Write-Up: Installing a Front Strut Tower Brace (STB)

Bend it so it fits, or make your own if you can weld.

And Its just the caddilac sts stb?

SuperRiv07 wrote:

And Its just the caddilac sts stb?

yes SIR! 98 STS in your case dude

AA wrote:

I think it's the bars more than anything. Make sure those bars are straight...

Mine was bent when it arrived. Even a slight curve will throw off the alignment.

I have NO doubt that the bars are anything BUT identical after cutting pipe, welding on brackets... I'm tempted to put a slight bend in my bar and do away with the washers (2 at each bolt). However, I seriously doubt the 2 washers have any negative effect on the bar's performance. What is really tempting is to take the bar into our shop at work, and have them cut and weld a spacer on the bottom of each bracket.

And I can only order this at gmpartsdirect?

Any GM dealer can order the number for you.

And its the part number givin on like page one? and should I buy 2 or is the rear something else?

There is no rear that I know of. I think somebody in here made their own. The part number for the front is in the first post, on the first page, in big bold numbers.

The rear bar is the same as front, modified to fit: https://rivperformance.editboard.com/brakes-suspension-f6/write-up-installing-a-rear-strut-tower-brace-t3131.htm

Here is my strut tower brace that I finally got around to buying and installing. I milled a slot in a piece of 6X4 aluminum with a 1 inch ball end mill so that I could take a piece of 8 inch round aluminum to put the dent in the bar with a hydro press. The milled slot held the bar perfectly while being pressed. As you can see I welded up the sloted hole in the front and added some material so that I could re-drill for the stud. I don't need any spacers under the mounts and it sits perfecly with about 1/8 inch clearance above the brake fluid housing.

I finally got a hold of some paperwork that shows the underhood dimensions for these Riv's. Used by body shops for straightening and such.
The diagrams show the dimensions from strut tower to tower as well as triangulating all underhood dimensions and.....The 1995-97 has one set of spec's and the 98-99 are totally different.
This would explain to some degree why people have more trouble with the earlier cars than the later ones. The bar I bought bolted right up without having to ream the holes at all. Just raised the whole thing up with spacers about 1/8" to clear the master cylinder.

96RIVMANN - That looks real good.

Rickw - Thanks for digging up that info. It's good to know there's an explanation.

NICE bar! MN reppin it up!

I just installed my front STB yesterday. All i did was get some longer bolts and use a couple of washers to get the clearance i needed without having to bend the tabs or mess with the holes. It worked fine and made a big difference in the feel of the car when cornering. I think for the rear brace, I will order the same bar as for the front and have the bar welded in place.

I'm more and more impressed with the difference these bars make. My Riv is really feeling like a nice car these days. I've got to drive like a maniac to make it roll. Most of the time, even when pushing it, it doesn't or it's very little. It's already more than I need and I haven't done sway bars or sticky tires yet.

Jack, that's largely why I decided not to do the heavier sway bars. The STB alone, with new KYB's, is sufficient for my driving habits.

Jack or Dave,
Did you all do the rear also ? If so, how much of a difference did that make in your opinion(s).
I've only done the front so far and have noticed an improvement.

Jack did a write up about the rear brace! SEARCH engine is your friend.

I tried the Search And It Is Not MY Friend !!!!!!

I have STB on both the front and the rear. the front was initially the Caddy bar but I decided to fab one up because of fitment issues... I did not like having several washers underneath the bar and it still rubbed the brake reservoir. I also wanted a much stronger bar considering the weight of our cars. When I put the rear bar on it made a noticable difference. The tail seemed more planted especially around bumpy curves and it made the feel of the car much more quick and responsive... almost twitchy but in a good way.

Front...


Rear...

Also, the doors shut more solidly it seems. Actually it is hard to describe but the entire car seems to be firmed up.

Eric, what thickness is the wall of your rear bar?

I don't recall off hand. They were left over tubes from a ASA car. I can probably find out for you tomorrow. The walls seem to be about 2.5 times the thickness of the Caddy bars at least. I guarantee they will never fail from abuse... The plates front and rear were made from 1/4".

okay, not a big deal. I'm sure it doesn't take much. Nice work!

1998 Riv - I hear ya. I'm a dumb fuck though and I'll eventually do sway bars just because I like building the car. It doesn't matter if the car ends up having 10X more capability than I use.

Rickw - https://rivperformance.editboard.com/brakes-suspension-f6/write-up-installing-a-rear-strut-tower-brace-t3131.htm

Keep in mind ewolfe and I have Rancho shocks. The Ranchos are more than the stock Riv chassis can handle. With the rear STB though the Riv can use them and the back handles surprisingly well. The change in handling dynamics from a rancho setting of 1, with no STB; to a setting of 6 with STB will make your eyes pop open. With the two STB's and Ranchos the Riv is a different car.

ewolfe0050 - Please find out what the thickness is. I like your design better and it looks like less work than modding the STS brace + it has a cleaner appearance. Can you find out the overall diameter of the bar as well?

What were the ends of the tubes flattened down with?

On the front are the end plates carved out of a square plate or were they round to begin with? That's the only part that looks hard to do.