Nice work on the truck! Are you aware that many Tahoes and Suburbans came with factory hydroboost? I'm guessing yes, but I just wanted to make sure.

Good luck with it!

Thanks man, I appreciate it.. It is doing a lot better than I anticipated actually.. Especially when I hit the Auto 4WD button and hammer down into a corner !

Oh and its 4600# the last time it was weighed by the guys doing the 4 link... I need to hit the scales and get some accurate numbers with me in it and post 4-link..


Yes indeed, thank you ! I just need to hit one of the local yards here and see if I can't get the parts I need to convert it over ! I'm going to convert the rear brakes over to the newer SUV brakes which are larger diameter and better calipers.. Gotta love the bolt on options for cheap !

Love this build!! Showing up in something completely out of the box and giving the regulars a run for their money is as cool as it gets.

When does the T56 get bolted in? That would be my next mod for sure!!

Please keep us updated on the build and runs...

Thanks man, I appreciate it.. I started off with a GMC Typhoon years ago so it is sort of the theme I am following on this build = Lowered AWD Truck with a few changes, a powerplant that is easier to build and a larger supply of aftermarket support.

As far as the T56 is concerned, it's not likely.. I'm not certain there was ever a 4WD version of that transmission made, its harder to swap in and retain AWD :G-Dub:

I do have a 4L80e in the shed, and the input drum for the Np246 transfer case is available all day long for like $75 since GM put them behind the 80e in the 2500's !!

I'll keep you guys/gals updated, I'm currently researching swaybars and planning more mods, while trying to keep the truck streetable so I can attend local SCCA events.

Earlier GMT800 2500s did have a 5 speed manual option that could be swapped in. I tried to buy one long ago. Not sure it would be worth it though. You can always run a stall converter in the auto.

Very cool build!

Nice build for sure! I just ordered a Watts 3 link for my Syclone from JSM. They build a nice product.

Ya know, I never really considered swapping to a manual, I know the ohh-ahh factor would be up there, but from everything I've read the NV4500 doesn't like to be power shifted, I dunno, not sure of any of that is true, it's just what I've read. I looked around briefly today, mostly on eBay, they aren't terribly expensive, but I'll be honest when I say I know I can build my 80e and forget about it once it's installed. It will take any abuse I plan to throw at it, and while the gear ratios aren't as favorable as the 60e, as you mentioned I can stall it up a bit..

Thanks man, I've been holding off on this project now for something like 5 years.. I am soo thankful to finally be moving forward it.. I have had some good people helping me along the way, and I'm having fun with it.

Congrats man, I love the Syclone !! It's a neat ass color, I had an Aspen Blue Typhoon back in the day and thats where I met the JSM guys from. Good peeps for sure and excellent quality. I told them if they had plans on selling the 4 link to the Fullsize guys, they should plan for guys throwing 800+hp in a 6000# crewcab with stickies on the back.. LOL, I think they responded appropriately, this will definitely handle the power and it's turning out to be a great mod so far for SCCA autocrossing.. I'm sure you'll be happy with the 3 link for the Syclone, they've sold a bunch of them !

Splined Swaybar Question
 

Has anyone messed around with splined swaybars ?? I've been doing some reading but I can't really find a definitive source that makes a comparison between splined bars (similar to Nascar style) and mass produced pre-bent bars..

I'll be honest, she rolls over on her side like a wet noodle with the stock bar.. I crawled under the truck today to look at the rear, egads theres a lot going on there with the 4 link, coil overs, gas tank, spare tire etc.

The front end of my Silverado is exactly 32" from outside mount to outside mount of the existing swaybar. I'm thinking I'd need a 34" bar plus the arms and links to connect to the lower A-arms...

I'm curious if anyone has any input on what diameter bar I should go with?? Are splined bars any stiffer than a pre-bent bar ? I know Hellwig offers a good sized bar for my truck, and a few others offer smaller bars..

My truck currently has a bar that's 1 1/8th thick now, can a person 'over bar' a truck ? I see splined bars running upto 2" in diameter.. I think that may be a bit overkill but I don't know...

I'm all ears if anyone has suggestions throw 'em at me !

Go the suspension and chassis sub-forum and read every sticky post at the top by Ron Sutton.

Quick synopsis on sway bars - All sway bars are just a metal spring. Mass produced pre-bent swaybars are notoriously difficult to model ie determine their exact roll rate, so its experimentation or crap shoot or follow someone else's lead. The splined bars are easier to model and the manufacturers provide rate charts for various diameters and widths with the catch that each manufacturer has their own method of rating them. Speedway Mfg is the most prominent manufacturer of the splined swaybar so you can easily stick with them. Determine what width of bar will work including a 0-5" bend in the arms themselves (arm lenght also affects rate).

Now you have no idea what rate you want, but if you are going from nothign to something, you probably don't want to go to far, especially since more rear roll resistance can lead to too much oversteer. My ballpark recommendation is to determine as I mentioned above the width and attachment points that will work, then go to the speedway site and see what is available. I would recommend starting with a 1" diameter hollow bar and fairly thin wall. Thinner wall means less roll resistance. Try it for awhile, and then maybe experiment with something thicker (easy to swap in and out).

You can also drill multiple holes in the arms, and by shortening the arms (by moving to the shorter holes) you can get a sense of what a thicker wall roll bar will do and give yourself some finer adjustment. IOW build something, buy a fairly thin wall bar and start in the longest holes, adjust to the closer holes to see if it performs better. If it does, you might want to try moving up the wall thickness.

For a rear swaybar I cannot imagine you woul dwant to use anything larger in diameter than 1", but who knows I've never tuned a heavy AWD truck.