So last month, after I installed the Autoexe chassis braces, I was hungry for more chassis stiffening mods for my car... while I was going through the JDM Mazda parts catalog, I found out that the Premacy came with stiffener plates on the rear strut towers. Mazda didn't bother fitting them on the Protege to cut costs and I guess they decided the Premacy needed them as it's a much heavier car.
The stiffeners are thick pieces of steel that sits on top of the strut towers to reinforce/stiffen the sheet metal beneath them. This greatly reduces the metal from deforming/flexing under load. Mazda added these to the front strut towers on the 01-03 Proteges but not in the rear! These stiffener plates work so well that, all new Mazdas now come with them. They greatly improve handling by not allowing suspension geometry changes like any chassis bracing does, despite the fact that real braces do a whole lot more, these are a cheap alternative.
Well I have a sedan, not a P5, so there's not really any rear strut bar options. There isn't a need for one to begin with as the rear parcel shelf IS the "strut bar"
So in other words, to fit a strut bar specific to the P5, I would have to cut holes in the metal in order to fit it! No thanks!
So the best thing to do was to get those stiffener plates from the Premacy. Thanks to a kiwi a few weeks ago, he was able to find them for me from the junk yard.
They're very thick... not flimsy pieces of metal... I couldn't even bend them by hand! They're 5mm thick with rolled edges to make them hard to flex!
A good comparison of all the CP/BJ stiffeners:
The top left one is used in both the CP and BJ, while the golden one at the top right is obviously only used in the CP. The bottom ones are for the LHD OEM strut bar used only in the BJ.
But why not just use the front stiffeners? They're just pieces of metal right?
Well not really...
Why not just make your own? That takes too much time... having to measure, cut a thick piece of metal, drill holes, paint.... too much trouble for $20 pieces of metal!
But making them fit in the BJ sedan wasn't straight forward though... it runs against the gusset frame leading away from the strut towers.
Old pic from 7 years ago which shows the guesset:
So I had to grind down the stiffeners quite a bunch...
Now it fits!
Around town, the car rides noticeably even more solid than before, but only slightly. The car feels a little more tail happy at the limit too, so I guess it's doing its job.
Is it worth it to most people? Probably not. If you happen to race and drive your car to the limit, then you will want them as you'll notice a difference then.
The stiffeners are thick pieces of steel that sits on top of the strut towers to reinforce/stiffen the sheet metal beneath them. This greatly reduces the metal from deforming/flexing under load. Mazda added these to the front strut towers on the 01-03 Proteges but not in the rear! These stiffener plates work so well that, all new Mazdas now come with them. They greatly improve handling by not allowing suspension geometry changes like any chassis bracing does, despite the fact that real braces do a whole lot more, these are a cheap alternative.
Well I have a sedan, not a P5, so there's not really any rear strut bar options. There isn't a need for one to begin with as the rear parcel shelf IS the "strut bar"
So in other words, to fit a strut bar specific to the P5, I would have to cut holes in the metal in order to fit it! No thanks!So the best thing to do was to get those stiffener plates from the Premacy. Thanks to a kiwi a few weeks ago, he was able to find them for me from the junk yard.
They're very thick... not flimsy pieces of metal... I couldn't even bend them by hand! They're 5mm thick with rolled edges to make them hard to flex!
A good comparison of all the CP/BJ stiffeners:
The top left one is used in both the CP and BJ, while the golden one at the top right is obviously only used in the CP. The bottom ones are for the LHD OEM strut bar used only in the BJ.
But why not just use the front stiffeners? They're just pieces of metal right?
Well not really...
Why not just make your own? That takes too much time... having to measure, cut a thick piece of metal, drill holes, paint.... too much trouble for $20 pieces of metal!
But making them fit in the BJ sedan wasn't straight forward though... it runs against the gusset frame leading away from the strut towers.
Old pic from 7 years ago which shows the guesset:
So I had to grind down the stiffeners quite a bunch...
Now it fits!
Around town, the car rides noticeably even more solid than before, but only slightly. The car feels a little more tail happy at the limit too, so I guess it's doing its job.
Is it worth it to most people? Probably not. If you happen to race and drive your car to the limit, then you will want them as you'll notice a difference then.
