Swaybars Vs Strut bracing

[Scienceman]

I was chatting to a performance mechanic recently about installing a front strut brace (AutoExe from MPSGarage) for my 6MPS. He suggest I do front and rear sway bars instead. Can anybody explain the differences between these in terms of the handling outcome? I was only thinking of the front brace as Mazda incorporated rear bracing behind the rear seats so I dont know if a rear strut brace would bring any additional benefit. Any opions / thoughts welcome

[tricache]

Front strut braces on the Mazdas don't really do a great deal due to the struts being so close to the firewall anyway, there isn't much flex there.

Sway bars have always been a great improvement on the Mazdas and I think a rear sway bar will help out BIG time

[AlanC]

Got Whiteline sway bars fitted to my 2006 MPS3. What a difference it made, like driving on rails!
They are situated not far from you at Somersby.
Phone: 1300882355. Tell them Alan Chadwick recommended them to you, they will look after you.

[RedDjinn]

A sway bar will force the body and 'opposite wheel' onto the road so in turn more grip. helps keep the car flat when cornering! body bracing does a simular thing but u will be served better wil sway bars..

[A Pirate]

on my sp23 and 2010 Subaru Forester sway bars have made a HUGE difference both cars have greatly reduced body roll and turn well into corners but the strut bars do SFA and are more engine bay bling.

[kmh001]

Back in the 80's I used to design, manufacture and test my own sway bars because it was impossible to buy what I needed, and I picked up a thing or two along the way which I’m happy to share.

Body rigidity and sway bars are two different things. But one affects the other and they both have an effect on handling.

Lets deal with body rigidity first. Car bodies flex a lot more than you might imagine. The down side to flexing is that it causes the wheels to deviate from their intended position, which leads to sloppy handling. To give an extreme example, when I was racing Commodores, a good roll cage reduced lap times by about 3 seconds. That's a huge difference and it was all because the cage increased body rigidity.

It's important to recognise that the 6MPS does not have struts at the front; it has double unequal length wishbones, which provide superior vertical control of wheel geometry. And the reason there is bracing at the rear is because there is a driven rear axle adding stresses to a part of the structure that an ordinary 6 doesn't have. There is also other bracing in various parts of the structure of the 6MPS. From memory, Mazda claimed the extra bracing made the 6MPS structure 50% more rigid.

Anything you can do to increase body rigidity will usually improve handling, up to a point. Even though the 6MPS doesn't have struts, the brace will still reduce some flexing of the structure, but the improvement would not likely be as noticeable as it would be on a car like the 3MPS that has McPhearson struts at the front.

I’ve discussed this with Alan Horsley and he made the point that the MPS is already an extremely rigid structure and it’s unlikely that bracing would have a significant effect on handling for a road car. But if you’re into racing and tenths of a second matter to you, then bracing would be on the list

An important thing to understand about sway bars is that they must be matched front to rear or else handling will be degraded. All production cars are designed to under steer, because it's safer for the average motorist. Driving enthusiasts prefer a livelier chassis so they often install a slightly stiffer rear bar to make the chassis more neutral.

If you go beyond a simple tried and tested rear bar change you’re heading into uncharted territory and I would strongly advise against taking the advice of someone who hasn’t developed and tested a matching front and rear sway bar combination, and actually proven that the car has good balance and is not unsafe.

Bigger sway bars are not without compromise either. They connect the wheels at either side, so the suspension is no longer truly independent. When a wheel on one side is disturbed by a bump, the other side is also disturbed through the sway bar. The bigger the sway bar, the greater the disturbance.

What this means is that a car with big sway bars might handle less well on bumpy roads than an ordinary car. Big sway bars will also cause the inside wheels to lift more readily during cornering.

And when you start making changes of this magnitude, you need to match sway bar stiffness to spring rate, and on and on it goes.

I’m not trying to discourage you, just making you aware of the risks that need to be taken into account and managed so you don’t end up with a dangerous car. Chassis tuning is an art with no room for error and it's much better to let someone else take the risks developing a package that works properly.

By all means get a front brace, but I would suggest paying attention to wheel alignment before changing sway bars. I have fairly neutral balance now with just the right amount of under steer at the limit to make the car nice to drive, but I can also induce that insane AWD over steer thing that tucks the nose in and makes the car go so fast through a corner that it even scares me.

[Scienceman]

Thanks for the info and opinion kmh001. I assume going with something like Whiteline with both a front and rear combination will ensure balance and compabilility with other suspension/steering components and wont be too stiff so as to cause issues on anything other than smooth tarmac?

[kmh001]

Thanks for the info and opinion kmh001. I assume going with something like Whiteline with both a front and rear combination will ensure balance and compabilility with other suspension/steering components and wont be too stiff so as to cause issues on anything other than smooth tarmac?

I'm probably over reacting a bit because of my experience with a well known suspension company in Australia that has a long history of producing poorly engineered rubbish. But it needs to be said that just because a company makes front and rear sway bars, doesn't mean they work well together as a pair.

I'm certainly not knocking Whiteline, they make good stuff which I've used in the past and been happy with. Just make sure the front and rear bar combination in the particular sizes you're looking at has been tested and proven to provide good balance. You don't want to be an unwitting test driver.

[Scienceman]

You can never be too cautious with safety. I have seen that quite a few others have put Whiteline on and been happy with the result so they are out there. However the difference between an OK set up and well balanced might not be so easily noticed.

[blackbetty]

Scienceman, I have a corksport front strut brace and a whiteline rear sway bar on my car and I feel the car is now well balanced for how I like to drive, the rear end feels like it stays in tighter going through corners when I push the car. Im nowhere near technical enough to explain if it is under or over steer or what it is. The nose seemed more tight after the strut brace and after the rear sway bar install it feels more grounded going through corners fast. I do however as a result have creaking coming from my rear, guessing its the springs as I was told the end bits (not sure the name) connecting the sway bar to where all the springs and stuff fit in is now solid not spongy.

Sadly yes Im one of those dreaded MPS6 drivers that doesnt know alot mechanically about my car, sorry Im not able to explain things better

Whiteline dont make a front sway bar for the MPS6, Im not really sure if there is a reason for that or not, ther might be

[lup15]

excellant posts here. it also comes to the rule of diminishing returns. you can brace the shit out the the car, but the effects to handling will become minor. like kmh001 said, if its tenths of seconds your after, then bracing is all well and good. on a road car you have account for the uneven surface on the road, unlike a smooth tarmac of a track.

having said that, you can always improve the car from how it left the factory. improving handling is very much an art. everything needs to be working together in sync, otherwise you will get imbalance and the car will more difficult to handle than stock.

for me, I'll be tuning the handling of the car for the road and hence NVH is also a player and unfortunately it means a compromise needs to be made between handling and NVH

[RedDjinn]

just to add. after visiting mps garage today driving back up the Putty road in my neo. i felt very happy puting the car throught the corners at the limit where i felt a little more hesitant in the mps.. the answer is that the mps was less forgiving in the corners compared to the neo. neo allowed u to push knowing the car will forgive a lot more and u are traveling slower( but still having fun tyres howling etc but it was at a forgiving level) mps had to travel faster for the same thrill... dont get me wrong im not a wetie but i got a simular enjoyment from the neo. set the car where u know works for u and ur driving and enjoy it..

---------- Post added at 11:29 PM ---------- Previous post was at 11:26 PM ----------

dont do to much so the car bits u or takes the thrill out of normal driving

[lup15]

quite hard to compare a NEO to a MPS :P power wise obviously different, but funnily I think the MPS' suspension setup from factory is SHIT especially the shocks riding on the bump stops and the dampening rates aren't matched. I'm sure once you can get the setup right in the MPS you an go fast safely

[RedDjinn]

lol understand y u say that.. i have now gone H&R coilovers

[esp22]

do sway bars cayse car to ride rougher??

[RedDjinn]

yes they do, anything u do to stiffn up the suspension will make the ride more harder! with daily drivers we try to find a balance between ride and handling. everyone has a different appinion on how hard/soft it should be, thats why we moddify to get it to our liking..

[rd415]

yes they do, anything u do to stiffn up the suspension will make the ride more harder! with daily drivers we try to find a balance between ride and handling. everyone has a different appinion on how hard/soft it should be, thats why we moddify to get it to our liking..

No where near as much as coilovers

[MattMPS3]

I'm probably over reacting a bit because of my experience with a well known suspension company in Australia that has a long history of producing poorly engineered rubbish. But it needs to be said that just because a company makes front and rear sway bars, doesn't mean they work well together as a pair.

Are their products powder coated orange by any chance ?

[kmh001]

I was refering to another colour, but now you mention it, I did install a set of orange springs in a Cordia once and the car looked like it was dragging its arse along the road. So they came straight back out.

I guess the moral to the story is that having a workshop with a furnace and a supply of spring steel, is not the same as being a suspension tuner.