71 Demon 15 x 10 Backspace Question
Hey everyone, I have researched on this forum about backspace. There is a lot of info but not finding exactly what I'm after.
For those running 295/50R15 on a 15x10 wheel in a Demon/Duster with only a 1/2" spring relocation kit (no mini tub), what wheel offset are you running?
We are building my daughters 71 Demon with an 8 3/4. We have moved the springs in 1/2" using Dr Diff spring location kit and perches to match. We are also using Dr Diff BB axles. When it was at the body shop last year, we had them remove the lip on the upper 1/4 panels. She is also running the Mopar Performance super stock springs and shocks so it will sit higher than factory.
The tire she is running on the rear is 295/50R15 Cooper Cobra's and she insists that this car has to have Magnum 500's. We will be running the 15 x 10's (overall wheel with is 11") and they only come in 2 different backspace options: 5" and 5.5".
I have the rear end mocked up with the brake backing plates, axles installed and drum on. With a straight edge on the front of the drum, the measurement to the spring is ~ 6 13/16.
If we go with the 5" backspace, that gives us ~ 1 7/8 to the springs but moves the wheel out further. (Note: The pic illustrates the overall with of the wheel at 11")
If we go with the 5.5" backspace, that gives us ~ 1 3/8 to the springs and moves the wheel in closer which we prefer. (Note: The pic illustrates the overall with of the wheel at 11")
I guess the part I don't know is how much we can expect the tire (295/50R15) to bulge on the 15 x 10 wheel. Sounds like we will have to run @24 psi as well.
Will the 5.5" backspace give enough room for tire bulge if we only have ~ 1 3/8" from the wheel to the springs?
Hey everyone, I have researched on this forum about backspace. There is a lot of info but not finding exactly what I'm after.
For those running 295/50R15 on a 15x10 wheel in a Demon/Duster with only a 1/2" spring relocation kit (no mini tub), what wheel offset are you running?
We are building my daughters 71 Demon with an 8 3/4. We have moved the springs in 1/2" using Dr Diff spring location kit and perches to match. We are also using Dr Diff BB axles. When it was at the body shop last year, we had them remove the lip on the upper 1/4 panels. She is also running the Mopar Performance super stock springs and shocks so it will sit higher than factory.
The tire she is running on the rear is 295/50R15 Cooper Cobra's and she insists that this car has to have Magnum 500's. We will be running the 15 x 10's (overall wheel with is 11") and they only come in 2 different backspace options: 5" and 5.5".
I have the rear end mocked up with the brake backing plates, axles installed and drum on. With a straight edge on the front of the drum, the measurement to the spring is ~ 6 13/16.
If we go with the 5" backspace, that gives us ~ 1 7/8 to the springs but moves the wheel out further. (Note: The pic illustrates the overall with of the wheel at 11")
If we go with the 5.5" backspace, that gives us ~ 1 3/8 to the springs and moves the wheel in closer which we prefer. (Note: The pic illustrates the overall with of the wheel at 11")
I guess the part I don't know is how much we can expect the tire (295/50R15) to bulge on the 15 x 10 wheel. Sounds like we will have to run @24 psi as well.
Will the 5.5" backspace give enough room for tire bulge if we only have ~ 1 3/8" from the wheel to the springs?