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.