BMW Strong-Strut Tower Brace

Pros: Price, quality, strength, breathtaking finish
Cons: Careless installation could “ding” your hood
Cost: $315 and up from Strong Strut

Not surprisingly, my M Roadster displays a subtle cacophony of assorted squeaks and rattles which seem to be standard equipment on even the stoutest of convertibles. MZ3 Netmeister Robert Leidy’s review of the Dinan Strut Brace suggested that a tower brace could provide help. Meantime, I had been seeing quite a few posts on the Z3 message board discussing the new Strong-Strut tower brace. Strong-Strut’s own web page made their strut seem particularly attractive so, as I’m always eager to try out the latest wrinkle, I ordered a Strong-Strut for my car.

The Strong-Strut arrived in a long triangular USPS Priority Mail box. Weighing in at 12 1/2 pounds, the all steel structure is clearly up to restraining errant movements of the strut towers. More, the Strong-Strut is absolutely beautiful to see. The flawless powder coat and deep chrome will look wonderful under my hood. I chose black powder coated tower rings with a chrome strut, but Strong-Strut offers a wide choice of attractive sounding finishes with prices ranging from $315 for an all black powder coated assembly to $365 for all chrome finish. Other, more expensive, special finishes are also available and Strong-Strut is even prepared to provide custom finishes to the buyer’s specs. How about candy-apple purple rings with a gold plated strut?

Strong-Strut provides six pages of instructions, most of which are concerned with insuring adequate under hood clearance. The penalty for failing to carefully follow these instructions would be two dings in your hood when you slam it closed on the Strong-Strut. Happily, the procedure is clearly explained, and Strong-Strut even includes two cubes of modeling clay to check under hood clearance. Once proper clearance is insured, the installation is a matter of ten minutes or so, using common hand tools. Take your time as you bolt it in and admire the lovely weld beads and precision stainless steel hardware. Note, too, how the tower rings are contoured to exactly mate with the complex curvature of the top of the strut tower.

Not only does the Strong-Strut look great under my hood, it works! I don’t track or autocross my car so I can’t comment on its handling benefits, but I noticed immediately on my road test that a persistent rattle from the dash area was gone. Problem is that some rattles from the back are now more obvious, but Strong-Strut is working on a rear brace and I’ve told them to put me first on their waiting list. I had thoroughly surveyed the list of available strut braces before I bought my Strong-Strut and I’m convinced that it provides an unbeatable combination of price,strength, quality, and under hood good looks. So, whether you’re looking for useful strengthening of the front end, or just eye candy, the Strong-Strut is hard to beat.

Dinan Strut Brace

Pros: Better Handling Characteristics, Keeps The Z3 Tighter In The Long Run
Cons: Need To Be Careful During Installation
Cost: $399

During the 1998 Z3 Homecoming I was walking around looking at all the vendor exhibits with Larry Nissen (BMW Tech). After we had seen most of the aftermarket products available I asked Larry “so what should I buy”. He replied “I would start with a good Strut Brace, it may help the handling a little now but where you will get your money back is three years down the road when your car is still as tight as it is now”. That sounded like good advice so we went back to the Dinan tent and as luck would have it I got the very last Dinan Strut Brace they had. I handed them my credit card and they installed it on sight (a process that took about 10 minutes).

My main concern with any strut brace was the low clearance available under the Z3 hood. I’ve heard of a few individuals denting their hood after installing a strut brace. The Dinan design has the lowest profile of the ones I have seen, but even with this low profile I still see some indications that it slightly rubs. There are some adjustments to the Z3 hood stops to slightly raise or lower the hood if you need additional clearance. I have not made any adjustments to the hood stops on my vehicle, I see that it is rubbing but this is after a year of use so I’m not concerned. But with ANY strut brace I would suggest being really cautious the first couple times you lower the hood to make sure you have enough clearance. One real good way to do this is to put silly putty or something similar on top of the brace and then lower the hood slowly until the hood latches or until you feel the brace contacting the hood. Then you can raise the hood, and see how much the silly putty got squished. Raise the hood stops if you need more clearance.

The strut brace attaches via three nuts and bolts that are part of the stock strut tower. Notice that the Dinan brace I received in 1998 has a notch that fits around the grounding plug. It appears Dinan has since redesigned the strut brace, I have seen pictures of a 1999 Dinan Strut Brace that has a different looking strut tower mount. The new design has a flat side instead of a complete circle. The newer design also appears to have a better black power coating on the strut tower mounts, where mine seems to just be painted.

One of the things I really like about the Dinan design is how the underside of the strut tower mount has machined groves that match the ridges in the strut tower. Before owning the M roadster I had a 1.9 Z3 and had installed a strut brace on it. That Strut Brace didn’t have the groves on it, instead it was a softer aluminum and the torque of the bolts would bend the strut tower mount around the strut tower ridges.

The brace itself is aluminum with the Dinan logo etched/engraved in the center. On either side of the Dinan logo are carbon fiber inserts which I assume are only there for cosmetic reasons. Overall the strut brace is very attractive.

The brace attaches to the strut mounts via some allen bolts that act like hinges. Once the Strut Brace is installed if you need to get access to the engine you can remove one of the allen bolts and raise the Strut Brace. (This had to be done when BMW needed to replace a crank sensor)

This is optional: BMW makes Strut Tower Caps that can be installed to keep dust and dirt from getting to the top of the strut tower. The part number is 31-33-1-133-729 they list for $3.75 each and you will need two of them. Installation was difficult, I had to soap the edges of the caps and push really hard to get them to snap down. A Z3 owner sent in a great tip that aided in his installation of these caps. He heated the caps with a hairdryer (which I’m assuming made the rubber temporarly softer) and used a rubber hammer to tap the caps down into place.

Since purchasing and installing these Strut Tower Caps I have been told that BMW makes another cap part number 31-33-1-129-512 that lists for $1.52 (remember to order 2). I’ve heard conflicting reports but it appears these strut tower caps might be even more difficult to install. Visually there is a difference in that this other cap is smooth on top.

Performance: I remember right after installing the brace taking a spirited test drive and I could notice a difference when I was pushing it really hard in a turn. The car felt more solid and stable but only during really hard cornering. During everyday driving I can not notice any difference. But I did not buy the brace for its performance characteristics. While I appreciate what the brace has done to the handling performance, what I really purchased the brace for is in an attempt to keep the car tight and solid in the future.

HMS Strut Brace for the 1.9

Pros: Easy Installation, Increased Stiffness, Less Squeaks
Cons: Cost, Not very effective for casual driving
Cost: $265.95

The sales pitch peaked my interest. “Reduce that jittery feeling when traveling around a bumpy corner. The HMS Front Upper Strut Brace ties together the two front upper strut towers, significantly reducing flex in the forward part of the chassis. This results in a much more stable feel during cornering and over road imperfections.”

Honestly, this was an impulse buy. I had prepared myself to be let down but I have to say I can actually tell a slight difference with it installed. The Z3 seems to exhibit more control and stiffness when you are just entering into a turn. Maybe more important than any increase in handling, I believe the strut brace might have decreased and/or eliminated some of the squeaks and rattles in the dash.

After installing I really pushed the Z3 around turns with a little extra speed just because it was so much fun. I had convinced myself that the difference was enough that it might be visually seen by a camera. This led me to spend a Saturday driving around the same turn with a friend snapping pictures of me with the strut brace on and off. After developing the two rolls of film you couldn’t tell a bit of difference in the pictures.

Oh well, I guess you will have to trust me you can feel it in the drivers seat. Comparing this upgrade to the sway bar kit, the strut brace has much less of an impact. the two together are a very noticeable improvement, but the strut brace takes a back seat to the sway bar kit.

Reduce that jittery feeling when traveling around a bumpy corner. The HMS Front Upper Strut Brace ties together the two front upper strut towers, significantly reducing flex in the forward part of the chassis. This results in a much more stable feel during cornering and over road imperfections.

Sold By:

HMS Motorsport

(888) HMS-3BMW


Pre-Installation Notes

* Start to Finish this shouldn’t take you more than 15 minutes.

* After unpacking and admiring your HMS strut brace you will realize that no installation instructions were included. But don’t worry, I went ahead and made about the only mistake you could make. Follow these instructions and you’ll be strut-braced in no time.

* After admiring your strut brace remove the circle shaped brackets on either end of the brace. I first attempted to install the brace all in one piece, but there is a nut under the brace and you will not be able to install it with the cross brace in place.

Strut Brace Bracket

1. Remove the six nuts (three on each side) from the protruding bolts on top of your front struts.

2. Put the bracket over the three exposed bolts

3. Put the nuts back on top, very loosely tighten two bolts and moderately tighten the third BUT DO NOT FULLY TIGHTEN. This is where I made my mistake, if you over tighten without the cross brace in place, the bracket will bend.

Strut Cross Brace Bracket

1. Install the cross brace and re-tighten it’s bolts (these you an fully tighten)

2. Finish by fully tightening the six bolt (three on each side) on the bracket. The bolt that is hidden under the cross brace will require an open ended wrench, this is why I let you tighten it a little more than the other before.