How much difference does sway bars really make?

[redbird01]

I'm a new owner of a 2025 G70 3.3T AWD (Sport Advanced). New to the car mods, a steep learning curve. Recently, I have been thinking really hard about upgrading my sway bars. Before I take the leap, could you guys help out with several lingering questions I have?

1) I have read a lot of positive feedback on a sway bar upgrade from G70 (mostly pre-facelift models) and Stinger owners. Does anyone have a similar model as mine (post- facelift with non adaptive dampers) and share your post-install experiences? I ask because there might be subtle differences between a G70 and a Stinger, and across different G70 model years, and therefore all the positive feedback I read may not be fully applicable to the model I have. For instance, the online photos shared by Stinger owners, who put their OEM and Eibach's bars side by side, seem to show that Stinger's OEM bar is significantly smaller. However, when I looked at my G70's front bar by peeking down the hood, it visually appears to be of similar size as Eibach's. So, I'm assuming the Eibach bar will still make a difference on a G70, just to a lesser degree than it would on a Stinger?

2) I live in midwest with a decent amount of rough roads, seasonal rain and snow. It's my daily drive, do not plan on tracking it. I was planning to choose "soft" for front and "stiff" for rear, as recommended by Volfy and others here. The Eibach instruction says do not choose the stiff setting if the road is "wet and slick". Does that mean the stiff setting in the rear may be a concern for the midwest winter? I wanted to experience a meaningful difference but at the same time be safe in spiritedly daily driving.

3) How often should the bushing be re-greased? The front appears to be easy, but how difficult is it to access the zerk fitting in the rear bar - did you have to remove the wheels? Did anyone replace the Eibach zerk fitting with a 90-degree fitting to make it easier to connect to a grease gun? If so, would you happen to know the size of the zerk fitting thread, 1/4"??

As a side note: I found it surprising that a few local indy shops did not want to do the installation, claiming "insurance/liability" concerns...??

Thanks in advance for any insights/confirmation.

 

[Volfy]

I was planning to choose "soft" for front and "stiff" for rear, as recommended by Volfy...

This is why you shouldn't listen to advice-spouting internet yahoos (myself included). I never "recommended" that.

Seriously, sometimes I regret posting my own suspension setup on public forums. Regardless of how much caveat and caution I throw up front, folks invariably just interpret it in whatever ways that fit their narrative. That particular anti-roll bar setup was for one of my Stingers, at one particular time, with one particular set of mods, for one particular suspension tuning. Is that what I run now on my 2.5T, which is suspension-tuned quite differently? No.

Unlike engine power boosting mods, suspension tuning is not an absolutely. What works best depends on your particular car, how you set up your suspension, how/where you drive your car, and under what conditions. Just because one setup works well for somebody else somewhere else doesn't mean it is best for everybody everywhere.

Changing your aftermarket anti-roll bar settings essentially changes the relative front/rear roll stiffness. That will alter your car's under/oversteer tendencies... hopefully for the better, but could be to your detriment if done willy nilly. To decide your your aftermarket anti-roll bar setting, you really need to establish a baseline. That means knowing exactly how your car handles- typically starting with suspension bone stock and tire pressures set to what you normally run:

1. At corner tip-in, with sharp steering wheel input, with front end properly weighted by trail braking
2. At steady state mid-turn, near the limits of tire grip (preferably done with a long constant radius sweeping turn)

And you need to do this with the stability control turned OFF. This prevents the electronic nannies from coloring your car's cornering attitude. Can you do this safely on public roads? Most of the time, no. Under some conditions and circumstances, maybe. However, it is really best done in a controlled close-circuit environment like at your local AutoX.

Tweaking your suspension without knowing this... that is just throwing the dice and hoping for the best. Most anti-roll bars mfrs design them to increase roll stiffness front/rear roughly equally - at standard settings - so as to retain similar cornering attitude as with stock anti-roll bars. This is where you should always start after a fresh install. I do the same, again to establish another baseline of the car's cornering attitude with the new anti-roll bars. If you are unable or unwilling to establish a baseline, the safest bet is to set the aftermarket anti-roll bars to the same setting F/R.

 

[blnewto]

Great reply @Volfy so informative and helpful as always!
FWIW the G70 pre & post facelift is the same under the skin so you can use any reviews/impressions for the pre facelift as you would for the newest design. I have a 21 RWD 3.3 w/ adaptive dampers but that shouldn't matter much regarding the overall sway bar upgrade. Yours is AWD though so that may make a bit of difference, but IMO it's an upgrade that has a huge upside vs. minimal concerns. If you have F&R set to soft (which is what mine are set to) you'll notice much more direct control when pushing hard into corners, it's dramatic and needed for this type of driving. I haven't really noticed any firmness in the suspension aspect when hitting ruts in the road or nailing a pothole, mainly just a huge improvement in lateral control.

I doubt I'll ever go firm in front or rear unless I have a track day, there's a track nearby where I'll be moving next month (Arroyo Seco, in New Mexico) so I may give it a go late this year. Even in soft F&R the amount of anti-roll is significant and IMO, perfect for spirited daily driving or just driving leisurely, it's ALL been good.

Install is simple if you have certain tools to get that rear drivers' side nut loose and tightened. Here's my install thread that should help with that.

Thread 'Whiteline Front & Rear Swaybar install'

Aug 19, 2024

Just installed F&R Whiteline sway bars today on our 21 G70, only driven it a bit but damn, what a difference! Car feels so solid and planted now and although I have it set on soft for both bars it's such a dramatic change. Took about 2.5 hrs to change both out, that one rear nut by the fuel lines was tight but not bad at all w/ this setup, a 14mm flex ratchet combo wrench , another combo wrench to provide extra torque (ghetto style), and a flex regular ratchet for the other 3 nuts/bolts . I removed the two fender liner cap nuts and the nut holding the fuel lines, allowed a bit more room...

• blnewto
• Replies: 0
• Forum: Suspension, Brakes, Wheels, Tires Discussion

• 

Been very happy w/ the Whiteline set, these are solid bars not just oversized tubes which I like. The Whitelines don't have zerk fittings in the bushing caps but in my link I used thicker yellow teflon gas-line tape coated w/ anti-seize. Bar and bushings have remained quiet for the 8 months I've had them. I think @Volfy used some tap in zerks on some caps so might ask him about that.

IMO it's the best $400 you can spend on an otherwise stock G70, at least in RWD form

 

[Volfy]

Yes, for those aftermarket anti-roll bars that don't come with greaseable bushings and brackets, you can always buy generic ones that convert them to greaseable. I did exactly that with Whiteline bars on our 2 Stingers and a G70. Since they are 24mm and 18mm, I just looked up those specs and found these kits on Amazon:

https://www.amazon.com/dp/B000CN5FUU
https://www.amazon.com/dp/B0038761HI

Both companies make good quality bushing kits. For different diameter bars, just go to their website and search up the correct kits for your bars.

Of course, you could just get anti-roll bars that already come with greaseable bushings. I like having choices and don't mind shopping around for generic bushings I can find replacement bushings readily available.

BTW, regardless of whether the bars come with greaseable provisions, all polyurethane bushings need some form of lube. Otherwise, they will make noise sooner or later. Leave them dry for too long, and friction will wear into the bar and eventually cause loose fitting issues.

 

[redbird01]

Thanks all for sharing your thoughts.

I have had the Eibach sway bars installed by an indy shop. Set to to soft both F&R. The OEM bars are 22mm front, 16mm rear; Eibach bars are 25mm front, 19mm rear. The 3mm difference plus the poly bushings did make a significant different in how the car corners and drives in general. From my experience (this may be illusory), it also adds a bit of tautness to the ride over even small lateral movements (ex. broken pavements). Overall, the car just feels "tighter" and more planted. Very happy with the mod!

It's almost perfect, except I started to hear a minor soft knocking/clunking sound from the front driver side. It only happens over mild broken pavements, which causes small side to side movement. Ironically, there is no sound over big potholes or road gaps or driveway gutter. I took it back to the technician and we could not figure out why. The bushing nuts are tight, well-lubed, and no play. The nuts connecting OEM endlinks and the bar are tight. I even asked him to loosen and re-tighten endlinks at ride heights to avoid pre-loads, but that did not make the sound go away. The bar was tight with no play, when I rock it side to side or up and down. We did notice that the endlink nuts connect to the bar holes at a slanted angle. But given the bar shape and OEM endlink lenght, there was no way to connect them at a flush angle. Could that cause the noise? Do I need adjustable endlinks? Any thoughts?

 

[blnewto]

Thanks all for sharing your thoughts.

I have had the Eibach sway bars installed by an indy shop. Set to to soft both F&R. The OEM bars are 22mm front, 16mm rear; Eibach bars are 25mm front, 19mm rear. The 3mm difference plus the poly bushings did make a significant different in how the car corners and drives in general. From my experience (this may be illusory), it also adds a bit of tautness to the ride over even small lateral movements (ex. broken pavements). Overall, the car just feels "tighter" and more planted. Very happy with the mod!

It's almost perfect, except I started to hear a minor soft knocking/clunking sound from the front driver side. It only happens over mild broken pavements, which causes small side to side movement. Ironically, there is no sound over big potholes or road gaps or driveway gutter. I took it back to the technician and we could not figure out why. The bushing nuts are tight, well-lubed, and no play. The nuts connecting OEM endlinks and the bar are tight. I even asked him to loosen and re-tighten endlinks at ride heights to avoid pre-loads, but that did not make the sound go away. The bar was tight with no play, when I rock it side to side or up and down. We did notice that the endlink nuts connect to the bar holes at a slanted angle. But given the bar shape and OEM endlink lenght, there was no way to connect them at a flush angle. Could that cause the noise? Do I need adjustable endlinks? Any thoughts?

Are you lowered? If not, no need to go aftermarket on the end links. I've only heard that aftermarket links are beneficial is you're dropped deep (like coilovers). That small side to side movement is concerning, not sure what would be the culprit there, especially since you've gone over everything you've changed. Any other changes or something that may have caused an issue like nailing a pothole??

 

[redbird01]

@blnewto
It's not lowered - no other mods other than the sway bar. I want to clarify: by "the small side to side movement" I meant to say during minor side to side rocking of the car over broken pavement is when I hear the soft clunking. The car drives just fine. I can live with the trade-off of having an occasional "noise", given the improvement in the driving feel. I can't hear it with music on

 

[blnewto]

@blnewto
It's not lowered - no other mods other than the sway bar. I want to clarify: by "the small side to side movement" I meant to say during minor side to side rocking of the car over broken pavement is when I hear the soft clunking. The car drives just fine. I can live with the trade-off of having an occasional "noise", given the improvement in the driving feel. I can't hear it with music on

Maybe it's an end link, they are a constant moving part that's greased and sealed but they can fail (or be starting to fail). Maybe @Volfy can chime in as he's the "suspension whisperer" around these parts

 

[Volfy]

Without being there in person and listening to it from the driver's seat, no way to tell what that noise might be - whether it's "normal" with aftermarket anti-rollbars, or something not right with the install. At the most fundamental level, adding stiffer anti-rollbars and swapping out OEM rubber bushing for aftermarket polyurethane ones will for sure introduce more NVH into the chassis. Whether that is what you are noticing or not, I wouldn't know. I myself am so used to the substantial stiffer suspension, particularly with coilovers, it doesn't bother me... much. Others used to plush stock suspension might consider it bone-jarring.

It's all relative.

Do I need adjustable endlinks? Any thoughts?

That is a hard no. We've got 3 Stingers/G70 suspensions more modified than yours. Zero issues with OEM endlinks. Those aftermarket adjustables are meant for racing applications to corner balance the chassis. If that's what you're doing with your G70, knock yourself out. However, on a street car, that is rather pointless and practically more troubles than they are worth. Peruse through what folks that installed them have posted about their clunking noise issues... might make you feel better about your own car.

 

[redbird01]

@Volfy Appreciate your insights.

Yes, reading others’ clunking reports will make me feel better I also like stiffer suspension. The suspension on my G70 (non-adaptive) is too soft for my taste. Funny to say this - even my previous Lexus IS 350F had tighter suspension (in Sports mode). The IS also had a better steering feel than the G70, in the sense of I could feel the road textures more. I wondered if it’s primarily because of the suspension type? IS uses double wishbone, rather than multi-link. Or do you think it’s more about damper tuning?

The sway bar definitely “saved” the car. With that minor mod, the car feels as if the damping rate is higher and suspension a tad stiffer. And with reduced body roll, the car now feels more like a “sports sedan”.

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[Volfy]

Yeah, if Lexus and Alfa Romeo can do double wishbone on their IS and Giulia, so can Genesis on the G70. They could have kept G80's front DW suspension, but they cheaped out to MacPherson. Granted, front struts can be made to handle with the best. Just ask Porsche and BMW. However, that takes lots of R&D budget to tune to perfection. That, Genesis cannot afford to spend on the G70... or more like, not willing. In that case, double wishbone would've been much easier to get right.

That said, G70's front end isn't all that bad. The key is to keep lowering to a minimum, so the dynamic camber gain built into the front strut geometry is maintained. That, and getting rid of the boat anchor OEM wheels to lighten unsprung weight and reduce rotational inertia. This is especially helpful if you're keeping the stock shocks. Because of the heavy OEM 19's and low profile tires, tock G70/Stingers are rather under-damped, mainly to make ride reasonably comfortable. That combination of soft suspension and heavy wheels make for less road feel. Think wallowy '80s Buicks and Lincolns. I exaggerate, of course, but the effect is very much the same. To improve handling and road feel, stiffening the suspension and lightening unsprung mass is absolutely crucial.

 

[redbird01]

I thought about lowering the car (for that bit more of stiffness - don't care about aesthetic at all), but I was concerned about messing with the alignment. When I bought the car a few months ago, the first thing I did was to swap out the OEM michellin primacy touring tires with Bridegestone Potenza Sport, which in theory should be stiffer and add more natural weight to the steering. I had them on my previous Lexus IS and they made a huge difference in ride stiffness and steering & road feel. I was hoping to replicate that on the G70, but I was wrong! I could barely feel any difference, in road/steering feel, after the tire swap. Any difference between the tires must have been absorbed by the under-damped multi-link suspension and the rubber bushings. With its weight, G70 does wobble quite a bit over larger road undulations.

Again, the sway bar definitely improves the car. I now look for reasons to get out the house again!

You may be wondering why I purchased the car in the first place . All I can say is: lesson-learned, a 20-minute test drive on smooth roads is not enough to "know" the car. I know BMW M340i also uses MacPherson front and multi-link rear; this suspension setup seems to be gaining more popularity? Not sure whether it's any better-tuned than the G70. Never test-driven one. (I loved my E90 3-series, but it was not reliable.) I do know my next car will likely have a double-wishbone suspension, to error on the safe side.

Next, I should look into wheels. Any specific recommendations in terms of weight? The lighter the better...?

 

[Volfy]

I thought about lowering the car (for that bit more of stiffness - don't care about aesthetic at all), but I was concerned about messing with the alignment. When I bought the car a few months ago, the first thing I did was to swap out the OEM michellin primacy touring tires with Bridegestone Potenza Sport, which in theory should be stiffer and add more natural weight to the steering. I had them on my previous Lexus IS and they made a huge difference in ride stiffness and steering & road feel. I was hoping to replicate that on the G70, but I was wrong! I could barely feel any difference, in road/steering feel, after the tire swap. Any difference between the tires must have been absorbed by the under-damped multi-link suspension and the rubber bushings. With its weight, G70 does wobble quite a bit over larger road undulations.

Problem with the 19s is that the stock sizing is already so low profile, there isnt much room to tweak between Handling vs. Ride.

This is another reason I prefer 18s for this platform. I could run 235/45R18 grand touring tires on 8" or even 7.5" wheels and get superb ride quality. Or, I could go with 245/40R18 sport Summer tires on 8.5" for a much tighter feel and quick turn in. Or run 255/40R18 all seasons and get a good compromise in-between. And yes, we have tire/wheel sets in all 3.

Again, the sway bar definitely improves the car. I now look for reasons to get out the house again!

You may be wondering why I purchased the car in the first place . All I can say is: lesson-learned, a 20-minute test drive on smooth roads is not enough to "know" the car. I know BMW M340i also uses MacPherson front and multi-link rear; this suspension setup seems to be gaining more popularity? Not sure whether it's any better-tuned than the G70. Never test-driven one. (I loved my E90 3-series, but it was not reliable.) I do know my next car will likely have a double-wishbone suspension, to error on the safe side.

Realistically, there is no right or wrong to suspension design. Everything is a compromise. What matters is how much efforts a car mfr puts into tuning the platform. Fact that we here all chose the G70 is a perfect example. Its the overall package that we buy. If i were to focus entirely on suspension and handling, I would've bought the Giulia. But, I doubt i would be happier with that choice in the grand scheme of things.

Next, I should look into wheels. Any specific recommendations in terms of weight? The lighter the better...?

Low weight is a principal consideration, but a lot depends on your use cases, budget and personal preference, and lastly your locale.

If your chasing ultimate performance, then consider forged or racing-focused flow-formed wheels, which should come in at 18 lbs or less. Prepare to pay accordingly and treat those wheels as consumables, because long service life and surviving everyday rough street abuse isnt top of their design goal. I have a set of 18x8.5 Enkei RPF1's reserved for track use only. Barely over 18 lbs.

All our other sets are slightly heavier flow formed 18's that are a bit beefier for everyday grind over rough roads and broken pavement. Typically between 19 to 22 lbs.

As a reference, the stock staggered 19s that came with our G70 6MT weighed upwards of 35 lbs. That's up to 17 lbs less upsprung weight the suspension has to control... per corner.

Lighter wheels is one of those rare mods that actually has few to no compromises. It improves everything - ride, handling, pothole survival.

As much as you might like your thicker aftermarket anti-roll bars, they do add NVH and they reduces the independent nature of the suspension - for better and for worse.

 

[blnewto]

I've been very happy w/ my Superspeed 18s, I'm running 18x8.5 +35 on 255/40/18 front 18x9.5 +45 0n 285/35/18 rear. Wheels weigh 18/19 lbs, the stock OEM 19 sport wheels are 32/33lbs.
Here's the wheel I have, and got them on a black Friday deal for about $225 each

FlowForm RF03RR _ Matt Black

RRMotorsport Competition Design, Max Weight Reduction The Most Popular model from the FlowForm Series line-up. The mission for RF03RR is simple and yet complex - to provide one product that is extremely lightweight, offers great rigidity, and excellent big brake clearance while able to cover...

store.superspeedwheels.com

 

[redbird01]

Realistically, there is no right or wrong to suspension design. Everything is a compromise. What matters is how much efforts a car mfr puts into tuning the platform. Fact that we here all chose the G70 is a perfect example. Its the overall package that we buy. If i were to focus entirely on suspension and handling, I would've bought the Giulia. But, I doubt i would be happier with that choice in the grand scheme of things.

That is a great perspective of looking at it. The fact that one owner likes it in a certain way does not make it the best design. We're buying the overall package and G70 definitely delivers on that front. I like what Genesis is doing; I'm hoping they will release a G70 Magma.

Lighter wheels is one of those rare mods that actually has few to no compromises. It improves everything - ride, handling, pothole survival.

Now I regret getting the new Bridgestone tires too soon! haha. I would've gotten a 18" set.

I've been very happy w/ my Superspeed 18s

Looks fantastic! Since I now have two sets of 19" tires, I'm probably stuck on a 19" set of wheels. Wife will kill me if I have too many sets of tires taking up garage space haha.

I have a few newbie questions for you gents:
1) The OEM spec tires, I believe, are 19"x8.0" front, 19"x8.5" rear. From looking at Tirerack and a few sites, it looks like most don't make both sizes. Any brand/seller suggestions (other than custom-made)?
2) How to decide on offset? (For the best "fit", not for the look)
3) Does bore width matter? I think the 19" OEM wheel has 67.1mm. I read one report that wrong size bore may cause slight vibration at highway (ex. 85mph) speed.

 

[blnewto]

I have a few newbie questions for you gents:
1) The OEM spec tires, I believe, are 19"x8.0" front, 19"x8.5" rear. From looking at Tirerack and a few sites, it looks like most don't make both sizes. Any brand/seller suggestions (other than custom-made)?
2) How to decide on offset? (For the best "fit", not for the look)
3) Does bore width matter? I think the 19" OEM wheel has 67.1mm. I read one report that wrong size bore may cause slight vibration at highway (ex. 85mph) speed.

Even though my Summer set are 18s it would also apply to 19s. Best to keep front offset close to the factory +34, this will keep your steering geometry correct, a few mm off is no big deal so like a +32 thru +36 would be minimal affect there. I run 8.5 +35 front 9.5 +45 rear. If you can find a 19x8.5 +32 to+36 and a 9.5 +40 thru +45 you could still run your factory tire sizes although the tires would now be stretched, this can be beneficial (to a point) as it firms up the sidewalls. You could also run a square 8.5 +35 set and when your 225s wear out replace the fronts with the same 255s you have in the rear, then you could do a full 4 tire rotation extending tire life. Or you could run that 8.5/9.5 set, use your current rear 255s in front and go w/ new 285s in back. lots of options there.

Didn't see you mention if you're AWD, if so, you need to be much more selective in tire sizes when you deviate from stock.

 

[redbird01]

Didn't see you mention if you're AWD, if so, you need to be much more selective in tire sizes when you deviate from stock.

It is AWD, unfortunatley.

 

[SoCalG90]

If you wanted more adjustability, you can try the Mando ECS10 suspension tuning module.

​

 

[blnewto]

It is AWD, unfortunatley.

If you run staggered w/ a different size than the OEM 225/40 & 255/35 you just need to take the time and try various setups on a site like this

Rim & Tire Size Calculator. Custom Offsets

Tire Tech Information - The Wheel Fitment, Tyre Stretch, Rolling Radius and Speedometer Error Calculator. Play with specs, try different settings, compare results

www.wheel-size.com

Ideally you want to have your rolling diameter within 1% from the stock size, and 1% or less difference front to back. Not sure what exact difference would cause issues but 1% seems to be safe w/ AWD systems these days.

 

[redbird01]

Update on the sway bar rattling/clunking noise, for those interested:

The noise started to bother me, so I decided to crawl under the car again one day. For the nth time, I rocked the sway bar up and down, left and right, no play at all; everything was tight. Then it occurred to me that it might be the end links. The car only has 7,000 miles, and it didn't make the noise before the new bar, so I assumed the end links are unlikely to be the cause. I rocked the lower part of the driver-front end link connecting to the bar and felt there was a few mm of play (the passenger side had no play). I was pretty sure that was the culprit. Took the car to the mechanic to confirm and they found that there was indeed a bit of play in the ball joint/socket inside the rubber boot. They said they couldn't further tighten the nut connecting the bar and the end link, and said the end link had to be replaced. I did, and now the noise is totally gone - hopefully for good!

Honestly, I'm not sure whether the end link had a bit of play since day one (manufacturing tolerance), and it worked fine with the softer OEM sway bar. Or, the added stiffness of the Eibach bar caused more stress on the ball joint and damaged it. I feel the car started making the noise within 100 miles after I install the Eibach bar. Even with extra stiffness, the aftermarket bar shouldn't have caused premature wear so quickly?? Regardless, I'm hoping it's due to the manufacturing tolerance and that it's not a long-term maintenance item. So far, after 300 miles, everything is still good . Will report back if noise returns after putting on more miles...

For those with aftermarket bars, are your end links holding up after some mileage??