SFI flexplate mandatory in all v8s Jan 2024

[Mark Yacavone]

Originally Posted by mike britt

Mark, you don't think it might have more to do with RPM rather than E.T.

It might but would be hard to regulate that in an equitable manor...Re: Eco-Tec 4

[Larry Hill]

I don’t think the ring gear knows any difference if it’s being spun to 7000rpm by a BBC, SB2, SBC, V6, or a 151.

[SSDiv6]

Originally Posted by Larry Hill

I don’t think the ring gear knows any difference if it’s being spun to 7000rpm by a BBC, SB2, SBC, V6, or a 151.

There are many variables applicable to flexplates.

Lots of considerations such as horsepower, RPM range, size/diameter, one-piece or two-piece design must be considered.

The SFI 29.1/29.2 test entails the flexplate turning 12000 RPM's for one hour. However, the test equipment does not simulate the effects of heat, engine load, flex, having a torque converter attached to it and transmitting the horsepower and torque to the drive line. When applicable, add a car with a transbrake and/or two-steps.

I consider both the SFI harmonic balancer, flexplate or flywheel/cluth a safety item. In the early days of Modified Eliminator, with heavy flywheels and OEM flexplate, saw them come through the floor, cut fuel and brake lines many times causing injury and damage.

Although high in cost, my preference are the Reactor Products (without the inertia ring) and Meziere flexplates. They have a great selection of configurations and weight for different end applications.

Other great options are the ATI, TCI billet line and ATF

[dragracerray]

Originally Posted by SSDiv6

There are many variables applicable to flexplates.

Lots of considerations such as horsepower, RPM range, size/diameter, one-piece or two-piece design must be considered.

The SFI 29.1/29.2 test entails the flexplate turning 12000 RPM's for one hour. However, the test equipment does not simulate the effects of heat, engine load, flex, having a torque converter attached to it and transmitting the horsepower and torque to the drive line. When applicable, add a car with a transbrake and/or rev limiter.

I consider both the SFI harmonic balancer, flexplate or flywheel/cluth a safety item. In the early days of Modified Eliminator, with heavy flywheels and OEM flexplate, saw them come through the floor, cut fuel and brake lines many times causing injury and damage.

Although high in cost, my preference are the Reactor Products (without the inertia ring) and Meziere flexplates. They have a great selection of configurations and weight for different end applications.

Other great options are the ATI, TCI billet line and ATF

SS,
Two Steps cannot be good for a flexplate either. Ray

[SSDiv6]

Originally Posted by dragracerray

SS,
Two Steps cannot be good for a flexplate either. Ray

Corrected...meant two-steps, not rev-limiter.