Atypical Sway bar mounting question

blamkin86

blamkin86

Well-known member
So,

I'm switching over to the same front sway bar many other people are using. Unlike many others however, my crank pulley has an arbor for an oil pump. Unfortunately, that oil pump arbor is interfering with the center of the sway bar.

This is not my car, but it appears to be a miata and the same bar I'm attempting to use:

IMG_0037%20(Custom).JPG


You can see in this pic, the engine is on the right, and the center of the crank pulley (not alternator pulley) is very close to the center of the bar. Because of my arbor, my crank pulley is about and inch longer than the one in the picture... meaning that the center of the bar hits the arbor and therefore cannot be bolted in to the white u-mounts.

I'm going to just fab a 3/4" spacer to lower the bar below the pulley. However, before I do that, I remember reading somewhere (circle track magazine maybe?) that the sway bar arms should not be pointing upwards.

Can anyone think of any suspension geometry reason why it would be "bad" to space the center sway bar mounts down 3/4"? (the white u-mounts in the picture would be lower towards the ground 3/4")

I suppose in the crazy extreme case, where the center of the bar is mounted completely below the arms, the sway bar could not twist and the suspension wouldn't move. I'm just talking about moving the bar down 3/4" below where it mounts stock.

Probably nothing to worry about, I know - just thought I'd see if anyone had any reason not to space it down. I went to all this trouble to do what others are doing and of course it didn't quite work out.

Thanks in advance,
--Bill
 
depending on how long the arms are on the sway bar, it may not be a big deal. the arms are short enough on mine that an upward angle like that pulls the mounting points on the arms forward a little bit, and then even more forward as the suspension compresses. This manifests itself in a lot of rearward force on the control arm vs. simply up/down like you'd want. since the front end is all heim joints it's not a big deal and doesn't affect the actual geometry, but I seem to lose (break?) a 3/8" GR8 bolt in one of the mounts every couple of races so it's necessary to check that every race. I'm not sure if that's due to the angle creating bind somewhere (I don't see any marks on the mounts to indicate the rod ends are hitting it), or if it's just that much force on the sway bar.
Different from your case, my sway bar has enough clearance on the front that it may be a smart idea to just move it back a couple inches and remove that angle on the endlinks.

Another issue I've seen is with the old 240Z chassis where the steering rack is in the front. They had an issue with the sway bar contacting the tie rods under hard braking and you would lose steering because of the interference.

They're a bit off-topic to your specific questions but are considerations based on things I've seen. I don't see any problem with moving the bar down 3/4" to clear the crank pulley. 3" problem. 3/4"- no problem. Then again, I'm just the peanut gallery so take that advice for what you're paying for. :)
 
After you lower the sway bar mounts, can you shorten your connecting links? That would keep your side arms from going "over center" and maintain a more balanced use of sway bar force on the suspension.

Ideally the connecting links should be vertical and the arms horizontal at ride height. It keeps the motion geometry consistent and the energy force equal in both directions, up & down.

You didn't mention how long the arms are. If they are less than 12" - 15" you have a lot of spring rate for a small amount of motion. That could contribute to small component failure if not kept in alignment.
 
don't forget that under hard braking the engine moves forward towards the swaybar.....to some degree even with front-rear limiting bar.......just consider this
 
3/4" lower on the bar is fine.......so long as the links remain perpindicular to the sway bar arm.

Do you have enough ground clearance to give up 3/4"???? On the sprite I did NOT have the clearance below so I mounted on TOP of the frame rail and did some monkey business with the links.
 
Jay I definitely have the clearance. What's ironic is the end links are not really that perpendicular to start with - so my "down" spacer will also move the bar somewhat aft to fix that problem.

Thanks everyone. I know it seems silly but just want to be sure I'm doing it right. I spent a couple of years with "something wrong" that I never figured out; I don't want to spend all this money to just introduce a different problem.

--Bill
 
why not just move it forward instead? an adapter plate with 2 sets of mounting holes (2 for the BIW, 2 for the swaybar brackets) would be EZ to make and also resolve the braking clearance problem
 
Bill, as some have said, arms horizontal to scales/
level ground. End links vertical. There are things you can do with the control arm pickup to keep the end links vertical. Also, unattached your swaybar should fall vertical from it's own weight. zero binding. with the above said and done you will have zero odd issues coming from your sway bar. Look at what a pro does with his/her swaybars and that will confirm the above.

Most of all, Have Fun. :wink:
 
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