What did you do to your NBS GMT800 Tahoe/Yukon Today?

[Rocket Man]

Had to replace the driver side view mirror glass after breaking it backing out of my new garage. Went OEM since it’s got the auto dimming etc. The first one I got was defective and looked like a fun house mirror. The second one was perfect. I can guarantee that won’t happen again.

If it was OEM I doubt it was defective, those are expensive as hell. What did you pay, $200-300? Might not have got it snapped in all the way. That happened to me. One of the clips wasn’t seated.

 

[iamdub]

Thanks Tony! It’s got the ARH Longtubes with cats, and stock pipes, but with muffler replaced with an 18” magnaflow, and deleted resonator. Actually, I was suppose to tell @iamdub the rpm where I get the most drone with this exhaust, to look into a Helmholtz resonator IIRC. So, iamdub, it’s worst at 2k, which I suspect is quite common.

Having it at your normal cruising RPM makes it worse! For a drone at 2,000 RPM, you'll need a 25.2" (640.08mm) resonator. I'd aim for a pipe the same as the factory pipe's diameter but no smaller than 2". The straighter, the better, but 25" of pipe can be tough to stuff. (giggity)

Also, you want it as close to the source as possible. Off the top of my head, I'm thinking it could come off the Y and run parallel to the crossover pipe. You may have a slight bend in it where it first comes off the Y, but you should be able to get the rest of the length as a straight shot. You could attach it to the crossover pipe to secure it.

 

[Sam Harris]

Having it at your normal cruising RPM makes it worse! For a drone at 2,000 RPM, you'll need a 25.2" (640.08mm) resonator. I'd aim for a pipe the same as the factory pipe's diameter but no smaller than 2". The straighter, the better, but 25" of pipe can be tough to stuff. (giggity)

Also, you want it as close to the source as possible. Off the top of my head, I'm thinking it could come off the Y and run parallel to the crossover pipe. You may have a slight bend in it where it first comes off the Y, but you should be able to get the rest of the length as a straight shot. You could attach it to the crossover pipe to secure it.

Thanks man! I’ll try to get this done. Going to be a challenge!

 

[Rocket Man]

Having it at your normal cruising RPM makes it worse! For a drone at 2,000 RPM, you'll need a 25.2" (640.08mm) resonator. I'd aim for a pipe the same as the factory pipe's diameter but no smaller than 2". The straighter, the better, but 25" of pipe can be tough to stuff. (giggity)

Also, you want it as close to the source as possible. Off the top of my head, I'm thinking it could come off the Y and run parallel to the crossover pipe. You may have a slight bend in it where it first comes off the Y, but you should be able to get the rest of the length as a straight shot. You could attach it to the crossover pipe to secure it.

Where do you get this info regarding resonators?

 

[iamdub]

Where do you get this info regarding resonators?

Interwebz- Wikipedia, geek sites, car forums, etc. Was researching Helmholtz resonators a while back for some reason and am really intrigued at the scientific application. It being a cheap, simple and harmless (non-restrictive) solution makes it that much better. I'm actually kinda hoping I have some drone when I get my exhaust sorted out just so I can play with it.

 

[Rocket Man]

Interwebz- Wikipedia, geek sites, car forums, etc. Was researching Helmholtz resonators a while back for some reason and am really intrigued at the scientific application. It being a cheap, simple and harmless (non-restrictive) solution makes it that much better. I'm actually kinda hoping I have some drone when I get my exhaust sorted out just so I can play with it.

Aha. The great treasure trove of knowledge. I started to think you used to work at an exhaust shop in a prior life. Should have known better.

 

[Fless]

Man, that was some work, and now I'm exhausted!

 

[Danny3737]

If it was OEM I doubt it was defective, those are expensive as hell. What did you pay, $200-300? Might not have got it snapped in all the way. That happened to me. One of the clips wasn’t seated.

It was definitely defective. You could tell before I even tried to snap it in. The dealer wanted close to $500, but I bought It online from another dealer in MD for $245.00 + shipping. I held the 2 side by side before I shipped the bad one back and there was a huge difference in the quality.

 

[Rocket Man]

It was definitely defective. You could tell before I even tried to snap it in. The dealer wanted close to $500, but I bought It online from another dealer in MD for $245.00 + shipping. I held the 2 side by side before I shipped the bad one back and there was a huge difference in the quality.

Weird, you can get a funhouse one on EBay with turn signal, heat and dimming for $40 all day if you can look at it without getting dizzy lol.

 

[Tonyrodz]

Got dem thangs!

Now I need lugs, spacers and bolts! DAMMIT Anybody ?

 

[Rocket Man]

Got dem thangs!View attachment 250921
Now I need lugs, spacers and bolts! DAMMIT Anybody ?

I got a set of chrome spikes for sale....

 

[Tonyrodz]

I got a set of chrome spikes for sale....

 

[SnowDrifter]

Trans seems to run 3 maybe 4 degrees higher with the filter. Difficult to tell if it's a flow reduction thing, or the fact the filter is mounted in the middle of a hot air stream. 97 ambient, 137-138f trans Temps @75mph. Pre filter under same conditions was 134 give or take. No notable downsides otherwise, still have the improved consistency in shift feel at light and heavy throttle input


Also hi from hiatus

 

[Sam Harris]

Trans seems to run 3 maybe 4 degrees higher with the filter. Difficult to tell if it's a flow reduction thing, or the fact the filter is mounted in the middle of a hot air stream. 97 ambient, 137-138f trans Temps @75mph. Pre filter under same conditions was 134 give or take. No notable downsides otherwise, still have the improved consistency in shift feel at light and heavy throttle input


Also hi from hiatus

Welcome back!

 

[Rocket Man]

Trans seems to run 3 maybe 4 degrees higher with the filter. Difficult to tell if it's a flow reduction thing, or the fact the filter is mounted in the middle of a hot air stream. 97 ambient, 137-138f trans Temps @75mph. Pre filter under same conditions was 134 give or take. No notable downsides otherwise, still have the improved consistency in shift feel at light and heavy throttle input


Also hi from hiatus

Where ya been?

 

[iamdub]

Aha. The great treasure trove of knowledge. I started to think you used to work at an exhaust shop in a prior life. Should have known better.

Lol

Nah, it's just one of those things that fascinated me so I geeked out on it. I've never gotten the impression from any exhaust shop worker that they could even begin to use compound mathematical formulas!

When it comes to exhaust, everyone's all about swapping muffler after muffler to balance a certain sound with no drone and that usually means they end up compromising with a quieter muffler than what they originally wanted. With two minutes of calculations and $10 in materials, you can keep the muffler/sound you want and target just the sound you don't want.

 

[Sam Harris]

Lol

Nah, it's just one of those things that fascinated me so I geeked out on it. I've never gotten the impression from any exhaust shop worker that they could even begin to use compound mathematical formulas!

When it comes to exhaust, everyone's all about swapping muffler after muffler to balance a certain sound with no drone and that usually means they end up compromising with a quieter muffler than what they originally wanted. With two minutes of calculations and $10 in materials, you can keep the muffler/sound you want and target just the sound you don't want.

Yeah I tried to get my exhaust guy to make me one. That’s not happening unless I tell him I’ll pay a lot to get it done. Lol. He’s going to get a factory resonator that was deleted from another vehicle to try it out. [emoji53] not sure how that will go, but it’s definitely not going to be 25.2” like it’s supposed to be. OTOH, I suspect the factory resonators have a longer chamber than they appear to. Perhaps.. hopefully it helps. We’ll see in a couple weeks when I can get back in to give it a shot.

 

[iamdub]

Yeah I tried to get my exhaust guy to make me one. That’s not happening unless I tell him I’ll pay a lot to get it done. Lol. He’s going to get a factory resonator that was deleted from another vehicle to try it out. [emoji53] not sure how that will go, but it’s definitely not going to be 25.2” like it’s supposed to be. OTOH, I suspect the factory resonators have a longer chamber than they appear to. Perhaps.. hopefully it helps. We’ll see in a couple weeks when I can get back in to give it a shot.

Strange that he wouldn't make one being how simple it is. It's just a straight piece of pipe that's capped off and welded to the existing pipe. With a hole in that pipe, of course. Maybe because the idea is foreign to him? It does seem weird, though. After all, it's "just a straight piece of pipe that's capped off and welded to the existing pipe".

The factory (Tahoe/Yukon) resonator is a 1/4 wave resonator. It's just a pipe wrapped around a pipe instead of a pipe extending perpendicularly off of another pipe- for packaging purposes. I don't know what it's target (center) frequency is, but it'd be whatever was produced with a stock exhaust at cruising RPM, so you at least have that similarity. Definitely worth a shot.

 

[Sam Harris]

Having a hard time finding the efan harness I want to convert. I know I definitely do not want the Nelson kit, since it likes to burn down trucks.. so since I haven’t been able to reach @ScottyBoy, I’m looking around elsewhere..

Does anyone have any experience with either of these? Or any knowledge? Good / bad..?


https://www.pcmofnc.com/product/2003-2013-full-size-truck-dual-fan-conversion-kit-3/


https://www.bp-automotive.com/product/1999-2006-gm-trucksuv-fan-harness/

Any feedback is much appreciated. I’m also 100% open to cleaning up a factory setup, and replacing anything needing attention, I can solder / wire, etc.. just fine, but there are so few NBS trucks in my junkyards around here, that it’s really tough to find one there as well.

 

[Tonyrodz]

Having a hard time finding the efan harness I want to convert. I know I definitely do not want the Nelson kit, since it likes to burn down trucks.. so since I haven’t been able to reach @ScottyBoy, I’m looking around elsewhere..

Does anyone have any experience with either of these? Or any knowledge? Good / bad..?


https://www.pcmofnc.com/product/2003-2013-full-size-truck-dual-fan-conversion-kit-3/


https://www.bp-automotive.com/product/1999-2006-gm-trucksuv-fan-harness/

Any feedback is much appreciated. I’m also 100% open to cleaning up a factory setup, and replacing anything needing attention, I can solder / wire, etc.. just fine, but there are so few NBS trucks in my junkyards around here, that it’s really tough to find one there as well.

I've read here that the nnbs fans work on the nbs also.
These guys were popular for awhile.

I just checked out their non ebay page and didn't see much of anything on there. Maybe their doing more ebay stuff now.

This is oem/used parts.