I'd like to reduce my understeer, but i'm not ready to invest in anti-sway bars (if i did my research right) quite yet.

I want to start modding slowly and mildly, so i'll have to choose between

1) MS strut tower bar (front OR back only)

-or-

2) Eibach springs

Which of these are closer to reducing understeer? FYI I'm thinking about rims in the future, but they WILL be the same dimensions as stock. Coilovers are not an option either.

Thanks for your help.

 

I would go with anti sway bars. They are not that much money and help the handling off the car big time. I have the racing beat anti sway bars holds the corners better than before.

 

even just an alignment can reduce understeer. i dont' think MS tower bar do much other then have a support for the brake master cyl, since we already have a stock front bar.

so maybe springs, and then alignment. more - camber up front, less or no toe in the back.

 

Then you will have uneven tire wear

 

no. camber isn't the major tire wearing angle. toe is.
and our rear already has quite alot of negative camber. tire rotation will help too.

and of coz, it depends on how hard you drive the car. If you put too much neg. camber doesn't matter front or back, and never corner hard enough. you are just wasting the tires.

btw, tire pressure can also help with car's handling.

alignment is just something you have to try out. i work at a shop, and i did alignment for like over 20times, until i get the setting i like. I also go to the track, and check the temp. of the tires after lapping and see if i m using all the tires. And after my driving got better, i tune my alignment again....to the way that i like it. My tires wearing out fine.

And i m not say sway bar is bad, just that the guy say he is not ready for sway bar yet for some reasons.

 

I would also say go with the anti sway bars. I would suggest the progress bars. They are the some of the stiffest bars and the are adjustable so you can have the rear set stiffer which will help with the understeer issue. They are also some of the cheapest bars at around 260 dollars. Contact Charles R. Hill, he sells them and I believe he also has the best price for them.

 

Hmm so no on the front tower bar for now huh. I really like that brake master cyl support too. I guess that can wait. I'm hoping someone will chime in on the rear tower bar.

So enlighten me on antisway bars. I'm thinking MS for these too. But I prefer a little bit oversteer. Will these bars eliminate that too? Oh, this is also my daily driver so I'm hoping these bars won't make my car twitchy at highway speeds.

 

The first mod I did after my first track day was MS sways both front and rear as well as MS stut bars both front and rear. I can attest that the handling on the track is way different, I have pictures of the same corner at the same track before and after. You can see the reduction in body roll. I'd say if money is a concern go with the sways first, then shocks and springs, lastly strut bars. Good luck

 

The front tower bar does little for our car. The front of the car is already stiff and there is a bar supplied with the car.
As for the brake support, look into this. You don't have to pay Mazdaspeed big bucks to accomplish that.
Axialflow 2004+ Mazda RX-8 Master Cylinder Brace: Price: $70.00
http://www.axialflow.com/products.htm
The twitchy-ness is due to tramlining. The pavement your driving on has grooves worn into them and the tires are trying to follow those grooves. Or, it's an alignment issue.

 

I agree with most everyone here. If you want to start with mild upgrades and want to minimize understeer, I'd tell you to start with a rear sway bar.

 

I know you weren't thinking it right away, but the best would still be doing the sway bars(both front and rear).
Then probably follow that with the springs and shocks.
I like some others currently have the RB sways and springs(still on OEM shocks), but I really noticed a big difference.
I plan on doing coilovers pretty soon.

 

def sways, stiffer rear = oversteer, stiffer front = understeer. The progressize sways are cheap and adjustable (3 settings I believe for both front and rear.)

 

One of the issues with having giant sways to stock dampers is that sways have very little damping by themselves; they use the dampers on the springs (unless you have a F1 style three damper setup). The stock dampers are already kind of marginal; matching them to even bigger sways might not be as good of an idea as some think...

Also, putting on a Progress rear bar with no change in the front seems like a recipe for constant oversteer, not to mention so much rear bar will probably hamper your ability to put the power down coming out of corners.

 

Need to do both...most of the aftermarket rear bars are designed to be used in conjunction with a MATCHED front bar...

You will likely have a very tail happy car if you increase the rear bar by itself

 

thanks for all of the input. so i'm convinced that the rear of the car needs to be stiffer to reduce understeer (hence my lingering curiosity about a rear strut bar) and that sway bars are the most significant way to go.

i'm no habitual track driver, but i do drive spiritedly. however i don't see myself purchasing coilovers, multiple-setting sway bars, or anything that requires dabbling. i can't imagine buying only a rear sway set either. do all sways have multiple settings, or are there reputable ones out there that i can just drop right in and forget about?

 

the whole car is plenty stiff..

what tires and tire pressures are you running? the stock car is pretty neutral..

beers

 

if you will only go with either those two!
then take the springs, the strut bars dont really help much IMO!

 

you might try adding 2-4lb pressure to the front tires to see if that helps front end traction

if your pressures are already raised well above 35lb, drop 2-4lb from the front, because you may not be using enough shoulder section of your tires if the pressure is too high

 

Alignment is the first step - it can change driveability in numerous ways!

If you do not think you are up to purchasing anything with adjustability it will be hard for you to tune your car to be precisely as you want.

Like swoope said, the car in stock form is very neutral, shouldn't plow too bad. Really, suspension tuning is not too difficult, it really seems to be trial and error until you get a read of how the product feels/adjusts.

Perhaps explore adjustable dampers such as koni yellows. Firming up the rear and loosening up the front may have the effect you are looking for...