[Smoothgrandmama]

One question i have not seen. The effects of a rear strut tower brace for an irs. . . . .

[ReverendDexter]

Originally Posted by Smoothgrandmama One question i have not seen. The effects of a rear strut tower brace for an irs. . . . .

Strut tower braces reduce the changing of the geometry of the suspension that would elsewise be cause by flex of the chassis.

It doesn't do anything in and of itself, much the same way that a strut tower brace in the front doesn't change the handling of the car in and of itself.

[Smoothgrandmama]

So further mounting to the frame via the brace wouldnt help at all with wheel hop or side to side axle movement?

[ReverendDexter]

Originally Posted by Smoothgrandmama So further mounting to the frame via the brace wouldnt help at all with wheel hop or side to side axle movement?

Depends on what's causing the wheel hop. I don't believe that it's due to the strut towers moving around, though, so my inclination is that it won't make a difference.

Regarding side-to-side axle movement, I'm not sure how that's relevant, as you asked about an IRS.

[Smoothgrandmama]

when Cornering it feels like body is slow to move into the corner as im i go into a turn but the weight of rear hits it later making the car very tail happy

[ReverendDexter]

Originally Posted by Smoothgrandmama when Cornering it feels like body is slow to move into the corner as im i go into a turn but the weight of rear hits it later making the car very tail happy

That sounds like an issue with the front suspension, not the rear.

What's your alignment up front? What suspension mods, if any?

[Smoothgrandmama]

Its a huge mess up front. . . . tubular k member worn out bilstein shocks on stock springs. i have eibachs in the rear . . . . lol

[ReverendDexter]

Originally Posted by Smoothgrandmama Its a huge mess up front. . . . tubular k member worn out bilstein shocks on stock springs. i have eibachs in the rear . . . . lol

My first suggestion would be to send your bilsteins in to get rebuilt. Maintenance before mods.

[Smoothgrandmama]

Oh and cc plates. . . . which uh is prob why the shocks are worn. . . . since did install them. . . with an impact gun

[ReverendDexter]

Originally Posted by Smoothgrandmama Oh and cc plates. . . . which uh is prob why the shocks are worn. . . . since did install them. . . with an impact gun

I installed mine with an impact, I've never noticed an issue.

What alignment specs are you running?

[Smoothgrandmama]

in reference to the gun and being worn i say that cause spun the crap out of the shocks taking off the top bolt. i hardly remember my exacts specs except for my cancer being .82 and .20 that was at max adjusted

[ReverendDexter]

Originally Posted by Smoothgrandmama in reference to the gun and being worn i say that cause spun the crap out of the shocks taking off the top bolt. i hardly remember my exacts specs except for my cancer being .82 and .20 that was at max adjusted

Really? With a tubular k-member and CC plates, you couldn't get at least a full degree of negative camber on both sides (not that I suggest running that much)? Something sounds messed up to me.

[Smoothgrandmama]

The other way around i believe. it was at negative 3 degrees before the c/c plates. it was killing my tires really quick

[Ke^in]

How much lowering are we talking here above?

[ModMustang97GT]

Please, no one on here EVER buy a rear shock tower brace. It will do NOTHING for your car.

Your frame is connected by a huge cross member there, you are basically just drilling a hole in the frame and mounting a tooth pick where it already had plenty of strength.

Describe more to me about your rear. It sounds to me like the front end is loose, and the rear end is really stiff.

The front is on a well dampered soft spring and large amount of camber, a very high grip set up. The rear sounds like the issue, the IRS does not have any side to side movement do to the wheels beeing triangulated in their location. However, if the springs or sway bars are stiff or binding, the suspension will be really slippery. You said you have eibach springs out back? I think your issue is more likely that your rear end has stock shocks and stiff springs, so its got no grip compared to the front.

I know you are thinking, that doesn't make sense, stiffer means more traction right? Only if everything is stiffer. If the front is really soft and the rear is really stiff, the rear will be really slippery compared to the front. In these cars, we tend to set it up similar to this so that we actually get neutral handling. The front end is so much heavier than the rear, that stiffening it up to match the weight to stiffness ratio of the rear end will even the car out.


It sounds like you car has taken this too far. You have created a drift machine. I think new shocks in rear and new springs up front will help you a ton. And if that doesn't even you out, an adjustable sway bar should.

Just to be sure, please give me a full run down of your suspension.

[HBK_2007]

Originally Posted by ModMustang97GT However, if the springs or sway bars are stiff or binding, the suspension will be really slippery.

that is kinda what mine does. the front feels really good but the rear is all over the place when i do some high performance driving

[Smoothgrandmama]

Originally Posted by ModMustang97GT Please, no one on here EVER buy a rear shock tower brace. It will do NOTHING for your car. Your frame is connected by a huge cross member there, you are basically just drilling a hole in the frame and mounting a tooth pick where it already had plenty of strength. Describe more to me about your rear. It sounds to me like the front end is loose, and the rear end is really stiff. The front is on a well dampered soft spring and large amount of camber, a very high grip set up. The rear sounds like the issue, the IRS does not have any side to side movement do to the wheels beeing triangulated in their location. However, if the springs or sway bars are stiff or binding, the suspension will be really slippery. You said you have eibach springs out back? I think your issue is more likely that your rear end has stock shocks and stiff springs, so its got no grip compared to the front. I know you are thinking, that doesn't make sense, stiffer means more traction right? Only if everything is stiffer. If the front is really soft and the rear is really stiff, the rear will be really slippery compared to the front. In these cars, we tend to set it up similar to this so that we actually get neutral handling. The front end is so much heavier than the rear, that stiffening it up to match the weight to stiffness ratio of the rear end will even the car out. It sounds like you car has taken this too far. You have created a drift machine. I think new shocks in rear and new springs up front will help you a ton. And if that doesn't even you out, an adjustable sway bar should. Just to be sure, please give me a full run down of your suspension.

Well i want to go coil over in the front i used to have eibachs up front but it sat too low. . . ripped my intercooler off once. so being able to adjust the height would be a great help. as far the rear should i go coil over on it too? i building it to race not for comfort

[ModMustang97GT]

if your aspirations are for racing and you don't mind the ride. Rear Coil Overs are the way to go. I would make sure to get a good quality Shock for them though. don't want to be setting your self up for failure with cheap or weak parts.

Also remember, if you do get coil overs, you need to have stock sway bars, just something to remember.

[HBK_2007]

y?

[ModMustang97GT]

Aftermarket sway bars are too stiff for the coil overs. The job of a sway bar is to make sure that the wheels move together.

The problem is, the design of them is simply a bandaid. Ideally you wouldn't have any sway bar at all, but at least in our case, this isn't really an option. So, when you get coil overs, they tell you to keep the stock sway bars. Otherwise, the sway bar will be subtracting from your coil over's ability to absorb the shocks. You are essentially adding the stiffness of the sway bar to your spring rate. But its not in a good way, it is hindering its movement both up and down. So adding to the wheel rate in the up direction, and subtracting in the down direction. There by making the wheel actually track worse.

In a corner, an overly stiff sway bar will cause the inside wheel to actually pull up off of the ground in a hard corner. So, the weaker the sway bar can be and still do the job the better.

Jazzer went through this all very recently. He didn't want to swap in a stiffer set of springs for his car due to ride quality issues. So he invested in an adjustable sway bar. It helped to dial in some needed Over steer, but it was highly recommended against by Bruce Griggs (owner of griggs racing), because of the negative affect on the wheel rate.