1.1g barrier?

[Cobra #3170]

CSX 3170 will pull 1.3 G on just about any surface using Bridgestone RE71 200 UTAG tires 285/30/18 fronts and 305/30/19 rears. On good concrete we have seen over 1.4. These are not spike loads but sustained through a corner. I have not tried it on a skid pad but assume it would be similar. We also get 1.0 to 1.1 in acceleration and 1.2 braking G. We are trying a different brand this weekend will let you know if it is better. BFG Rivals pulled about .1 G less cornering and .1 G more acceleration and braking so we switched to Bridgestone three years ago. Under max G load the car lifts both front and rear inside tires slightly off the pavement like a gokart. There is a picture in my gallery of the car doing that. Cobra cornering power is helped by weight put hurt by track width. These numbers are all in the 40-65 mph range. Aerodynamics will limit high speed cornering loads unless you do what Morris has done and fix the high speed aerodynamics.
After watching that video not sure we could pull those G's on a 200 foot pad, would be fun to find out though.

[Jdata]

Originally Posted by Cobra #3170

CSX 3170 will pull 1.3 G on just about any surface using Bridgestone RE71 200 UTAG tires 285/30/18 fronts and 305/30/19 rears. On good concrete we have seen over 1.4. These are not spike loads but sustained through a corner. I have not tried it on a skid pad but assume it would be similar. We also get 1.0 to 1.1 in acceleration and 1.2 braking G. We are trying a different brand this weekend will let you know if it is better. BFG Rivals pulled about .1 G less cornering and .1 G more acceleration and braking so we switched to Bridgestone three years ago. Under max G load the car lifts both front and rear inside tires slightly off the pavement like a gokart. There is a picture in my gallery of the car doing that. Cobra cornering power is helped by weight put hurt by track width. These numbers are all in the 40-65 mph range. Aerodynamics will limit high speed cornering loads unless you do what Morris has done and fix the high speed aerodynamics.
After watching that video not sure we could pull those G's on a 200 foot pad, would be fun to find out though.

Thanks for the response! I really appreciate it.

[Cobra #3170]

Originally Posted by Jdata

Thanks for the response! I really appreciate it.

About 20 years ago I participated in a test at Tire Rack in Indiana. It was in preparation for an event that a friend was running for max G load. We used a timer and ran on a 200 foot circle. My friend had a winged A mod car. He pulled over 2 G just nosing out my Son's Gokart. We found that both the kart and the A mod car had to be set up with a large percentage of oversteer to do well. They had so much oversteer they would not negotiate a normal course very well at all. An ill handling car might do well on the circle but not so well in real world conditions.
Wasn't the new ZR1 supposed to pull 1.19 G, I think I read that somewhere.

[spdbrake]

You're correct on the ZR1 number.

Top 100 "Grip Kings" - fastest cars around skidpad 2018 - FastestLaps.com

[vntgspd]

Originally Posted by Cobra #3170

About 20 years ago I participated in a test at Tire Rack in Indiana. It was in preparation for an event that a friend was running for max G load. We used a timer and ran on a 200 foot circle. My friend had a winged A mod car. He pulled over 2 G just nosing out my Son's Gokart. We found that both the kart and the A mod car had to be set up with a large percentage of oversteer to do well. They had so much oversteer they would not negotiate a normal course very well at all. An ill handling car might do well on the circle but not so well in real world conditions.
Wasn't the new ZR1 supposed to pull 1.19 G, I think I read that somewhere.

I was going to say something very similar...
Many years ago I worked on a small project with BFG and a Japanese Tuner company to prove that the street tire could pull 1g on the skidpad (for an advertisement). Neither the car nor the tire could do it out of the box but after I did about 50 laps continually tweaking the car setup along the way I was successful in hitting the target. However, I would have to periodically run the car around the adjacent racetrack to cool the car off and found the handling to be diabolical with the fast skidpad setup.

All that to say that high skidpad numbers do not necessarily equate to excellent handling or low lap times. I suppose they are more relevant when comparing stock vehicles as equipped from the factory.

[Cobra #3170]

Today we tried (4) ACR Viper front tires on the Cobra. They were 295/25/19 Kuhmo's. We tried multiple spring rates, rake angles and shock settings. The car pulled 1.57 G with Kuhmo's vs Bridgestone's at 1.35. This illustrates why these tires are not legal in Optima or SCCA because they are in no way a 200 TW tire. I looked at some of the data and saw where average G for .4 seconds was over 1.4. These tires are still legal for Goodguys autox so we will run them at the next Pleasanton Autox. I need to bring a gun to the gun fight not a knife so on go the Kuhmo's. I hope they are outlawed next year because it is not fair to others that are on real 200 tw tires,

[Grey 65]

Originally Posted by Cobra #3170

CSX 3170 will pull 1.3 G on just about any surface using Bridgestone RE71 200 UTAG tires 285/30/18 fronts and 305/30/19 rears. On good concrete we have seen over 1.4. These are not spike loads but sustained through a corner. I have not tried it on a skid pad but assume it would be similar. We also get 1.0 to 1.1 in acceleration and 1.2 braking G. We are trying a different brand this weekend will let you know if it is better. BFG Rivals pulled about .1 G less cornering and .1 G more acceleration and braking so we switched to Bridgestone three years ago. Under max G load the car lifts both front and rear inside tires slightly off the pavement like a gokart. There is a picture in my gallery of the car doing that. Cobra cornering power is helped by weight put hurt by track width. These numbers are all in the 40-65 mph range. Aerodynamics will limit high speed cornering loads unless you do what Morris has done and fix the high speed aerodynamics.
After watching that video not sure we could pull those G's on a 200 foot pad, would be fun to find out though.

My car pulls about 0.1g less than 3170 does, but still over the threshold you are asking about.

How might you ask? I normally stay in a Holiday Inn Express before racing events. That and my Backdraft has been setup as close as possible to the same setup CSX3170 runs. Bruce is kind of my unofficial crew chief. I have reaped the rewards of the countless hours of research and testing Bruce has done on his car.