blackbeauty

Hi everyone,

My car had a 30mm sway bar in the front and a 13mm bar in the rear. I replaced the skinny rear bar with a 24mm bar and new rubber bushes. The difference was night and day, the car handled so amazingly, I could throw it into any corner I wanted and it would never lose grip. But...

then I replaced the front 30mm bar with a 36mm bar with Spohn poly bushes for the end links and D bushes. My old end link bushes were so stuffed that when I took them off the car they virtually fell apart. Even with those old crappy bushes the car still handled awesome, with no body roll.

Now because of the above changes my car has oversteer and I'd prefer not to have it. My searches have told me that I can either soften the rear springs, or stiffen the front springs to correct this problem. My shocks are less than a year old, my rear springs are probably factory and the front springs look aftermarket to me (I didn't swap them in).

Are these the only options available to me? Would using rubber bushings in the front correct the problem? If I did change the springs which end of the car would be best if I wanted to keep a happy medium between comfort and performance? My car has a harsh ride as it is so if I can improve it a little I'm all for it.

Thanks!

vsixtoy

Don't you mean understeer? A bigger front bar will cause the nose to push and the car not turn.

Question- Do you have relocation brackets? If so where is your rear mount setting (which hole- top, middle, bottom) and what the angle of them at normal ride height.

vsixtoy

You disaappeared for now so let me elaborate to help you understand and solve yourown problem.

You, if anything, should have had oversteer with the 30f/24r setup. Why?- With a heavy nose V8 car especially, the front will lean more into a cornerand the rear will stay rigid as the car roll on its axis. This will cause more weight transfer from the opposite side rear tire to the front. With the stiff rear bar and the front swaying, the inside rear tire will unweight more and cause oversteer (the *** end to come around easier).

By adding the larger front bar, you are controling the front sway more (the heavier end of the car) and thus keeping the inside rear more planted (making more of a push, or understeer). Reducing the rear bar size doies the same principle.

blackbeauty

Maybe I used the wrong term. When I go hard into a corner, the car feels like it wants to keep turning just a bit more and the back of the car feels like it wants to swing out. So, is that oversteer or understeer?

Since 36/24 is a factory option, I figure that my situation is telling me that there's something wrong with the suspension elsewhere in the car, but where is an interesting question.

I don't have relocation brackets installed. It's all factory in the rear end, apart from my larger sway bar.

FruityOne

Oversteer is when the car wants to step out of line more easily.

Understeer is when the front end doesn't want to turn easily. It pushes ahead, even when the wheel is turned.

With 36/24 you should experience much in the same way less oversteer than you did with the 30/24 setup.

My GTA has the 34mm hollow, and 24mm solid setup and it doesn't want ot oversteer much. Handles damn good in my opinion.

blackbeauty

Now that I think about, if I'm driving along the road straight and turn the wheel, I feel like I have to turn the wheel more in order to get the car to respond.

But, when I throw the car into a corner (i.e turn real sharp), it does feel like the back end wants to swing out.

Are you confused? Me too!

RB83L69

A car that has oversteer (what people call a "tight" condition, where the front has less traction than the rear) will often do that.

What's really going on is, you turn the wheel, and nothing (or not enough) happens; so you turn the wheel some more; you turn it some more; ooops, still not enough, you turn it some more; all of a sudden, the front tires get grip, from hittiing a bump just the right way or whatever; now the wheels are turned SO FAR, that when the front does grip, the car instantly tries to go into a spin.

From your description, that's exactly where you have it now. You mostly have understeer, and then you experience sudden oversteer from driver input; that's caused by too much front bar, or not enough rear bar.

Nearly all of the factory configurations will make these cars have serious understeer. A car that has oversteer is much more difficult for yerbasic average consumer driver to control, so the factory seigns them to have understeer, always.

You can tell fairly easily what it's really doing. Go around a long fairly tight curve on a highway or something, someplace like an expressway ramp that has a long constant-radius 270° turn is ideal. Speed up until you just start to hear a tire complain. If it's the inside front tire, the car is tight (understeer), and needs more rear sway bar or less in the front; if it's the inside rear tire, then the car is loose, and needs more bar up front or less in the rear.

That will get it set up to neutral for steady-state consitions. Then you'd need to start working on the shocks to control what happens at the moment you move the wheel, while the car's attitude is in the process of changing from straight ahead to leaning. The stiffer your sway bars, the less dramatic an effect the shocks will have, because the car won't roll as much; but too much sway bar will make the car skip across bumpy roads.

It's a compromise based on track (road) conditions that you specifically face where you are and the way you drive, as opposed to one absolute right perfect combination that works for everybody.

MrDude_1

when was the last time you replaced your shocks?

RB83L69

Incidentally, my description also doesn't include what happens when braking. When you hit the brakes, more of the car's weight (vertical force tending to plant the tires, without being additional horizontal inertia) is transferred to the front tires and off the rears, which makes thee fronts grip more and the rears less, which will aslo induce sudden oversteer. Another reason for the factory's deliberate understeer design: a typical retail consumer driver in a panic situation will stab the brakes and yank the wheel at the same time; if the car is neutral off the brakes, it will instantly become VERY VERY tail-happy when they do that, and will swap ends so fast that they won't even know what they're backing into until after they've already hit it.

vsixtoy

RB somewhat labeled this correctly- sounds like you now have the traditional too much weighttransfer no turn- then kink over- and all of a sudden get loose syndrome. This is very common on the V8 cars.

Remedy- You need to increase spring weights to reduce front to rear weight transfer. Then possibly still reduce that rear bar size to a 22mm (thats were the fine tunning comes in.

If you have LCA relocators and are into handling(Not launchingfor dragracing) you can use this "tool" to help the *** end stay tighter based on geometry. But alot need to click- You have to have most things upgrades with adjustments availiable.

Making a car handle is not just bolting on parts, its also knowing how to adjust them to get what you want out of them. Your smaller bars were better married to your spring rates and bushing deflection. Bolting on the larger bars overpowered everything else and became the dominate factor. This is bad because swaybars should only be used to fine tune the suspension, and not to be the main support.

vsixtoy

I'll list my recommendations for priority when buying suspension performance parts- I strongly suggest thhings be bought in this order to show progressive gains.

1st) thing should be good roadrace shocks (need to control the chassis better, even with stock suspension.

2) best tires you can afford

3)billet strut mounts (this will stabilise the upper mount point of the front suspension- this is a biggy for those who haven't) Best modification that can be made for turning response. "And then have the car aligned if no other mod is to be made at this time."

4) now nuy your STB. Without solid strut mounts, STBs are useless. The stock rubber strut mounts flex way too much to make a STB worth the money. Only do this after #3

5)panhard rod (Adjustable)

6) A good quality torque arm with its own crossmenber mount. (get that crappy stock front mount off the transmission) The toquearm HAS TO BE ADJUSTABLE for later pinion setting.

7)LCA's and relocators. Put them on at the same time but leave them the rear mount poition in the stock location for now until car is lowered (Relocators are only needed if car is lowered- if you have wheelhop, then you need better shocks at this point- that should have been #1).

8) Now put your springs in and lower the car. You now have all the proper adjustments to set things correctly.

9) At this point SFC's will start to matter for cornering forces. This will help keep the chassis stiff.

10) Now do the swaybars. If is a full weight interior car (not stripped for race weight) then might I suggest Spohns 34mm solid front/22mm solid rear for V8s. And 34mm f/25mm r on a V6

That basic 10pt rule willl get you a decent setup happy.

MrDude_1

dean, on #7 there, its worth it to point out that 90% of the 3rdgens out there on stock springs have been lowered..

the springs have sagged over time, and the LCA angle IS inducing wheelhop thru the geometry... the shock isnt going to compensate for inproper geometry.

their car HAS been lowered... by saggy springs.

vsixtoy

All I can suggest then is not to hammer your car if it doesn't have the proper equipment (but thats like telling a 3yr old to stay away from the cake)

Dewey316

Can we make that a sticky.

Dean and RB nailed it. wieght transfer will kill you everytime, you really have track back and see what really caused the problem. Our cars are horrible from the factory when it comes to balance. then once you cross the line and really start to plow and start that forward weight transfer, the snap overstill starts in. There is alot here that can be fixed mechanicly to get the car to respond better, but you also have to learn to drive the car. no matter what you do to the suspension, if you get the car unsettled its going to bite you.

a couple of my thoughts on your setup. with those old, worn out soft springs. the weight transfer should be on your hit list right off the bat. sway bars are great, but they don't do crap for for/aft weight transfer on accell/decell. Deans list is a good logical order, and is the way to go. but i don't think it is the way to go about fixing your issue. the 36/24 combo is a great balance combo, 34/24 also works well. so does 36/23. any of those combo's will get you where you need to be, with the right springs and shocks. first order of buisness, shocks, shocks shocks. you will hear everyone on this board who really handles, tell you that. get a GOOD set of shocks/sturts. next, springs. fix you weight transfer issue now, springs and shocks will do that for you. you can balance the car out, to get rid of the understeer and it will help keep it form getting unsettled and going into the snap oversteer.

Dale

iTrader: (12)

not on that list, but not needed for everyone, get rid of the pegleg spinner

Take a right hand turn, and the pegleg pulls up loosing traction.
Plus it pushes on the right side while the left is "dead weight"

blackbeauty

Thanks to everyone who's replied to my query, it's greatly appreciated.

The Monroe shocks/struts in my car are less than one year old. I wanted to put Koni's in but they're too expensive for me at the moment and that's all that's on offer round here. Anything else and I'd have to import. My old struts/shocks were that stuffed the improvement in handling was incredible with just having the Monroes. Having SFCs installed was also the best thing I've spent money on.

OK, so to me it seems I either put my old 30mm bar back on, or I put stiffer springs in the front. Would that be a fair statement? Is having stiffer springs going to make the car less comfortable to ride in? What about WS6 springs, would they be a good choice?

I do drag race the car, and one day will get round to having LCAs installed.

Thanks!

contactpatch

blackbeauty wrote:
>Since 36/24 is a factory option<
\
With whatever factory setup that used that,
perhaps there were spring rate differences
(compared to what you have now),
that made the setup useable.

Also, I think this is mostly a spring-swaybar issue.

contact

Dewey316

blackbeauty,

if you go back to the 30mm bar, it will help inital turn in, but it won't cure the front/rear weight transfer. i would suggest a spring change both front and rear. the ws6 or IROC OEM would be descent here.

RB83L69

I'm using the stiffest possible Moog replacement IROC spring..... 700 some-odd lbs/in rate. Part # is either 5662 or 5664, I don't recall for sure.

wdigitog

so what moog spring do you recommend for the rears? 700 rate for the fronts....? for the rears?? for a more neutral balance.

CamaroMike

I am using 5662's with 1/4 coil cut and stock replacements out rear with 1 1/2 coils cut. I had the 5664's and they were way too high. Better cut those 5664's if you don't like the 4*4 look. 5662's with 1/2 coil cut aslo looks damn good. Just my experience.

blackbeauty

Wow, thanks for all the awesome feedback guys. Reckon I'll look into some replacement springs. Which will be interesting since Trans Am springs probably won't be plentiful in this country. Hope the stiffer springs doesn't kill the comfort factory too much.

Thanks again.