Write-Up: Front/Rear (Addco) Stabilizer/Sway Bar Installation

Jason wrote:

The largest front bar gm offered for the G-body was 30mm (FE2/FE3).  T  I believe it is safe to assume a wall thickness between .125" and .25" for the stock STS rear FE3 bar.
==== edit:  stiffness figures edited to account for stock bars being hollow =======

for reference:
assuming all OEM rear bars have a 3mm wall thickness; and
assuming all OEM front bars have a 5mm wall thickness

30mm front is 27.5% stiffer than the 28mm stock front
20mm rear (FE2) is 76.5% stiffer than the stock 17mm rear
22mm rear bar (FE3) is 144.9% stiffer than the stock 17mm and 23.1% stiffer than the FE2 20mm rear

02018 1.25" (31.75") front ADDCO:  99.4% stiffer than the stock 28mm bar or 56.3% stiffer than the 30mm bar.  This is considering they have the same overall and lever length.  The addco had a very slightly different bend to them, but it should not affect stiffness dramatically.
02015 7/8" (22.2mm) rear ADDCO: 254.2% stiffer than the stock 17mm bar,  62.7% stiffer than the 20mm bar or 44.6% over the FE3 rear bar

Sorry if I missed it somewhere, but how does the F41 front bar differ from the FE2/FE3 front bars? Is is stiffer or not?

Thank you!

[quote="AA"]https://rivperformance.editboard.com/t10096-complete-gm-f41-suspension-upgrade[/

https://rivperformance.editboard.com/t10096p15-complete-gm-f41-suspension-upgrade

F41 front bar is 29% stiffer than stock front bar
FE2/FE3 front bar is 27.5% stiffer than stock front bar

Got it.

Has anyone had any issues with the bigger bars in terms of ripping bolts out or anything?

Has anyone actually welded them in on the Riv?

Can we be sure that the addcos are completely safe bolted up?

charlieRobinson wrote:

Has anyone had any issues with the bigger bars in terms of ripping bolts out or anything?

Has anyone actually welded them in on the Riv?

Can we be sure that the addcos are completely safe bolted up?

My Addco front bar tore the metal off the subframe around the sway bar bushing bolts. As far as I know I'm the only one who had that problem. I also had 8" wide rims and 255s and cornered hard, often. (had a favorite offramp on my daily commute...)

Aaron had some issues, along with someone else, with the supplied bushing bracket deforming which some speculated might contribute over time to damaging the frame if left undetected.

But Aaron solved that with high performance UMI bushings brackets that appear to have held up.

If I were installing the Addco front bar, that $100 set of UMI bushings would be part of the package as insurance.

Al

You don't want to weld brackets or fasteners to the subframe - the bushings can't be removed when they wear out. If you did weld, the bushings would melt anyway.

If you push the car hard in corners, the way to be completely safe is to use UMI brackets, or something similar (fender washers might work). The stamped steel rackets supplied by ES and Addco can deform under extreme cornering. If you just want more solid cornering feel and don't intend to push the car that hard, the supplied brackets will probably hold up just fine, at least for a while.

FWIW the brackets were not deformed on mine. They had the steel plate underneath to hold everything in place, and looked fine. It wasn't until we got under the car while bouncing up and down on it that we figured out the subframe itself was moving! Tore the threading and surrounding metal right out of the subframe. I'm not sure the UMI brackets AA used would have made any difference, I think the subframe was getting thin from New England salty winter roads.

If any issue with the bolts/frame, I think it would be fine to drill through the bottom of the cradle and use longer bolts + nuts/washers to mount the brackets more securely. Mine are holding fine, but that's what I'd do if needed.

ok ok.

Got to go test out the new suspension set up.

I couldnt help my fits of uncontrollable laughter!
THIS IS AWESOME!

I knew the rear addco bar would make a difference but I didnt expect it to be so perfect!
The car 'feels' lighter when turning. You know what I mean?
It just snakes around turns. It's incredible. I'm doing everything I can to stay inside tonight and not go for drive.

I really want to experiment with this set up for a bit and then try to lower the rear and see what effect that has on the set up. I am just a wuss and afraid of bottoming out with these dumb max air shocks and messing something up.

Robo, dont even say coil overs. I know, man. I know.

I don't get much of a choice when it comes to 96 suspension robo and these coil over conversions are pretty damn expensive but they seem like an ultimate choice im performance

I installed the front addco bar today while changing the sub frame bushings.  Don't think it would fit if you don't drop the rear of the subframe.  I just need to buy the rear one.  From the short drive, the car does seem to handle better.  I think the car rides a little rougher, but it might be in my head.  I haven't driven the Riv in a while so I don't know how much the bar will change the ride.  I ended up using the supplied bushing with the addco bar.  I might change it for the UMI brackets and bushing sometime.  I was able to reuse my Moog endlinks (they are only about a year old or so).

Wait until you do the rear bar. Makes things really fun, but like all the other mods it just becomes normal after awhile.

matt270avian wrote:

Wait until you do the rear bar. Makes things really fun, but like all the other mods it just becomes normal after awhile.

Yup.So true.

Quote :

I ended up using the supplied bushing with the addco bar. I might change it for the UMI brackets and bushing sometime. I was able to reuse my Moog endlinks (they are only about a year old or so).

If you stay with the Moog links, your Addco bushings and brackets should be adequate. I never had an issue until I upgraded to ES poly end links.

I noticed that my car wants to follow the ruts in the road now that I have changed the front sway bar. It seems like I have to fight with the steering wheel more now. It is fine on the interstates, but not in town. Is this common with a new sway bar or is something else going on? I also recently got my alignment changed.

Mine does that too. I don't remember if it was after the sway bar install or after I got new tires. I haven't done it yet, but thought maybe a wheel alignment might help. Planning on it this spring.

A stiffer sway bar will allow the car to track more.Less compliance = more response imo

My Riv does the same thing since the sway bars were installed. Throw some 245 wide tires on there too...makes it way worse. The fatter bar is trying to keep the car flat instead of allowing it to flex from side-to-side.

This is normal with stiffer sway bars. You'll notice it pulls with the crown of the road more, too. It's just a function of the bar transferring the spring rate from one side to the other. If you roll over a road imperfection that's even across the road, the bar has no effect, but an imperfection only on the left side will be felt on the right side as well. The result is a heightened sense of steering response, to the point where the wheel can actually move on its own, because the stiffer bar is now applying force to the opposite wheel instead of only one. Definitely keep your hands on the wheel when going over bumps or rough roads, but I've got used to it. On the plus side, when you are on smooth roads there is a heightened sensitivity for feeling the road, and better turn-in/steering response.

I noticed it on mine too. I also had 255s on it which made it worse.

I did notice the symptoms you are describing with my rear bar. Not that big of a deal, but it is there.

Thanks everyone!  It is kind of annoying with the roads we have in town and this winter hasn't helped any.  I guess I am used to the softer suspension.  I might go back to stock and sell the bar. I need new tires and rims, so the extra money would help in that area.   

I've noticed that turning the steering wheel seems a little stiffer after I put in the front sway bar.

98riv wrote:

Thanks everyone!  It is kind of annoying with the roads we have in town and this winter hasn't helped any.  I guess I am used to the softer suspension.  I might go back to stock and sell the bar.  I need new tires and rims, so the extra money would help in that area.    

Well,all things considered,It's preferable to swap out the rear bar instead of the front.Where front drive cars are concerned.