Just got the Magnaflow Catback Performance Exhaust with Dual Exit, installed about a week ago, and i must say it has definently gave the H2better acceleration and a few more horse's that you can definently feel, sounds great too, it is just a little too loud to carry on a conversation while driving, seems most of the Loudness is comming right tru the back lift gate especially at highway speeds, any one else come across this? and if so what have you done to reduce some of this noise? I was thinking about installing some dynomat on the inside of the rear lift gate in hopes that it cuts down some the noise, anyone else done this? did it help reduce some the noise? thanks for any input you guys and gals might have...

 

yes, at 3k rpm the interior is resonant with the exhaust. If you use dynamat, you will have to do the rear of the vehicle. Lift gate, floor, walls and roof. I installed dynomat extreme thru the entire interior and all noise is gone, period. It took four bulk pack boxes of dynomat extreme to do do the entire interior.

 

Thanks to Quijyfor his very detailed directions on getting the entire interior out of the truck, I just finished up dynamatting the whole interior, doors , liftgate, roof, a, b,c, d pillars and the floor, now i am much happier with the magnaflow catback exhaust system i had installed ,but just couldnt live with the increased noise from the exhaust it caused, will say it did add some weight to the truck but well worth it......... thanks again Quijy.............

 

Yup......LOVE My Magnaflow!!!!

 

Your are most welcome for the directions and help, anytime. Glad the directions helped as i did it from my head having done it myself with trial and error.

 

Quijy
Any chance of getting a copy of those directions?
Thanks.

 

Hey Lionel,

Heres the directionsQuijy
had sent me with a few changes to the correct sizes of the external torx sockets to remove the front seats,

"The vehicle comes apart reasonably easy. I have a 2005 H2 Lux and I will
assume it is the same interior if not, this may not be of much help. I
pulled out the entire interior, seats, dash board and all out. Then rolled
it our from the front to the back.

Most of the panels are in with snap-in spring clips and generally need to be
pulled straight off. No real trick other than getting the off in the right
order.

Main Body:
First thing off, door sills, front and rear doors.
Then take out the B pillar covers, there is a screw in the top of them
behind a little 1"x2" cover that will pops off.
Next, C pillar covers, you will need a T50 to get the rear shoulder harness
out, they weave thru the C pillar panel
Next, take the sill plate off at the tail gate.
Next take out the panels on each side with the rear tweeters in them.
Then you can take out the two panels on each side in the cargo area.
Next take out the rear seat, you need help getting these out.
Nest take out the front seats, you will need a external torx sockets anE20 and an E14to get these
out. Watch out for the harnesses and again you will need help to get these
out.
Next, pull our the rear carpet section and padding, be careful, the padding
is molded and goes over the rear wheel wells
Now, if you want to venture the dash board you are on your own here, this is
a real pain and took me two weeks to get it out, roll the mat and put it
back in. If you are going to take it apart, it comes apart from the bottom
first them the top, then the middle.
Take out the center console, this will help working under the carpet in the
front. The front carpet will not come out unless you pull out the bottom
arir box and shift assembly. You can work under the carpet by lift it up
towards the center of the vehicle, it is a pain to work this way but once
you do one side the other will be cake.

Most of the vehicle should be exposed, start rolling the mat out. I would
get several rollers as they help to be in different sizes.

One more note, get some Aluminum duct tape. You can find it in most heating
sections of your hard hardware or home depot stores. 2" wide will be fine.
Get four to six rolls. Once I had all the dynamat is rolled out I covered
the edges and seems between sheets with the tape. It adds a nice touch and
keep the butyl from leaking out from under the aluminum backing on the
dynamat in the warmer weather. And when steped on once you have truck back
together.

Once you have it all rolled out and seems covered, put the truck back
together.

It you want to do the roof, getting the sun visors will be the biggest pain.
I would start with them and make sure you get them out before taking down
the headliner. The headliner is really simple to get out once you have the
sun visors out. I attached the way they come out. One of mine came out first
try, the second one took an hour.

Headliner:
Remove the sun visors from the body, they will still be connected to the
headliner and cannot be removed from the headliner.
Remove the overhead center console
Remove the grommet around the sunroof holding the headliner to the opening.
Remove the grab handles fromt he A pillars.
Removed the covers on the A Pillars.
Hopefully you still have the B Pillars and C Pillar covers off still.
In the rear:
Remove the panels over the side windows int he cargo area
Remove the panel in the ceneter by the rear gate hinges
Remove all the push button in the headliner, there approx, 12 I think.
Now the headliner is ready to come down.
Go to each door and remove the gromet surrounding the door opening, this is
the only thing holding it in place. Once these are down it will come down.
The area around the sunroof is super industrial velco and it will come lose,
just find them and pull on that area.

Repeat the dynamat install process used on the main body area. You will have
to work around the headliner as it will not come all the way out unless you
disconnect the harnesses.

Doors:
Remove the screw under the door handle.
Remove the small cover behind the handle
Pull the door panel off. It is really on there with plastic pop clips, it
will sound like it is breaking. Start in one corner and work your way
around. If the clips break you will have to get them at the dealer. I only
broke one in all four of the doors.
Disconnect the harnesses from the door panel.
Remove the weather shield from the door. Start in one corner and work your
way around. This is a two piece panel that needs to be removed as one. Just
slowly peel the what looks like a silicone bead off from the door steel,
then set this aside.
Remove the speaker
Remove the window control from the door panel and plug it back in. This way
if needed you can move the glass. I opted to take the glass out instead of
fighting with it.
Next I installed the Dynamat to the interior of the outside skin of the
door. This allowed the best solution to all noise coming in from outside.
Make sure you clean the panel before you apply the Dynamat. Make sure you
use the aluminum tape here on the edges and seems to seal the Dynamat to the
door, you do not want any water getting in under the mat and peeling it off.
Then it will get stuck in the winds tracks and glass, what a mess that would
be. I used a sheet and half in each door. I cut the 18"x32" sheet in half
and installed one half above the center support and another below the center
support. Then took a second sheet and cut it to fill in the gaps.
Once done, put the door back together and move on to the next door

I have not done the tail gate yet, but I will tell you once this was done
the exhaust cannot be heard from inside. It is super quiet."

Like I said I am at the end of very long upgrade process and hope to be done
soon. I did the dynamat while I have the truck apart to do other things. I
must admit this is well worth it to do but you need to take your time or you
are just wasted you time and dollars. Sorry for the length here and I am
sure I forgot something.

 

Thanks a lot ! Nothing worse than breaking interior plastics because you twisted instead of pulled, or the like.