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@Run_Amok, lots of good replies on this thread. Here's another vote for Billy Johnson's article over on moto-iq, it's excellent. A couple more thoughts in response to your questions:

1. No, I don't think corner-balancing adds very much at an intermediate HPDE level. I'd put it lower on your list.
2. Some of the best advice I got was to pick your track tires first and then find track rims to work with those tires. The biggest decision here is that most true race tires for Mustangs come in 18" diameter but the majority of good 200tw "tweener" tires are in 305/30/19 or similar. So you sort of have to decide what type of tires you want to use.
3. PHB vs. Watts seems to be more personal preference than objectively one is faster than the other. Plenty of very fast cars using both. As true racers on here have explained (@Fabman etc.) my understanding is one of the biggest advantages of the WL is you can adjust rear roll center, and thus rear roll stiffness, pretty easily. I think a lot of the reported "improvement in driving feel" posts you see with a WL comes from what is sometimes a lower roll center. But you can get similar results and benefits by softening your rear roll rate, such as by removing or reducing the size of the rear roll bar which is easy to do. Billy's article has the details.

I'm not familiar with your SR springs but yes, I think you do want adjustable rear LCA brackets if you have lowered the car significantly. Which it seems you have if you were in need of a front bump-steer kit?

IMO your next best ROI upgrades are good wheels and tires and front camber plates.
I think everyone agrees across the board that the most dramatic effect comes from the tire/ wheel package, that is by far, the easiest ( maybe not the cheapest) change that makes the biggest difference.
Do that, do the camber plates, and see where that gets you. I think you'll be surprised.
And FWIW, the " golden" sway bars are the Ford " blue" bar, and the 18mm or no bar in the rear, I forget the part numbers, but some of these guys will have them.
 
42
13
Exp. Type
HPDE
Exp. Level
5-10 Years
Texas
Boyington and when I was a firefighter.

I don't think you need to mess with the rear suspension attachment points at all.
BTW, I crewed on Billy Johnsons car in IMSA last year. His article was very good, I think he still drives that car, it was parked at Kohr.
Understood. Thank you, sir.
@Run_Amok, lots of good replies on this thread. Here's another vote for Billy Johnson's article over on moto-iq, it's excellent. A couple more thoughts in response to your questions:

1. No, I don't think corner-balancing adds very much at an intermediate HPDE level. I'd put it lower on your list.
2. Some of the best advice I got was to pick your track tires first and then find track rims to work with those tires. The biggest decision here is that most true race tires for Mustangs come in 18" diameter but the majority of good 200tw "tweener" tires are in 305/30/19 or similar. So you sort of have to decide what type of tires you want to use.
3. PHB vs. Watts seems to be more personal preference than objectively one is faster than the other. Plenty of very fast cars using both. As true racers on here have explained (@Fabman etc.) my understanding is one of the biggest advantages of the WL is you can adjust rear roll center, and thus rear roll stiffness, pretty easily. I think a lot of the reported "improvement in driving feel" posts you see with a WL comes from what is sometimes a lower roll center. But you can get similar results and benefits by softening your rear roll rate, such as by removing or reducing the size of the rear roll bar which is easy to do. Billy's article has the details.

I'm not familiar with your SR springs but yes, I think you do want adjustable rear LCA brackets if you have lowered the car significantly. Which it seems you have if you were in need of a front bump-steer kit?

IMO your next best ROI upgrades are good wheels and tires and front camber plates.
Steve, thanks so much for the direct answers. Based on your and others' input, I am now at a 90% confidence level that I will not be on coilovers and 100% confidence that I will not go for the Watts-link solution.

SR may be American Muscle's house brand? It appears that these springs lowered the car by at least 1"... I don't know if they do anything other than that.
I think everyone agrees across the board that the most dramatic effect comes from the tire/ wheel package, that is by far, the easiest ( maybe not the cheapest) change that makes the biggest difference.
Do that, do the camber plates, and see where that gets you. I think you'll be surprised.
And FWIW, the " golden" sway bars are the Ford " blue" bar, and the 18mm or no bar in the rear, I forget the part numbers, but some of these guys will have them.
Rims and Tires. Sigh. Here's what I am going with per Apex's wheel and tire fitment guide:

19x10 - ET40
285/35-19
Square

I may be opening a can of worms, but I would love you hear y'alls opinion on this configuration mated to the Steeda Kit that EF1 referenced:

A big thank you to everyone that has commented thus far!
 
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Whatever you do, try to make sure you source the parts from one place, nothing worse than calling xyz suspension about a problem and they blaming ABC for the issue, then ABC does the same thing.
Those Ford kits have hours upon hours of development time on them.
 
42
13
Exp. Type
HPDE
Exp. Level
5-10 Years
Texas
Whatever you do, try to make sure you source the parts from one place, nothing worse than calling xyz suspension about a problem and they blaming ABC for the issue, then ABC does the same thing.
Those Ford kits have hours upon hours of development time on them.
Great point and sage advice, Mr. blacksheep-1!
 
1,199
1,204
Exp. Type
HPDE
Exp. Level
5-10 Years
Lenoir City TN
Understood. Thank you, sir.

Steve, thanks so much for the direct answers. Based on your and others' input, I am now at a 90% confidence level that I will not be on coilovers and 100% confidence that I will not go for the Watts-link solution.

SR may be American Muscle's house brand? It appears that these springs lowered the car by at least 1"... I don't know if they do anything other than that.

Rims and Tires. Sigh. Here's what I am going with per Apex's wheel and tire fitment guide:

19x10 - ET40
285/35-19
Square

I may be opening a can of worms, but I would love you hear y'alls opinion on this configuration mated to the Steeda Kit that EF1 referenced:

A big thank you to everyone that has commented thus far!
It really depends on your end game for the car. I like the plan for a dual use street/HPDE car. The Steeda/Billy J kit was picked to handle both the street and the track. It does not come with adj. pan hard bar or strut mounts which in your case is good. You already have an adj. pan hard bar and it allows you to choose which upper mounts/camber plates you want all for less money than the Ford Performance kit. The upper strut mounts that come with the Ford kit are not adjustable for camber/caster. I ran Steeda Sport Springs with Koni oranges, which Steeda said were comparable to their shocks, on my car for several years. Everyone that rode in it on track was surprised at how well it handled.

Apex wheels are generally well thought of on the forum. The differences of opinion come when choosing size. That is really dependent on your future plans for the car. Someone in a previous post said to choose your tires first and build the car around them. That is really good advice. If you aspire to run competitive classes (time trial or wheel to wheel racing) look at the rules for the class you intend to run and get the widest stickiest tire you can within the the rules.

All other things being equal a wider tire will be faster. Many choose an 11" wide wheel with 305 or 315 wide tires. This requires a fair amount of negative camber, wheel spacers around 25mm thick and extended studs. If you are wanting to go as fast as possible this is your best best.

If you are looking at HPDE classes and don't care about a couple of seconds a lap a 10" wide wheel is fine. You can usually run tires from 275 to 295 wide without issue. This is the route I have taken. I run the 19 x 10 Apex wheels you mentioned and have run both 275 and 285 wide tires depending on price/availability. I plan on trying 295's next time around. Yes I agree that the car could be a little faster with more tire, but I am not racing, just having fun.

This is just my opinion and I am sure others will chime in with theirs.
 
6,453
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It really depends on your end game for the car. I like the plan for a dual use street/HPDE car. The Steeda/Billy J kit was picked to handle both the street and the track. It does not come with adj. pan hard bar or strut mounts which in your case is good. You already have an adj. pan hard bar and it allows you to choose which upper mounts/camber plates you want all for less money than the Ford Performance kit. The upper strut mounts that come with the Ford kit are not adjustable for camber/caster. I ran Steeda Sport Springs with Koni oranges, which Steeda said were comparable to their shocks, on my car for several years. Everyone that rode in it on track was surprised at how well it handled.

Apex wheels are generally well thought of on the forum. The differences of opinion come when choosing size. That is really dependent on your future plans for the car. Someone in a previous post said to choose your tires first and build the car around them. That is really good advice. If you aspire to run competitive classes (time trial or wheel to wheel racing) look at the rules for the class you intend to run and get the widest stickiest tire you can within the the rules.

All other things being equal a wider tire will be faster. Many choose an 11" wide wheel with 305 or 315 wide tires. This requires a fair amount of negative camber, wheel spacers around 25mm thick and extended studs. If you are wanting to go as fast as possible this is your best best.

If you are looking at HPDE classes and don't care about a couple of seconds a lap a 10" wide wheel is fine. You can usually run tires from 275 to 295 wide without issue. This is the route I have taken. I run the 19 x 10 Apex wheels you mentioned and have run both 275 and 285 wide tires depending on price/availability. I plan on trying 295's next time around. Yes I agree that the car could be a little faster with more tire, but I am not racing, just having fun.

This is just my opinion and I am sure others will chime in with theirs.
Whatever you do, you will need somebody's camber plates, and the Vorschlag jig to cut the strut towers... which I may have.. someplace. Live in Florida?
 
42
13
Exp. Type
HPDE
Exp. Level
5-10 Years
Texas
It really depends on your end game for the car. I like the plan for a dual use street/HPDE car. The Steeda/Billy J kit was picked to handle both the street and the track. It does not come with adj. pan hard bar or strut mounts which in your case is good. You already have an adj. pan hard bar and it allows you to choose which upper mounts/camber plates you want all for less money than the Ford Performance kit. The upper strut mounts that come with the Ford kit are not adjustable for camber/caster. I ran Steeda Sport Springs with Koni oranges, which Steeda said were comparable to their shocks, on my car for several years. Everyone that rode in it on track was surprised at how well it handled.

Apex wheels are generally well thought of on the forum. The differences of opinion come when choosing size. That is really dependent on your future plans for the car. Someone in a previous post said to choose your tires first and build the car around them. That is really good advice. If you aspire to run competitive classes (time trial or wheel to wheel racing) look at the rules for the class you intend to run and get the widest stickiest tire you can within the the rules.

All other things being equal a wider tire will be faster. Many choose an 11" wide wheel with 305 or 315 wide tires. This requires a fair amount of negative camber, wheel spacers around 25mm thick and extended studs. If you are wanting to go as fast as possible this is your best best.

If you are looking at HPDE classes and don't care about a couple of seconds a lap a 10" wide wheel is fine. You can usually run tires from 275 to 295 wide without issue. This is the route I have taken. I run the 19 x 10 Apex wheels you mentioned and have run both 275 and 285 wide tires depending on price/availability. I plan on trying 295's next time around. Yes I agree that the car could be a little faster with more tire, but I am not racing, just having fun.

This is just my opinion and I am sure others will chime in with theirs.
^ Great info! A quick Google reveals the Steeda dampers are made by Koni and the springs by Eibach. I was not able to find who manufactures FP's suspension pieces, but I didn't spend more than a minute looking. I am fan of Koni and Eibach, so...

The fact that the Apex rims are direct fit (Enkei's need hubcentric rings for S197 fitment, IIRC) is the tipping point. Made Stateside as well!

I am sure a stock GT is more capable than I am at this point, meaning any upgrade in tire cross section will be more than enough. Cost and utility bring me to the 285s.

Interestingly, the SR springs have induced the front to -1.8° camber. I doubt I will need more negative camber, but I will get camber plates as a precaution and a "while we are in there".
Whatever you do, you will need somebody's camber plates, and the Vorschlag jig to cut the strut towers... which I may have.. someplace. Live in Florida?
I appreciate you willingness to lend me the jig! I live in Austin, TX. If I was in FL, I would like to have met you in person.

MM says thier plates do not require modification to the strut tower, so I will probably go with those.
 

JDee

Ancient Racer
1,817
2,018
Exp. Type
W2W Racing
Exp. Level
20+ Years
5 miles from Mosport
^ Great info! A quick Google reveals the Steeda dampers are made by Koni and the springs by Eibach. I was not able to find who manufactures FP's suspension pieces, but I didn't spend more than a minute looking. I am fan of Koni and Eibach, so...

The fact that the Apex rims are direct fit (Enkei's need hubcentric rings for S197 fitment, IIRC) is the tipping point. Made Stateside as well!

I am sure a stock GT is more capable than I am at this point, meaning any upgrade in tire cross section will be more than enough. Cost and utility bring me to the 285s.

Interestingly, the SR springs have induced the front to -1.8° camber. I doubt I will need more negative camber, but I will get camber plates as a precaution and a "while we are in there".

I appreciate you willingness to lend me the jig! I live in Austin, TX. If I was in FL, I would like to have met you in person.

MM says thier plates do not require modification to the strut tower, so I will probably go with those.
They also won't get you much camber. Mine barely got -2.2 and that is nowhere near enough. Worse, the spherical bearing in one seized up and the top plate sawed its way well into the shaft of an expensive strut. I replaced with Vorshlag plates, far better quality and they get you lots more camber, mine max out at over -4. You need a ton of neg camber for best tire wear/max cornering g's and buying a cheap product that won't get you anywhere is not going to save anything in the long run. Doing the mod for the max Vorshlag setup is not a big deal. If I can do it anyone can.
 
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^ Great info! A quick Google reveals the Steeda dampers are made by Koni and the springs by Eibach. I was not able to find who manufactures FP's suspension pieces, but I didn't spend more than a minute looking. I am fan of Koni and Eibach, so...

The fact that the Apex rims are direct fit (Enkei's need hubcentric rings for S197 fitment, IIRC) is the tipping point. Made Stateside as well!

I am sure a stock GT is more capable than I am at this point, meaning any upgrade in tire cross section will be more than enough. Cost and utility bring me to the 285s.

Interestingly, the SR springs have induced the front to -1.8° camber. I doubt I will need more negative camber, but I will get camber plates as a precaution and a "while we are in there".

I appreciate you willingness to lend me the jig! I live in Austin, TX. If I was in FL, I would like to have met you in person.

MM says thier plates do not require modification to the strut tower, so I will probably go with those.
Yeah, they will in order to get enough camber, the strut towers opening is simply too small for the correct amount of adjustmentScreenshot_20230228-104050_Imgur.jpg
 
1,199
1,204
Exp. Type
HPDE
Exp. Level
5-10 Years
Lenoir City TN
^ Great info! A quick Google reveals the Steeda dampers are made by Koni and the springs by Eibach. I was not able to find who manufactures FP's suspension pieces, but I didn't spend more than a minute looking. I am fan of Koni and Eibach, so...

The fact that the Apex rims are direct fit (Enkei's need hubcentric rings for S197 fitment, IIRC) is the tipping point. Made Stateside as well!

I am sure a stock GT is more capable than I am at this point, meaning any upgrade in tire cross section will be more than enough. Cost and utility bring me to the 285s.

Interestingly, the SR springs have induced the front to -1.8° camber. I doubt I will need more negative camber, but I will get camber plates as a precaution and a "while we are in there".

I appreciate you willingness to lend me the jig! I live in Austin, TX. If I was in FL, I would like to have met you in person.

MM says thier plates do not require modification to the strut tower, so I will probably go with those.
I have had two sets of Steeda linear rate springs for the S197 the Sports and Competitions. Both were manufactured by Hyperco for Steeda. The Eibach springs I have seen for the S197 were progressive rates. I have heard that the Ford Performance springs are rebadged Eibachs, but I haven't been able to confirm it. I do know that Maximum Motorsports made the S197 bump steer kits for Ford Performance.

I am not sure who makes Steeda shocks but one of their reps told me that the Steeda shocks and the Koni Oranges had similar valving. They interchanged them based on stock and pricing. I ended up with Koni since the Steeda's were out of stock the first time around. They also said the Koni Yellows on full soft were similar to the Oranges or their shocks.

No camber plates require you to cut the towers, but you will get more adjustability if you do. Like @blacksheep-1 said, the openings in the stock towers are just too small.
 
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Fabman

Dances with Racecars
6,580
8,243
Exp. Type
W2W Racing
Exp. Level
20+ Years
Pleasanton: 1/2 way between Sonoma and Laguna Seca
I think everyone agrees across the board that the most dramatic effect comes from the tire/ wheel package, that is by far, the easiest ( maybe not the cheapest) change that makes the biggest difference.
Do that, do the camber plates, and see where that gets you. I think you'll be surprised.
And FWIW, the " golden" sway bars are the Ford " blue" bar, and the 18mm or no bar in the rear, I forget the part numbers, but some of these guys will have them.
Agreed, just a note though, the ford racing sway bar kit comes with a 22mm rear bar. The preferred 18mm rear bar is from a v6 mustang convertible I believe and has to be purchased separately. Get the ford racing front bar and then source the 18mm rear bar. Pretty sure cortex racing has the v6 bars in stock. @Run_Amok
 

Fabman

Dances with Racecars
6,580
8,243
Exp. Type
W2W Racing
Exp. Level
20+ Years
Pleasanton: 1/2 way between Sonoma and Laguna Seca
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Just an FYI that what Cortex will send you if you buy their 'Ford 18mm rear bar' listing is Dorman 927-203. You can find this kit on RockAuto for $90 and Amazon for $100.
 

Fabman

Dances with Racecars
6,580
8,243
Exp. Type
W2W Racing
Exp. Level
20+ Years
Pleasanton: 1/2 way between Sonoma and Laguna Seca
Just an FYI that what Cortex will send you if you buy their 'Ford 18mm rear bar' listing is Dorman 927-203. You can find this kit on RockAuto for $90 and Amazon for $100.
That's incredibly affordable.
 
42
13
Exp. Type
HPDE
Exp. Level
5-10 Years
Texas
They also won't get you much camber. Mine barely got -2.2 and that is nowhere near enough. Worse, the spherical bearing in one seized up and the top plate sawed its way well into the shaft of an expensive strut. I replaced with Vorshlag plates, far better quality and they get you lots more camber, mine max out at over -4. You need a ton of neg camber for best tire wear/max cornering g's and buying a cheap product that won't get you anywhere is not going to save anything in the long run. Doing the mod for the max Vorshlag setup is not a big deal. If I can do it anyone can.

Yeah, they will in order to get enough camber, the strut towers opening is simply too small for the correct amount of adjustmentView attachment 84415
Understood. Thank you both for the clarification.
I have had two sets of Steeda linear rate springs for the S197 the Sports and Competitions. Both were manufactured by Hyperco for Steeda. The Eibach springs I have seen for the S197 were progressive rates. I have heard that the Ford Performance springs are rebadged Eibachs, but I haven't been able to confirm it. I do know that Maximum Motorsports made the S197 bump steer kits for Ford Performance.

I am not sure who makes Steeda shocks but one of their reps told me that the Steeda shocks and the Koni Oranges had similar valving. They interchanged them based on stock and pricing. I ended up with Koni since the Steeda's were out of stock the first time around. They also said the Koni Yellows on full soft were similar to the Oranges or their shocks.

No camber plates require you to cut the towers, but you will get more adjustability if you do. Like @blacksheep-1 said, the openings in the stock towers are just too small.
For the most part the resellers, vendors, and manufacturers do not list spring rates. Perhaps if they did share this data it would be revealed that there is very little differentiation across the products / brands? I'll probably make a few phone calls to see if / where this information is available.
Agreed, just a note though, the ford racing sway bar kit comes with a 22mm rear bar. The preferred 18mm rear bar is from a v6 mustang convertible I believe and has to be purchased separately. Get the ford racing front bar and then source the 18mm rear bar. Pretty sure cortex racing has the v6 bars in stock. @Run_Amok

@Run_Amok
The eibach front bar is the same size (35mm) as the ford racing blue bar and is a suitable substitute.

Front:

Rear:
Thank you, this is great info!
Just an FYI that what Cortex will send you if you buy their 'Ford 18mm rear bar' listing is Dorman 927-203. You can find this kit on RockAuto for $90 and Amazon for $100.
Well heck yeah. That seems like the way to go.

It appears that Cortex sells only adjustable rear bars now (Eibach and their proprietary unit).
 
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Understood. Thank you both for the clarification.

For the most part the resellers, vendors, and manufacturers do not list spring rates. Perhaps if they did share this data it would be revealed that there is very little differentiation across the products / brands? I'll probably make a few phone calls to see if / where this information is available.



Thank you, this is great info!

Well heck yeah. That seems like the way to go.

It appears that Cortex sells only adjustable rear bars now (Eibach and their proprietary unit).
Ricky at Cortex is a great guy, he was the manager of a team I worked for at Daytona a few years ago.
Also, if you want, I can loan you the jig to cut those strut towers, just make sure I get it back.
 
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1,199
1,204
Exp. Type
HPDE
Exp. Level
5-10 Years
Lenoir City TN
This thread has most of the rates for springs common to the S197.


Just remember that most springs are progressive rate. If only one number is given instead of a range it is usually the average. Steeda is one of the few that sells linear rate springs for this platform if you have a preference.
 
42
13
Exp. Type
HPDE
Exp. Level
5-10 Years
Texas
Ricky at Cortex is a great guy, he was the manager of a team I worked for at Daytona a few years ago.
Also, if you want, I can loan you the jig to cut those strut towers, just make sure I get it back.
Wow, yes, thank you! Amazing. Very kind of you, blacksheep-1. I will PM you at the appropriate time to coordinate.
This thread has most of the rates for springs common to the S197.


Just remember that most springs are progressive rate. If only one number is given instead of a range it is usually the average. Steeda is one of the few that sells linear rate springs for this platform if you have a preference.
Very helpful! Based on this, I am keeping the SRs and Konis that are currently on my car. Woop woop!
 
42
13
Exp. Type
HPDE
Exp. Level
5-10 Years
Texas
Fellas, so... regarding the 'Spring and Sway Bar Rates' thread, the SR spring rates specifically, I cannot locate a second source to verify the posted Front: 230 lb/in. Rear: 200 lb/in.

I called American Muscle and waited 20 minutes while the rep did looked for the info, scoured Hypercoil's website (I think I read on TMO that Hypercoil makes the SR springs), and searched the web. Do y'all know where the OP of that thread, Grant302, sourced the rates?
 

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