Cobra weight distributions?

[RET_COP]

Rick,Dwight thanks for the posts.
So three cobras
Front/Rear with driver
Tom 48/52
Rick 49/51
Dwight 48/52

Being that the driver sits behind the center of the car F[0"------90"]R dashboard is about the center 45" and driver butt is about 70" these cars are built about 50/50 without driver.
Is 50/50 optimal?
I think of a car like the GT40. with the mid engine, it must have been rear heavy yet I read where it cornered great
Lou

[scottj]

Originally Posted by RET_COP

Rick,Dwight thanks for the posts.
So three cobras
Front/Rear with driver
Tom 48/52
Rick 49/51
Dwight 48/52

Being that the driver sits behind the center of the car F[0"------90"]R dashboard is about the center 45" and driver butt is about 70" these cars are built about 50/50 without driver.
Is 50/50 optimal?
I think of a car like the GT40. with the mid engine, it must have been rear heavy yet I read where it cornered great
Lou

Mine is 45F/55R w/driver and 10 gallons of gas. I can get 57R with a full load of fuel. The driver accounted for +1% rear...

Scott

[Silverback51]

Originally Posted by RET_COP

......Is 50/50 optimal?
I think of a car like the GT40. with the mid engine, it must have been rear heavy yet I read where it cornered great
Lou

Is 50/50 optimal?

That is a yes/no question. There are so many factors in the equation that there is no one answer. The variables range from tire size and spring rates to the CG of the vehicle. For that matter tire pressure can have an influnce on how the vehicle handles.

Let's take the GT40 as an example. It is far from being 50/50 as it's a mid engined car. But then you look at the tire sizes. Much larger in the rear than the front. Not unlike a F1 or Indy car. Now look at a NASCAR (as much as I hate to refer to them) car. All four tires are the same size and I'm willing to bet the car is close to 50/50 weight distribution, with a side to side bias due to them only turning to the left.

Since a Cobra is not able to run same size tires front and rear (and by size I mean tread width) you would generally want a little more weight on the rear. The spring rates would be such that under acceleration you transfer the weight to the rear of the car for traction. The same is true under braking for a corner. The weight is transferred to the front to help in the braking and turn in at the beginning of the corner if you are trail braking.

Hope that helps a little, and didn't just confuse you more.

[scottj]

In steady-state cornering, such as a skidpad, the heavier end will lose traction first, everything else being equal. Road racing is more about transitions than steady state cornering. Since heavy braking transfers weight to the front tires, road race setups favor a static rear weight bias to counter weight transfer that would otherwise result in a turn-in push. Rear bias also helps forward bite off the corner. Being a short wheelbase car increases weight transfer.

[RET_COP]

Good stuff here guys, I'm taking notes.
Thats why the QA1 Proma Star double adjustable are $300.00 for one!!!
Its tough to set up for cruising with sometimes a passenger and then go autocrossing. Either its a compromise sacrificing on both ends or have two completely different setups.
I just set up for cruising, very neutral without a driver at this time. Next winter could be a different upgrade.

Two Cobra's would be the answer

Lou