GT350R tires

[8250RPM]

This road racing / autocross is new to me. I have a long past of drag racing. When ford announced that they were building the GT350 I knew I had to have one and now I'm lucky enough to have a 2016 GT350 track pack.

In drag racing, the taller and wider the tire the better for traction. A taller tire gives more contact surface from its circumference as of course so does the width. My question is why did Ford use a 315/30 and 305/30 on the GT350R and 305/35 and 295/35 on the GT350? When a 315/35 and 305/35 would add a bit more surface area. If it's a gearing issue they could of done so.

 

[cloud9]

The low profile tires used in road racing give you improved feel and enhanced response on initial turn-in when cornering. The big difference between road racing and drag racing is you win in the corners road racing and you win with straight-line speed drag racing.

 

[8250RPM]

The low profile tires used in road racing give you improved feel and enhanced response on initial turn-in when cornering. The big difference between road racing and drag racing is you win in the corners road racing and you win with straight-line speed drag racing.

Thanks, I understand the difference between the two sports lol. But can you really feel or notice the difference between the 30 and 35 tires? Wouldn't a softer tire gain more advantage?

 

[VoodooBoss]

I was specifically told by one of the engineers that worked on the suspension that the lower profile and gearing from the R tires is part of the performance improvement. The sticker and wider rubber more than make up for the minimal contact patch lost from the lower profile tires.

 

[CSL]

Yes, you definitely notice a difference between a 30 and 35. The 30s are going to feel more precise. It's kind of like shaving with a new blade or an old one. Not sure about your specific question regarding a softer tire, but obviously a softer tire provides more grip and the R tires are a softer compound than the regular 350.

To get started, I would definitely just get out on the 350 tires to learn road course driving. They are more than capable for someone new to the sport and will help the learning process by being more predictable as to when they have met their threshold and will provide auditory feedback.

 

[8250RPM]

Does anyone know what the lap times are between the GT350 Track pack and GT350R on the same track and with the same driver? How much faster is the R? Let's say you took a track pack GT350 and put the R wheels and tires on it and then compared it to the R what difference would the times be then between to two cars?

 

[VoodooBoss]

Does anyone know what the lap times are between the GT350 Track pack and GT350R on the same track and with the same driver? How much faster is the R? Let's say you took a track pack GT350 and put the R wheels and tires on it and then compared it to the R what difference would the times be then between to two cars?

I was told around a second a lap depending on the track. The sticky tires and lighter wheels are where most of the performance difference come from. The others are suspension, lighter weight and aero. You'll immediately gain back some of the weight difference with lighter wheels.

 

[8250RPM]

I was told around a second a lap depending on the track. The sticky tires and lighter wheels are where most of the performance difference come from. The others are suspension, lighter weight and aero. You'll immediately gain back some of the weight difference with lighter wheels.

But how much of that second is from the shorter tire?

 

[VoodooBoss]

Your guess is as good as mine. If you can find higher profile tires in those sizes that are sticky give them a try. You're worrying about something that you won't have many options with. If Ford thought a custom 35 profile tire was better they would have put it on the car. The profile and "softness" of the sidewall also play into suspension setup. Ford already did that work for us.

According to C&D there is a 58 pound weight savings with the R wheels and tires. I expect the N4SM R spec wheels to be 25 lbs each or 32 pounds lighter than stock GT350 wheels to that will be a nice chuck of the wheel weight difference. More will be gained from your Forgeline wheels which I expect to be around 22 not 25 lbs each.

To be clear: There is only about one second difference in overall lap times putting the R wheels on the TP not it improves lap times by one second.

 

[8250RPM]

Your guess is as good as mine. If you can find higher profile tires in those sizes that are sticky give them a try. You're worrying about something that you won't have many options with. If Ford thought a custom 35 profile tire was better they would have put it on the car. The profile and "softness" of the sidewall also play into suspension setup. Ford already did that work for us.

According to C&D there is a 58 pound weight savings with the R wheels and tires. I expect the N4SM R spec wheels to be 25 lbs each or 32 pounds lighter than stock GT350 wheels to that will be a nice chuck of the wheel weight difference. More will be gained from your Forgeline wheels which I expect to be around 22 not 25 lbs each.

To be clear: There is only about one second difference in overall lap times putting the R wheels on the TP not it improves lap times by one second.

No worries. I was just curious about the tire height and advantages and disadvantages. As I said in drag racing it's like changing gear ratios. I'm supposed to have my wheel and tires the week of February 22. Can't wait. I just installed my headers the other day.

 

[cloud9]

Looking forward to seeing your new wheels. You raise an interesting point on the profile though as it relates to the sidewall stiffness of the Michelins versus the Hoosier R7. Anyone know if they're similar?