From updates to the NHRA rulebook:
"CLUTCH, FLYWHEEL, FLYWHEEL SHIELD
Flywheel and clutch meeting SFI Spec 1.3 and flywheel shield meeting SFI Spec 6.2 mandatory. Maximum depth of flywheel shield: 9.4-inches (inside). Aluminum flywheels prohibited. Refer to General Regulations 2:3, 2:5, 2:6, 2:7 and SFI Spec 10.1C for complete motor plate and bellhousing guidelines."
From the website:
"Fidanza flywheels are made from 6061 T6 aluminum"
Like I said before, I'd go chromo... so ACT. But the choice is yours. If you go Fidanza I'd at least like to see a scattershield on there. You'll gain (well, probably break even or still lose compared to stock) static mass but you will still be losing the more important rotational mass. As for NHRA legality you'll never get called on that at tech inspection but they don't just make up rules for the hell of it. Actually I'm not even sure if that apllies to cars running 7.50 and slower, but still. There's SFI specs and NHRA regulations for a reason: Safety.
In Fidanza's defence 6061 T6 is good stuff for alot of things and it's really quite strong. If I was running a race car and the rulebook allowed it I'd definitely consider an aluminum flywheel. But then race cars get stripped down for inspections on a regular basis. Who here has taken torn their motor down just to take a look at the bearings and rings and see how it's doing? Or pulled a tranny to inspect the clutch and flywheel? I'm guessing not many, if any...
