Strut Tower Brace: Functional or Frivolous?

[MadBill]

OK: We all know that STBs look great and make the statement that we are serious about our Vibes' performance, but is our chosen chariot really such a flexi-flyer in need of this help, or are those wonderfully techie-looking braces strictly cosmetic, and the claimed results due entirely to the well-known Placebo Effect?Well, to shed some light on the subject, I fabricated the highly sophisticated device shown in the accompanying photos. The wooden bar is screwed to the strap mounted on the driver's side tower and rides between the bent-up locator tabs on the indicator plate mounted to the passenger side tower. The elastic band ensures contact is maintained between the scribe tip (seen in the close-up pic) and the marker pen-coated indicator plate. Any relative movement between the towers will result in the scribe creating a visible trace on the indicator plate. The length and the direction from the contact point at rest will show how far and in which direction the towers move, and by simple trigonometry, the resulting camber change can be calculated. (A one degree camber change would result from a displacement of about 5/16" in one tower.) After installing the MBSBVI (MadBill's Strut Bar Value Indicator) device, I drove around my favourite corner at increasing speeds, checking the indicator plate at intervals to see how much movement occurred. Eventually, I was bailing through at maximum warp, sliding a half lane wide on the exit and hitting every bump I could, to induce additional flex. The cumulative result can be seen in the second pic. Despite all the G-loads my giant (275/40 x 17") Firehawks could generate, there was absolutely NO movement! The scribe never strayed from the pinpoint contact in which it began.What's it mean? Well, I really like the look of a nice STB, and I'd just love for one to do good things for my handling, but if the towers don't move even a 1/16", I just can't see how one can possibly help! >End Technobabble AlertWhaddya think people? Can someone show me I'm wrong? If I e-mail a copy of this to Hotchkiss, what will they tell me?

Attached files

[MadBill]

...and here's the damning close-up:Let the comments begin!

Attached files

[millster]

Another fine test from our resident mad-scientist. Good show MadBill! I wouldn't have believed it if I hadn't seen it. So I wonder what causes the sensation of change after the install of such a device. Is it all just placebo, or could there be another result somehow?

[scherry2]

quote:Let the comments begin! Man is it dirty under your hood! (comment #1)must be the placebo effect.

[MadBill]

I know, I know! Conditions are tough out there on the test circuit... (that's my story and I'm sticking to it)

[Flip-Side]

Great Idea applied Bill! I like it...in fact I think my new home made "Red Oak" strut tower bar concept might now be a reality! Future prototypes will involve duct tape, KY, and a sombrero, but I cant elaborate.

[ragingfish]

Thanks for the info bill!You've given me good reason to save my money and not purchase a STB...But how do you stand on sway bars?

[drunkenmaxx]

i suspected this. if the car was so flimsy, i figured they would put one on in the factory.

[dmitri]

very good info.one thing i can attest too is that the rear sway bar really helps.

[MadBill]

quote:Great Idea applied Bill! I like it...in fact I think my new home made "Red Oak" strut tower bar concept might now be a reality! Future prototypes will involve duct tape, KY, and a sombrero, but I can't elaborate . By all means Don't! PS: A rear bar is definitely in my plans, the front end was washing out pretty badly during my "stress tests"!

[AKLGT]

thanks for the great scientific experiment, madbill! i'll save my money and continue to pay off bills...

[coratz]

wow thanks , that was cool. i could imagine if that was a weak link of the car----warped hoods messed up alighnments etc...... i always thought that a strut tower brace was a cosmetic improvement or a way for advertisment. gm DID make some weak unibodys in those sunbird with the 3.1 motors in 91, those towers i have seen twist!!! The vibe is strong!!!! thanks for proven it

[Roadpig]

Very interesting indeed! I was considering buying one, but I think I'll get a rear sway bar instead. I've read in several different posts that they do make a difference.Thanks!

[Hawke]

Some cars have the top mounts for the struts attatched to the firewall where the firewall basically acts like a STB, like the Vibe. Other cars have the mounts further away. I had a car where the mounts were further away. On that car it definately made a difference. I haven't even considered a STB on the Vibe because of this.

[mistamatrix]

quote:Some cars have the top mounts for the struts attatched to the firewall where the firewall basically acts like a STB, like the Vibe. Other cars have the mounts further away. I had a car where the mounts were further away. On that car it definately made a difference. I haven't even considered a STB on the Vibe because of this.A very good point. STB's are effective and utilized more when a car's design has the struts placed further away from the firewall.

[Thxalot]

Excellent work MadBill.One question. Are you sure the wood can move the scribe pretty easily? It wouldn't surprise me if the scribe had dug into the aluminum plate a little bit. The down force of the rubber band would keep it fixed in place. We all know that wood will absorb compressive forces better than steel or aluminum.Can you stick a ballpoint pen where the scribe is, and throw in some paper instead of the metal plate? Of course you'd need to sand out the divot left by the scribe (if in fact there is a divot at all).Despite my cynicism, I had suspected that the STB does nothing. I picked up springs and the Progress RSB, but hadn't bothered with an STB. The firewall is just too close to the shock towers.FWIW, I spent all day yesterday tearing apart the suspension on my Vibe GT. Put in the RSB, and a set of Eibach (aka TRD) springs. Putting the struts back together was a serious b!tch, but it's done now. I just have to wait for the G2 paint to dry on my calipers before I can take her out for a spin. I have high hopes!I've got 235-45-17's on my ride. Bill, how did you get 275's in there? Surely it's got to be rubbing somewhere, no? My calcs also show that your running about 1/3 of an inch bigger diameter. Although that's only a littler more than 1% over stock, do you notice the effects on speedo and final drive ratio? How's your mpgs with those slicks underneath? My tires ate up 1-2 by themselves.One more thing, I got my suspension hardware from a guy named George at http://www.adventon.com He was a nice guy, and the prices were excellent, so when he asked me to further his cause with a little grassroots PR, I couldn't help but say yes. In case you are wondering, he gave me the antiroll bar for $85, and the springs were $189. Oh, and he doesn't have all the instock goodies up on the website yet. So if you don't see what you want, give him a call.-Burt

[Geo]

Very interesting!I don't want to chalk it up to the placebo effect. I can honestly say that when I first put on my STB, I did notice a difference - and had to actually adjust my driving style because it seemed to steer that much sharper.I'm also running 17x8 wheels and Yokohama tires. I have a RSB on now as well (and seriously looking at springs) so it handles a /lot/ better than stock.Thxalot has a point about the wood though. I wonder if there could be a way to fabricate metal brackets and the like to test how much the car flexes.Or perhaps it doesn't flex at all, and the STB just does something else ... I'll rack my brain for a bit see if I can come up with anythingGood work though, makes me second guess my original feelings ... but it just seemed too real to be just a placebo thing.

[MadBill]

Hi Thx.The scribe moved pretty freely when I was setting everything up, but I can lash in a ball point and a piece of cardboard, just to be sure. Will try it and report back. (the divot is just a tiny pin (removed), so wont impede the pen's motion)There are some old posts re my wheels, but the condensed version is that they are aftermarket Corvette pieces I've had around for years for my "Hanger Queen" '70 Z28 (275/40 Firehawks on 17" x 10" Dymags with 46 mm offset) and I decided to wear them out before they rotted out. I made up 1/2" thick adaptors to change the bolt pattern from 4-3/4" to 100 mm, which gave me an offset of ~34 mm, just enough to clear the struts and inner fender wells without fouling the outer fenders. I didn't get any rubbing until I installed Tein S springs; the 2"+ drop was a bit too much on a combination corner and bump, so I cut the stock springs 1/2 turn and put them back in. It's only about a 1-1/4" drop now, but I just get a slight scuff in the rear on big dips with 4 passengers. When I wear out the 275s, I'll likely drop down to 245s, which should match the OE diameter and maybe allow a full drop (can't go any smaller than 245 on these rims). I only had the car a few days with the stock wheels and tires, I sold them and put on 195/65 x 15" Dunlop Winter Sport M2s on steel wheels for the winter. The gearing definetly feels taller than with the snows, but I haven't actually measured the circumferences to verify the increase. The mileage is down a bit, but without knowing the odometer error, it's hard to say how much is added tire drag/rolling resistance. (will get to it soon)That rear bar sounds like a deal! You should have a great looking and handling package. With winter coming on, I'll probably wait for spring to pick one up. One thing I want to do is determine which ones will work by themselves, as I don't realy want to go to the trouble of a front bar install, and one matched to a heavier front would be too much by itself. PS: Here's a shot of "Big Boots"PPS: No it isn't! The site's not yet back to full function and I can't attach the pic. Will try again later

[MadBill]

Hi Geo.I'm very sure the scribe isn't binding. When I was installing it, I completed the scribe end attachment before I bolted down the driver's end. I tried pushing on the wooded bar from the driver's end, and it moved very freely. Nevertheless, as per above reply, I'm going to try the "roller bearing" version just to be sure. Will keep you posted.

[satur9]

have you considered the fact that mabey your wheels are the problem. with increased contact patches and weight on the front end .your car may be less(not a lot mind you)flexy as stock. with skinnier tires a sharp enough corner corner can have you on the edge of your tires. which probably never happens with yours. try another run with stock front tires. i also agree with the strut towers close to firewall thing. but not the placebo. i bought a brace for my old sunbird and it made a difference in fact my brother drove it two days latter and asked me did i get an alignment or something. so i popped the hood and showed him that simple piece of metal.simple as that

[goodvibe]

I love your rig. It should tell the story but I also felt a bit of a difference but I don't think it actually helped the handling limits. Got a cheap bar because the Vibe seams stiff and I just wanted to try one. For $30, why not. Progress rear bar is the best mod going.

[MadBill]

A strut definetly helps on some cars. Cavaliers/Sunfires have them factory installed on some models, and Carmaros/Firebirds (especially convertibles) are transformed by them.My big Firehawk tires have a lot more grip than stock, and it is the cornering loads that distort the towers, but I'll have the skinnies back on for Winter soon, and will see if that changes the results.

[goodvibe]

Are your tires Firehawk SZ50 EPs and if so how do like them? I've got a set of 16x7.5 Borbets waiting for spring tires, 225/50 probably or 245/45 if I can be convinced it will actually handle better with a 7.5 wide wheel on this car.

[Geo]

MadBill - I am curious as I don't remember: Are you running the moon & tunes package?I wonder if a STB would make more of a difference in a vehicle w/the moonroof, because of the less metal. I remember all the posts way back when the Vibe first came out about "shattering moonroofs" with 17" tires and the like.Just something that popped into my mind, thought I would bring it up

[Thxalot]

Bill,Thanks for the update. I'll keep an eye on this post for the ball-point results. I'd love to see a pic of your car with the big wheels on. You might try some progressive rate springs to cure your bottoming out problems. I put Eibach ProKits on. They handle small bumps better than stock and they give the handling a good punch in the arm. Directional changes are much quicker and it really squats down and takes a bite in the corners. Because the springs have a higher resistance to compression with more load, they'd be just the cure for your carfull of people rubbing problems.Good point on the change in mpg from the difference in odo due to a larger circumference. Your winter tires are almost exactly the same as stock. Your big tires are running 3.1% more circumference. That means that the odo is short by 3 miles for every hundred. On my set, I'm down 1.8%. Now I know I'm only going 60 when I think I'm going 61. Acutally the random variation in odo calibration is probably greater than that. Either way, I'm not taking it down to a shop unless one of the CHPs nabs me. I've heard that a bad speedo calibration can be a pretty good defense.-Burt

[goodvibe]

I love my TRD springs and think they ride fine but I have to disagree about bumps being handled better than stock. The rear is the worse end stock and the Pro-Kits/TRDs are about 20% stiffer and not progressive in the rear. The fronts are progressive and feel closer to stock on road seams. Contrary to most posts I've seen, I bet those cut springs are fine with only 1.25" cut off.

[MadBill]

quote:Are your tires Firehawk SZ50 EPs and if so how do like them? I've got a set of 16x7.5 Borbets waiting for spring tires, 225/50 probably or 245/45 if I can be convinced it will actually handle better with a 7.5 wide wheel on this car.Got a little behind in my answers, but:The tires are pretty old but unused. They are Firehawk SZs and they are a little noisy, but ride better than my 195/65 x 15" Dunlop snows. They are a bit twitchy on rutted pavement. Dry grip is very good, wet is not bad, but I think they'd be better in the wet about 3 sizes smaller! I think the 245s would be a little much for a 7.5" rim; perhaps a 235 of suitable section height? (also, 245/40 x 17" is closer to stock height)

[MadBill]

quote:MadBill - I am curious as I don't remember: Are you running the moon & tunes package?I wonder if a STB would make more of a difference in a vehicle w/the moonroof, because of the less metal. I remember all the posts way back when the Vibe first came out about "shattering moonroofs" with 17" tires and the like.Just something that popped into my mind, thought I would bring it up :DI remember the talk about shatterd moon roofs, but I think the issue was actually a Federal vehicle rollover calculation, based on the slightly larger diameter of the 17s. There was a note to that effect in the Canadian order guide. I don't have the moon roof, but I can't see it changing things much.

[MadBill]

quote:Bill,Thanks for the update. I'll keep an eye on this post for the ball-point results. I'd love to see a pic of your car with the big wheels on. ...-BurtCouldn't post a pic with the site problems, but see thread on Project Big Boots, 4 pages in on the Wheels and Tires Forum.

[MadBill]

quote:...Contrary to most posts I've seen, I bet those cut springs are fine with only 1.25" cut off.Yes, I've put 15,000 km and 6 months on them. So far no problems

[QUIKAG]

Madbill,I'm late to the party. Good work! I bought my STB off Ebay for like $40 shipped and it was fun to put on and look at whenever the hood is up. With the shock towers being so close to the firewall, I knew the structural enhancement would be minimal at best. Thanks for proving that the STB on the Vibe platform is a cosmetic mod. On some other models, it's definitely a good improvement structurally. I noticed a definite turn-in improvement on my old Prelude with the addition of a Neuspeed STB.

[Stang2Vibe]

I don't mean to spoil the party, but I'm not quite convinced yet. I would propose that the body flex that occurs during cornering may not be showing up in this fascinating experiment. I am thinking that the body flex may be getting lost at the point were the wooden bar is attached with a screw on the driver's side strut tower. Probably the only way to really test a STB is to perform slalom and lateral G-force tests with and without the STB and compare the results.That's certainly not to say that MadBill didn't make a tremendous effort to test for Vibe body flex. BTW MadBill, you must drive your wife nuts with all these experiments. Do you apply your experimental nature to things around the house as well, or do you reserve your "madness" for automotive purposes only?

[goodvibe]

Test method seems as good as any I could imagine without spending a fortune.

[MadBill]

quote:I don't mean to spoil the party, but I'm not quite convinced yet. I would propose that the body flex that occurs during cornering may not be showing up in this fascinating experiment. I am thinking that the body flex may be getting lost at the point where the wooden bar is attached with a screw on the driver's side strut tower. Probably the only way to really test a STB is to perform slalom and lateral G-force tests with and without the STB and compare the results.That's certainly not to say that MadBill didn't make a tremendous effort to test for Vibe body flex. BTW MadBill, you must drive your wife nuts with all these experiments. Do you apply your experimental nature to things around the house as well, or do you reserve your "madness" for automotive purposes only?Hi again Stang.1. It can't be seen in the pix, but there is a big #12 screw up into the bottom of the wooden bar on the driver's side. The set up is plenty stiff. It takes ~ 20lb. force to move the scribe (bends the bar) by pushing the passenger end towards the driver's end, and only a fraction of an ounce to move the scribe across the plate. If either the bar or the towers were bending/moving, they would create a scratch, and there is none. (Will still try the ball point scribe test, as it is ~zero friction)2. Ooh, you've got my number on the Wife Thing, Stang! Aside from the usual comments re molesting the Vibe: "It's a perfectly good little car just as it is! Why can't you leave it alone? If you want to work on something, why don't you fix the Camaro -it's been parked for over 20 years!", there have been a "few" domestic incidents. Examples in Mrs. MB's words: 1. "I came home to find him on the top of a step ladder set in the bed of a pick up truck in the laneway. He was gluing carpet tacks along the power line to keep the birds from roosting and pooping on the car." 2. "He wanted a TV in the bedroom, but I didn't want that big box sitting there on the bureau staring at me, so he knocked a hole in the knee wall, built the TV into a recess and hung a mirror on drawer slides in front of it. Now he wants to wire a power antenna mechanism to the on switch to open the mirror." 3. Etc., etc....What can I say?

[drunkenmaxx]

i tend to think bill is right. if it was that flimsy, they would probably have one in there stock.bill, your last name isn't by chance nye is it??? ha ha

[Stang2Vibe]

LOL LOL!!! I knew it! You are just one of my fellow practical geniuses who likes to tinker with gadgets and drive others nuts. The tacks on the power line thing cracked me up.Anyway, I'm convinced that there is some noticable body flex somewhere in this car. My handling absolutely sucks compared to the Mustang I had. I get considerable body roll as well. Keep in mind that I don't typically drive like I'm just going to the grocery store. When I'm going somewhere, I'm usually in a big hurry and have to be there NOW! Also, I don't think there is a road around me that runs straight for longer than about 100 feet. I've already spun my Vibe sideways and almost crashed the whole side of the car into a jersey barrier on an on-ramp leading to one of the main bridges in town. To me, the handling is scary sloppy. The approach is a 90 degree turn that I tried to make at around 40-45 MPH. Good thing I have practiced this maneuver before and was able to recover the car before crashing sideways into the barrier. I have now found that I have to take this bend at max speeds around 35 MPH so I don't lose grip of the road. And the road surface was clean, dry concrete that was in good shape. Handling is even worse now with the snow tires on, but that is understandable. My alignment is out a bit now too. I noticed it with about 5,000 miles on the car. When going straight, i have to keep the steering wheel aimed a bit to the left to maintain course. My 94 GP was over 6 years old and had 50,000 miles on it and never had an alignment. On the highway I could let go of the wheel and it tracked straight and true. And I drove even crazier with that car than I do with this one. And I still have these goofy creeking and popping noises when I turn the steering wheel with the motor off or as I am turning while going up or down a slope. Those started with 750 miles on the car. I should take it in to the dealer, but I never have time and I have to have a car every day. I purchase an extended warranty when I bought the car and one of the perks with it is that they have to give you a loaner vehicle if they are going to have your car in for repairs for 2 hours or more (yes, that is 2 hours). I just don't want to be stuck with some POS stripped-down Sunfire that reeks like cigarettes for 3 days. This is why I like to fix things myself. And if I screw something up and have to take it back apart, then I only have myself to be angry at. I don't have to drive 30 miles out of my way again just to get stuck with that crappy Sunfire for another 3 days.This test is certainly making me rethink the STB purchase, though. Maybe I'll put it off and buy some upgrade parts that are more certain to help out handling like the sway bars, lowering springs, wheels, and performance tires.

[Thxalot]

Stang2Vibe,I think the best money you can spend is on rubber. Nothing contributes more to handling character than the contact patch. Since all handling forces go through the tires to the road, the tires are key. (FWIW, Vehicle weight is probably just as siginificant.)My GT came with a horrendous set of all season Continental tires on the 16" rims. If you check out the Car & Driver stats, you'll see that the 17" wheel and tire package makes a huge difference in braking and skidpad numbers. As I recall the 17's stop 15-20ft shorter from 70mph.After I put some serious rubber on my GT, the handling limits took a huge jump upwards. However, it was then that I noticed that the car has way too much body roll at the high g's. Sucker was leaning way too much. That's what made me decide to drop the coin on springs and the rear bar. AFAIAC that $300 was the best money I have ever spent on any car, period!Your Mustang was a rear wheel drive car designed for a bit of oversteer. The Vibe, being front wheel drive is destined to understeer. With a bit of tuning, you can temper the tendeny to push, but I don't think you'll ever eliminate it. I think Honda is the only company capable of designing FWD suspensions with neutral handling characteristics.-Burt

[Stang2Vibe]

Almost too bad I hate Hondas with a passion, then. I hear what you are saying and understand. My GT is a great car, just the handling makes me want to pull my hair out. I am an oversteer junkie. I think after I graduate college, I'll probably be addicted to BMW's because of their abundant available power and their excellent handling characteristics that come from the 2 big factors you noted--body weight (and how it is distributed) and rear wheel drive. Will probably keep a hopped up monster Suburban or Expedition around for bad weather/winter use.As Bill and I have discussed at great length previously, I have a set of 245/45/17 tires that are Z-rated that were on my Mustang and took it from good handling to excellent. I am hoping that they will help move my Vibe's handling up from "ok" to "pretty good" in addition to lowering springs and front and rear sway bars I want to get. I already have the body roll issues (remember, I put every car I have owned to its limits) and hope they will be at least reduced by the lowering of the car and the stiffer ratio. I believe that any of these mods alone will do more for handling than the STB will. And being that the STB is more expensive than any of the other mods (except the tires, but I already have them), it will probably be the last thing I get for the Vibe right now. I also want to change the muffler and remove the resonator, but that is fairly minor and doesn't serve any functional purpose. I just don't like the buzziness of the stock setup. I don't want to go with a Folger's brand sounding muffler either. That's why I think that the newer Flowmaster 60 series muffler will work for me, especially with the resonator removed.But anyway, thanks very much for your thoughts and insight!