Rear sway bar... Can I get poly bushings?

[elwesso]

I just got my Q45a rear sway bar in the mail today (w00t!) and Id like to knowif i can use poly bushings.....

I would assume energy suspension makes some. Maybe a whole end link kit, those end links look very wimpy..... Might help make the rear bar stiff enough ot make the front bar not give as much understeer..... I recall dennis saying he uses washers to help this.....

Here are some useful threadshttp://forums.nicoclub.com/zerothread?id=84055

It seems that if you want to stiffen the rear bar to make understeer less, am I correct? I hate understeer... I hope its not my tires because i have some pretty decent tires (sumitomo HTRZII+).....

If OEM bushings are the way to go, maybe with a washer then ill do that..... I dont mind a little vibration.....

[DAEDALUS]

You can probably get a poly kit from Pep Boys for $20. Perfect Circle is the brand they usually stock. Should come with the links, nuts and spacer cups--everything you need for the ends. They probably also stock the frame bushings, not sure about the clamps.

[elwesso]

What do i get it for... Universal, or for a certain car?

What about the center bushings, best to just stick with OEM there?

[qship96]

wes,if i remember correctly,increasing rear bar stiffness increases understeer-to lessen understeer-firm up front bar/bushings

[elwesso]

I thought the idea was to increase the rear stiffness to take away from the front sway bar...

Thats the reason why you get the smaller rear sway bar.. Otherwise (if what your saying is true) youd be smarter by running no rear sway bar, and thats obviously not the case......

I think i might be confused......

[qship96]

Wes,you are correct,increasing rear roll stiffness will reduce understeer,and increase over-steer.my brain must need some new poly bushings to firm it up!

[squeefoo]

Duh !! All this has been covered ad infin.Measure and go to energy suspension and look it up.

OMG !! even the spacer dimensions are there !!

[elwesso]

Heres some more threads for reference.

zerothread?id=1345

I read about every thread in Inf Gen and IOM and couldnt find anything definite.. Ill do some more searching.....

What Ive found thus far is that some people have used stock bushings and washers, but the bushings dont last real long... Poly seems to be the way to go...

ill do some more research and post the part numbers.....

[Q45tech]

Remember the rear and front bar attach at the lower suspension midpoint so you divide bar stiffness by 4 plus of course and bushing slop.

A 3" wheel movement only moves the bar 0.75", so slop is important.The angles of the endlinks change as the bar is moved -0.75 to static to +0.75.......thus too tight will wear the poly bushings from sideways scrub [the angle change]..........maybe half and half [rubber and poly], as you have 4 endlink bushings per side.

The front has 2 bushings per side plus the joint in endlink so the rate of engagement [bushing compression] front to rear is critical.......don't tighten up the front [bushings much] as that will increase understeer.

The rear bar at 160 [40 pounds per inch wheel rate ...../4] is more than enough with 123 rear springs..........1/3 increase in rear roll stiffness or a shift to the rear of ~~ half of that in total ratio.

Easy to get the rear too stiff [ratio wise] a good compromise is to find a softer front bar from a t or active car [not worth buying new] as the 15% less stiff front [7% reduction in front stiffness] adds to the rear ........moving the ratio rearward by 22%............making Q almost neutral in dry........depending on the precise preload setting of bushings front and rear..........a 1/4 of a turn on the end link bushing nuts will be feelable when you get everything just right.

Most Q have very worn and hard cracked bushings with differnt than brand new stiffness.

The purpose of all the rubber is to make the Q smoth on 1" bumps but engage the bars as the body rolls beyond 1" progressively to 2 then 3".

Tricky to get right with changes, as speed bumps will kill you with too stiff fast engaging sway bars [poly] !

Bar size [diameter] is nothing without a properly isolated [for the street] rubber coupling system.

Have seen 24 mm rear bars [too stiff] bend and break aftermarket endlinks. The oem is stronger than it looks [for a 20mm bar] since the movement angle is so small.

In many way I like the 20mm rubber isolated with the Eibach rear springs even though they are progressive.........progressive towards neutrality and oversteer.........all depends on having softer [newer rear than front tires].....always put my newest sofest Pilots on the rear.

No rock climbing allowed.

[elwesso]

i think this time ill try the rubber end links with a small washer, and then decide on poly later...

I have the Q45t so i have the smaller front bar...

Also, how will the 20mm bar react with HICAS?

[jamesmost]

wes i have the explorer sport 24 mm rear sway w/ energy susp poly bushings and very happw endlinks as well

[elwesso]

I decided to go with the OEMs and the washer thing.....

4 washers on each side for a total of 8, will post a writeup!

[Q45tech]

The right durometer [Shore A] bushing stiffness and ramp up to effectively solid..............is a poor mans variable sway bar.

Tricky to get the adjustments: non engagement, then slop, then progression to full compression all in less than 1.5" of body roll [0.375" of endlink to bar movement]. They change with the temperature of bushing.

Not sure you need more than 2 per side to start [between top and bottom nut..........too much bushing compression and the bushing will crack and split........treat the rubber bushings frequently [every 3-6 months] with Wurth rubber protectant or tire dressing