2008 V8 Gibson 3" Exhaust

[banditxp]

Not sure if i posted this in the correct place, still new and all to this forum.

So the mod bug bit me and I had to get something nice.

I found a great deal on a Cat-Back 3" Stainless Gibson Exhaust.
Got it for $403.36 shipped. From wcpdiesel.com
Gibson 619692 Single Stainless

Took about 2 weeks to get it because Gibson had to make some parts for it lol.


So dont know how many of you guys have done a full cat-back system but its pretty easy on these trucks

Took about 30min to remove the old stuff with the huge water tanks for mufflers lol. Then about 3 hours to put the new one on.... yea.. ill explain.

So the in the instructions it says to reuse the stock bolts at the flange by the Y pipe. But the problem i found and this is true for most cars/trucks is the end of the bolts that stick past the nuts rust and the threads get small.
So they wont work anymore the way Gibson wants yo to reuse them.

I went to lowes and bought some Grade 8 hardware and just made my own setup. (see pics below for all this) Another thing they say it is a tight fit around the axle... yes VERY tight . so tight it rubbed a couple days after i put it on after a few WOT runs when it got very hot it grow backwards. So wheat needs to be done while fitting it together is use a wooden wedge of some sort and put it between the pipe as it goes up around the front of the CV/Axle joint and hammer it in there. Then use a pipe or something that can rest on the hanger off the pipe behind the muffler so you can tap it as far forward as it can go with no clamps on at all. Make sure you mark the pipe in the front and back of the muffler so you can see it move. You are going to want to get as much space as yo can by the from of the axle/pipe. the first time I Put it together i was able to fit my fingers between the pipe and the axle, after doing this i was able to fit my hole hand and now it does not rub.

The Kit comes with normal U Bolt clamps but i wanted something better and that would not rust. So i got some stainless Lap Joint Band Clamps from Summit Racing for about $9 each shipped. They work great!

Ok enough typing time for a video and pics.

Ill take a better video after i have someone to hold my camera lol.






Ok here are some side by side pics

Nice band clamps

This is the one thing i dont like is how they do the bolts/flange up front.

you can see how my bolts with only 47K miles on them are rusting away at the end of the threads.

This is a photo that Gibson tech support sent me when i emailed them about the problem it found, and i must say there tech support is fast and helpfull.

This is how i made my setup with the bolts i bought.

How it sits, i think it looks good beside it being dirty lol. Sorry its been raining and iv been busy.

Ok and here is a video of how it sounds

 

[Sams01XplrSprt]

sounds good

 

[willied]

Great write up and excellent video! It sounds great. It seems pretty tolerable in the video, but how do you feel about the sound of it in normal driving compared to stock? Is it still very liveable? Will it annoy passengers who don't like exhausts?

The sound of it accelerating hard makes me want something similar quite badly.

 

[banditxp]

thanks guys,

yea at normal speeds around the 40-60mph you can barely hear it over the road noise and with the music on at low level its gone. at 70MPH or so you can hear it a little more but its easily covered up buy conversation or music.

when you give it a little more gas to go up a hill it gets a little louder but still no drone. also with the more low end torque i have now it down shifts/unlocks the torque converter less now up the normal hills around my house.

now as you can hear when you get on it allot it does get loud, but still i would say its not really too much louder then a stock new mustang 5.0 or the Dodge Rams with the Hemi's. though no more vacuum cleaner sound at all LOL

I still need to hear it for my self outside and or have someone take a video when im at WOT.

 

[willied]

Alrighty then, that's good to hear. Don't forget to update your signature!

 

[jupiterak]

I see Gibson made some improvements on the band clamps and flange screws. When I did mine 4 or so years ago, it came with the elcheapo clamps. I later had blowout on my muffler on the housing weld. After two months of BS emails, Gibson offered me a replacement but wanted the original and pay all shipping expenses. Luckily, I snagged a used Magnaflow for $230 off ebay.

 

[banditxp]

Nope those Band Clamps are ones i bought form Summit racing because they still use the crappy ones.

I dont know why they dont use band clamps, their so much better.

 

[Ronin8002]

I've been going back on forth a little bit on whether I want to bother doing any exhaust mods on my new truck. I had a Gibson catback on my 2004 V6 and it was fairly mellow but definitely didn't sound this good. I really, really like the way this one sounds on the V8. Might have to look into doing this at some point.

 

[banditxp]

yup and now that iv put over 10,000 miles on it sense i did it wow, it sounds even better. iv got to do another video.

 

[SirManny]

Niceeee. I stuck with Flowmaster though!

 

[matsavol]

Waking up an old thread...

I'm thinking to buy this exhaust. Any recent good or bad experiences about this exhaust kit? I might go with the aluminized steel version since where I live winter and rust is not an issue... Aluminized steel version is less than $300 so it is really tempting.

EDIT: A followup question: Banditxp, how did you get into the OEM exhaust clamp that is over the driveshaft? Is that the reason you removed the rear left wheel?

 

[banditxp]

Waking up an old thread...

I'm thinking to buy this exhaust. Any recent good or bad experiences about this exhaust kit? I might go with the aluminized steel version since where I live winter and rust is not an issue... Aluminized steel version is less than $300 so it is really tempting.

EDIT: A followup question: Banditxp, how did you get into the OEM exhaust clamp that is over the driveshaft? Is that the reason you removed the rear left wheel?

Well its now been almost two years.
Over this time it has gotten a little deeper and rumbles more like a bigger V8.
Its really nice. There has been no problems, rattles or anything yet. It had one winter in Up State NY one of the worst places doe rust in the US and one winter here in UT. So far no rust other then now stainless heat tarnish stuff.

Far as the rear clamp, yes you remove the rear wheel and it makes it much easier to get the clamp off. Also when you putting the new stuff on you need it off to put the new clamp on. I would suggest getting the truck up as high in the back as you can because it makes it much easier to wiggle stuff around.

One suggestion that i learned after having to wiggle and refit mine a couple times so it stopped rubbing on the CV Axle in the back where it goes over on the front side of the axle. You want to loosen the clamps and wedge something between the pipe and the axle and then bang on the exhaust foreword to give it as much room as you can buy the front part of the CV axle knuckle. Mine looked fine but after the exhaust got hot and grew some backwards it started rubbing. 3" is a tight fit on our trucks. But it does work if you take time on fitting it.

far as Aluminized or Stainless... Well if you dont live in a state where metal rust in the winter or by the sea whee the sea salt rust cars then save the money and get the Aluminized. but if you want something you know will last the life of the truck. get the stainless.

 

[matsavol]

Got it!

So I got it and installed yesterday and spent couple hours today tweaking...

Thanks banditxp about the installation tips!. Even with those I ended up cutting about 3/8" off from the first pipe. I could not get enough clearance to the CV axle and keep the tailpipe not rubbing against the spare tire shield without shortening it a little bit. That 3/8" made a huge difference on fitting!

banditxp, how did you get the OEM pipe out without lifting the truck all the way up? I figured that I would have needed to lift it at least 4 feet or so to get the front section into steep down angle before the OEM tube last bend would have been able to get around the CV axle and truck chassis. Since I did this in the garage using just floor jack and jack stands I couldn't get it high enough. I ended up cutting the OEM pipe to get it out.

The sound... It sounds good but for my personal preference it may be a bit too loud. Let's see how long it takes for me to get used to it.

 

[banditxp]

cool glad you got it all installed and working. Yea im sure every truck is a tiny bit different and may need more or less in the fitting.

But far as the sound, it will change over a few months. it will get deeper and i think at lower RPMs a tiny bit quieter. but still just as loud up higher. Wait till you floor it going under a bridge or something like that. its sounds sooooo good.

Far as the stock pipe over the axle, mine came apart with a 10mm bolt i think it was. but yea. just undid the bolt and knocked it apart.

 

[matsavol]

Few days driving impressions:
- After cold start the exhaust note is rather loud but does smooth out when engine (or exhaust?) warms up. When warm it does seem reasonably quiet.
- I'm still having problems on the exhaust growing length when it heats up. It starts touching the heat shield around spare tire and causes some rattling noise. I don't think the last pipe design is optimal, and Gibson could have done better.
- I tried today first time 0-60mph times and to my surprise I did shave about 0.3 seconds! Now I can do the 0-60 run between 7.2-7.3s consistently. Now I'm starting to have issues with rear tires loosing traction, which wasn't really an issue before.
- I did order and installed today Dynomax 24250 mini race muffler at the end of the tail pipe using band clamp. It replaced the Gibson chrome tip. (yeah... it looks a bit ugly...) This reduces the exhaust noise levels couple decibels. I need to do more driving to decide if it is worth keeping in place. (In which case I'm going to shorten the tail pipe by ~8 inches to fit both the race muffler and put the Gibson exhaust tip at the end.)

 

[Ronin8002]

I fixed the spare tire heat shield vibration issue by getting some exhaust wrap from the local auto parts store and wrapping the pipe where it touches the shield and securing it with hose clamps. Problem solved.

 

[matsavol]

Ronin8002, that is a good idea! Once that around pipe heat shield wrap is installed the spare tire heat shield is no longer needed. When I looked at it, it seems that it can be removed rather easily.

 

[matsavol]

I did remove the spare tire heat shield after I put the fiberglass wrap around the pipe.

In addition I finally got the sound level down to a level that I want. The race muffler I bought just didn't do much, and it also looked ugly. I had to find another solution that both brings down the sound and looks good.

What I did I built a home-made glass pack inside the Gibson chrome tip. I bought 1/4" pitch steel net from Home Depot and formed a 3" "net pipe". I wrapped three layers of the fiberglass wrap around it and then tucked it inside the tip. I was able to slide part of the net between the chrome tip and exhaust pipe so that tightening the tip clamp will secure the muffler in place. This muffler did bring down the sound quite significantly! Now it has mostly the low frequency, deep rumble sound left.

 

[matsavol]

Quieting down...

The exhaust certainly has quieted down after some miles on the truck. It actually started to sound too quiet and I took out the extra glasspack muffler. Now it sounds about right again: Almost inaudible during normal cruise and when floored it forms nice balance between the engine roar from front and exhaust roar from back.

Wondering what has caused this? Most likely some carbon deposits have collected into the muffler and it makes all the difference in sound level. What else could it be?

 

[banditxp]

The exhaust certainly has quieted down after some miles on the truck. It actually started to sound too quiet and I took out the extra glasspack muffler. Now it sounds about right again: Almost inaudible during normal cruise and when floored it forms nice balance between the engine roar from front and exhaust roar from back.

Wondering what has caused this? Most likely some carbon deposits have collected into the muffler and it makes all the difference in sound level. What else could it be?

huh Extra glasspack? Mine only came with a muffler. did you get a different kit then i did?