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.