Upper Strut Bar for the DA6 Honda Integra XSi/RSi.

The front upper strut bar, also called the front tower strut bar is probably the most popular and common modification amongst enthusiasts after the air-filter mod. The theory of the function of this strut bar is very straightforward. The front absorbers in our car are mounted on the front strut towers on either side of the engine bay. During high speed cornering, these towers will flex along the car chassis itself. This flexing changes the geometry of the suspension, interfering with the proper functioning of the absorbers. The upper strut bar bolts on to either special mounting points on the strut tower body or to the mounting bolts of the absorber themselves. It serves to 'lock' the relative position of top of the strut tower and thus the top of the absorbers relative to each other, reducing flex and allowing the absorbers to function more precisely. Sometimes a lower strut bar is added below the chassis near where the suspension lower arms are to further reduce chassis flex and preserve the suspension geometry. The nett result is a more consistent front suspension geometry when cornering and thus more precise cornering.

The effectiveness of the front upper strut bar is such that it has now become a standard item on performance oriented cars. All of Honda's Type-R models has an upper strut bar and often spots other suspension strengthening bars as well. The SiR variants of the EG6/9 and EK4 Civics and DC2/DB8 Integras all spots one as well, as do the FD2 Civic 2.0S and even the CM6 Accord 2.4 i-VTEC.

Designing the mounting bracket

Designing the bar

Spot-welding the bar to the mounting brackets

Final Design - the 3Max upper strut bar

Driver side tower mounting bracket

Passenger side bracket - note the unusual bar attachment

'Vintage' Honda Performance models

However, strut bars were not popular or common back in the decade when my DA6 was designed. Cars like my DA6, or the EF9/8 Civic & CRX SiRs do not come with an upper strut bar. In fact, even aftermarket strut bars for the cars are very rare. I have never seen any aftermarket upper strut bar for the DA6 though my friend managed to find one for his EF9 Civic SiR. In the case of my DA6, the engine bay itself was clearly designed without thoughts of putting an upper strut bar in mind. It is literally packed with components, and not spared are the strut towers. On the passenger side tower (bearing in mind JDM cars are RHD) is the ABS modulator unit. On the other, Honda put the main fuse box right on top of the driver's side tower. These items blocks access to the towers and makes it very difficult to fit an upper strut bar. Perhaps it is because of this that I have never found any upper strut bars for the DA6. After so many years of looking and failing to find one, I have actually given up hope of ever getting an upper strut bar for my DA6, much as I really want one.

3Max

3Max changed all that. 3Max is a local (Malaysian) manufacturer of car chassis strengthening mods like strut bars, fender bars, room-bars and anti-roll bars. They are what I would term a 'proper' manufacturer meaning they make their bars from raw materials, i.e. not assembling their bars from components supplied by others. 3Max itself operates as a subsidiary of a steel manufacturing plant, sharing the same SMI factory. When I first visited the 3Max factory, I was greeted by massive metal stamping machines, pipe benders, metal cutters, and welders. These machines are true heavy duty industrial monsters, over 10feet tall and weighing several tons. As a result, 3max can design and make any bars they wish to.

I got to know about 3MAx through Kevin, a local GRA (grassroot racing, local version of gymkhana or auto-cross) who markets them. After some negotiation, Kevin managed to arrange for a one-off, custom designed upper strut bar for me, meaning that 3Max will actually custom design and manufacture one for my DA6. Naturally I was ecstatic and accordingly we arranged for me to drive my DA6 to the 3Max factory for them to study and design the bar.

As I expected, their first reaction to my engine bay was how tightly packed it was. Nevertheless, the 3Max strut bar 'sifu' quickly got down to work and studied my engine bay carefully, first looking around the top of the strut towers for suitable mounting points. Next he look at the area between the towers above the intake manifold, to confirm that there is enough space to route the bar. To my relief, we found that there is space to put a custom designed bar if we use specially fabricated mounting brackets. With this decided, he proceeded to design the brackets using a template. Because of the blockage from the ABS modulator and the main fuse box, the mounting brackets had to be asymmetric, with both facing to the left (passenger side) of the engine bay.

After about a week, I went back for them to test fit the custom brackets. The brackets were made by welding custom cut thick metal plates. This was because they are a one-off design. For the regular strut bars, the mounting brackets were made using their metal stamping machines. The custom plates/brackets were near ideal fits and only needed a little bit of machining to ensure clearance. With the custom mounting brackets bolted to the top of the strut towers, they next selected the bar to tie the two brackets together. 3Max prefers welding to bolting the bar on, for reasons of rigidity. From a long metal bar, they put the first bend in using their pipe-bender machine. They measure it against the mounting brackets to find out where and how the 2nd bend should be made before putting in the 2nd bend. They then spot-welded the bar to the brackets to fix the relative positions before taking the whole assembly out for proper mig-welding and final grinding. One more test-fitting to confirm everything and the bar was finally completed. But I still would not get the bar yet at that point as they next needed to send it for powder coating with high temperature black paint. It was only a few days later that the bar is really ready and I went for one final fitting. I left the 3Max factory very happy, with my DA6 finally sporting a proper upper strut bar in the engine bay.

Experience

Honda's performance-oriented models of my DA6's vintage have a common weakness and that is the relative lack of stiffness of the chassis. There is a certain amount of chassis flex when the car is driven on uneven roads, uphill, or around banked turns, etc. This manifests itself as a slightly 'untidy' handling; the car seems to moves about quite a bit during high speed cornering especially when the corner is slightly banked (like on highway ramps). When parked on an angle up an incline or when the car is jacked up along one side, the door glass will even go out of alignment with the rubber pocket. Fitting at least an upper strut bar will improve this tremendously.

With the upper strut bar in place, the car is a lot more stable when taking a fast corner. Previously the car 'settles' when entering a corner fast. The back twitches a bit, giving a feeling like the car will lose its tail, or produce snap oversteer. But it won't and I had to be brave and continue pushing before the car will finally settle into the corner. The car actually gives mild understeer when reaching the limit. With the 3max, the tail exhibit little if any twitch and as a result, i could take corners with a lot more confidence. The chassis definitely feels stiffer and the suspension clearly works better. The combination of HKS Hiper Max Dampers (the rear used with Eibach ERS while the front uses the supplied HKS spring) and Eibach anti-roll bar seems to finally have a chance to do their work properly. The car corners a lot more flatter with less body roll (a function of both the coil-over and the anti-roll bar). Steering response seems a lot more responsive and positive as well.

Conclusion

A common question asked to me about my 3Max bar would be how I think it would compare to something 'branded' from the likes of Spoon or Mugen. Well, to be honest I would not know because I don't think Spoon or Mugen ever made one for my model. So there is really nothing to compare it to - the alternative is having no strut bar at all ! Neverthelesws, what I can honestly say is that the 3Max custom-designed upper strut bar is very well made and more importantly, it has also improved the handling of my DA6 quite significantly. Everytime I take a corner in my DA6 now, I enjoy pushing the car a lot more, and with more confidence as well. I am very happy with my 3Max bar.

There are still many fans and owners of the DA6, Honda's very first model to spot a VTEC engine. So if you have one and like me, have been looking for an upper strut bar to improve handling but with little success, this article is probably good news for you. For more details about 3Max bars or to contact Kevin, visit the 3Max Forum.