anobii

I've got a s5 t2 and i was just wondering if the improvements were worth it. I was loocking at suspension tecniques or eibach bars, maybe RB because there rear bar is thicker. Or would it be just as good to use the stock bars with poly bushing and the Heim joint endlinks that mazda trix sells? thanks,

-E

91_fc

im planning to get the ST sway bars soon. in my opinion, i think that they are a good investment if you are gonna be drifting or pushing your car hard on the track. if your just using it as a daily driver or dont care much about precise handling then the stock ones should be suitable.

CarmonColvin

Usually sway bars are used to balance a car out. They actually decrease grip at the end of the car they are used on. Most ITS racers remove the rear sway bar completely. On my race car I would run a stock T2 bar up front (incrase in size from stock) and NO bar in the rear for a road course. For an auto-x I would just install the smallest rear bar I could find (bar from a '86 base, it was tiny).

I used the adjustable sway bar end links and when set properly they did adjust out a bit of preload but they make no noticable difference. The only gain you will probably get from them is from them replacing worn out bushings. For a street car that money might be better spent elsewhere.

If this is your first suspension mod just save up and buy better shocks and/or aftermarket springs.

anobii

Yeah, i was leaning towards the St bars myself, I read an issue of (god forbid) import tuner and they used them on their project 240, I seem to remember i was impressed with the out come, cant remember what it was now. oh well, doesent matter. Anyone know if the ST bars come with new endlinks? I know they come with poly bushings. Any way thanks, i think i've made up my mind.

-E

anobii

Stiffer bars in the rear cause more over steer, right.? But Isn't it up to a certain point, for instance useing a slightly larger bar could increase cornering stability where a much larger bar could upset the whole thing? I dunno, I've always just put poly bushings on the factory bar on other stuff i've owned mainly because they weren't meant to handle very good....at all. In any case like you suggested carmon, springs, struts, and poly bushing are my priorities at the moment, i was just wondering, just in case i came across a "deal I couldn't refuse" situation. Thanks again,

-E

edmcguirk

I have heard the story that the "hot" ITS setup is small camber and no sway bar in the rear but I just don't get it.

That would be the correct setup for a nose heavy car or a high HP car and my Rx7 is neither of these.

Now, if I removed the rev limiter and tuned my engine and transmission to stay in the upper RPM all the time, I might qualify as a high HP car. But that setup puts the engine in the "consumables" category so I won't be doing that. I don't need to win that bad, I'm just having fun.

I do have about 3 degrees camber in the rear and I do run the ST sway bar in the rear. My tire temperatures and handling seem to agree with that.

Am I missing something?

ed

CarmonColvin

There are countless threads on this and probably just as many books written about it.

A sway bar decreases grip at the end of the car it is on. It is all about weight transfer. The more each side of the car is tied together the more weight transfer takes place which decreaes grip. Some will argue that a swabar will increase grip at the other end of the car. In some cases it does, in others it does not; that all depends on the suspension style, tire grip, vehicle weight distribution, etc. etc. Even if it does incrase grip at the other end of the car it does not overcome the loss at the end it is installed on and thus redueces overall grip.

Another aspect that makes the sway bar a performance loss is because it is an undampened spring. It is essentially a spring that only does work when in a turn or when a bump effects only one side of the vehicle. If you have shocks valved to take into effect the spring rate including the sway bars then it will be too much for straight bumps that effect both sides of the car. If you have the shocks valved so it does not take into effect the sway bars then you don't have enough dampening for when the sway bars are in effect. This cannot be completely eliminated but running the smallest sway bars you can will help out.

The only benefit on an FC that I see from a sway bar is because of camber gain/loss during heavy body roll. That is the reason for me retaining a slightly heavier bar than stock up front. I felt I gained more grip due to camber gain/loss than what I lost by having a bigger front sway bar. And it helped balance out a tail happy car.

My car was not "high horsepower". It was stripped down with a rollcage. It weighed around 2450lbs and dynoed around 145hp (high milage motor w/headers and intake). I played with my suspension for two years. I tried every combination of swaybar you can imagine. At one time I had the RB kit. I eventually sold it when I settled on the T2 bar up front and the base rear bar when on a short course.

Just because it is for sale and labled a performance item does not make it work! Companies will sell you anything labled a performance item just to sell it. Prime example of this would be the compaines that sell larger rear sway bars for late 80's or early 90's VW's. Why on earth would you want a stiffer rear bar in a car that can lift the inside rear wheel in a turn when completely stock?

ZenkiBrokie

i know of a guy with an A80 supra that runs without a rear sway during autoX, first time i've heard of it. works really well as even the stock one would lift the inside tire during hard cornering.

sirx7

sway bars are cheap on ebay..and worth it

edmcguirk

I don't completely agree with you about sway bar losing traction. They reduce traction at the end of the car they are on but they add traction to the opposite end based on chassis stiffnes and weight distribution. If the chassis twists or a wheel lifts off the ground, you will not see the benefits at the other end.

Great reading: Fred Puhn's "How to Make Your Car Handle" ISBN: 0912656468

My car is no lightweight. It's still street legal and weighs about 2600 pounds with the roll cage, full tank, etc. I've got 450F/325R springs and ST sway bars. I really need to get the car corner weighted because I have slight wedge in the suspension right now.

Anyway, the car leans about 3 degrees so that's my camber all around. The car handles fairly neutrally and the tire temps are fairly balanced.

If I were to drop the rear sway bar you would think that I would get more rear traction but I would probably lose some in the front. I would think I could balance the handling back to neutral by reducing the rear camber but it seems to me I would have just reduced my overall traction.

Of course my chassis isn't as stiff as it used to be. Maybe I'm fooling myself about how much traction I am transferring to the front. On the other hand I have seen other Rx7s lift the front wheel in a corner at the track.

Anyway, I would say sway bars are a "good thing" on the street but once you start playing with spring rates looking for the ultimate track performance the answers are not so obvious.

ed