Stats: 2015 Z28 vs. 2016 GT350R

[Dr G]

I found this comparison stat sheet interesting:

https://static1.pt-content.com/images/pt/2016/01/GT350R20vs20Z28-1.jpg

The cars weigh around 3800 lbs. They make around 500 HP. That is comparable to a lot of "Pro Touring" cars or trucks. My truck is about 500 lbs lighter and makes less power (until I turbocharge it).

What strikes me is that both cars use (min) 15 inch rotors front and rear. That seems to be the new de facto standard with modern performance cars (Porsche, BMW, Audi, Ferrari etc). Some even use 16 inch front rotors. Some of these cars do have the option of carbon ceramic rotors to reduce weight, but often they are plain ole' cast iron.

The other thing I note is the wheel and tire size. Essentially a square setup. In this case both cars run 19"x11" front and 19" x 11.5" rear wheels. The Z28 runs square tires (305 section front and rear). The Mustang has slightly larger rear tires (315 section). These cars still have 54% or so front weight distribution.

I think it is established that a stock Z28 or GT350R can outpace just about any Pro Touring build around a race track. Why is that?

Pro Touring builds often exceed the power output of these two cars. Yet so often they run a strong rearward bias in tire width. Why? Because it's easier to get wide rear tires to fit? Because it looks good? For traction? The inevitable consequence is a tendency to understeer during cornering. This is Pro Touring, not Pro Street after all. Unless some folks are going for a blend of the two.

Also, why install 19" or even 20" wheels and then run 12" or 13" front rotors? Sure they weigh less. But in my opinion, cars like the Z28 and GT350R demonstrate that it's not the optimum setup in today's world. The written review on the GT350R does imply that the lightweight carbon fiber wheels are a real game changer, making the car feel hundreds of pounds lighter.

Just some rambling thoughts...

[WallaceMFG]

Here's my thoughts.

Pro Touring cars may get newer suspension components, but unless you go to extreme measures it is still a car that was designed 40+ years ago. Both the Z28 and the GT350R have 40 years worth of technological advances. They've learned over the years better ways to design suspension and chassis components to get the most out of them. Also, I doubt any Pro Touring car has millions of dollars worth of engineering development invested into them.

From what I learned at GM, brakes tend to be biased to their intended use. They only put carbon brakes on vehicles that were intended for heavy track use. Lets be honest, even 15" steel brakes are overkill for normal street use. But if the owner decides to attend a HPDE they will be up to the job. If the owner knows they will be doing lots of racing, then the carbon brakes on the Z28 seem like a better choice because the carbon can absorb more heat without fade. The trend of brakes growing seems to be from the advances in tires to increase grip. Newer tires have more grip, so they can handle more brakes.

For tire sizes, keep in mind that long before a vehicle has ever been built they have decided if there will be a performance model of that car. In the case of the Gen 5 Camaro, they knew there would be a Z28 so they designed the car to be able to fit wide tires on the front. Same with the GT350. On my 69 Chevelle I put a 275 front tire. I did this because I did not have to modify the inner or outer fenders to keep them from rubbing. On the other hand, on the rear I could fit a 315 if I wanted to with no mods. Other cars can take more in the front, others can take less. Many people do not want to modify their car to the extent it would take to fit a 305 tire on the front.

Then there's the ever growing input of computers in modern cars. Most Pro Touring cars have no electronic controls on them. Computers in modern cars make it damn near possible to drive around a track with your foot on the floor and the car sorts everything else out. Audi built a car that once it was shown a track the car could drive itself around the track at nearly the same time as a professional driver. How can a person in a garage compete with that?


I love Pro Touring cars, but just as in racing it's harder to beat somebody with more money than you. And none of us have more money than Gm and Ford haha.

[Dr G]

Here's my thoughts.
Pro Touring cars may get newer suspension components, but unless you go to extreme measures it is still a car that was designed 40+ years ago. Both the Z28 and the GT350R have 40 years worth of technological advances. They've learned over the years better ways to design suspension and chassis components to get the most out of them. Also, I doubt any Pro Touring car has millions of dollars worth of engineering development invested into them.

Agreed. But of the items on which development money is spent by the manufacturers, how many of those items are really pertinent to the comparison to Pro Touring cars? Fuel efficiency? No. Emissions? No. Sound deadening? Maybe. Ride comfort? Maybe. Mass reduction? No. Chassis stiffness? Yes (though installing a full cage in a PT car negates this as a factor).

Also, the suspensions on today’s factory cars are always compromised to some degree for packaging reasons. The Z28 and GT350R use McPherson struts up front. Not ideal suspension geometry but great for packaging. On Pro Touring cars the compromise can be tilted much more toward performance, and since it’s often blank slate in terms of layout, a PT car should not suffer in terms of suspension dynamics, as I see it anyway. Though one thing both of the aforementioned cars now have is IRS, which most PT cars to not have.



From what I learned at GM, brakes tend to be biased to their intended use. They only put carbon brakes on vehicles that were intended for heavy track use. Lets be honest, even 15" steel brakes are overkill for normal street use. But if the owner decides to attend a HPDE they will be up to the job. If the owner knows they will be doing lots of racing, then the carbon brakes on the Z28 seem like a better choice because the carbon can absorb more heat without fade. The trend of brakes growing seems to be from the advances in tires to increase grip. Newer tires have more grip, so they can handle more brakes. For sure, the Z28 and GT350 have such large brakes because it is anticipated they will be driven hard, though not necessarily always on a racetrack. But in principle Pro Touring cars are also built to be driven hard (on racetracks as well), so I propose they warrant having brakes just as large. It is my understanding as well that carbon ceramic rotors are mainly used because they are light and have better dynamic response. A 15” cast iron rotor can absorb a lot of heat.



For tire sizes, keep in mind that long before a vehicle has ever been built they have decided if there will be a performance model of that car. In the case of the Gen 5 Camaro, they knew there would be a Z28 so they designed the car to be able to fit wide tires on the front. Same with the GT350. On my 69 Chevelle I put a 275 front tire. I did this because I did not have to modify the inner or outer fenders to keep them from rubbing. On the other hand, on the rear I could fit a 315 if I wanted to with no mods. Other cars can take more in the front, others can take less. Many people do not want to modify their car to the extent it would take to fit a 305 tire on the front. Yes, fitting large front tires can be a pain on older cars. Pro touring trucks have it easy in this regard. What size tires do you run on the rear of your Chevelle out of curiousity?



Then there's the ever growing input of computers in modern cars. Most Pro Touring cars have no electronic controls on them. Computers in modern cars make it damn near possible to drive around a track with your foot on the floor and the car sorts everything else out. Audi built a car that once it was shown a track the car could drive itself around the track at nearly the same time as a professional driver. How can a person in a garage compete with that? I read that article about the Audi. I remember as far back as the early 90’s DTM cars, where they had sway bars and ballast that adjusted mechanically as the car circulated the track. It was said even then that the engineers could have made the cars drive themselves around the track, though not via GPS but via track recognition (basically a very accurate map of the track programmed into the computer). But you do bring up a very important point that I totally overlooked. The presence of modern electronics on new cars. That is a big advantage.

Gustave

[72BBSwinger]

Both of those cars also come with tires that would be "to good" for the PT world. Put 200tw Rivals on those cars and see what happens.

[badazz81z28]

A new car can be bought cheaper than an older pt car too, However.....it's more than having the "best" performance, the car also needs to be unique, different, not as common and that what makes the older cars cool. I know I could spend less and get a better performing car in a 2016 camaro, but I like having something different.

[F-Body International]

For me it's hard to see why you can't build an older car to be faster than these new ones in stock form. The Camaro and Mustang are both 12 sec cars. The '79 Hot Rod Magazine E-Rod Camaro (stock LS3) was running faster quarter mile times with a small shot of nitrous. What if that car had the stock GM E-Rod LSA engine (100hp more) in it?
https://www.youtube.com/watch?v=BfCpbZNCAZE

Like you guys mentioned on the tire size. Tire size/quality matched to the right rim size can generate the loads and suspension tuning can be made from there. It takes a lot of work on early cars to fit bigger tires. 305 is a big contact patch on those new pony cars and most regular people aren't fitting that size on early cars in the front or rear. Most people aren't buying new Z28's or GT 350's either...although my friend is waiting for his GT350 to arrive from the dealership right now.

[Peter Mc Mahon]

I would guess that aerodynamics has a big part in new cars being quicker

[badazz81z28]

I would guess that aerodynamics has a big part in new cars being quicker

Anything can be fast in straight line performance. Its the overall package of handling, comfort, acceleration etc. Any old car can have a monster engine shoe horned under the hood, but when you start looking at suspension technology and design the new cars win in that category. You can get the older cars to that level of handling performance, but your bolting new technology on an older designed platform. The perfect comparison in the article featuring the Z28 and Finch's Camaro. He drove both cars and even though his 71 is one of the best out there, the new car performed better despite being underpowered. Clean sheet designs have better potential as the new parts and the body can be designed together. If you have watches any OUCSI events, the new cars are performing spectacular. Even still, old cars with performance goodies are still cool to watch.

[F-Body International]

Anything can be fast in straight line performance. Its the overall package of handling, comfort, acceleration etc. Any old car can have a monster engine shoe horned under the hood, but when you start looking at suspension technology and design the new cars win in that category. You can get the older cars to that level of handling performance, but your bolting new technology on an older designed platform. The perfect comparison in the article featuring the Z28 and Finch's Camaro. He drove both cars and even though his 71 is one of the best out there, the new car performed better despite being underpowered. Clean sheet designs have better potential as the new parts and the body can be designed together. If you have watches any OUCSI events, the new cars are performing spectacular. Even still, old cars with performance goodies are still cool to watch.

I still don't agree. You just dropped in on a thread for new cars pushing $70k-$80k. Old cars are now getting active electronic shock kits as well...Thank You ViKing. There's a lot of drivetrain you can install on a clean $10k muscle car before you get to the price of a new Z/28 or GT350.

[ICrombie]

For me it's hard to see why you can't build an older car to be faster than these new ones in stock form. The Camaro and Mustang are both 12 sec cars. The '79 Hot Rod Magazine E-Rod Camaro (stock LS3) was running faster quarter mile times with a small shot of nitrous. What if that car had the stock GM E-Rod LSA engine (100hp more) in it?
https://www.youtube.com/watch?v=BfCpbZNCAZE

Like you guys mentioned on the tire size. Tire size/quality matched to the right rim size can generate the loads and suspension tuning can be made from there. It takes a lot of work on early cars to fit bigger tires. 305 is a big contact patch on those new pony cars and most regular people aren't fitting that size on early cars in the front or rear. Most people aren't buying new Z28's or GT 350's either...although my friend is waiting for his GT350 to arrive from the dealership right now.

Getting an old car to run faster than these cars in the 1/4 mile is a lot easier than getting them to run faster on the track. I suppose it could be possible if you build a substantially lighter car with a lot more power, but there are still a lot of things that are out of the reach for most everyone here (reliable ABS, traction control, carbon fiber wheels, etc.).
And there's no doubt that the amount of money it would take to build something that could beat newer track orientated cars would be astronomical, you could probably buy the new car and still have enough left over to build a fairly good pro touring car too haha.