Hi all, just a quick question for you. I want to install a 4" turbo back exhaust. Reading all the posts suggest that there have been no bad comments from this brand of exhaust. The muffler shop I was in contact with will install turbo back for $650 cdn. However they also told me that they do not replace the downtube that runs from the turbo alongside the firewall as it is not needed and increases the cost dramatically. My truck is a 2006 lbz. Should I drop this guy or does he make sence on what he is telling me.
When going from turbo back am I correct in thinking it should be from the actual turbo back.

not on the duramax the (turbo back system ) is just down pipe back

correct the d-max's don't have a true turbo back system unless you do teh diamond eye down pipe.

was that price they gave you the kit + install?

Yes the 650 is for the install and kit.
I was talking to two muffler shops and both had conflicting stories. One told me that yes they change the down tube and also that I will have big gains if I go to a high flow air intake as well. The second shop said that in order to change the down tube that it would cost hundreds more and that it was not needed.
With the new info given will a 4" from the downtube back still increase HP and lower EGT's.
Thanks to all.

yes. Go to the shop that told you down pipe back The other doesn't know what they are talking about.

I've heard the LBZ intake is good to about 600 hp. Otherwise you are spending $300+ on an intake for only 5-6 hp. Most exhaust systems don't come with the down pipe. The down pipe I heard was worth another 50 degrees cooler on the EGTs. The DP itself is about 200-$300 depending on where you order, so a "few hundred" more is proably true esp if they do the install. If you look around, the DP doesn't account for much HP, thus its not a big bang for the buck thing. The $300 spent elsewhere may be a better idea. Now, a down tube may be different thing. The actual downpipe as we all know, is the piece that goes from the turbo to the cat. However, the LBZ downpipe only goes about 3/4 the way down the firewall. The other 1/4 to the cat is what most "LBZ" owners call the down tube or a turbo back system even though it doesn't get to the turbo.

Yes the 650 is for the install and kit.
I was talking to two muffler shops and both had conflicting stories. One told me that yes they change the down tube and also that I will have big gains if I go to a high flow air intake as well. The second shop said that in order to change the down tube that it would cost hundreds more and that it was not needed.
With the new info given will a 4" from the downtube back still increase HP and lower EGT's.
Thanks to all.

i'm willing to bet they are both talking about the same system. b/c unless they are selling you a Magnaflow system and a Diamond Eye down pipe magnaflow doesn't make a downpipe. and $650 installed would be a killer deal for the system w/ a downpipe... depending which system they are selling you.

Thanks to all who posted. I very much enjoy reading everyones opinions and experiences. I did get the 4" Magnaflow pro system all stainless for $650cdn installed. As Serpa mentioned in his post he is correct that the down tube is very short and only runs to the middle of the fire wall. A very simple clamp is all that holds the new pipe that takes place of the bottom half and catalitic, after that straight back to the muffler and tail pipe.
Next question, does anyone know of a place in Canada to purchase the drivers side pillar plastic to mount a couple of gauges. The pillar also has the small speaker on the bottom. Any opinions on brand of gauges as well.
Thanks again

Autometer makes a very nice one that works with the stock speaker in the pillar. Many of the vendors here on the site carry them.

Jody