GTI Rear Sway Bar, Part 2

by "LimitedTimeOnly @ opposite-lock.com" (limitedtimeonly)
Published 12/22/2017 at 15:00

Tags: Sway bars ; Autocross ; GTI
STARS: 3

I have reached out to manufacturers of rear anti-sway bars (a.k.a. rear sway bar, or RSB) for my 2016 GTI in an effort to get weight information and a spring rate performance curve . . . how much the bar is displaced for progressive levels of force. I’m trying to make a purchase decision when otherwise there is very little information to use for comparison. I’m sharing this here for the benefit of other random internet searchers.

First, for those who don’t know, RSBs are generally either solid or hollow. Hollow ones are tubular material, and are lighter weight for the same diameter, but typically offer less stiffness when compared to solid RSBs of the same diameter. Also, there are adjustable RSBs, which offer more than one hole at the end to allow for different connections with the end-links, and thus different stiffness response to suspension forces.

What I’ve found:

SuperPro makes the endlinks that many prefer for replacement of the OEM when replacing the RSB. I plan to buy these endlinks.

Some retailers offer a bundled discount when buying the SuperPro endlinks with a SuperPro RSB, which makes the SuperPro RSB product much cheaper as far as I am concerned, given that I plan to buy their endlinks regardless. SuperPro offers a 22mm solid adjustable RSB (one website tried to sell me the SuperPro 24mm RSB for my GTI, but that is for the Golf R, apparently).

And Brett from SuperPro is the one who gave me really good data! He even had guys at the warehouse weigh the 22mm RSB to find out that it is 7.8 lbs.

Every manufacturer should offer a chart like this, and weight of the product. But they don’t.

One may interpret this as showing the 22mm bar on the hard setting as having a spring rate of up to 600 kg/50 mm of displacement, or 672 lb/inch by my math.

034Motorsports offers a solid 25.4mm adjustable RSB that would seem like a really good match for me, but the customer representative was unable to provide any information on performance or weight (I found a weight online somewhere that put it at 8 lbs). I was given a discount code that provided $14 off of the $280 price for the RSB. This is not competitive with the bundle discount for SuperPro, so, since I lack any other metric, I’m going to pass on it.

The Neuspeed 25mm hollow, non-adjustable RSB weighs 5.4 lbs, per the manufacturer rep, and offers double the stiffness over the stock options supposedly. Using the SuperPro chart and conversion, that might mean a spring rate of 448 lb/inch.

The APR 25.4mm hollow, non-adjustable RSB weighs 12 lbs, per the manufacturer’s rep, and has a spring rate of 1,050 lbs/inch. This weight and spring rate makes me think the bar is solid, but their website claims that it is hollow. Ultimately I suspect that this would be too stiff for my preferences, since I daily drive my car besides autocrossing it.

The ST 25mm solid, non-adjustable RSB weighs 11.2 lbs, per the manufacturer’s rep. No performance information was offered.

H&R did not reply to my inquiries.

So, I’m going to get the SuperPro bundle of the 22mm adjustable, solid RSB with the SuperPro endlinks. Here is hoping that it helps in my autocross competition. Now to research Evo school to improve the nut behind the wheel . . .

Post-write up, my autocross rival offered to sell me a used SuperPro 22mm like I was just about to buy. Now I can’t decide how much used is worth to me versus new. I was so close to finally making a decision! Edit: After bargaining, I’m getting the used one for a great price. Now I need to order those end-links.

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Replies (8)

"TahoeSTi" (tahoesti)
12/22/2017 at 16:12, STARS: 0

Sway bars are band-aids and tuning devices.......but if you are in a class that won’t let you update your spring rates I guess it’s all you got.

"I have another burner, try to guess it!" (ihaveanotherburner)
12/22/2017 at 16:16, STARS: 1

Rear sway bars are important on FWD cars because they help eliminate understeer. Ideally the inner rear tire should lift mid corner in FWD car.

"arl" (arl1968)
12/22/2017 at 20:36, STARS: 1

Excellent, let us know how it handles after the upgrade

I’ve been looking at the front sway bar links from SuperPro to see if they helps quiet the occasional squeak from the front suspension. I’m lowered on driver gear springs, and 95 percent of the time they’re quiet. But in the cold over bumps they squeak a bit. Besides the links I’m looking at LCA’s with poly bushings, and a subframe deadest kit. Kind of overkill for a squeak that almost never happens, but I’m a sucker for a quiet car.

"LimitedTimeOnly @ opposite-lock.com" (limitedtimeonly)
12/23/2017 at 07:28, STARS: 1

My rival mentioned a squeak after putting in his sway bar with the stock endlinks, and thought that the upgraded endlinks would help. I plan to grease the bushings, although I’m not sure yet what grease would be most appropriate.

"TahoeSTi" (tahoesti)
12/23/2017 at 14:38, STARS: 0

You could do the same thing with Spring rates and dampeners, then use an adjustable rear roll bar to tune the car for each course. Lifting a tire is great on tight low-speed corners, not so hot on fast sweepers.

"Wrong Wheel Drive (41%)" (rduncan5678)
01/05/2018 at 13:05, STARS: 0

Hopefully you get one with adjustable end link holes, definitely a good thing to have. Not always the best to just have maximum stiffness. Although once you set it where you like, its unlikely you will ever need to change it after that. I’m thinking about a rear sway bar on my STi since it does tend to understeer a bit. With the front sway bar on my Miata set to full stiffness it does actually understeer also but only on hairpin type stuff on cold tires. Once the tires warm up it definitely oversteers still. So its a good balance there.

"LimitedTimeOnly @ opposite-lock.com" (limitedtimeonly)
01/05/2018 at 14:21, STARS: 1

Glad you’ve gotten the balance right on your Miata.

I did get the adjustable SuperPro RSB for my GTI, and will install it next weekend when things warm back up a bit. I expect to install it on the stiff setting, but I agree that it is good to have the option to decrease the stiffness. I have heard that in rainy autocross conditions it will be helpful to change the setting.

"Wrong Wheel Drive (41%)" (rduncan5678)
01/05/2018 at 17:08, STARS: 1

Yeah apparently the terrible alignment that ruined my tires also was making the car understeer more than it should. Uphill hairpins are understeer city though, it actually understeers more than the STi around those, but thats to be expected.

Curious to know if after install how much of a difference it makes. The Mk7 GTI I drove felt relatively balanced so I bet once you put in the RSB, it will be amazing.