Action shots! 2003 Suburban 2500 8.1 vs. Mother Nature

[Buddha.]

I was curious, it didn't look stock. All of ours have been Z-71 style with its different rack. I wasn't sure if that was part of the normal LS/LT accessories, or it was some aftermarket piece. I like the idea of it and I'm wondering if it would help the mileage on my Sub or if I could even install it without interference with the back end of my Z-71 rack / roller. I do a lot of highway driving, too fast, and anything that helps with conformal airflow would be good. Was there a brand name on it?

Those rear spoilers for lack of a better word probably reduce mileage. They're designed to catch air(bad for mpg's) and send it over the back window to keep the back window free of dust and snow. The rear spoilers on the newer more aerodymamic suvs don't catch the air but extend the sloping roofline which makes for less turbulent air behind the truck.

 

[legendaryandrew]

Did you have any clearance issues with the front driveshaft hitting the exhaust pipe since the front diff was lowered? I saw one instance where a guy with an 8.1L truck had to have the drivers side down pipe modified with the Cognito 4-6 because of that but I am not sure if it is an issue with the SUV's. I'm planning on putting a Cognito 4-6 on my 8.1L Yukon XL sometime this summer. I'm also doing an NP241 swap so I will have to mess with the driveshafts anyways.

Yes the exhaust has to be modified, and there is absolutely no way around it lol but it didn't cost too much. I'm also starting to look into t-case swaps. How do you plan to use a 241? There is no way to put a floor shifter in my Suburban without mutilating the center console.

As for the spoiler rayra, I just checked. It's a GM accessory part, so the PO got it from the dealer.

 

[bknudtsen]

Nice rig!

 

[PGW]

Yes the exhaust has to be modified, and there is absolutely no way around it lol but it didn't cost too much. I'm also starting to look into t-case swaps. How do you plan to use a 241? There is no way to put a floor shifter in my Suburban without mutilating the center console.

As for the spoiler rayra, I just checked. It's a GM accessory part, so the PO got it from the dealer.

The t-case shifter will work with the center console, I plan to use this for reference on mine: http://www.dieselplace.com/forum/76...85-center-console-t-c-floor-shifter-pics.html

I already have the GMT800 t-case shifter and a 32 spline input NP241. I'm planning on tearing the case down this winter/spring to rebuild it and add a SYE kit (probably not necessary but may as well). I will have to disconnect the TCCM plugs under the dash to disable the autotrac and send a ground signal to the right pin on the TCCM connector when in 4-low to get the trans to shift right. Will also have to splice the speed signal from the NP241 into the factory wiring. Then get new driveshafts made. Will also install a posi-lok in the front diff to have the 4x4 system 100% manual with no electronic crap.

 

[legendaryandrew]

The t-case shifter will work with the center console, I plan to use this for reference on mine: http://www.dieselplace.com/forum/76...85-center-console-t-c-floor-shifter-pics.html

I already have the GMT800 t-case shifter and a 32 spline input NP241. I'm planning on tearing the case down this winter/spring to rebuild it and add a SYE kit (probably not necessary but may as well). I will have to disconnect the TCCM plugs under the dash to disable the autotrac and send a ground signal to the right pin on the TCCM connector when in 4-low to get the trans to shift right. Will also have to splice the speed signal from the NP241 into the factory wiring. Then get new driveshafts made. Will also install a posi-lok in the front diff to have the 4x4 system 100% manual with no electronic crap.

Holy crap, it actually doesn't look bad!! I may have to go that route instead, because I firmly believe that simplicity is the best way, thanks so much for sharing that link. Seriously, you just opened a new door for me haha

 

[Bushcoat]

Good info on the cognito stuff, always good to hear the real world results. I've been thinking about the cognito upper arms and steering supports, plus some reasonable tie rod ends (think GM accidentally put leftover Geo metro tie rods on the GMT800 trucks). I'm also planning fox 2.0 shocks but have not decided yet on lift spindles or not, which affects which shocks to order.
Anyhow, I wanted to do everything at once, once my balljoint's were worn out, shocks collapsed, and tie rods falling out but its not going to work that way (unfortunately lol)... But I'm due for the shocks by now so I should order the rest of the parts and decide to lift or not. I only want to have to do one wheel alignment with all the new parts on at once.

 

[chilliwak]

Nice looking machine Andrew! Of the look of your beast tearing it up in the snow. Looks like some huge upgrades you have done to the suspension. Perhaps you might want to get rid of those big blocks you have in the rear and replace it with springs arced to the lift you need. Look into BDS. They probably have something that would give you the right lift. Cheers, Chilli...:wings:

 

[legendaryandrew]

Thanks for the compliments and info! Here are some more shots from todays trip to the mountains.

I tossed in some scenery just for S and G's

Side note, today really illustrated my need for traction aids. Got stuck twice. Good thing I had my trusty shovel...and some locals, to get it unstuck! This thing is a lot of metal for the frozen crusty snow, heh.

 

[chilliwak]

Absolutly:Wow1:stunning pics Andrew! Looks like you have had fun out in the snow :drool:covered landscape. Looks like there is a lot of snow in your area right now.. Thanks for posting up. Cheers Chilli...

 

[rayra]

Those rear spoilers for lack of a better word probably reduce mileage. They're designed to catch air(bad for mpg's) and send it over the back window to keep the back window free of dust and snow. The rear spoilers on the newer more aerodymamic suvs don't catch the air but extend the sloping roofline which makes for less turbulent air behind the truck.

I'd thought the whole point of rear airfoils like that was to duct air down along the back to keep it conformal and specifically to reduce that rear turbulence / drag. Kinda moot really, driving such a huge box anyway. Just looking for a slight edge.


legendary, take another look at the rack, it has the same ribs on teh roof skin and airfoil crossbars, but the side and rear rails are much more robust and a few inches taller than the LS/LT racks.

I looked at aluminum plate and hell no, way too much. Ballpark $600 for the raw materials. + oversize shipping. Not worth it too me. Going to look at alternates.

And as for shade, I'm messing around with a few ideas on that - http://www.expeditionportal.com/for...eas-for-a-lightweight-compact-flexible-design
Need to finish up that sewing and get all the config pictures done.


Anothe ridea discussed in that prior white roof topic and in pappawheely's build thread is something like a tensioned fabric deck, akin to the deck of a hobie cat. It would be a good shade skin on an otherwise bare roof. Laced on much the same as the hobie cat deck, with the fabric panel being made from somethign like 1000D denier nylon, with edge reinforcement and grommets. Something like paracord for the lacing. Or maybe some rack track mounted locations for a quick and sturdy attachment. Something that can take freeway speeds. That's another project for later this year.

I might do a plywood deck as an inexpensive proof of concept. Getting that huge black roof under shade has GOT to help. But I think it's going to have to be mounted with some metal strapping that goes clear across it both top and bottom, trapping the wood, and not just a couple angle brackets bolted in at the edges. Imagine a 1/2" thick sheet of plywood tearing off at 80mph. Pure murder for someone behind me