Hey all I have a ‘21 Mach 1 with handling package parts and some aftermarket parts for better alignment. I do maybe 4-8 track days a year and run 200TW 305’s square. For my purposes I need to keep at or close to factory ride height and good ride while keeping the dust boot (I drive on some roads where I don’t want the shaft exposed). I’m running HP rear springs (742) and GT500 CFTP front springs (268) that I just mounted on the struts. I haven’t installed the struts yet so this a prime time to upgrade the front sway bar. I just so happen to have a Steeda front bar, but the factory Mach 1 bar is a bonded bushing bar. I’ve heard this is to help on center feel, but I’ve also heard it is to help add spring rate in bump (bonded so there is resistance not just in roll). Would it be a bad idea to ditch the factory bonded bar when running soft/compromised front springs? Obviously the steeda bar would greatly increase roll stiffness in the front, but would I miss the added rate? Right now it’s easy to swap bars since struts are out.

With the factory HP setup I felt the car a little too loose, including some corner entry oversteer. I could drive around this, but I feel it could be better.


Factory front sway bar
GT500 CFTP 268# front springs
Steeda camber plates and enlarged opening
-3.5 camber
Zero toe

HP 742# rear springs
24mm solid HP rear sway bar
BMR CB005
AAD camber arms
AAD vertical links
Cortex toe links
Ford Performance toe knuckle bearings
-2.0 camber
0.24* total toe in

305/30/19 200TW tires square on 19x11’s

Contact Sam Strano. His rear ARB is the one you're looking for. It's adjustable and has a better range. My car came with the 24mm RARB as well and it's too much. I run the 20mm bar off of a V6 Convertible, but when I buy one, it will be Sam's. It's not listed on his site, but call him and you'll either be able to get one or get on the list for the next run.

Replacing the rear lower control arm bush and toe link bush with bearings would also be a good idea. They do nothing for NHV.

TeeLew said:

Replacing the rear lower control arm bush and toe link bush with bearings would also be a good idea. They do nothing for NHV.

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Thanks. I have the toe bearings and I actually pulled the knuckles to press the bushings out and bearings in. I regret not doing the control arm at the same time.

I’ll give Sam a call. I did find references to his rear bar. Of the aftermarket ones it’s frustrating because most are far too stiff and the steeda comp looks too soft. I’ve debated putting the non-HP 24mm rear bar on (it’s hollow) but may need softer.

My opinion is that we don't need much rear bar. If running unhooked, it disconnects the car front-to-rear a little too much. The grip is awesome, but it needs a little bit of rear bar to make it turn and tighten transitions. Sam's bar spans a range that runs from about my 20mm bar to about the 24mm solid.

There are a couple of places/situations that I can see wanting that much rear bar, but generally speaking, I think something on the low side would be the better choice, especially on tracks that have several traction corners.

TeeLew said:

My opinion is that we don't need much rear bar. If running unhooked, it disconnects the car front-to-rear a little too much. The grip is awesome, but it needs a little bit of rear bar to make it turn and tighten transitions. Sam's bar spans a range that runs from about my 20mm bar to about the 24mm solid.

There are a couple of places/situations that I can see wanting that much rear bar, but generally speaking, I think something on the low side would be the better choice, especially on tracks that have several traction corners.

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I meant to ask, what is your opinion on changing the front bar? It was your comments I had seen regarding to the bonded bushings adding wheel rate. I’m a little hesitant to give that up given how soft the CFTP springs still are. That being said a rear bar will likely fix most of my current criticisms.

RobZ71LM7 said:

I meant to ask, what is your opinion on changing the front bar? It was your comments I had seen regarding to the bonded bushings adding wheel rate. I’m a little hesitant to give that up given how soft the CFTP springs still are. That being said a rear bar will likely fix most of my current criticisms.

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Obviously, I think more spring stiffness is best, but if you're running the CFTP front spring, then it's a toss-up.

You want both more roll stiffness and more ride stiffness. The bonded bushings gives you a bit of ride stiffness, so probably a good thing. With the adjustable rear bar, you'll be able to find something that balances it. But, more front roll stiffness would be nice to improve response and try to limit the camber loss on the loaded tire.

This is probably zero help, but you'll just have to put one on and try it.

@RobZ71LM7 Out of curiosity, which tire were you running? I am in a very similar situation as you, finding the car to be a little too unpredictable and oversteer-y in some longer sustained turns. I do have the Steeda rear sway bar, inherited from the previous owner, which I agree is too stiff for me even in the softest setting. But one big caveat is that the tires I currently have are just not great for my car and/or driving style (Continental ExtremeContact Force 315 square x 11). I had my instructor buddy, who owns a GT350 and is MUCH faster than me, drive my car to make sure I wasn't crazy and he concluded that the tires were the number one problem with my current setup, with the rear sway bar maybe being the next thing to look at.

I was about to pick up the stock HP rear sway bar but it sounds like perhaps the GT Performance pack rear bar at 22.2mm may be a good compromise here?

I was using Falken 660’s in 305 square with 2022 date code, autocrossed in 2023, and they sat until 2025. So they weren’t great but had some grip left. I know it’s not best to make changes with non-ideal tires but they weren’t quite dead. Ironically tomorrow will be my first track event (Putnam Park) with the GT500 CFTP front springs and a Steeda front bar set one setting from full soft. I have stock HP springs and HP solid bar in the rear. I think the balance will be closer to neutral than my buddies believe, but we’ll see. My personal thought is the front of these cars are so soft that it will not make the car understeer to the extent a textbook understanding would predict. I’m going to be on new Nankang CRS V2’s in 305 square. I was close ordering the 315 ECF’s that are on closeout and probably should’ve, but I want to give these a try. I’m a little frustrated at the lack of options in adjustable rear sway bars with the correct amount of stiffness-most seem overly stiff. The Strano, if you can find one, might be the best option. I’m admittingly trying a softer rear than many based upon my readings of TeeLew’s posts.

I don't do any autocross, but my buddy swears by the Nankang CRS on his GT350 so it's looking like those will be the next purchase before I do VIR next month. I know some people seem to like them but after a few track days now, I kinda regret buying these ECF's...

jaylarold said:

I don't do any autocross, but my buddy swears by the Nankang CRS on his GT350 so it's looking like those will be the next purchase before I do VIR next month. I know some people seem to like them but after a few track days now, I kinda regret buying these ECF's...

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I don’t autocross anymore and although I’m newer to HPDE, it’s hard for me to get a less grippy tire than the 660 I’ve used. Back in the day I used to autocross a 4th gen F-body with 315’s at all 4 corners and a weight of about 3200lbs so I consider these cars under tired.