2002 Suburban K2500

Hi Steve, muffler has been problem-free so far. I did a ton of research on this, and you can't buy just the muffler from GM parts...it comes as part of an "assembly" that includes the front pipe, one of the catalytic converters, etc and the dealer price is $2000! Everything aftermarket was a "performance" exhaust and my biggest fear was getting a drone in the cabin while towing.

Finally decided on the FloPro 2506. Was $150 shipped, and it cost me another $150 to have the local exhaust shop weld it on. I even talked to the local shop for advice before ordering the FloPro, and he said that mufflers perform differently depending on the vehicle. A muffler on vehicle A may be fine but may drone if installed on Vehicle B. So while he had done installs on other 8.1 trucks, he had never done an 8.1 Suburban, and couldn't guarantee how the same muffler would perform.

If you scroll down to the bottom of the Flo Pro page in the link, they have a sound level chart. The mufflers that fit the 8.1 come in a few different sound levels, the 2500 is the one they are saying is the "stock" sound level, the 2506 is a little louder, the 2505 is the loudest.

I was also concerned that it's not stainless, and would have preferred a stainless unit, but more important to me that it be quiet when towing. So far it's held up well, and I'll likely get another of the same when it's time.

I was also looking for something that was a direct fit since I planned on installing it myself, but once the new arrived and I saw the SIZE and weight of the muffler, I decided that changing was a job for a guy with a LIFT!

response in less than two hours, now that's service Burbman!

You want fries with that :B

BurbMan wrote:
Hi Steve, muffler has been problem-free so far. I did a ton of research on this, and you can't buy just the muffler from GM parts...it comes as part of an "assembly" that includes the front pipe, one of the catalytic converters, etc and the dealer price is $2000! Everything aftermarket was a "performance" exhaust and my biggest fear was getting a drone in the cabin while towing.

Finally decided on the FloPro 2506. Was $150 shipped, and it cost me another $150 to have the local exhaust shop weld it on. I even talked to the local shop for advice before ordering the FloPro, and he said that mufflers perform differently depending on the vehicle. A muffler on vehicle A may be fine but may drone if installed on Vehicle B. So while he had done installs on other 8.1 trucks, he had never done an 8.1 Suburban, and couldn't guarantee how the same muffler would perform.

If you scroll down to the bottom of the Flo Pro page in the link, they have a sound level chart. The mufflers that fit the 8.1 come in a few different sound levels, the 2500 is the one they are saying is the "stock" sound level, the 2506 is a little louder, the 2505 is the loudest.

I was also concerned that it's not stainless, and would have preferred a stainless unit, but more important to me that it be quiet when towing. So far it's held up well, and I'll likely get another of the same when it's time.

I was also looking for something that was a direct fit since I planned on installing it myself, but once the new arrived and I saw the SIZE and weight of the muffler, I decided that changing was a job for a guy with a LIFT!

Thanks for the update, BurbMan!

Yes, I looked at buying the stock factory muffler (which includes a bunch of pipes attached , but noticed the $2000 list price that you mentioned. Even at gmpartsdirect it would have been $1250 (plus a lot of shipping).

What is the advantage of the 2506 over the "stock-sound" 2500? Does the 2506 flow better or just have more sound?

I also need to check the pipes to makes sure they are OK. Just in case, have you found a place that has pipes for the sub, or does the muffler place have to custom-bend new ones from blanks?

Thanks
Steve

I dunno...the 2506 sounds stock to me...maybe call call FloPro tech support and ask them, I know they were very helpful when I called. I can tell you there is NO drone at any speed towing the 8500 lb TT. If I recall, FloPro said they all flow the same, but better to call them since it may have changed in the last 3 years.

I had a minute after lunch, so I snapped a quick pic of the muffler so you can see how it's holding up after almost exactly 3 years. Granted I'm in Louisville now, so the winters aren't as bad, and I haven't been out driving on the beach either:





Now about the pipes....it depends on which one you need. Most of the pipes are standard 3" mandrel bent pipes, any exhaust shop should be able to make a pipe or two from the cat back. Now the front pipes are another story...

When I had the transmission changed, they had to drop the front pipes to get it out, and the right pipe broke. The pipe has a flange on it that bolts to the manifold and the flange cracked in 3 pieces. Apparently the dealer or local shop in NY must have had issues with it during some previous repair and make a half-arsed attempt to weld it, and never bothered to mention it...

Here's the pipe:



If you look at the flange that bolts to the manifold, you can see a groove running around the inside face. There is a gasket that sits in that groove and seals the pipe to the manifold. The problem with re-welding the flange back together is that the groove would then need to be re-machined, so it would cost more in labor to fix it than to replace it. The pipe/flange is only available as an assembly, and only available from GM. Cost me 5 days of waiting and $450 to get a new pipe delivered to the shop that was installing the transmission.

The good news....the FloPro has the inlets/outlets in the stock locations so you shouldn't need any pipe work to install the muffler, unless the pipes are bad for whatever reason. If you go with a Magnaflow or other than has generic inlet/outlet locations, then the shop will need to do pipe work to make everything line up.

Thanks for all the info and pictures.

I'll call the company and ask about the different mufflers.

I have a little while as my patch seems to be holding pretty well.

Steve

Any of you guys with the 8.1 Burbs have issues with excess oil consumption? If so, what did you do about it?

I've got an 2002 8.1 Sierra P/U. I put the quietest Flowmaster (Rustmaster) and it rumbles at low speeds, but surprisingly not towing at highway speed. But, it looks like a rusty piece of cr-p, hanging under the truck.

And Captnjack, not sure what you mean by (excess oil consumption), my 8.1 has used some oil since new (100k, now). I've read on the GM and truck forums about people who went to full synthetic oil and stopped or reduced the consumption. Apparently the 8.1 is vaporizing the dino oil, and most, if not all, do it.

Mine used 1 quart every 3000 miles since it was brand new. Consumption is about half that since I changed to Mobil 1 Hi-Mileage a couple years ago. Guys that complained to their dealer were told that the official GM standard for oil consumption is more than 1 quart of oil to 100 gallons of gas....so at 12 mpg, it would need to use more than a quart every 1200 miles to be considered problematic.

FYI, it does have an oil level sensor in the pan, and you'll get a "low oil level" message if it's 2 qts low.

BurbMan wrote:
Mine used 1 quart every 3000 miles since it was brand new. Consumption is about half that since I changed to Mobil 1 Hi-Mileage a couple years ago. Guys that complained to their dealer were told that the official GM standard for oil consumption is more than 1 quart of oil to 100 gallons of gas....so at 12 mpg, it would need to use more than a quart every 1200 miles to be considered problematic.

FYI, it does have an oil level sensor in the pan, and you'll get a "low oil level" message if it's 2 qts low.

X2

My Suburban has 152K miles on it and, like BurbMan, has used about 1 quart per 3000-5000 miles since new. When I tow, it seems to burn a little more oil (1qt per 3000 miles)than when not towing (1qt per 5000 miles). I bought it with 5K miles on it and have been running Mobil 1 since I got it.

I talked to an engineer at the Tonawanda, NY plant that built the 8.1 engine. He said the oil consumption is due to the fact that it was designed to also run on natural gas. The rings had to be made of a harder material, which don't seal as well as softer rings.

I have to keep my 2002 Sub running, as there hasn't been an equivalent replacemnt since 2007(?) when they got rid of the 8.1L.
Now the new (2015+) subs don't even have a 3/4 ton version anymore. There are some rumors of a HD version coming out, but it still won't have a BB or Diesel.

Steve