Davard

Having had the Quickor 1" rear bar straighten the hoops (frame mounts), and pull the frame mounts off the subframe, I figured I'd broken everything you could break.

Wrong!

My wife Julie (who uses the Protege as her daily-driver) shows up having gotten a ride home. Seems the car was handling "scary" and "like it was on ice." But she said it felt like something was loose in the front end.

So, I drive down to see what's up with the Protege. I park behind it, and it looks OK, but walking around, I notice something weird. 1-2 inches of toe-out in the rear is definitely not normal. So, flashlight in hand, I look under the car, not sure what I'll see.

Turns out the leading lateral arm is snapped in two, right next to the sway bar mount.

Fortunately, she was only doing about 35mph, and with no one around her. Three minutes later, and she would have been on the freeway doing 70mph in traffic, and probably spun.

It was too late at night to due much tonight (the neighbors get upset with late-night auto repair), but I took off the wheel and it looks bad. I'll get some pics tomorrow night (I don't have a digicam, but have a friend who does.)

Needless to say, I'll be buying two new pieces (if one broke, how far behind is the other one?).

So, add one more broken part to the list claimed by that 1" rear bar.

UCSBgeek

Yikes! I think I remember there being a blurb about the swaybar causing problems in your GRM article.

I guess that swaybar is really worth all the hassle, huh.

Davard

The alternative is 500lb rear springs, which would make the ride worse than an unloaded 5-ton truck (having driven one with a 12 foot bed and 23,000lb rear springs).

zenilder

Weird. I guess I don't understand it...

How did the rear bar cause this to happen? ...Or I'm thinking of the wrong part.

mazdaspeedwest

Man, very happy to hear she did not make it to the freeway.....

I'll talk to you more about it tomorrow night (still gonna be there right?) but Your both welcome to drive my car (if Julie wants to run STSL) Maybe we can devise some sort of stiffener bar/bigger mount/thingy to help beef it up.

Davard

I took the whole rear subframe out and welded up the sway bar mounts fully, and rewelded the lateral link. It shoud be fine for the autocross and until I get the new part from Mazda next week.

I took photos but left before we got around to pulling them off the camera. Hopefully I can get them up here tomorrow.

Davard

Assuming your SOHC comes with the same front bar as the US DX, you could probably use either the ST rear bar only, front and rear ST bars, the rear Whiteline bar, or some of their front and rear bars (although changing the front bar redefines PAIN). The cheapest option for a bigger front bar may be the 1" bar out of the ZX-2, but you'd need a 1" rear bar to balance out the understeer that front bar would create.

As a general rule of thumb, the front and rear bars should be the same size for neutral handling, slightly larger front gives understeer, and larger rear gives oversteer.

Playing with springs would obviously change things. Most aftermarket springs are 30-40% stiffer than the rears. Going with stiffer rear springs would reduce the need for a bigger rear bar size.

bpt323

what could be the possibilities ( good or bad ) of having custom made lateral links made thicker and stronger....???? how would this affect the car overall??.... i could easily have this done...my machinist would be more than willing.

mazdaspeedwest

Well, i can think of one advantage of a thicker/stronger link

Davard

Thanks, Jesse, for posting the pictures. Apparently, this has been broken for a while (the rust in the top, under the washer), and just waited to break. The flange in the front of the top photo was actually stretched about 3/16" before it finally failed.

Well, the rewelded part seems to have held together through 3 drivers at the autocross last night. And with a 300lb passenger in the back seat driving the 85 miles to and from the event. Still doesn't mean I'm not going to replace it as soon as the new one comes in.

As to reinforcing/replacing: The only reasons not to are class legality, or ability. It isn't straight (the bushings are offset, but the bolts are parallel), and might be tricky to get right. Personally, I'd like on 1/8"-1/4" longer for more negative camber :-) , but that isn't legal in the class I race in. It would also be neat to have a rod-end on the end of the swaybar.

One thing that I did that should help is I enlarged the swaybar bolt hole to 1/2", so that the bolt won't bind during suspension travel. I also looked closely at the other side, and added a weld-bead all the way around the washer.