet get it when u said u installed a Flowmaster Big Block 70 series 3 inch inlet/outlet and backed it up with a Megnaflow XL 2.5 inlet/outlet, are they both mufflers, why do u have to buy two of them and wut do uy mean u use Megnaflow XL as a resonator, it just that im not use to this kinf of stuff. THanks

The TB has 2 mufflers you should take it to a garage and get it in the air.
The 1st muffler from the engine is HUGH for this size truck. If you read the TRENDS about mufflers, Best Mufflers & Dual Exhaust are TBE Brothers talk about it. The second muffler is the resnator at the back of the truck, that's the one you can see.Some guys removed the resnator and some don't.Some guys change the main muffler for aftermarkrt mufflers and they are very loud inside and out and don't sound good.Then they add a 2nd muffler to lower the inside noise, if you read my quotes, I tried 3 diffrent things before, I found what I liked. Even when you buy dual sets they come with 3 mufflers(1main & 2 resnator). Check out Brola and Corosa they have dual kits.They cost a pretty :m2: :cool: You are doing the right thing by asking these question. Don't just let tham sell you what they think will work, TrailBlazer & Envoy I-6 engines are a special breed. If the shop can't tell you about the stock muffler before he puts it on the rack he's never dealt with the special breed. Find someone else cause everything don't work on this truck.
Stay in touch :cool:

[goldbergv95]

The TB has 2 mufflers you should take it to a garage and get it in the air.
The 1st muffler from the engine is HUGH for this size truck. If you read the TRENDS about mufflers, Best Mufflers & Dual Exhaust are TBE Brothers talk about it. The second muffler is the resnator at the back of the truck, that's the one you can see.Some guys removed the resnator and some don't.Some guys change the main muffler for aftermarkrt mufflers and they are very loud inside and out and don't sound good.Then they add a 2nd muffler to lower the inside noise, if you read my quotes, I tried 3 diffrent things before, I found what I liked. Even when you buy dual sets they come with 3 mufflers(1main & 2 resnator). Check out Brola and Corosa they have dual kits.They cost a pretty :m2: :cool: You are doing the right thing by asking these question. Don't just let tham sell you what they think will work, TrailBlazer & Envoy I-6 engines are a special breed. If the shop can't tell you about the stock muffler before he puts it on the rack he's never dealt with the special breed. Find someone else cause everything don't work on this truck.
Stay in touch :cool:

so if i were to get a 3.00" IN (C) / OUT 2.25" (D): 70 Series (Big Block II)
( FLOG530722 ) will this fit with 2 magena flow 7" Round XL 13743 as resonators will that work because I get what u just told me but i dont get is will the mufflers come with pipes that will connect the 70 series to the magena flow or do u have to buy ur own pipes???

[goldbergv95]

The TB has 2 mufflers you should take it to a garage and get it in the air.
The 1st muffler from the engine is HUGH for this size truck. If you read the TRENDS about mufflers, Best Mufflers & Dual Exhaust are TBE Brothers talk about it. The second muffler is the resnator at the back of the truck, that's the one you can see.Some guys removed the resnator and some don't.Some guys change the main muffler for aftermarkrt mufflers and they are very loud inside and out and don't sound good.Then they add a 2nd muffler to lower the inside noise, if you read my quotes, I tried 3 diffrent things before, I found what I liked. Even when you buy dual sets they come with 3 mufflers(1main & 2 resnator). Check out Brola and Corosa they have dual kits.They cost a pretty :m2: :cool: You are doing the right thing by asking these question. Don't just let tham sell you what they think will work, TrailBlazer & Envoy I-6 engines are a special breed. If the shop can't tell you about the stock muffler before he puts it on the rack he's never dealt with the special breed. Find someone else cause everything don't work on this truck.
Stay in touch :cool:

where can u read "the TRENDS about mufflers"??Thankz

[kaycee42]

so if i were to get a 3.00" IN (C) / OUT 2.25" (D): 70 Series (Big Block II)
( FLOG530722 ) will this fit with 2 magena flow 7" Round XL 13743 as resonators will that work because I get what u just told me but i dont get is will the mufflers come with pipes that will connect the 70 series to the magena flow or do u have to buy ur own pipes???

goldberg, what's up man. that (D) you put after the outlet size. Does it stand for dual because when Flowmaster uses a D it means dual outlets. Check out the pics on there website www.JustFlowmaster.com If you go to #12 in this trend, Ive listed all the part #'s. Your muffler shop will cut out the factory mufflers and install the Flowmaster & Maganaflow and will add any exhaust pipeing needed. Go talk to a couple of shops.
Stay in touch :cool:

p.s. ARE YOU TRYING TO TO DO DUALS ? IF SO THE ANWSER IS YES THE 70 SERIES WILL STILL BE 3in INLET/OUTLET AND THE MUFFLER GUY WILL TAPER THE 3in EXHAUST TO FIT AT THE 2.25 MAGNAFLOW RESNATOR
HE WILL HAVE TO CREATE THE EXHAUST PIPEING FOR DUALS "NO BIG THING FOR SHOPS TO DO"

[kaycee42]

where can u read "the TRENDS about mufflers"??Thankz

Right Here in FOURMS>Tech Talk> Engine and Drivetrains Dual Exhauast/2mufflers or Best Muffler :confused:

[goldbergv95]

goldberg, what's up man. that (D) you put after the outlet size. Does it stand for dual because when Flowmaster uses a D it means dual outlets. Check out the pics on there website www.JustFlowmaster.com If you go to #12 in this trend, Ive listed all the part #'s. Your muffler shop will cut out the factory mufflers and install the Flowmaster & Maganaflow and will add any exhaust pipeing needed. Go talk to a couple of shops.
Stay in touch :cool:

p.s. ARE YOU TRYING TO TO DO DUALS ? IF SO THE ANWSER IS YES THE 70 SERIES WILL STILL BE 3in INLET/OUTLET AND THE MUFFLER GUY WILL TAPER THE 3in EXHAUST TO FIT AT THE 2.25 MAGNAFLOW RESNATOR
HE WILL HAVE TO CREATE THE EXHAUST PIPEING FOR DUALS "NO BIG THING FOR SHOPS TO DO"

do u think gas stations can install mufflers for u, and when u install flowmaster as the muffler and magnaflow as the resonator, u said it makes a nice sound and it curves the noise, do u mean that the noise is not very loud where everybody around u can hear ur muffler or do u mean that is not that loud compare to the Borla Exhaust system??Thanks

[kaycee42]

do u think gas stations can install mufflers for u, and when u install flowmaster as the muffler and magnaflow as the resonator, u said it makes a nice sound and it curves the noise, do u mean that the noise is not very loud where everybody around u can hear ur muffler or do u mean that is not that loud compare to the Borla Exhaust system??Thanks

I've never heard a Borla System. The reason we have two muffler is the noise you hear in the cab of the car. Some people call it a drone sound. it will drive you crazy. Remember the I-6 engine will not sound like the Big Chevy V-8.
It's a special breed. I would go to a speed shop that installs muffler or a muffler shop that you feel you can trust. Do you have Midas Muffler in your area or a muffler guy in your hood that you can pull into his shop and talk shop and feel no pressure. Maybe your gas station guy is a muffler guy and can do it. Send me a Private Message and we can exchange phone #s.
Stay in touch :cool:

[spearenvoy]

Hey Kaycee42....Any posibility of you getting a sound clip outside of the Envoy and perhaps one of you while driving inside the cabin. It will give people a good idea of what kind of sound you got from the setup. You probably have the most experience (by trial and error) and you seem to know what a good sound is so it will help if you can post a clip
Spear

[kaycee42]

Hey Kaycee42....Any posibility of you getting a sound clip outside of the Envoy and perhaps one of you while driving inside the cabin. It will give people a good idea of what kind of sound you got from the setup. You probably have the most experience (by trial and error) and you seem to know what a good sound is so it will help if you can post a clip
Spear

I'll give it a try. Need to talk to some people with some know how and equipment. :cool:

[DetroitTB]

How much was the cost of the flowmaster/magnaflow/and labor?

Also I'm doing alot of traveling this summer so any gas saving mods that have been proven to work let me know.

[kaycee42]

How much was the cost of the flowmaster/magnaflow/and labor?

Also I'm doing alot of traveling this summer so any gas saving mods that have been proven to work let me know.

Gas saving tips. "K&N Air Intake System :cool:
Cost parts and labor about $300.00 to $350.00
If you order parts from manufacture Flowmaster/Maganaflow web site cost is less. Seek labor price before you order and seek parts & labor to compare price from shop. :m2:

[blazingdan]

i have an 05 TB and th inking of doing the K&N. have you had any probelms with OBD, check engine light showing its face maybe? :undecided

[kaycee42]

i have an 05 TB and th inking of doing the K&N. have you had any probelms with OBD, check engine light showing its face maybe? :undecided

Everything has been fine. NO PROBLEMS :cool:

[Rescue16]

I just dropped a K&N Drop in replacement filter in My 2002 Trailbazer EXT 4X4 and had it in for about a week and yesterday the check engine light came on. Took Truck to the shop and they reset the light since I did not have time to mess with it but on Saturday they are going to Blow smoke through the system and see if there are any leaks. I have also noticed a slight fuel smell since I put the K&N filter in.

Has any one else had this problem. Please advise. I like my TB but it is turning into a Garage Queen for mostly minor fixes but this is starting to get old already!!

Thanks

[chasmanz28]

I just dropped a K&N Drop in replacement filter in My 2002 Trailbazer EXT 4X4 and had it in for about a week and yesterday the check engine light came on. Took Truck to the shop and they reset the light since I did not have time to mess with it but on Saturday they are going to Blow smoke through the system and see if there are any leaks. I have also noticed a slight fuel smell since I put the K&N filter in.

Has any one else had this problem. Please advise. I like my TB but it is turning into a Garage Queen for mostly minor fixes but this is starting to get old already!!

ThanksI dont see how just adding an K&N filter you should be smelling gas :confused: . I just installed and entire CAI Volant intake and no check engine light or gas smell, maybe you sprung a leak somewhere. Ide be curious to see what they find

[Rescue16]

Well took the Trailblazer back in again for the check engine light since the first time the checked it out could find nothing so they just reset the check engine light:duh:

Well it came back on again today and I am still smelling gas so I took it back again. 30 minutes letter they finally figure it out. There is a crack in the filler neck of the gas tank which is kicking of the CEL and also the reason why I am smelling gas.:undecided

Well next monday the new gas tank will be in and installed so I guess we will just have to put up with gas smell and CEL for a week and hope no one tosses a cigarette towards the back of the truck:confused:

[h0tr0d]

kaycee please take a pic of your exaust so we can be spared the torture of these redundant questions buy the same confused members.

[ieatglue]

CAI's don't really do anything to the system, I got a $35 off ebay 3 months ago and have had no problems with it :)