Perrin 16mm Rear Swaybar and Polyurethane Endlinks Review
 

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20121111-PerrinWrapUp_RearSwaybar_Endlink-01 by VictorN07, on Flickr


Looking to set the foundation for power modification, I'm looking to sharpen up the car's handling ability. Today we are looking at rear sway bars, specifically @PERRIN's 16mm swaybar. I believe aftermarket swaybars from recent WRX, STI's will drop in, but currently most vendors start around 18-19mm which is pretty darn stiff over OEM. This 16mm swaybar is a way to sharpen up the rear suspension without going overboard with the stiffness. @PERRIN_Jeff and @PERRIN_Chris were helpful and professional as always with my questions. Great to work with.

Theory

The swaybar is designed to handle the transfer of energy laterally across the car. It does not affect front to back transfer aka pitch of the vehicle (dive). Looking at just the rear, stiffening the swaybar reduces body roll and decreases changes in camber while cornering. Both of these are good! The overall change is that stiffer swaybar increases oversteer while softer swaybars increase understeer.

There is a limit on how much you can make the rear bar stiff. In cornering weight transfers from the inside wheel to the outside outside wheel. You know your sway bar is too stiff when your outside tire gets overloaded, breaks traction, and causes oversteer. The wider, grippier tires you have, the stiffer you can make the swaybar.

You can balance the understeer/oversteer tendency by installing a properly stiff front swaybar, and/or adjust the swaybar's stiffness. Generally speaking both swaybars should be upgaded if doing any sort of modification. I'm waiting for front swaybar options to come.


Perrin's 16mm Rear Swaybar

All of Perrin's Rear Swaybars are 3 point adjustable. This gives good flexibility and choice in various settings. Leave it soft on the street, hard in drift events :) The stock bar is fairly soft; I can flex it just by pulling on it. I assume the engineers at Toyota/Subaru want to limit oversteer, keeping us from slamming into trees. As far as adjustment goes, if the OEM 14mm bar is 100% stiffness then the Perrin's 16mm is
Here is a video demonstrating the softness of the OEM 14mm rear swaybar
[ame="http://www.youtube.com/watch?v=5G8yugiH9qQ"]2012 11 11 OEM14mmSwaybar - YouTube[/ame]



They also come with polyurethane bushings to hold the endlink. The OEM rubber endlinks are soft and can be deformed by hand. This means that the swaybar has to exert some energy to overcome this play in order to do its job. Polyurethane bushings are naturally stiff, and make the swaybar more efficient. The video below compares the OEM bushing to the Perrin bushing.

[ame="http://www.youtube.com/watch?v=eC9SssT3ytY"]2012 11 11 PerrinBushingComparo - YouTube[/ame]




Endlinks

Stiffer swaybars are known to bend/break OEM endlinks in very hard driving. The OEM endlinks may not even reach all the adjustment points on the swaybar and are very thin. Therefore it is important to upgrade the endlink to prevent these from happening. The stiffer endlinks also helps the swaybar be more efficient in transferring weight energy. The stock endlinks move around quite a bit and have soft rubber bushings. I only photos showing the OEM endlinks.

Competition

Many vendors make great products. The first that comes to mind is Whiteline. Why did I choose Perrin? The main reason is that I have good experience with their products and customer service. Like Whiteline they also have a strong reputation. Second, Whiteline currently doesn't have a small rear sway bar for sale. Made my choice easy :) Given that the hardest setting on the Perrin is 210% I feel that plenty and is in line with my goals. I am currently considering the Whiteline for the front.

Driving Feedback

I believe these the real benefit will be felt in hard driving. I haven't got a chance to do that yet mainly because of inclement weather in my area. I'll update this when I get a chance to ring it out.

The Good Stuff

I'm sure y'all are aware of my style. Let's get to it :)
DIY Guide: http://www.ft86club.com/forums/showt...040#post552040


Here is a short video walkthrough of the installed items
[ame="http://www.youtube.com/watch?v=dAhGKM6Yuzw"]2012 11 11 Perrin16mmSwaybarInstalled - YouTube[/ame]


http://farm9.staticflickr.com/8200/8...2597331a_c.jpg
20121111-PerrinPressShot_RSwaybar_Endlink-01 by VictorN07, on Flickr

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20121111-PerrinPressShot_RSwaybar_Endlink-02 by VictorN07, on Flickr

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20121111-PerrinPressShot_RSwaybar_Endlink-03 by VictorN07, on Flickr

Shot of the polyurethane bushing. There is a hidden surprise in the mountain.
http://farm9.staticflickr.com/8199/8...7d1d2c55_c.jpg
20121111-PerrinPressShot_RSwaybar_Endlink-04 by VictorN07, on Flickr

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20121111-PerrinPressShot_RSwaybar_Endlink-05 by VictorN07, on Flickr

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20121111-PerrinPressShot_RSwaybar_Endlink-06 by VictorN07, on Flickr

The 3 point adjustments. The hole at the tip is the softest setting and gets progressively harder as you go back. The red finish on here is very very good.
http://farm9.staticflickr.com/8488/8...e53e25bd_c.jpg
20121111-PerrinPressShot_RSwaybar_Endlink-07 by VictorN07, on Flickr

http://farm9.staticflickr.com/8201/8...07b5147f_c.jpg
20121111-PerrinPressShot_RSwaybar_Endlink-08 by VictorN07, on Flickr

Made from aluminium. Polyurethane bushings on both ends.
http://farm9.staticflickr.com/8207/8...d5f41d70_c.jpg
20121111-PerrinPressShot_RSwaybar_Endlink-09 by VictorN07, on Flickr

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20121111-PerrinPressShot_RSwaybar_Endlink-10 by VictorN07, on Flickr

Not related
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20121111-PerrinPressShot_RSwaybar_Endlink-11 by VictorN07, on Flickr




Comparison

http://farm9.staticflickr.com/8062/8...988cd2e9_c.jpg
20121111-PerrinProductComparo_RearSwaybar_Endlink_02 by VictorN07, on Flickr

OEM rubber bushing comes greased from factory
http://farm9.staticflickr.com/8340/8...8908e99d_c.jpg
20121111-PerrinProductComparo_RearSwaybar_Endlink_03 by VictorN07, on Flickr

OEM swaybar has one setting. Soft
http://farm9.staticflickr.com/8206/8...0dbd7488_c.jpg
20121111-PerrinProductComparo_RearSwaybar_Endlink_04 by VictorN07, on Flickr

http://farm9.staticflickr.com/8069/8...cf8e09d7_c.jpg
20121111-PerrinProductComparo_RearSwaybar_Endlink_05 by VictorN07, on Flickr

http://farm9.staticflickr.com/8209/8...c602623b_c.jpg
20121111-PerrinProductComparo_RearSwaybar_Endlink_06 by VictorN07, on Flickr

Comparison of the OEM endlinks to the Perrin Endlinks
http://farm9.staticflickr.com/8477/8...390b7eda_c.jpg
20121111-PerrinProductComparo_RearSwaybar_Endlink_07 by VictorN07, on Flickr

Both ends of the OEM endlink move to adjust to the suspension travel. The Perrin endlinks are solid and don't have any movement
http://farm9.staticflickr.com/8068/8...22156330_c.jpg
20121111-PerrinProductComparo_RearSwaybar_Endlink_08 by VictorN07, on Flickr

Closeup of the end that goes in the rear lower control arms
http://farm9.staticflickr.com/8064/8...d1380b19_c.jpg
20121111-PerrinProductComparo_RearSwaybar_Endlink_09 by VictorN07, on Flickr

Closeup of the end that goes into the swaybar
http://farm9.staticflickr.com/8488/8...cd49dcae_c.jpg
20121111-PerrinProductComparo_RearSwaybar_Endlink_10 by VictorN07, on Flickr


Installed
All of these were taken with the car in the air


OEM Swaybar
http://farm9.staticflickr.com/8065/8...e19085f9_c.jpg
20121111-PerrinProductComparo_RearSwaybar_Endlink_01 by VictorN07, on Flickr

Perrin Swaybar
http://farm9.staticflickr.com/8486/8...c373f8fe_c.jpg
20121111-PerrinWrapUp_RearSwaybar_Endlink-02 by VictorN07, on Flickr

http://farm9.staticflickr.com/8203/8...79b9e68b_c.jpg
20121111-PerrinWrapUp_RearSwaybar_Endlink-03 by VictorN07, on Flickr

http://farm9.staticflickr.com/8482/8...09b25696_c.jpg
20121111-PerrinWrapUp_RearSwaybar_Endlink-04 by VictorN07, on Flickr

http://farm9.staticflickr.com/8337/8...481cfa4d_c.jpg
20121111-PerrinWrapUp_RearSwaybar_Endlink-05 by VictorN07, on Flickr

http://farm9.staticflickr.com/8065/8...bdaaefe7_c.jpg
20121111-PerrinWrapUp_RearSwaybar_Endlink-06 by VictorN07, on Flickr

http://farm9.staticflickr.com/8337/8...817b45da_c.jpg
20121111-PerrinWrapUp_RearSwaybar_Endlink-07 by VictorN07, on Flickr

http://farm9.staticflickr.com/8350/8...4c6c9255_c.jpg
20121111-PerrinWrapUp_RearSwaybar_Endlink-08 by VictorN07, on Flickr

thanks for the awesome write up!

How extreme are the angles of the end links when on the stiffest setting?

oh, and AMAZING write up!! Thanks

Getting very colorful under your car!! Nice review as always.

Putting mine on the softest setting, there is some angle added. The medium setting will put the least stress on the endlink. Here is an excerpt from the manual showing the positions of the spacer and the angles on the endlinks.

How is the clearance with the diff bolts?

As for the wisdom of just upgrading the rear sway on a RWD car.... Perrin should sell a matched set.

There is slightly less clearance to the rear diff bolts than OEM since the Perrin bar bends up instead of out like the OEM 14mm. I still think we want to drop the bar to properly access the diff bolts.

Agreed on the matched set. Looking to do a 20mm front ASAP. I believe the OE front swaybar is 18mm. I tugged on it while under the car and it is meatier compared to the rear. For now I'll have my dorrriftu machine

I think I'd stick with the stock endlinks, they look like they'd do a much better job of dealing with the angular stresses. Though, without the spacers to help limit the angle and having never tried it, I don't know for sure. Did you size it up? What are you're thoughts?

IMO, I agree with you the stock endlinks so better with angular stresses, but being so thin, I'm afraid using them at the medium or hard setting may bend or break them in half over time.

The Perrin endlinks do transfer energy better than OEM due to the materials used in the design. I do believe the the aftermarket ones what use pillowball mounts might be better; those handle angular stresses better while being robust. I like these because they are not complex. I don't have to worry about having to tweak them when tuning the handling.

22mm front perrin swayer
 

whats the best rear sway bar size?, I have 22mm in the front

There isn't a "best" size. It's dependent on how you want to set up the vehicle. Different drivers will have different preferences for certain situations where they might prefer one sway bar size/setting over another.

Do you know that altering the relationship of the front and rear sway bar alters the way the car steers? What is it you are trying to achieve?
Awesome necro by the way.

Decrease body roll, and keep the rear end more firm around tight curves

Try it and be willing to eat the cost of switching to a different bar if you're not happy. Welcome to the world of suspension tuning.

:cheers: