[regtor]

thanks kova and thanks to the S40 crowd for allowing the C70 digression. I definitely agree with you on the benefits of the front strut brace on the C70 (newer US market C70s don't have the OEM brace but I put one in -- should be standard).

 

[kova]

I hate to say Kova but this is one of the few times when your C70 will behave very differently than an S40.
The weight and its distribution will have a bit of an impact on sway bar between the two. I'm not saying you're not implying that in your comments but the other guys should understand that.
You can't use the C70 to properly assess sway bar effects on an S40 unfortunately...
All this said the front traction side theory is true especially for an FWD.

Actually I think it would be good to compare sway bar with FWD vs. AWD.
Being a FWD I know I don't need to think much about the front sway bar, just as you described. But I have no idea what the deal is with AWD cars and sway bars effects.

I'm not implying my C70 behaves the same way as V50 or S40, but it is truth in general that if you want to reduce understeer you first have to work to increase front traction: install front strut bar, lower front end, increase spring rate, increase rebound/compression, increase camber, use better front tires, play with the front tire pressure etc.

Installing stiffer rear sway bar is not primarily supposed to be your first action in reducing understeer although understeer is affected with stiffer rear sway bar.

 

[TG]

I'm not implying my C70 behaves the same way as V50 or S40, but it is truth in general that if you want to reduce understeer you first have to work to increase front traction: install front strut bar, lower front end, increase spring rate, increase rebound/compression, increase camber, use better front tires, play with the front tire pressure etc.

Installing stiffer rear sway bar is not primarily supposed to be your first action in reducing understeer although understeer is affected with stiffer rear sway bar.

I realize that and agree. . . I just wanted to make sure it wasn't miss interpreted simply because they two cars are very different in weight and there is always a part of experience in what we believe so what may be beneficial to one tyoe car might be too excessive to the other or the other way around.
I'm actually surprised some C70 did not come with front sway bar which I assume to be standard with these platforms

 

[kova]

I'm actually surprised some C70 did not come with front sway bar which I assume to be standard with these platforms

Front strut bar should be standard on any Volvo P1 cars as it really improves the front handling but I guess Volvo thought that drivers who need it would purchase it by themselves and those who don't drive that aggressively would feel safer with some more understeer. My dealer charged $170 with the install for it.

 

[TG]

Front strut bar should be standard on any Volvo P1 cars as it really improves the front handling but I guess Volvo thought that drivers who need it would purchase it by themselves and those who don't drive that aggressively would feel safer with some more understeer. My dealer charged $170 with the install for it.

That's just weird for the C70 which is a premium car but if they can charge extra why wouldn't they I guess . . . Considering the competition I'm still surprise they do that. If you know nothing about sway bar and test drove two convertible for their handling you might be turned off for what $170. That's just really silly for a +$40,000 car!
. . . Well I don't need to understand fully their motives

 

[kova]

That's just weird for the C70 which is a premium car but if they can charge extra why wouldn't they I guess . . . Considering the competition I'm still surprise they do that. If you know nothing about sway bar and test drove two convertible for their handling you might be turned off for what $170. That's just really silly for a +$40,000 car!
. . . Well I don't need to understand fully their motives

To conduct such test you would have to put max performance summer tires (like Michelin Pilot Super Sport), turn off DSTC to allow for some more sliding and drive really fast through curves with tires screaming and heads turning all the way. I believe their logic was that not too many people do that with cabrios and those who do anyhow do some more suspension tweaks like changing springs, shocks etc.

When I was buying my car the only real competition to C70 T5 was BMW series 3 cabrio and Volvo handled better when I drive tested them - although later I discovered that the dealer test car had the OEM front strut bar installed.

 

[pczeilon]

I suggest we do this... State what car you have, which sway bar(s) you are running & your take on the situation. I'll start:

2005 S40 FWD 2.4i 5 speed. Base model, no sunroof etc. Probably the lightest weight S40 of them all. Stock springs, Koni Sport shocks all around.
I have the standard "comfort" front bar paired with the factory "sport" (21mm vertical links) rear bar. I autocross in stock class on street tires. It's a year round daily driver through all weather conditions.

Quite happy with this combo. Very little tire spin exiting corners, almost neutral on a skid pad yet easy to step the rear out with a little pitch & trail brake. Slaloms well, won't bite you unless you do something stupid (lift). Very easy to step the rear out in rain or snow but not with "normal" driver inputs. Perfectly comfortable having my wife or son drive the car. No hidden surprises.

 

[MyNameIdeasWereTaken]

Quick digression to the C70 thing. Those cars pack a lot more weight near the back with the mechanics for the roof. I'd honestly be curious as to the under/over steer differences between the roof being up and the roof being down.

When you all say oversteer, do you mean back end sliding out from the front? I almost find that hard to believe in a modern Volvo... I can understand a neutral sideways slide, and understeer, but oversteer?

I'm going to have to look to see if there are any B pillar cross bars. Like said, ideally for a harness.

So what would be recommended for a FWD T5 sedan that's been lowered in GA where it has only seen 1" of snow once? Wanting to keep things relatively neutral to oversteer, a lot of fast cornering and mountainous roads for fun.

 

[kova]

Quick digression to the C70 thing. Those cars pack a lot more weight near the back with the mechanics for the roof. I'd honestly be curious as to the under/over steer differences between the roof being up and the roof being down.

Not that much of a difference one might expect. A little bit more stable with roof down, probably because the center of ravity has been lowered. I tested only up to 140 km/h as the wind makes the drive uncomfortable.

When you all say oversteer, do you mean back end sliding out from the front?

Yes, that's what I mean.

So what would be recommended for a FWD T5 sedan that's been lowered in GA where it has only seen 1" of snow once? Wanting to keep things relatively neutral to oversteer, a lot of fast cornering and mountainous roads for fun.

Most important are the tires. Get Michelin Pilot Super Sports or similar high performance summer tires. Get maximum width you can install without rubbing.

For a truly sport experience get a set of Bilstein B16 PSS9 coilovers (or KW V3) and have them adjusted by professional suspension shop. They can be adjusted in height and compression/rebound in 9 steps.
Alternatively, get a set of H&R or Eibach springs paired with Koni FSD or Bilstein B8/Koni Yellows shocks, depending which level of comfort/ handling you prefer.

Set your front toe to 0 deg, your rear toe to 0.3 deg. Your rear camber should be at least -2.2 deg for sporty ride.

Make sure you have front strut bar.

Get Powerflex or Whiteline lower control arm bushes.

Forget front and rear sway bar, stock units are fine.

 

[apav]

If you are referring to ride quality (bump, noise & sound isolation) then a sway bar will not help. In fact it will slightly degrade the ride. Again, in simple terms... Let's say you hit a pot hole with your right front wheel. No bar, the wheel moves up & down. Sway bar installed, some of that impact will now be transferred to the left front wheel causing it to rise into the wheel well also.

Yes I am looking for a more smooth, comfortable ride. I want try to minimize the shakiness of the road and the (pretty harsh in my car) impact of hitting a hole. I do love my S40, but I miss that comfort, luxury, or even sporty feel my old S60 had. I understand that the S40 is not the S60 and physics is physics, but I still want to improve the feel of my ride if I have options. So far I've heard bilsteins, new tires, and replacing other common worn out parts is my best bet. After all, this is a 7 year old vehicle and I have no idea what my dealer did besides the basics to tune it up before they sold it to me.

I was actually going to ask this in my thread when I finish the lighting, but I'm impatiently waiting for them to get here, so I just wanted to ask in the meantime

Oh and I don't mean to derail this thread. You can pm me instead if you'd like.

 

[pczeilon]

but I still want to improve the feel of my ride if I have options. So far I've heard bilsteins, new tires, and replacing other common worn out parts is my best bet. After all, this is a 7 year old vehicle and I have no idea what my dealer did besides the basics to tune it up before they sold it to me.

Good information. This is indeed the path you want to take. I'll assume you have somewhat high mileage.

Common Worn Parts: Lower control arms. Check the many threads with pics. You are looking for tearing of the large rear rubber bushing. Check for play in the sway bar links. Motor mounts. Again, check the many threads.

Shocks: Koni FSDs hands down. Replace front strut bearing & both front/rear mounts while you're there. Check the bump strops.

Tires: You're probably on 16" or 17" wheels. Don't go any bigger. Check Tire Rack & pick a tire from the "Grand Touring" or "High Performance" group (Summer or All-Season). Pay close attention to the reviews or tests & how they rate impact harshness & ride comfort.

 

[Jonxy]

your best starting point is to examine your sway bar bushings, lower control arm bushings, and all bushings in general. then start replacing anything worn or almost worn with something like Movotech swaybar links (the blue ones with polyurethane bushings) for lower control arms you can press polyurethane bushings into your factory lca's or have a shop press them for a small fee if you dont have access to a press. while examining everything, look at your rear swaybar, measure its thickness and see if you have the the thicker factory one (21.5mm i think it is?) if the busings holding the mounts for the swaybar are also worn, swap out the rubber ones for poly ones. At this point you need to decide how you want your car to react. do you want it very stiff and give less response before loosing grip? (this is how i setup cars when i used to race in scca and nasa) but makes it more difficult for bumpy roads .

 

[apav]

Good information. This is indeed the path you want to take. I'll assume you have somewhat high mileage.

Common Worn Parts: Lower control arms. Check the many threads with pics. You are looking for tearing of the large rear rubber bushing. Check for play in the sway bar links. Motor mounts. Again, check the many threads.

Shocks: Koni FSDs hands down. Replace front strut bearing & both front/rear mounts while you're there. Check the bump strops.

Tires: You're probably on 16" or 17" wheels. Don't go any bigger. Check Tire Rack & pick a tire from the "Grand Touring" or "High Performance" group (Summer or All-Season). Pay close attention to the reviews or tests & how they rate impact harshness & ride comfort.

It was 85,700 when I got it. I think someone put on new Michelin tires before I bought it, but I'm not sure when or how they're holding up. I am taking my car today to a trusted mechanic so he can raise it up and take a look at it. I am very new to this stuff, I'm only able to handle the little things so maybe I'll ask him to specifically look out for worn suspension parts and specifically the ones you said.

I want to feel more in control (because right now it just feels like sloppily driving) but at the same time have a more comfortable, smooth ride. Whether that means feeling stiffer, idk. But driving on the highway, the amount of shock I get from hitting holes or going over bumpy road is too much! So something smooth, something more in control.

Sent from my Nexus 7 using Tapatalk 2

 

[pczeilon]

look at your rear swaybar, measure its thickness and see if you have the the thicker factory one (21.5mm i think it is?)

Thanks for jogging my memory. I checked my notes & the largest "sport" rear bar is indeed 21.5mm (only .5mm smaller than the IPD). I've edited my previous posts to correct the info & add the part #. Please note this is a vertical link bar, you need the heim joint style endlinks to use it. All bushings for the attachment bracket to subframe now supersede to the number below. Links (if you need them) are listed below as well.

Part Number 30683231
Part Name Rear suspension Stabilizer bar and components Stabilizer bar
MSRP $179.74
Online Price $133.32

Part Number 30714683
Part Name BUSHING
MSRP $20.09
Online Price $12.94

Part Number 31329966
Part Name LINK
MSRP $59.86
Online Price $38.55

 

[MyNameIdeasWereTaken]

I want to feel more in control (because right now it just feels like sloppily driving) but at the same time have a more comfortable, smooth ride. Whether that means feeling stiffer, idk. But driving on the highway, the amount of shock I get from hitting holes or going over bumpy road is too much! So something smooth, something more in control.

Avoid the bumps and lower it first. That'll make the biggest difference, everything else is just fine tweaking to your personal liking.

 

[apav]

Avoid the bumps and lower it first. That'll make the biggest difference, everything else is just fine tweaking to your personal liking.

Lowering my car? I thought the opposite, that raising it helped (but what do I know). This car is already super low, and because of the weather here in the winter and the occasional rain I'm not so sure that's a good idea.

Hard to avoid holes, our roads need serious work but the state neglects the highways. I always see them working on smaller busy roads or on/off ramps. They put potholes in the middle of the freaking highway and usually I can't change lanes in time. If there are no holes, they're just super shaky.

Side comment: The area of road I hate the most isn't even bumpy. It's the exit off the highway for my house coming from the west. You come over an slight hill, for your car to decline and then the exit itself is on a slight incline. No matter how slow I approach it, every time I get off on that exit my car feels like it's bouncing. 2 big dips so low I feel like the bottom of my car is missing the road by a hair, and when the car raises back up it reminds me of a roller coaster lol. I've gotten use to it, but man was that feeling scary. Scared for my car, I enjoy that sort of stuff

 

[jschinito]

kova, i'm generally with you on things... and, in fact, i am following your recommendations on getting powerflex lca bushings (ordered just last night in fact).

but at least on my 2008 C70, the elevate rear sway bar was a fantastic improvement in body roll. i had added the oem front strut tower bar months prior to the rear sway bar upgrade and noticed only mild improvement in the car's steering precision but not much else. but with the rear sway, there was major improvement in body roll on high speed sweepers. i could hold lines much more easily because of the sway bar. in terms of money spent, the elevate rear sway bar has provided much more value (side note: biggest bang for buck is the elevate torque mount).

i think the additional weight of the C70 over C30/S40s really make a beefier sway much more significant. the car just rolls and bounces way too much to offer crisp handling. cruising straight over rough surfaces is great of course, but if you try to throw it through the twisties, it's very vague and bouncy at the limit. i'm looking forward to lowering springs and koni fsds to improve that.

i believe the face lifted C70s got beefier rear sways (21mm vs 19-20mm oem non-face lifted) so an IPD (22mm) would be pretty much a waste. but i think most any stock p1 volvo will have noticeably reduced body roll on high speed turns with the elevate (25mm) or racing beat (27mm).

re: too much oversteer with the elevate rear bar, that has not been my experience at all. granted i also just had new continental dws tires put on about 1 month before the elevate bar, but i have no sense of the rear end coming around. definitely no scary moments yet.

and if i ever did, i wouldn't give up the improved body roll and would instead just run the rear tires 2-3 psi less than the front.

 

[MyNameIdeasWereTaken]

Lowering my car? I thought the opposite, that raising it helped (but what do I know). This car is already super low, and because of the weather here in the winter and the occasional rain I'm not so sure that's a good idea.

You're at stock ride height, correct? aka the monster car height The size of the wheel well gap is immense, even with springs there's still more gap than I'd like...

Lowering the car places the center of gravity lower, it also stiffens up the corners, so you'll be able to take turns faster than before. Taking them faster with everything else stock will result in you experiencing more understeer, so that's when you'll want to start stiffening everything else up. But lowering your center of gravity is one of the better starts.

I understand about the roads though. We have some pretty bad potholes here too, I've just memorized where all of them are. Thankfully GA's pretty good about filling them.

You don't have to lower your car, it is one of the more costly mods. Start with a strut brace, you most likely won't change a strut brace based on other mod conditions.
Many people will say that strut braces are just placebo effect, daily driving this is true. But really throw your car around and you'll notice an improvement. Plus it looks cool

Based on the replies in this thread, I would then say get a rear sway bar. If you decide to lower, you may find you want a different thickness sway bar down the road.

 

[kova]

kova, i'm generally with you on things... and, in fact, i am following your recommendations on getting powerflex lca bushings (ordered just last night in fact).

but at least on my 2008 C70, the elevate rear sway bar was a fantastic improvement in body roll. i had added the oem front strut tower bar months prior to the rear sway bar upgrade and noticed only mild improvement in the car's steering precision but not much else. but with the rear sway, there was major improvement in body roll on high speed sweepers. i could hold lines much more easily because of the sway bar. in terms of money spent, the elevate rear sway bar has provided much more value (side note: biggest bang for buck is the elevate torque mount).

i think the additional weight of the C70 over C30/S40s really make a beefier sway much more significant. the car just rolls and bounces way too much to offer crisp handling. cruising straight over rough surfaces is great of course, but if you try to throw it through the twisties, it's very vague and bouncy at the limit. i'm looking forward to lowering springs and koni fsds to improve that.

i believe the face lifted C70s got beefier rear sways (21mm vs 19-20mm oem non-face lifted) so an IPD (22mm) would be pretty much a waste. but i think most any stock p1 volvo will have noticeably reduced body roll on high speed turns with the elevate (25mm) or racing beat (27mm).

re: too much oversteer with the elevate rear bar, that has not been my experience at all. granted i also just had new continental dws tires put on about 1 month before the elevate bar, but i have no sense of the rear end coming around. definitely no scary moments yet.

and if i ever did, i wouldn't give up the improved body roll and would instead just run the rear tires 2-3 psi less than the front.

Interesting..

Let's put body roll aside, as there is anyhow more body roll coming from front side then from the rear. Not to mention that it is hard to measure that.

When you are entering relatively sharp turn at app. 90-100 km/h in 2nd gear with DSTC off which side starts to slip firs? Btw, I have Quaife diff which certainly helps to increase front traction in curves, so probably that is the reason why my car is less prone to understeer.

P.S. my stock rear sway bar is 21 mm

 

[jschinito]

Interesting..

Let's put body roll aside, as there is anyhow more body roll coming from front side then from the rear. Not to mention that it is hard to measure that.

When you are entering relatively sharp turn at app. 90-100 km/h in 2nd gear with DSTC off which side starts to slip firs? Btw, I have Quaife diff which certainly helps to increase front traction in curves, so probably that is the reason why my car is less prone to understeer.

P.S. my stock rear sway bar is 21 mm

haven't tried driving with dtsc off to be honest. maybe on a rainy day i'll find an empty parking lot and try it ;-)