Steeda IRS braces

[Bluemustang]

I just want it to keep up with a C6. I'd have bought a Vett but it is too damn hard to get in and out of it, plus I can drive one any time I want.

Yea, the Mustang disappointed me. Actually my F150 feels better in a high speed constant radius curve.

The Base GT is very softly sprung and the dampers aren't very good. Some proper spring setup, dampers, and thicker front sway bar would take care of that.

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[K4fxd]

Can you give some rates? Strut, shock and Bar recommendations?

Just ordered S550 Mustang IRS Subframe Bushing Support System All (2015-2020) from Steeda. They said this should take away most or all of the looseness. Funny, they said not to do the RLCA bearings as that is a drag race item and would make the car harder to drive in a corner. Scratches head. They said vertical links would help more.

 

[Bluemustang]

Sure. Spring rates -
Option 1 - Sport/Street - 200F/800R - Like Steeda Sport Linear or Eibach Pro kit
Option 2 Street/Track, handling emphasis - 250F/980R

I've been recommended to the Eibach bump stops as the best over any of the others including stock/trimmed ones.

Dampers - Ford Performance track or Bilstein B6

Bars - BMR or Eibach Front, preferably middle setting, GT350/R front bar would work also albeit slightly softer. You have more choices in the front bar; I'd just avoid going super super stiff on it, otherwise it will understeer in a not so good way. Stock or PP rear bar, or Strano rear bar.

So those are just my recommendations from time spent tweaking and changing multiple setups. The ride frequencies would be well matched and the balance of the bar would be shifted towards a stiffer front, which is where it is most needed, and avoiding going too stiff on the rear bar and compromising ability to put power down out of corners. I prefer Option 2 for the springs which is what I am running. It's a big increase in stiffness and thus roll resistance vs. stock base. Pretty much perfect imo for an ultimate road car w/ dual purpose abilities. Personally I wouldn't go stiffer than this on the street, unless maybe you have high $$$ coilovers. And you'd be surprised how decently it rides despite the huge rate increase. The reason for that is because of the ride frequency balance F/R and the dampers doing their job.

I don't have experience with the Bilsteins but hear they are amazing and a bit better than the Ford Performance. I plan to try them once my current dampers wear out.

 

[K4fxd]

I've got Bilsteins on my F150 and love them.

The car already pushes (understeers) so I am leary of increasing the front bar. I suppose with different springs it may change. I was leaning toward the 200 F and 800 R setup. 250/980 Who makes them and can I get them without a ride hight drop? I already scrape on my driveway and some parking lots.

 

[Norm Peterson]

Stiffening the front sta-bar has two effects, one effect being more understeerish (from increasing the front's proportion of lateral load transfer) and the other less understeerish (from reduced roll not hurting outside front camber as badly). A separate effect is that biasing the lateral load transfer a little more forward can also help forward bite on corner exit.


Norm

 

[Bluemustang]

I've got Bilsteins on my F150 and love them.

The car already pushes (understeers) so I am leary of increasing the front bar. I suppose with different springs it may change. I was leaning toward the 200 F and 800 R setup. 250/980 Who makes them and can I get them without a ride hight drop? I already scrape on my driveway and some parking lots.

It won't really understeer if you have adequate front camber and good tires. It can understeer stiffening the front bar, but it's more complicated then that. What you could do is leave the bars to last to tweak the handling balance.
With all stiffer springs you will have to accept some drop. The BMR SP083 250/980# springs will drop only 0.88", 0.75" front and rear. Eibach and Steeda will drop about 1". The highest rate minimum drop spring out there is the GT350R spring setup - also not a bad choice. FYI the Ford Performance dampers are repackaged GT350 monotubes. They're very good. But the 350 or 350R spring is set without a doubt the highest rate within the smallest drop. The BMR SP083 is the highest linear rate spring you can run with stock style struts/shocks. Well - you can run higher in the rear with MMI adjusters, but that's beside the point.

 

[Norm Peterson]

Springs that lower the car too far for individual preference can usually be shimmed in some fashion. IIRC, Steeda makes spring spacers in various thicknesses for the S550. I'm not sure if they have them for both ends of the car, but push come to shove you could probably roll a set of your own.


Norm

 

[K4fxd]

So the BMR 083 springs with steeda spacers and B6's should get me in the ball park?

I looked and Ford is real proud of the 350 springs.

 

[SteedaTech]

Having some fun with a C7 Corvette out at Palm Beach In'l Raceway!

 

[TeeLew]

He must have washed that Vette with apex repellent before taking it to the track.

 

[K4fxd]

If the guy in the vette knew how to drive.....

 

[Roadway 5.0]

I've got Bilsteins on my F150 and love them.

The car already pushes (understeers) so I am leary of increasing the front bar.

Look into getting both the front and rear bar adjustable. You can fine tune handling characteristic to your liking.

I went big rear adjustable bar for years and liked it. Now I’ve added the adjustable front and love it. The driving dynamics make it hard to believe I’m in a Mustang. I run 225/880 springs, btw, with Bilstein shocks and ProAction struts (Bilstein struts in the garage — hesitant to install as I might reduce spring rate a tad).

 

[K4fxd]

My plan of attack is to first stiffen up the chassis, which I have accomplished. Although I do think if I modified the BMR 4 point front brace to add connection points on the actual car body, where the front jacking rail would bolt to, will make it better. Then find the next weak link, at this time it is bushings. I'm actually kinda happy with the stock springs, the dampeners, not so much. Front has plenty of compression but no rebound, the rear has neither. Before I started the braces I thought the springs sucked.

As it is now the car is pretty flat in corners and under braking, it does raise up under acceleration. Too much IMO.
I'd like it to be as flat as the Steeda Q500 in the above Vid, but that might beat me up in daily driving. ;)

 

[K4fxd]

(Bilstein struts in the garage — hesitant to install as I might reduce spring rate a tad).

The bilsteins are advertised to work with stock spring rates. So I'm on the fence to use them with increased rates. I have no idea what rates they consider stock. Will have to give them a call.

Why are you considering a different rate?

 

[Roadway 5.0]

Why are you considering a different rate?

I do a lot of long distance rally-type trips, so I’m looking for a bit of a softer ride. I’ll probably go for 200/800 springs or something close to it.

To note, my Bilstein shocks handle my 880lb/in rear springs very well, so I wouldn’t fear pairing them with stiff springs (to a point, of course).

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