[AlphaDog]

I'm prepping a new-to-me SS 1LE for autocross in FS, and need a bigger front bar to get the car to transition more quickly. I ran the BMR 35mm bar in the middle hole on my CAMC Mustang, and it helped significantly, but I could run a BMR rear bar too (on soft) - won't be able to do that in FS.
I ordered a set of Hotchkis bars, but they won't respond, so I guess that's out. AFE front bar appears to be too stiff to use alone and also appears to be out of stock, can't find any info on the Nolathane bar and it's also out of stock. No info out there on the UMI bar either.
So looks like best current options are Whiteline, BMR, Hellwig.
BMR is the only one I could find info on arm length and OD/ID, but also see the issues with the bushings. Energy Suspensions makes 1.25" bushing kits with 1 1/8, 1 1/4, and 1 3/8 wide brackets - has anyone measured to see which kit BMR packages with their bar? BMR bar appears to be the softest.
Whiteline is solid 30mm, so should weigh ~40% more than the hollow ones, no info on arm length, but assuming similar arm length to the BMR stiffness should be between BMR and Hellwig. Any actual arm measurements would be welcome.
Hellwig appears to have better bushings, and is hollow, but again assuming similar arm length, should be the stiffest. Actual arm measurements would be welcome.
So looking for feedback from anyone who has used one of those 3 bars in FS. Did it speed up transitions enough? How much more understeer did it create? What were you using for F/R tire size and pressure, and F/R camber?
Thanks for any info!

[VR Baron]

Originally Posted by AlphaDog

I'm prepping a new-to-me SS 1LE for autocross in FS, and need a bigger front bar to get the car to transition more quickly. I ran the BMR 35mm bar in the middle hole on my CAMC Mustang, and it helped significantly, but I could run a BMR rear bar too (on soft) - won't be able to do that in FS.
I ordered a set of Hotchkis bars, but they won't respond, so I guess that's out. AFE front bar appears to be too stiff to use alone and also appears to be out of stock, can't find any info on the Nolathane bar and it's also out of stock. No info out there on the UMI bar either.
So looks like best current options are Whiteline, BMR, Hellwig.
BMR is the only one I could find info on arm length and OD/ID, but also see the issues with the bushings. Energy Suspensions makes 1.25" bushing kits with 1 1/8, 1 1/4, and 1 3/8 wide brackets - has anyone measured to see which kit BMR packages with their bar? BMR bar appears to be the softest.
Whiteline is solid 30mm, so should weigh ~40% more than the hollow ones, no info on arm length, but assuming similar arm length to the BMR stiffness should be between BMR and Hellwig. Any actual arm measurements would be welcome.
Hellwig appears to have better bushings, and is hollow, but again assuming similar arm length, should be the stiffest. Actual arm measurements would be welcome.
So looking for feedback from anyone who has used one of those 3 bars in FS. Did it speed up transitions enough? How much more understeer did it create? What were you using for F/R tire size and pressure, and F/R camber?
Thanks for any info!

A lot to think about. I don’t run FS so hopefully the experienced guys that are on the forum will chime in with ideas. If you search there is a lot of swaybar info here. Hotchkiss should be available now unless they sold out. Look at Jeggs or summitt racing. I never ran the car in autocross stock, but with the stock tires I like the stock bar for mountain runs and canyon carving, has good balance, turn in and pretty neutral.
For autocross , but not FS class, I run cam c, I run 19x11 wheels and 305s. I feel my hotchkis front bar was a touch to stiff with its 1/4” wall. I use it to offset oversteer from the square tire setup, better weight transfer to keep the rear in check with the EDiff snap oversteer potential. Also less roll to help keep static camber better and better use of tread. My camber is maxed out at -2.8/-1.8 without camber plates, which you can’t use in FS anyway. My current setup has the whiteline rear bar set stiff and EDiff autocross tune, this combo is great, I still run hotchkiss set soft and car is pretty neutral now. I even like the hotchkiss set middle, it now has great turn in and is great in slaloms, though a bit more understeer on turns. Point is, I needed the bigger rear bar and EDiff tune to negate some of the front big bar understeer even with square tires.

If you had my setup, or I was to need a bar now, I would go whiteline. 30mm solid,three positions and weight is same as the hotchkiss 32mm x1/4 wall bar.
By my rough math, the bar is about 24,40 and 60% stiffer than stock. I would set it at the soft 24% setting (equal to 29mm diameter per whiteline) with square or staggered tires, though staggered will have more understeer. The mounts are strong, the bushings are designed so the grease doesn’t run out
also.
This is some basic info and there are a lot of factors obviously, course design can dictate what bar also as to stiffness, tight courses like softer bar, big fast course with sweepers and big slaloms could like a stiffer bar.

[clyde]

There is no consensus, but quite a few have been happy with adjustable rear bars where the middle setting is close to stock.

I may be stupid (several that post here can confirm), but I've been running the stock bars and never felt the need to "fix" something. In 2021-22, i wanted to do some experimentation, but supply/availability issues led me to run what I had and found I was pretty happy with them.

When I compare my data/video with others that were quicker than me, the differences are consistently driver, not equipment.

[VR Baron]

Originally Posted by clyde

There is no consensus, but quite a few have been happy with adjustable rear bars where the middle setting is close to stock.

I may be stupid (several that post here can confirm), but I've been running the stock bars and never felt the need to "fix" something. In 2021-22, i wanted to do some experimentation, but supply/availability issues led me to run what I had and found I was pretty happy with them.

When I compare my data/video with others that were quicker than me, the differences are consistently driver, not equipment.

Yep. My whiteline rear bar is same as 1le bar set middle, with one step softer and one stiffer, 16% either way.

[Msquared]

The adjustable BMR bar I'm familiar with is 1.25" in diameter, which is 31.75mm, not 35mm. So is the Hotchkiss adjustable front bar. Any bushing with a 1/25" inner diameter will fit the bar. I had good luck running the bushing and bracket that comes with the Hotchkiss bar on my BMR bar. You could call them and tell them you'd like a replacement set and maybe they'll it to you. BMR also sells a billet bracket and bushing set that probably works well, though it's expensive and you shouldn't have to buy that to run their bar.

In the bigger picture, I'm not sure I agree with using a bar to affect the car's behavior in transitions. Bar and spring rates are more about steady-state handling balance. Although it is true that increasing roll stiffness will slightly reduce the time it takes for the car to "take a set," in transitions the car never really stays in a steady state and therefore never really takes a set. And the side effect of cranking up front roll resistance is that the car will be less neutral, so you get understeer and the car becomes less willing to turn at all. As the suspension moves throughout a transition, we really are looking at damping rates to tune its behavior in that phase. I think the thing you should focus on to tune your car's transition behavior is damping rates. You have two options: 1) add a DSC controller for the shocks and get your laptop out to start adjusting, or 2) ditch the MRC dampers altogether and move to manually adjustable shocks and struts (there are solutions for that).

[VR Baron]

Originally Posted by Msquared

The adjustable BMR bar I'm familiar with is 1.25" in diameter, which is 31.75mm, not 35mm. So is the Hotchkiss adjustable front bar. Any bushing with a 1/25" inner diameter will fit the bar. I had good luck running the bushing and bracket that comes with the Hotchkiss bar on my BMR bar. You could call them and tell them you'd like a replacement set and maybe they'll it to you. BMR also sells a billet bracket and bushing set that probably works well, though it's expensive and you shouldn't have to buy that to run their bar.

In the bigger picture, I'm not sure I agree with using a bar to affect the car's behavior in transitions. Bar and spring rates are more about steady-state handling balance. Although it is true that increasing roll stiffness will slightly reduce the time it takes for the car to "take a set," in transitions the car never really stays in a steady state and therefore never really takes a set. And the side effect of cranking up front roll resistance is that the car will be less neutral, so you get understeer and the car becomes less willing to turn at all. As the suspension moves throughout a transition, we really are looking at damping rates to tune its behavior in that phase. I think the thing you should focus on to tune your car's transition behavior is damping rates. You have two options: 1) add a DSC controller for the shocks and get your laptop out to start adjusting, or 2) ditch the MRC dampers altogether and move to manually adjustable shocks and struts (there are solutions for that).

Matt is absolutely correct. In my testing with bar settings over the years the only time the hotchkiss front bar set in the middle felt like it was doing as it should is when I stiffened the rear bar and did the autocross EDiff tune to counter the to much understeer and lazy response. It had a Very solid and responsive feel and was great in slaloms and getting power to the ground , but on sweepers and all tight turns it still had a bit to much understeer , though not as much as before the rear changes. While the softer bar setting is a bit lazier on turn in response, but not much, I feel it is faster overall with all the tight turns in autocross and , with the rear ended changes , pretty darn neutral.
All about overall good balance and response. In fact hitting the gas before the apex of a sweeper to the finish to see how the car would react, I got a some rear step out oversteer and had to back off, so in the balance ballpark!

[AlphaDog]

Appreciate all the inputs. The Hellwig front bar should be very close to the Hotchkis front bar, and I suspected it might be too much without a bigger rear bar - thanks for confirming that. BMR and Whiteline bar rates are pretty close, and both softer, I'll give the Whiteline bar a try.

[VR Baron]

Originally Posted by AlphaDog

Appreciate all the inputs. The Hellwig front bar should be very close to the Hotchkis front bar, and I suspected it might be too much without a bigger rear bar - thanks for confirming that. BMR and Whiteline bar rates are pretty close, and both softer, I'll give the Whiteline bar a try.

BMR is stiffer. Whiteline is a 27mm solid in the mid hole, like our stock 1le bar. The other holes are 16% softer (like a 26mm) and 16% stiffer(like a 28mm)
The stiffer hole is a subtle change, not a lot but it’s noticeable. I picked that one to balance the front bar set soft to negate any oversteer from square tires. I now have about a 20% front bias is all to help with any of that oversteer issue.

Side notes for you, with the limited camber I can get, the bigger bars help to keep the roll down and camber from changing to much. The heat in the tires is pretty even across the the tread surface and I can run less psi in the tires.
Example: a guy I race has a stock 1le, alignment same as me, same re71rs 305 square setup and stock bars. He has to run 34 psi to not roll into the tire arrows. I can start at 30 psi ant am right at the arrows. The mid bar setting I can run at 28.

[DaveC113]

My feeling is a stiffer front bar keeps the rear end from stepping out as much in slaloms and tight corners which is much better for autox, it basically makes the car narrower in some situations, and imo overall faster as the tradeoff for understeer is improved exit, and understeer can be compensated for with trail braking. But there's a lot to look at, diff tune and running a square wheel/tire setup will have it's impacts and with my car running 18x12 square the rear end can feel pretty light at times, but I do have coilovers with stiffer springs.

The autox rear diff tune is legal for FS, as is the DSC Sport shock controller, both are worthwhile but I found the DSC to be a bit too much, the damping can vary according to any sensor in the car, but otoh you can approximate what a regular comp/rebound dial would do. For me, those 2 adjustments are enough so I went with MCS 2-ways, and they do have shocks that work with the oem springs now which would be FS-legal.

If you can, just ask some of the fast FS guys. Mike often posts here, @Apexit52 I think? If so that should tag him.

Also, theoretically I agree with Msquared, but some of the car's handling characteristics have been unexpected, namely it's resistance to deviation from fairly neutral steady state cornering, which means the stiffer front bar has less downsides than it might otherwise. I found mainly upsides with the caveat I got the eDiff tune very early on, but so should you... it's well worth it.

[AlphaDog]

I've got the eLSD tune already. Trying to change one thing at a time to get a better feel for what each change is doing. Whiteline front bar is the next change - results I saw on my Mustang were similar to what you're saying, going somewhat stiffer in the front helps transitions without causing too much understeer, just can't overdo it. When I finish off my current tires, going to square 305s will be the next step.