I’m trying to find a rear strut brace for my mk1 to go in the boot and attach to the rear strut tops. Has anyone fitted one to their car and does it fit around the space saver?
None of them go around the spare wheel. One of the more marginal upgrades.
Is there an alternative to fit a brace in the cabin ?
I looked into them 3 years back during my Mk1 refurb but ditched it as simply not worth my while or money. I preferred the relative security of a spare.
I suppose a spare-securing mod could be done at the loss of boot space.
Bar even the questionable turret brace, the only “brace”…(which isnt)…in the NA cabin is the often misinterpreted brace behind the seats which is really a lip service side impact item, not a torsional reduction modification. Additional footwell bracing was added later in production but I’m not aware which year…maybe from 1840cc on.
Apart from that, the only effective NA bracings I’m aware of are chassis oriented eg rail braces and the usual OEM bar braces.
From memory…there are rather odd inner front wing triangular items as well. I also recall a cross shaped boot brace to be bolted on behind the spare. Long time ago…
Ahhh,
I guess the big question of return of effective investment per £ is the thing.
Added weight of brace plus still hauling a heavy spare around, for me I just could not see the benefit for urban use.
Then again…I don’t autosolo , track any more, or any form of sport.
These are my (red) new ones. OEM, but refurbed. If you don’t have them, PM and Ill let you know where my rusty originals are. They are Hiroshima fitted…I think…from 92/93 on…or summat.
Firstly, the MX5 doesn’t have struts. Strut braces were invented for cars with Macpherson struts (eg. Mk1 Escort). Macpherson struts are load bearing at the top, MX5 double bone suspension is not (rally Escorts will have double plated strut towers). The added stress means under cornering, the car’s alignment is affected, and so you want to reinforce those struts by adding a brace to stop the top mount moving.
“Strut braces”, or more precisely, shock tower braces on the MX5 won’t do this, and it doesn’t really matter if the movement of the shock top is not limited all that much. STBs serve to limit body flex.
Subframe braces are acting more like those strut braces, by limiting the flex in the subframe under cornering. The STBs use whatever pathetic little studs and 14mm nuts sandwiching the thin sheet metal between the brace bracket and the shock top mount. The subframe braces use bolts, heavy welded captive nuts, thick steel pressing.
The rear subframe doesn’t need additional bracing over the top.
At the front, the engine closes the top of the subframe.
The rear subframebrace was added to the MX5 with the 1991 updates, not so much to improve the handling, but to tame it a bit in the hands of less experienced drivers. Some Mazda engineers preferred that it wasn’t added, reportedly.
The front subframe brace was added with the 1993 1.8 update, probably to do with the additional power/weight of the BP motor trying to use the same 1.6 subframe. Around then, the aftermarket seized upon this by coming out with their own front braces. These all, conveniently utlise an existing hole in the pressing, to fit a nut and bolt. Mazda never used this location. So I think the aftermarket front braces aren’t particularly designed with any specific handling improvement in mind. The improvements are marginal, and possible have a placbo effect (less shimmy, smoother over railway crossings etc).
Interestingly, in Spec Miata, Mazda Motorsports weldable subframe braces are the only permitted subframe brace. These aren’t bolt on, but welded in. The blub for these ran:
The Mazda Motorsports subframe braces are made from 12 gauge laser cut steel and are designed to be welded into place to help alleviate stress cracking at the factory weld on the subframe caused in the harsh racing environment.
The braces weld into place in between the lower control arm mount and the main body of the subframe and have a large dimple die hole in the center of them to help give them strength and also serve as an inspection hole for tech to be able to see the original OEM subframe welds.
Price: $17.70 is for quantity two (2) subframe braces to brace one (1) front NA or NB subframe.
These aren’t braces that you can show off to people crawling under your car:
Its the first reference I have seen to NA/NB front subframes possibly cracking. Learn something new everyday.
As described, the factory “cockpit brace” is nothing of the sort. Peel away the plastic, and its 5mm flat stock. In cars that don’t have this fitted as standard, given the way it is bodged in with nuts and bolts, I doubt its even mounted as solid as the factory piece. On 90hp cars, the subframe and cockpit bracing are not fitted, to save weight (indicating how important Mazda actually thinks these are). But the captive nuts are all in place, so the factory pieces can be aded easily.
Other options to stiffen the car. Add a 4-point roll bar. Western rollbars mount to just in front of the seatbelt tower and somewhere in front of the rear shock top; I wonder if its better to be behind (further to the back) the shock top (or maybe it makes no difference). Japanese bars fit to the same spot in the rear, but usually the main bar mounts to the floor behind the seats, limiting seat travel.
Side bars can be adding, further affecting access. A side bar knackered my right ankle because of the way it forces the foot to be angled
Cockpit transmission tunnel gussets from the NB can be added to the NA, and neatly hidden behind stock trim. NBs had these pieces added as part of several measures to stiffen the shell. Seems to be more of a mod in Japan, and its not clear if the parts can be had from Mazda anymore.
The front gusset needs the dash to be taken out to fit.
There are tubular harness bars about that bolt to the seatbelt towers, but they are attaching to thin sheet metal.
Others have brackets that allow fitment to the seatbelt points. I had one of these at one time, for a short while. Not sure I’d entrust my life with it though. This is basically a copy of the JDM piece I had. Most rollbars will have an integram harness bar.
