AJ312

So i have staggered wheels on my 8 9.5 in the rear and 8.5 on the front and from both experience and what i have read on here the car understeers when i try to take turns too aggressively because of the balance being thrown off from the staggered wheels. I have been looking into sway bars(have my mind kinda set on RacingBeat) and have read that if they are too stiff in the front then it will cause the car to oversteer.

Now my question is if i get stiffer sway bars put on the front of my car(currently on have stock ones) do you think it will balance the understeer i get from the staggered wheels?? To me it sounds logical but any info would be greatly appreciated.

stinksause

iTrader: (5)

This is definitely your problem ... my suggestion? Buy 9.5 inch wheels for the front

Try disconnecting front sway bar before you spend money .... you will lose road feel tho

stiff = less grip
loose = more grip

However, you are trying to correct a problem with your tire width by using your sway bars (wtf are you doing) ... go for even width all around ...

go for the same size all around instead of trying to work around it

JCrane82

iTrader: (3)

Things that effect oversteer/understeer ratio:

-front/rear wheel widths/grip
-front/rear tire pressures
-front/rear roll stiffness (set by anti-roll bars)
-front/rear spring stiffness (set by spring rate of springs)
-front/rear camber settings (more camber in rear increase understeer, more camber in front in creases oversteer)
-front/rear toe settings

You also stated increasing the front roll stiffness as increasing oversteer. This is backwards. The axle with the most traction will be the last to slid. Increased front roll stiffness will provide less traction compared to rear, therefore understeer.

Highway8

iTrader: (11)

The 2 replys both were right in saying that a stiffer front sway bar will increase understeer but it can go the other way IF the car is getting excessive body roll and bottoming the front suspension or causing the tires to roll over on their sides. Both will cause understeer. Without seeing and feeling what is really happening and when, its hard to really know what needs to be changed.

8.5 front wheel width, and 9.5 rear, but what tire sizes? Getting a square setup is better but you can make a staggard set up work just fine. To start, you will likely need to increase front negative camber and decrease rear.

AJ312

i am getting an excessive amount of body roll, hence the intersts in sway bars. i am sitting on the stock shocks and tein s tech lowering springs, plan on getting koni yellows this summer. my rear tires are p245/40/r18 and the fronts are p225/45/r18.

JCrane82

iTrader: (3)

The short answer to your original question is: Yes.....you can adjust the above mentioned settings to increase your oversteer. What you need to understand though, is that this will be a band-aid and you are not fixing the problem. If you are serious about setting up a great handling RX-8, then I suggest you investigate a square set up. There are plenty of people on this forum that are willing to buy staggered setups because they don't care about handling. I strongly suggest a square setup if you want to do it right...

AJ312

Thanks for the info and yes i also would have preferred a square setup but the wheels were already on the car when i bought it and at the time i wasnt so worried about it untill now when i have become more serious into building up the 8.

stinksause

iTrader: (5)

^this

JCrane82

iTrader: (3)

My suggestion is to list them up for sale on here, you may get some buyers. Plus who doesn't like getting a new set of wheels/tires? This also lets you choose the perfect wheel/tire package suited to your needs.

AJ312

True but the only problem i have is that if i sell, i have no other wheels for the front. i mean i like the wheels that i have on my car now so if i could find someone with the size i need i would just straight up trade but doubt that could happen.

but back to the original question, as far as sway bars are concerned, which would work best as of right now, stiffer or softer in the front. stiffer or softer in the back?

JCrane82

iTrader: (3)

I was implying you could buy your new set of wheels/tires, then list your old set on here. You could even list your current set on here before picking out your new set. That would give you an idea as to what your current set is worth and how much is needed to step up to a new set.

Front/rear anti roll bars would work, just make sure they are adjustable. Tanabe, Progress Technology, and Whiteline are some of the companies that produce front and rear adjustable bars.

An alignment would also help. What are your current alignment numbers? I am guessing you are running up to 1 degree more negative camber in the rear than the front (stock specs)?

AJ312

This is correct.

Highway8

iTrader: (11)

I always run square on the track but when I did street drive my car I ran staggard tires, it still handled fine, but thats because it was set up for a little oversteer on the track.

No matter what you do with the wheels/tires, you will still have a poor Strut/Spring setup. Stock struts with Tein Springs will not yield a good handling car. If I remember correctly, they drop the front a lot and the rear a little. The point was to get an even wheel well gap, but it is too low in the front and you might be getting into the bump stops, or at the very minimum your running out of suspension travel. Both will cause a huge decrease in grip and understeer.

The rx8 likes suspension travel and a near stock ride height. A slight drop is fine but anything more then .5" is usually doing more harm then good. You need to start with the basics, Tires, springs and struts are your top 3 components in the suspension. Assuming a proper alignment of course.

JCrane82

iTrader: (3)

What is correct? That you have 1 degree more negative camber in the rear compared to front?

If this is true, adjusting the rear to -1.5 degrees (or whatever the minimum possible) will help. Currently you have larger rear tires as well as a flatter contact patch (under compression in a corner) in the rear.

What is it are you really looking for in a car? I only say this to make you step back and think forward to what your end goal is. Far too often people chase the symptom without fixing the issue or seeing the big picture. Spending $300 on anti-roll bars now may not fit into your "perfect" set-up. Find your perfect set-up and work towards that.

Also.....there is nothing wrong with body roll. The RX-8 has a very nice camber curve with suspension travel. Stiffer is not always better.

AJ312

1 degree more negative in the front and what im looking to get in the end goal as far as suspension would be to eliminate as much body roll as possible and no understeer/oversteer. now i know i will eventually have to get squared tires for that but what i am thinking is i could try to find parts that would be adjusting, that way i could use them now and once i get squared away with the wheel situation i could adjust them then as well.

alnielsen

iTrader: (4)

Agency Power and Whiteline sway bars are adjustable.

JCrane82

iTrader: (3)

Why is your goal to minimize body roll? Do you associate minimizing body roll with improving the handling?

If you were to ask me the same question, my answer would be, "to build a car that is enjoyable to drive at the limit and to improve my times as much as possible".

JCrane82

iTrader: (3)

Yep, I forgot to list Agency Power as another adjustable anti roll bar option.

List includes:

Tanabe
Progress Technology
Whiteline
Agency Power

Did I miss any?

alnielsen

iTrader: (4)

I have the AP sway bar. It and WL were the first ones available.

I believe there is one available through Mazdaspeed Competition dept. It will cost you your first born.

AJ312

Sounds good, ill take your answer.lol but yes that is what i was trying to get at, just went he wrong way with wording it. very wrong way.ha

JCrane82

iTrader: (3)

I just want to reiterate again that stiffer is not always better (aka...faster). In order to understand things, I always find it easier to imagine the extremes. Imagine that you have a very rigid, stiff suspension. Now take a corner hard.....what happens? You will skid out (especially when you hit bumps) since you are loading the tires quickly.

You have to think of this as a system. The parts of the system are the tires, wheels, springs, anti-roll bars, alignment, etc... This is why I am trying to get you to take a step back and figure out what kind of system you want. I am not saying that some adjustable anti-sway bars will hurt anything, but they may not be needed based on the kind of system you want to build. Anti-sway bars are, in a sense, a band-aid in themselves. They provide roll stiffness without increase spring stiffness. Too much bar and you will start lifting inside wheels. This usually happens when your anti-sway bars account for more than 30% of your roll stiffness.

The nice thing about stiffer bars is that it improves roll stiffness without increasing spring stiffness (ride does not suffer). This makes bars a great option for those who daily drive or need a compliant ride. If you are a serious racer and don't care about ride compliance, I would suggest some coilovers instead of bars.

Question of the day is: What is your budget and what are your design requirements?

AJ312

right now i am just looking into increasing the handling a bit better right now. After i get another car as a dd i would go in the direction of a setup for drifting. so im looking ofr all these changes to happen over night, it will take time. with that being said, as far as my budget, i dont have one set seeing as i am not looking to buy all the suspension parts needed at one time. just add things as i go i guess.

Spin9k

Given what you say, it's really a no brainer to get *adjustable* sway bars front and rear as have been mentioned. As you want, you can adjust now for what you have and later for what you get. There is no downside to adjustable bars even on an otherwise stock suspension and they are not expensive. In your case, however you have a bastard suspension setup (oem shocks-shortened coils) which is the worst of combinations as oem shocks do not handle the limited spring travel well at all and extreme understeer (suspension travel is over) can easily result under sharp cornering loads.

One other take away that may be nice to know is that (anti-sway bar) use on street car and use on track car should be temepered by the effect they have on overall dynamics. Example, on street you really don't want terribly stiff bar anywhere front or back. Why? You couple both sides of the car together with stiff bars and loose some of the 'independence' of the independent suspension, IOW your overall ride quality will suffer, so keep it softer.

Alternatively, on track, ride quality is of no real importance, and at extreme suspension stresses a stiff roll bar setting (vs street setting) will help keep the suspension/car in a correct posture to perform best under extreme transitions conditions. That being said, if you start to enjoy tracking, a good set of coilovers will **correctly** allow some lowering, stiffen the overall suspension, and assist in reducing lean so that anti-roll bars are the 2nd, not 1st, line of prevention.

Balance in all suspension parts, not using just one component to much to fix any condition, and taking the time to find the **right** balance thru trial and error are most important. Good luck!

AJ312

Thanks for the info. yes i know the spring/stock shock combo is crap.lol i was thinking about coils but right now they are out of my budget, hence why i was considering getting koni yellows. what is your take on going that route instead of coils? for now of course...

Spin9k

^ as far as koni-yellows, I'm not sure, some other w/experience w/them should chime in, sorry.