So why does my S650 GT not handle as well as my S550 GT?

[young at heart]

Let me first be clear: I really like my 2024 GT coupe a lot. A whole lot. And overall it’s a nice handling street car. But try hard as I may to ignore it, the fact is that when both are pushed a bit into a corner my 2020 GT convertible is just flat out a better handling car. The term “better handling” is subjective of course but I mean that the ‘20 easily goes into a corner faster, deeper and flatter than the ‘24. It’s not my imagination. And there’s nothing mechanically wrong with the ‘24. It’s completely up to snuff. The ‘20 has 5,000 miles and the ‘24 has 1,000.

Both cars are equipped the same. They’re both non-PP premium GTs with the A10/3.15s and both have the slightly upgraded 19x8.5 wheels with the 255/40 19” tires. To add insult to injury, the better handling ‘20 vert is rolling on the PZeros that everyone loves to hate and the ‘24 coupe has the Conti Pro Contacts. Pressure is correctly set.

The ONLY variable I can see is that the ‘20 GT being a convertible has the strut tower brace and the ‘24 does not. If I thought the STB made this big a difference I’d slap one on the ‘24 immediately but generally nobody thinks this matters much.

Any thoughts as to what the variable might be would be appreciated. It’s making me a little crazy.

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[BoostRabbitGT]

My guess would be that the S550 has a heavier steering weight feel than the S650. For me that translates to feeling more engaged heading into and out of turns with the S550, even though I technically feel more confident with the S650's lighter weighted steering (less feedback from the road, but more accurate in the sense that wherever I point the steering wheel, that's exactly where I'll go).

 

[robvas]

Strut tower braces don't do shit, especially stiffen a convertible up to coupe levels...

tires/alignment/imagination is where I would start

but it's kind of pointless if you don't have any recorded numbers for each car (skid pad, slalom, etc)

 

[MAT1955]

@young at heart ......first get the strut tower brace. IMO no Mustang convertible should ever leave the factory without that strut brace. I guess you did not get the premium or it should have had the strut brace from the factory. Get one - like as of yesterday. It will make a significant difference. I wouldn't even push it into a corner without one. Massive difference when g forces come into play and even a significant difference in every day driving. Makes the car feel so much stiffer. Google how to properly install it so you don't break a stud. For the 2024 you need to see what customizations you have done or want regarding steering, etc. NOOOO way does an S550 handle better that an S650 - not even close..... just watch the Ford technical videos on what went into the engineering changes. Have you checked your front end alignment. That too may be off. I drove a number of new S550's before selecting the S650. The S550 is no where near the same class as the S650.

 

[MAT1955]

@robvas..... I respectfully disagree. A fellow Mustang enthusiast wanted to see the how much a strut tower brace affected the stiffness of the front end. He installed three metered rods all connected to the strut tower and back to the firewall. All had pull gauges. The cross strut front lateral change was 5/8" the strut to firewall was 3/4" and while he pushed the car, he did not run it really, really hard. We were all amazed. This guy was a physicist for the National Research Council. No strut brace on a Mustang convertible = IMO waaaay too much front end play. BTW on my 2014 mustang convertible the under body braces that ran from the rear trunk underside , were then bolted to the underside of the floor before ending at the front of the car looked a bit worn and had some rust on them. I replaced them and the difference was immediate. On my 2024 S650 these two frame stiffening bars are now joined by a thick steel plate for extra reinforcement. the combination of these plus the two firewall to tower braces plus the strut tower brace - in combination - give massive synergy to the stiffening potential of the convertible. BTW I do agree that if the front end alignment is off the handling will be janky.... and I would have that checked after I ordered my strut tower brace. Will try to add picture of 2024 front bracing (3 bars) and the frame stiffener plate and bars.

 

[robvas]

So why doesn't the Dark Horse R have a strut brace?

companies like Vorschlag have said there is no measurable improvement in track times from a strut tower brace.

 

[erocker]

s650 is using a quicker steering rack, which is one difference. I'd start with getting the alignment checked.

 

[Upacurb]

@young at heart ......first get the strut tower brace. IMO no Mustang convertible should ever leave the factory without that strut brace. I guess you did not get the premium or it should have had the strut brace from the factory. Get one - like as of yesterday. It will make a significant difference. I wouldn't even push it into a corner without one. Massive difference when g forces come into play and even a significant difference in every day driving. Makes the car feel so much stiffer. Google how to properly install it so you don't break a stud. For the 2024 you need to see what customizations you have done or want regarding steering, etc. NOOOO way does an S550 handle better that an S650 - not even close..... just watch the Ford technical videos on what went into the engineering changes. Have you checked your front end alignment. That too may be off. I drove a number of new S550's before selecting the S650. The S550 is no where near the same class as the S650.

you obviously have no idea what you are talking about. No where the same class??? It’s the same car … same chassis with a few minor tweaks

I’ve seen some clueless fanboi posts in my life but congratulations you may have set a new standard

your post screams I’ve never driven an S550 and get all your information based on only things you have read

 

[young at heart]

@young at heart ......first get the strut tower brace. IMO no Mustang convertible should ever leave the factory without that strut brace. I guess you did not get the premium or it should have had the strut brace from the factory. Get one - like as of yesterday. It will make a significant difference. I wouldn't even push it into a corner without one. Massive difference when g forces come into play and even a significant difference in every day driving. Makes the car feel so much stiffer. Google how to properly install it so you don't break a stud. For the 2024 you need to see what customizations you have done or want regarding steering, etc. NOOOO way does an S550 handle better that an S650 - not even close..... just watch the Ford technical videos on what went into the engineering changes. Have you checked your front end alignment. That too may be off. I drove a number of new S550's before selecting the S650. The S550 is no where near the same class as the S650.

MAT1955, I’m afraid you misread my OP. It’s the other way around. The ‘20 vert DOES have the STB and always has. The ‘24 coupe does not have an STB and never has. And they’re both premiums.

Unless the alignment is somehow off without showing a single other symptom anytime, anywhere or in any other situation whatsoever, it’s just fine. And even if the ‘24’s alignment were janky, it wouldn’t explain the car having more body roll than the ‘20.

I can assure you that engineering changes notwithstanding in this case the ‘20 outhandles the ‘24.

 

[Upacurb]

Let me first be clear: I really like my 2024 GT coupe a lot. A whole lot. And overall it’s a nice handling street car. But try hard as I may to ignore it, the fact is that when both are pushed a bit into a corner my 2020 GT convertible is just flat out a better handling car. The term “better handling” is subjective of course but I mean that the ‘20 easily goes into a corner faster, deeper and flatter than the ‘24. It’s not my imagination. And there’s nothing mechanically wrong with the ‘24. It’s completely up to snuff. The ‘20 has 5,000 miles and the ‘24 has 1,000.

Both cars are equipped the same. They’re both non-PP premium GTs with the A10/3.15s and both have the slightly upgraded 19x8.5 wheels with the 255/40 19” tires. To add insult to injury, the better handling ‘20 vert is rolling on the PZeros that everyone loves to hate and the ‘24 coupe has the Conti Pro Contacts. Pressure is correctly set.

The ONLY variable I can see is that the ‘20 GT being a convertible has the strut tower brace and the ‘24 does not. If I thought the STB made this big a difference I’d slap one on the ‘24 immediately but generally nobody thinks this matters much.

Any thoughts as to what the variable might be would be appreciated. It’s making me a little crazy.

I think your just more used to the S550… the turn in was much better on the S650 GT I drove but the steering feel not quite as good…

have you seen the throttle house review of the S650 GT? I suggest you watch… I think it explains what you are experiencing…

I think you just need to progressively push a little harder each time to find the limits but given that they are fundamentally the same car underneath the limits should be about the same …

 

[MAT1955]

@robvas.... The Dark Horse R is a fastback, (coupe) isn't it? If so not having a strut tower brace is not as crucial as it is in a convertible where it is absolutely crucial. That said I have seen supercharged Mustangs where there was no room for Ford oem strut towers where the owner has fabricated a strut tower for them even though it has the much, much stiffer "fastback frame". The owner who purchased my 2014 convertible from me also installed stiffeners in the trunk frame area I can't remember if LMR or Steeda made them. Lots of convertible owners and a lot of fastback (coupe) owners also upgrade their sway bars and particularly front end parts including new adjustment shims and parts. IMO all of this helps Mustangs but convertibles in particular as they are more prone to axis twist and flex in general.

 

[young at heart]

I think your just more used to the S550… the turn in was much better on the S650 GT I drove but the steering feel not quite as good…

have you seen the throttle house review of the S650 GT? I suggest you watch… I think it explains what you are experiencing…

I think you just need to progressively push a little harder each time to find the limits but given that they are fundamentally the same car underneath the limits should be about the same …

Upacurb, thanks for your serious thoughts.

I’ll try to dig out that video. I’m not one to discount the power of suggestion. It isn’t impossible that I experienced it once in some situation and now have become sensitized to it. I’m human and this is subjective on my part. Seems real enough, but…

There is no doubt about the S550 having a heavier steering feel. This is obviously borne out by the 650’s intentional change to a quicker ratio. I’m not sure how this could trick one into thinking the S550 was the better handling car of the two, but it certainly isn’t impossible. An aside comment: back in the day when I came along a quicker steering box meant more effort, not less. Then along came EPAS to change the rules!

 

[MAT1955]

@Upacurb .....there are a quite number of authoritative videos wherein the differences in the S550 and S650 are concerned. One of the most informative is a lengthy one from Ford.

 

[young at heart]

@Upacurb .....there are a quite number of authoritative videos wherein the differences in the S550 and S650 are concerned. One of the most informative is a lengthy one from Ford.

If you come across it again would you post a link?

 

[CVCashmere]

FYI

I am a convertible owner.

The convertible is about 180 lbs heavier than the fastback, and has a slightly more neutral front/rear weight ratio as most of the additional weight is over the rear axle. They will flex more than a fastback even with the rear subframe added.

The vert will typically have a slightly smaller sway bar than the same car in a fastback to reduce the possibility of oversteer.

You may like the feel of the vert because of the above factors. With similar alignments, I believe the fastback will outcorner my vert as it came from the factory.

CVCashmere

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