Firewall, & Ride Height LCA Torquing

[freds]

I couldn't figure out how to torque the rear LCA bushing nuts (of the front suspension lower control arms) after setting the ride height....with the fire wall already in place......with my 1/2 " drive torque wrench.

So I set ride height first (with front suspension all in place) and then did the fire wall.

How did you guys do it?

Thanks forum for pointing me to Clicos.....very important help!!!


F W Half Done.jpgF W Half Done2.jpgF W Done.jpg

fred

[metalmaker12]

The rear lower control arms have plenty of access, maybe I am misunderstand you

[freds]

The rear lower control arms have plenty of access, maybe I am misunderstand you

Sorry, I should have been more clear.

I'm talking about the rear BUSHING of the FRONT lower control arms.

I'll edit the post.

fred

[metalmaker12]

It was already torqued going in, installed it as a complete unit. I did have to shave the threads down to top of nut on drivers side to clear the firewall. I have frame 13 , I am unsure what frame you have, but a change was made at some point soon after my frame design.

[freds]

It was already torqued going in, installed it as a complete unit. I did have to shave the threads down to top of nut on drivers side to clear the firewall. I have frame 13 , I am unsure what frame you have, but a change was made at some point soon after my frame design.

Hi MM,

See http://thefactoryfiveforum.com/showt...-bushing-mount about swapping the rear bushing mounts. I swapped mine and therefore had to "untorque" and reassemble on the opposite LCA.

That being the case, there was no preset position.

Secondly, the pre-torqued position (either new or from a donor) is presumably set for the ride height of a stock WRX....not the 4 1/2" for the 818S.

What I did was put the wheels on the roller, loosened all the bushing bolts/nuts and set the bottom of the chassis at ride height.....then I torqued up all the bushing bolt/nuts (front and rear) so now the "neutral" position of each bushing is at standard ride height, and any movement of the suspension up or down while riding doesn't twist the bushings beyond their "reasonable" range.

Naturally when the car is complete and at full weight you have to adjust the spring preloads to get the chassis at ride height.

Since I already have my engine and transmission mounted, my rear springs are already cranked up some!

Anyway, that is how I see it and what I have done.

Correct me if this is all wrong...there's still plenty of time to make changes.

My chassis is #18

fred

[metalmaker12]

There is not much movement in the control arms, and it should work either way we have done it .

[Oppenheimer]

I see what Fred is saying. If this is not done right, the bushing becomes a sort of torsion bar that is adding extra spring to the suspension (or taking it away). Not sure how much that really is compared to the coilover spring itself. But this car is all about the handling, so why not make sure this part is right? Would it help to replace this bushing with a free-floating one, like a polyurathane? Something that could be lubed up and would not provide any 'sprung' resistance?

[freds]

I see what Fred is saying. If this is not done right, the bushing becomes a sort of torsion bar that is adding extra spring to the suspension (or taking it away). Not sure how much that really is compared to the coilover spring itself. But this car is all about the handling, so why not make sure this part is right? Would it help to replace this bushing with a free-floating one, like a polyurathane? Something that could be lubed up and would not provide any 'sprung' resistance?

1. Exactly my point and
2. Good question about the polyurethane bushings. I don't know...have no knowledge or experience with them. Hope someone answers that one for us.

Thanks

fred

[metalmaker12]

I totally understand your points, and there might be something we can do to improve upon the current design, that's why there are such things as revisions. Am I going to, not currently, it is working for FFR to run 1.7gs around a track guys, but we can keep coming up improvements as we go. A poly bushing which will allow free movement will work very well, and down the road maybe I will come up with something.

[Xusia]

Two thoughts occur:
1. You could install it pre-torqued, set the ride height, use some kind of angle indicator, remove the parts, set the angle accordingly, and re-torque.
2. Would it be harmful to add some kind of lube to the existing, non-poly bushing prior to torquing and installing it? That would allow it to move after installation.

[longislandwrx]

Just torque it and then install it. If it's too loose tighten it afterwards, if too tight loosen... Just check after a few miles to make sure it didn't loosen.

If you are worried about it, drill 2 1" holes in the firewall and install grommets.

[freds]

Just torque it and then install it. If it's too loose tighten it afterwards, if too tight loosen... Just check after a few moles to make sure it didn't loosen.

If you are worried about it, drill 2 1" holes in the firewall and install grommets.

I am/was not worried about it. As I stated, I installed the firewall after I set the ride height...no problem, and was wondering what others had done.


fred

[longislandwrx]

I am/was not worried about it. As I stated, I installed the firewall after I set the ride height...no problem, and was wondering what others had done.

Fred

Sorry, if others share the same concerns rather, or if you have to unbolt yours in the future to make changes/repairs.

[freds]

Sorry, if others share the same concerns rather, or if you have to unbolt yours in the future to make changes/repairs.

No offense taken...no problem. I seriously considered the hole, and have the chassis punches to make a clean hole through the aluminum (if done before installing the LCA) but don't really like torquing to that level with an extension between the torque wrench and the socket/nut. So after considering all I decided to do the firewall after the front suspension was done. It wasn't much of a bother working that way.

Then I wondered what others had done, in case I had missed something simpler....hence the original post. Seems to have set off a bit of consideration of the issue, which might not have been done before...also it may not be a big deal at all, I just have a mind that works that way, especially if I'm working on stuff I have never done before....and setting up suspension is/was new territory for me.

Cheers

fred

[Oppenheimer]

Do we know what the 818R that pulled 1.7 G's used for this bushing? G's are about static handling, and this is something that would mostly affect dynamic. Though agree the 1.7 G's that was recorded occurred while things were looking rather dynamic.

I like the hole with plug idea. Lubing the stock bushing won't help, as the rubber is bonded to both the inner and outer metal. The stock bushing is not floating like polyurathane, etc would be.

My guess is if you torque this with the control arm even close to the correct angle at ride height, you will be fine. The amount of extra torsion spring the bushing would add is probably negligable compared to real spring on coilover. That said its probably a good idea to not just blindly torque it on a bench with no thought to angle of control arm, then mount it to car. I could see a novice getting this wrong and not realizing it.

[Xusia]

It can't be bonded everywhere, otherwise this whole discussion would be pointless. If the relative angle can be adjusted, then there has to be something that is free moving and could therefore be lubed. The question is whether or not that's a good idea!

[D Clary]

They are bonded everywhere. The movement of the arm works the rubber bushing. That gives you smooth and quiet movement. It also moves in all directions opposite the force applied. In a street car it is fine, a race car not so much. The bushings need to be torqued at ride height or the bushing will destroy themselves very quickly.

[freds]

It can't be bonded everywhere, otherwise this whole discussion would be pointless. If the relative angle can be adjusted, then there has to be something that is free moving and could therefore be lubed. The question is whether or not that's a good idea!

My understanding of those rear LCA bushings is (and I'm not at all sure about this but will check further) is that the rubber is bonded to both the outer aluminum housing and the inner steel sleeve that the end of the LCA goes goes through. So when setting the ride height position with the nuts loose but the housing bolted firmly in place, the LCA can be pivoted freely (inside the steel sleeve). Then when you have settled on the correct position for the LCA (for ride height) and you tighten (to the substantial torque specified) the end nut....the steel sleeve (which has tapered steps in it) is clamped firmly against the tapers on the LCA shaft. Locking the sleeve in place...and with the outer rubber bonded to the outer housing, when you now move the LCA up or down from the set (neutral) position you are actually "twisting the rubber". As Oppenheimer described it ...its like a torsion bar.

That is why, I believe, it is good to clamp it in its neutral position. If too far off that position it is going to require force to twist it to the ride height position, and in extreme could tear the rubber.

Please...any expert...who can teach us...jump in!!!

That rear bushing is supplied as a complete unit with housing.

Other bushings (like the front LCA bushing) can be bought as a separate piece. Also I know (as I had to replace one) the rear suspension lower control aluminum arms have separately available bushings which are not difficult to insert into the arms. So those types of bushings may very well be candidates for Polyurethane replacements...they are not bonded to the outer housings.

As I say...this is my understanding...I'm not lecturing as an expert.

fred

[D Clary]

That is correct

[freds]

Thanks