stash64

I am considering purchasing and installing ECS's sway bar and end links. I suspect this is probably the biggest bang for the buck to improve handling on the Q5 by reducing/eliminating understeer. I know this mod on front wheel drive vehicles can be a huge improvement, but I see very little discussion on sway bars when I search the Q5 forum. Could anyone who has done the mod chime in on the results and whether or not you think it was worthwhile?

urs6_ma

Tires will be be biggest factor in handling. What are you running now?

....and tire pressure alone could address your perceived handling issue. Drop two pounds in the front, raise two pounds in the rear...

Dan99

I have not done this mod on a Q5, but I can give you some guidence on how to approach it.

Tires are the single most important component in handling as they are the only point of contact between the car and the road. Tire pressure alone can shift handling from over to understeer and vice versa. Make sure you start with the tire pressures in your manual, and not those on the door jam, then you can make small adjustements (1 or 2 psi at a time) to tweak things farther. The goal is to find the correct inflation for the tires, not to over or under inflate them. Correct air pressure will exert equal force on the road across the entire tread surface, give you the most traction possible for your vehicle and tires, and result in even tire wear. If your tires wear more in the center of the tread they are over inflated; if they wear more on the outside edges of the tread, they are under inflated.

If your tire pressures are as dialed in as they can be and you still need to modify handling more, sway bars are a reasonable next step. Sway bars modify the relative force (aka traction) applied to each tire in turns and on uneven road surfaces, but probably not in the way you think, so you have to approach it with some understanding in order to get the change you want.

The independent suspensions in today's cars provide better traction than fixed axle designs because each wheel is able to independently adapt to changes in the road and the shifting weight of the car on uneven road surfaces, in corners, etc. Sway bars link the independent suspension components on opposite sides of the vehicle, making them less independent and resulting in a loss of traction at that end of the vehiicle.

Armed with this information, you can adjust the handling of your car. To do so, stiffen the sway bar in the rear to decrease understeer and/or increase oversteer. Likewise, if you put a stiffer sway bar in the front you will decrease oversteer and/or increase understeer. If you stiffen both ends, the outcome will be dependent on the relative difference front/rear. If they are equivalent, the vehicle will have the same under/oversteer, but will corner flatter with less overall traction in turns or on rough roads.

S4'ed

Read thru this long thread about the installation of larger swaybars on the nearly identical chassis of the Porsche Macan.
I recommend upgrading both the front and rear swaybars.

Start reading at post #66, onward. I am VAGfan on that forum. The spacer and shims for the rear bar center brackets are not needed to install the H&R bars on the Q5.

(1) Aftermarket Sway Bar Upgrades? | Page 12 | Porsche Macan Forum

stash64

I agree that a good high performance summer tire can make a big difference but it is also quite a bit more expensive than a new sway bar. And the cost will go up even higher over time as the summer tires will not last as long as most all season tires. I have Michelin Premier LTX all seasons on an 18" wheel that is at least a couple pounds lighter than my factory 18" wheels (which I use with snow tires). I may play around with tire pressure as suggested, just to get an idea of what a sway bar might do, but I think I would still rather achieve more neutral handling via the sway bar. It's just a little surprising that it is not a more common mod for the Q5, though I realize the benefit is likely greater on a typical fwd vehicle.

stash64

Thanks... I will check out the link. I really want to get some first hand opinions before trying a sway bar upgrade.

urs6_ma

@stash64 Those Michelin Premier LTX are a weak link in your handling journey. All season touring tires are not designed for *handling.*

Move up to a Conti DWS06+ or a Goodyear Exhilarate (which I'm running on my Cayenne) and you will see dramatically better handling.

My daughter's Q5 came with some nondescript midpack Conti all season touring tires, and when we replaced them with the DWS06, the car was transformed.

Tire pressures first.

Tires second.

Other stuff third

...otherwise you're wasting your money.

Scotty (UK)

I've just read all of the 12 page Macan thread. Most is about Audi compatibility with the Macan. Everyone is talking about thicknesses but I saw only one post that even mentioned the materials. Not all 3rd party bars are made from the same stuff.

stash64

I agree that the role of tires is very important. I have been running snow tires during the winter for some 25 years now. And if I wanted all out handling and grip, I would not have purchased a Q5 for my one and only vehicle. Rather than high performance grip/handling, I am really just interested in a bit sharper/quicker steering response at normal driving speeds. Just not sure if that would be the end result with a heavier sway bar on an AWD vehicle. My only similar experience was a mod I did on a FWD VW Passat more than 20 years ago. It had a torsion beam rear and there were a number of aftermarket "stiffeners" for the torsion beam. The one I installed worked wonders with no tire change and it was immediately apparent that the Passat had less understeer. I'm tending to think that the rear sway bar upgrade on the Q5 would not be as significant or more owners would be making the upgrade and talking about it.

stash64

Assuming all OEM and aftermarket bars are some form of steel, there will be little impact on the spring rate. There is very little difference in Modulus of Elasticity between different types of carbon and alloy steels, which means very little difference in bend resistance at a given cross section up to the point of yield.