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

I think the only part that's subjective is how much each of us notices the result, but it's fair to say there is definitely a result.

I was trying to think of an example to better understand how lateral forces transfer to the top of the strut. It's hard to think about, but if you've ever been in a canoe and got it going sideways, this is like your car siding in a hard turn. The difference is, the canoe doesn't have tires, so doesn't "grab" the water like a car's wheels grabs the road. But if you stick an oar into the water, on the edge facing the direction the canoe is moving, the paddle "grabs" the water, and it pulls it under the boat. It's pretty hard to hold on to the top end of that oar - it wants to pull you out with considerable force!

Here's another example:



This guy skidded into a curb, hitting the back wheel hard. Look at what and extreme lateral force does - it snapped the axle right off. Now imagine it's the front wheel, and instead of hitting the curb, you are hanging on for dear life. That's still a crap ton of lateral force exerted on the bottom of the wheel. An opposite force is transferred to the top of the strut, and to anything that's connected to it.

All,

Belive me guys.. i knkow and understand how lateral forces exert on wheels and im not detracting how much any of your findings were before or after the fitting, I did post as a devils advocate and said toung in cheek.

One thing that troubles me is how chinese whispers change the understanding of a mechanical system. there was a good post with diagrams and theoretical weights etc shame it was incorrectly drawn. It also was over simplyfied. suspension and steering are so bound together and are very hard to understand.

it was stated that .5 of an inch will change the negative camber of the suspension buy almost a degree what they dont mention is if the suspension was at full extention of full compression as each end of the range will change camber slightly.

Any way as long as your happy with you $30 body mod thats all that counts. Me personally i like the look of the high tech looking struts in a well prepared engine bay. I dont think i could drive this car any where near its limits on everyday road so enhancing the handleing would be pointless.

Nigel, I do respect your opinions, and would like to hear more about your views on this topic.

Maybe the drawing was a bit oversimplified. I won't deny that. But the drawing was never intended to fully explain the complex relationship of suspension and steering geometries, it was only meant to show how the strut bar is in tension during a very hard corner. The context of the discussion was concerning whether the bar might be in compression, and if putting a dent in the bar was a bad idea.

I'll admit there's a lot about suspension I don't know, but I feel I know a little more now that I've researched, installed, and recorded some results. Being that you seem experienced on the subject, I'm sure there's a lot we could benefit from reading your points. Feel free to share anything that might help us better understand.

If you could, please give your opinion on this - Do you think if a 4000 lb Riviera were pulling near 1 lateral G in a hard corner, would the addition of a strut tower brace have much impact? If so, how much would you guess, and why?

You guys can analyze this if you like. All I know is the addition of the brace made a very noticeable difference in the stability and tightness of the car. Best 30.00 I ever spent. I'm going to add the rear when I get a chance.

Sweet. Just ordered one. Price has gone up!!! But still at $30 it isn't too bad. Looking forward to the install.

nigelf wrote:

I dont think i could drive this car any where near its limits on everyday road so enhancing the handleing would be pointless.

GM disagrees, that's why the STS (basically the same chassis) got the STB.

It's not just about handling, as the STB will also improve the ride quality. You'll find yourself going over rough roads at a higher speed than you otherwise would, because the suspension does a better job of dampening the bumps.

That said, the handling improvement is totally useable on public roads. Actually, it isn't even enough. Next time you go out, when you've got a spot of road where you can do it safely, whip the steering wheel back and forth like in a slalom manuever. Notice how much the body rolls? It rolls like there's marshmallows for struts. With the STB, it rolls like it has chocolate for struts There's still more roll than most of us want, but it's a big improvement. I'd like to eliminate the rest of the front end roll. Even if it did nothing to make the car go through curves faster, it would improve the driving experience.

Ugh.... this part is no longer available!!!! Or at least that's what my sources say.

I think the last ones went to Jack and I, or something like that.

Darn! LOL

I'll keep my eyes out. Which year STS did they come off of? I can go to the JY for them.

i believe 98-99, same years that we can use the eibach kit from the sts.

I see STS's in the junk yard all the time.. I just never think to go and take the bar off.. hmm maybe i sha'll start doing it..

98riviera98 wrote:

I see STS's in the junk yard all the time.. I just never think to go and take the bar off.. hmm maybe i sha'll start doing it..

I'd buy one off you. Please let me know if you find one kicking around. I'll start looking and let you know if I find any. It stinks that a few parts for these cars aren't available anymore.

DEMonte1997 wrote:

98riviera98 wrote:

I see STS's in the junk yard all the time.. I just never think to go and take the bar off.. hmm maybe i sha'll start doing it..

I'd buy one off you. Please let me know if you find one kicking around. I'll start looking and let you know if I find any. It stinks that a few parts for these cars aren't available anymore.

Technically they never were available.. They are for a STS

DEMonte1997 wrote:

98riviera98 wrote:

I see STS's in the junk yard all the time.. I just never think to go and take the bar off.. hmm maybe i sha'll start doing it..

I'd buy one off you. Please let me know if you find one kicking around

^x2, DEMonte did you go to www.gmpartsdirect.com and put 25653157 in the part number search box? the stb comes up for me.

The part number comes up, but you get an email following that says part is no longer available.

Rickw wrote:

The part number comes up, but you get an email following that says part is no longer available.

ahh ok , is that the only place you can order the stb from? does GM just not make them anymore or are they on some type of backorder?

Try ordering from www.monsterpartsonline.com
They have been less expensive and more resourceful in getting OEM GM parts for me.

Rickw wrote:

Try ordering from www.monsterpartsonline.com
They have been less expensive and more resourceful in getting OEM GM parts for me.

nice! DEMonte if youre still looking dont enter the make/model/year on monster parts just enter 25653157 and then select cadillac

I got the same email from monsterparts.

After 10 years time the manufacturer is no longer responsible for supplying parts.
It sucks but that is why i try to keep an eye out on Ebay for NOS parts and have stockpiled some useful stuff for the future as I plan on keeping this car for a while.
It looks like you will have to make a custom STB or have a metal fab shop make you one.
Just bring pic's from this site and they can do it.
I still want to make a custom one for the rear.

Yeah, you can get a better one custom made if you have anyone capable in your area.

So I had 1/2 hr or so to kill tonight and decided to make a sub-$10 strut tower brace. I've tried aftermarket braces in various cars over the years and have never felt any difference,...but I figured what the heck,...there's always a first time right?

So anyways,..after reading a few threads about the subject,...noticing the issues like master cylinder reservoir clearance,...and studying the shape of the engine compartment and seeing how close the rear of the strut tower was to the firewall,...I came up with my design.

Being that the rear of the strut tower is practically part of the firewall, I guessed that the rear wouldn't benefit much from linking the two towers together.

So the front was the area I would tackle. I'd love to weld on a hunk of steel to the front upper corner of the towers and bolt to that,...but that messes up the stock paint. So I decided to use the strut-mount bolts like most people do.

Two ways to go about it I figure. One would be to make it curve around obstacles, but that is time consuming and can be a bit heavy if you're not careful. The second method is to make it perfectly straight. Simple and light,....if you can pull it off. I was going to attempt the second one.


First the materials.
Two 3/8" thick spacers. Mine were galvanized, so I wire-wheeled the galvanizing off of them so I could weld them later. On the way home I bought a 4' length of 1/2 steel box tubing from my favorite racing supply house (Lowes). That ran $6.97. And last is some spray-paint. I had some gloss black engine paint I was planning to use,..but it was old and clogged up,....so Rustoleum Hammer brown it is.


After tack-welding the bar to the spacers, I pulled it off and finished up the welding. I filled the inside of the ends of the bar with a bit of weld to stabilize it.

All done.


Here's the clearance to the MC reservoir. Maybe 1/16",...but that should do.

The bolt only goes 2/3 of the way on the strut mount stud now,..but I figure the torque-spec on these is probably only around 20 ft lbs,...and 4 turns or so is plenty for that.

How does it drive?

I am just happy to be driving my new riv so performance mods past gutting my airbox are out of the question for a very long time..

I do need the caddy strut tower brace, should I be shopping in the local pick a part yard, here, or find a vendor?
What is the exact application of it?

I do have a welder, how about a pic if I cant get one easily.

From what I read recently, i think the OEM $30.00 braces are no longer available.
So a junkyard or making your own is probably whats available.