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BJ strut springs on mx3?

Posted: September 4th, 2014, 10:24 pm
by valk1317
a little curious what different things people have tried. im not really that interested in paying $500 for a set of eibach for this car.. but i have a set of sportlines on my BJ chassis protege. ive been reading around about a possible 5 bolt swap to the mx3 that could be done on the cheap, but for now ill ask if anyone has ever tried 3rd gen protege springs on the mx3 struts. or have you been able to run a 3rd gen strut on the mx3 directly?

ill prob get the msp up on blocks and check it out while its retired, it will get coils anyway. just curious.

Re: BJ strut springs on mx3?

Posted: September 5th, 2014, 1:23 am
by RobMinhas
I have BJ coilovers in my car, as well as one other member here.

The fronts share a strut mount pattern on the top so a BJ mount would work, the strut however is wider where it meets the spindle. YOu could put a spacer in or swap in a GD spindle instead. If you do this you would need a BJ strut, BJ strut mount, BJ spring and GD spindle. No modification necessary. If you were to attempt a BJ spring on an mx3 strut and mount you should know that the BJ spring has a considerably smaller diameter, I would guess it would unseat or be impossible to correctly seat. I don't think the BJ spring alone would work on the front. A BJ strut, spring and mount combo with spacers or a GD spindle however woudl work.

For the rears, it's worse.

The spring diameters are different and you can't get away with using a BJ strut mount and strut(sorta). The BJ strut mount has three bolts and you would have to sacrifice some serious mechanical integrity to modify it to fit the MX3. The strut is also wider then the MX3 spindle so you could upgrade to GD spindles(would need to modify them by cutting down a portion). Maybe you could use an MX3 strut mount, BJ spring and strut then either use a GD spindle or spacers but I doubt it. i don't think the spring would seat properly but maybe it's doable in the rear with the spring mount.

I know this from mucking around with the BJ coil overs and accidentally buying BJ struts and attempting to install them.

Re: BJ strut springs on mx3?

Posted: September 5th, 2014, 3:06 am
by valk1317
well it saves me a weekend or more with two cars in peices. a shame as i like the drop and ride of the sportline springs.

I guess ill have to wait for a set of used springs to pop up perhaps. or could i buy springs for another bg chassis car? like a zx2?

id like to get a 2" drop or close to it thats driveable on crappy roads. it rides pretty high atm.

on the topic of struts i ask as the struts and mounts are pretty worn and will probably need to be replaced soon. hard to say no to a set of kybs but when i get those and a set of lowering springs im almost halfway to a set of ksports.
I could have sworn i saw bcracing coils in this flavor and yellowspeed but cant find them anymore.

Re: BJ strut springs on mx3?

Posted: September 6th, 2014, 3:31 pm
by valk1317
well this might seem like a silly question but you say the upper strut mounts are the primary problem, is there enough material left on the shock tower to just drill new holes for the strut mount? maybe add a steel plate for support and just make holes for the bj strut?
im not too worried about having to shim the knuckle. steel washers should be plenty up to the task of that.

Re: BJ strut springs on mx3?

Posted: September 8th, 2014, 1:27 pm
by valk1317
Could I not simply measure the difference in spring diameters and just machine some aluminum hats on my cnc? If its a seating problem, why not justmake spring hats; use a bj strut, bg strut mount and shim the knuckle as needed?
I know the aluminum woildnt cost a lot and solidwords/ machine time is free for me. Why not?

Re: BJ strut springs on mx3?

Posted: September 9th, 2014, 8:21 pm
by valk1317
did you happen to know the hole center measurements for the different strut tops? i was thinking of a way to use the springs with caps but the easiest way would probably be just to redrill the bolt holes in the strut tower. could always add additional metal if strength is an issue but i doubt it if the original holes could be adapted to fit the bj strut top.
i was even half considering cutting springs as i dont need to lower it a lot but the chance of them rolling unseated isnt worth it. even if all id cut is half a coil or so. .