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[Droopy1592]

If you look at the spring rate changes percentage-wise, the delta is rather small. This isn't complicated. The biggest potential gain lies in the tire. Without a good tire the other changes mean little as you simply can't take advantage of them.

we don’t know damping rates, camber angles, minor changes in anti-roll bars can make a significant difference...

In some cars, having adjustable camber can alone be the difference of 1-3 seconds per track. Same tires.

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[9secondko]

If you look at the spring rate changes percentage-wise, the delta is rather small. This isn't complicated. The biggest potential gain lies in the tire. Without a good tire the other changes mean little as you simply can't take advantage of them.

Adding Cup2's to a base car will definitely make it faster. Adding CFTP springs or bars while staying on 4s's....not so much.

The cftp has specific rates. Yes or no.
Also the way they did it. Spring vs. damping (vs. 350R) is interesting and provides better results.

it’s a total combo of which tires of course play a part. But it’s a package. The performance wouldn’t be anywhere near what it is with just the tires.

and even changes in spring and damping tune that aren’t amazingly large are exponentially different AT SPEED. the delta is not small on the track. It is a near exponential difference. And I think you know the difference between a spring and damper sitting still at a certain rate vs. a spring and damper at that rate at speed. Especially when you factor in specific damping tune differences. It’s not a small difference.

 

[Epiphany]

I can't explain it to you any other way. The biggest potential lies in the tires. When everything else is tuned to match it gets even better, nobody is arguing that point.

we don’t know damping rates, camber angles, minor changes in anti-roll bars can make a significant difference...

In some cars, having adjustable camber can alone be the difference of 1-3 seconds per track. Same tires.

Negative camber was increased on CFTP cars which helps the car on the track while still allowing it to be perfectly streetable (and I'm not referencing the recommended track alignment settings). The rear bar was changed on the CFTP cars (Diameter increased by 1.4mm and wall thickness increased by .9mm) that should provide for a "stiffer" bar (assuming the link locations are the same) and as such an understeer "correction" allowing the car to rotate. The changes made here would benefit the Base car as well and are exactly what those that track will be doing to their cars. Nothing new.

On the S550 chassis, increased negative camber and better tires can make a substantial difference at a given track. Of course a camber change alone can make a difference. When combined with an improved tire the benefit increases substantially. Spend some time in the pits at a few IMSA Michelin series GT4 races and you'll see exactly what I'm talking about. And yes the dampers are different, yada, yada. You get the point.

 

[kilobravo]

E: I gotta say, you (and others,) sure know a whole lot about racing cars. I've learned SO much from this Forum being "the waxer" from outta nowhere who has a thing for graphic images and who somehow, with no clout, snagged a 2-seater. <grin>

Please, keep 'em coming, and even being a geezer, i still love to learn.

 

[9secondko]

I can't explain it to you any other way. The biggest potential lies in the tires. When everything else is tuned to match it gets even better, nobody is arguing that point.





Negative camber was increased on CFTP cars which helps the car on the track while still allowing it to be perfectly streetable (and I'm not referencing the recommended track alignment settings). The rear bar was changed on the CFTP cars (Diameter increased by 1.4mm and wall thickness increased by .9mm) that should provide for a "stiffer" bar (assuming the link locations are the same) and as such an understeer "correction" allowing the car to rotate. The changes made here would benefit the Base car as well and are exactly what those that track will be doing to their cars. Nothing new.

On the S550 chassis, increased negative camber and better tires can make a substantial difference at a given track. Of course a camber change alone can make a difference. When combined with an improved tire the benefit increases substantially. Spend some time in the pits at a few IMSA Michelin series GT4 races and you'll see exactly what I'm talking about. And yes the dampers are different, yada, yada. You get the point.

You referenced more details than I did. All of which prove to distance your point from reality.

you’re a smart guy. You’re just not correct here. There is less weight - including less unsprung weight, Multiple spec changes, and tires.

the tires aren’t the most of that. They didn’t gain 3 seconds on tire. Let alone 5.

negative camber is definitely a part. The Corvette c8 was kind of a letdown from the factory. But change the camber and it’s pretty good. That’s something common to any car.

the 509 CFTP performs to the sum of its systems. Tire being a Fraction of.

 

[BmacIL]

Tire being a Fraction of

That's pretty laughable. The gap between a 4S and Cup 2 is pretty huge. If you don't recognize that the majority of the gap is tires, not a small fraction, you're simply wrong. If it's 5 seconds, 3-3.5s of that is Cup 2 over the 4S.

Have you driven on both? You'd know this if you have.

 

[Epiphany]

Everyone has their opinion or point of view, I get it. I was lucky enough to have been embedded with a GT4 effort during the 2018 season (the last for Continental). You see first hand and near immediately the changes on the track as a result of a tire change or a suspension adjustment. I talked to the drivers at every race about the track itself and listened firsthand when they commented on track conditions as well as that of the car, etc. You can dial in the suspension settings, alignment, etc, prior to the race but when it counts it is all about the tires.


Here's my good friend Tom at Road Atlanta checking camber. They were running near -4*.

And of course, accurate and repeatable (as well as quick) camber changes can benefit the car and be used to tune for different tracks, etc. The "plates" from Multimatic are fantastic in this regard.

I watched different teams set their cars up at the same tracks. It was interesting to watch and talk to the Volt team in '18 as they strung up their car. I set my own car up the same way, albeit without the $hiny equipment they use.

Put a Cup2 on a Base car and put the 4S tires on a CFTP car. You'd see very quickly how much difference the tires make. And yes they won't be tuned to perfection, blah, blah.

On edit...here's a post from a guy that races and has a good grasp. Spot on...

...the single greatest mod you can do to a car turning left and right is add good wheels and tires.

I’d still want a CFTP car for my preference. Just that if I had a base model with the handling pkg, I’d put on lightweight wheels and tires to narrow the gap between the two cars.

Regardless, don’t take my post the wrong way, CFTP for the win! But if you have a non CFTP, you’ll be well within 80-90% of one at the track if you spend another $5k on wheels and tires for the track.

https://www.mustang6g.com/forums/threads/motor-trend-track-test.132598/page-4#post-2735808

 

[JR369]

I feel like the CFTP option along with the painted stripes is more for collectors. I totally agree that the CFTP option is 100% functional and better than a Base with the handling pkg and cup2's tho. But for the money, and the level I drive at, the Base with handling and cup2 would be a smarter choice for me..

 

[Droopy1592]

Tires still aren’t 5 seconds or a complete majority of it. Half, yes, more than likely. Generally a track like VIR 4S-> Cup 2 have been about 2-2.5 seconds. Suspension (including unsprung mass reduction, camber, etc), and aero is the rest. Again, at VIR there’s a difference of ~5 seconds between a GT3 and an GT3RS, same tires.

 

[Epiphany]

Regarding aero. Note that regardless of configuration, Base with Handling Package or CFTP - the front end aero is identical. The difference in aero between the two lies exclusively at the rear. CFTP wing is quoted as having a maximum amount of downforce of 550 lbs at 180mph and the Handling package produces 379 lbs of downforce at the same speed, 180mph. There are downforce curves for each but of interest, how often/long is the car at 180mph at VIR? How do the two compare at 80, 120, or 150mph? Just a data point but the C7 Corvette Z06 with the Z07 (track) package produces 350lbs at 150mph. All relative.

 

[Droopy1592]

Regarding aero. Note that regardless of configuration, Base with Handling Package or CFTP - the front end aero is identical. The difference in aero between the two lies exclusively at the rear. CFTP wing is quoted as having a maximum amount of downforce of 550 lbs at 180mph and the Handling package produces 379 lbs of downforce at the same speed, 180mph. There are downforce curves for each but of interest, how often/long is the car at 180mph at VIR? How do the two compare at 80, 120, or 150mph? Just a data point but the C7 Corvette Z06 with the Z07 (track) package produces 350lbs at 150mph. All relative.

Still not the majority of the five seconds. You’re nitpicking aero but the whole package is lighter with more downforce, wheels are easier to accel and decel, camber allowing for quicker and more accurate turn in, suspension dialed in more for the track. There not THAT much of a difference in lateral grip between the two tires to make up 4 out of the five seconds. I’ve seen 1-2.5 seconds going from PSS to Cup 2s at most tracks. Unless Michelin suddenly developed a compound with drastically more lateral grip than before, I don’t see the majority of the five seconds being due solely to tires. Find another car that makes up that kind of time at a similar/same length track...

 

[Epiphany]

I'm not nitpicking anything but rather pointing out factual data. I already mentioned that the GT4 Mustangs were seeing a ~3 second improvement per lap with Michelins over the same size Continental slick used in the prior series. I'm not talking about the Porsches you keep mentioning and am sticking to the S550 chassis. The Michelins on the CFTP are about as good as a street legal tire could possibly get and a marked improvement over the 4S tires on a road course. That said, the 4S tires are the better of the two for the strip which is a bit of a surprise.

As I said, put the 4S tires on the CFTP and the Cup2's on the Base with HP and watch the difference evaporate. And that's without any bar/spring/damper/aero changes.

 

[shogun32]

put the 4S tires on the CFTP and the Cup2's on the Base with HP and watch the difference evaporate. And that's without any bar/spring/damper/aero changes.

why can't these magazine test regimens do something like this? It's called control group and essential to scientific method. Re-iterating that the factory stacked the deck in favor of the R over it's base isn't useful information. Or are they afraid the truth might get out and the $18,000 advantage can be closed with a mere $2000 in tires?

 

[Epiphany]

I suspect you are pretty close to the truth regarding image/option choices.

 

[Eritas]

I guess the GT4 wing doesn't make a difference. Maybe the race teams should use the base spoiler

iirc, the carbon wheels are worth about 1 second per lap.

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