Lightened flywheel

[Twentyover]

..........Yes, each vehicle is different and you are partially right but, I look at the 1st gear ratio, differential ratio, tire diameter, car weight, camshaft profile, heads, exhaust system & displacement........

That's the information I'm looking for. The only stated criteria I found was the 11:1 overall first gear. How to these other factors enter the decision making process? If I missed you explanation on my read, can you point out where you use weight, cam, etc?

[Randy67]

My car has a Ram Oval Track "Stock Rule" clutch setup which weights 24 lbs (flywheel is 10 lbs). It has a 4.06 first gear & 3.36 rear gear (13.64:1 overall) and still can be tricky to get moving, especially since the engine isn't happy below 2,500 rpms. But it works great for autox and isn't too bad for driving, although the rpms drop quickly between gears. I wouldn't want to drive it everyday though.

[70camaro406]

BTW- its an ext balance 406, (168 tooth)

I also have an ext balanced 406, and I, too, plan to use an aluminum flywheel, probably a RAM with billet steel inserts - #2523, that weighs 18 lbs. I think you'll be fine with one of those too. Remember, 406's are pretty torquey and can afford to give up a little down low to allow for launches without all the tire smoke. I even plan on the TKO-600 with 3.42 gears and 27" tires. From what I've read and heard from many people, if you go too deep with the rear gear when using a TKO-600, it renders 1st gear almost useless. I know many people that can start out in 2nd gear even when using 3.73's. Now I'm not sure if they are using aluminum flywheels or not, but with a torquey engine, it shouldn't matter. I'm looking forward to the quicker revs, as I had a heavy 10" converter hanging off the flexplate, and even though it revved relatively quick, you could tell that it was a heavy converter.

[JodysTransmissions]

My car has a Ram Oval Track "Stock Rule" clutch setup which weights 24 lbs (flywheel is 10 lbs). It has a 4.06 first gear & 3.36 rear gear (13.64:1 overall) and still can be tricky to get moving, especially since the engine isn't happy below 2,500 rpms. But it works great for autox and isn't too bad for driving, although the rpms drop quickly between gears. I wouldn't want to drive it everyday though.

I would think your camshaft rpm band is too high. It is definitely not your gearing! What's your vehicle and weight?

[JodysTransmissions]

That's the information I'm looking for. The only stated criteria I found was the 11:1 overall first gear. How to these other factors enter the decision making process? If I missed you explanation on my read, can you point out where you use weight, cam, etc?

An MGB is a light car even with a SBF. The lighter the car, the more forgiving. Obviously, a camshaft that kicks in at 3500rpm would not be ideal.

Carroll uses aluminum flywheels on his newly built AC Cobras. Ford also used an aluminum flywheel on their Cobras about 5-6 years ago, not sure if they still do.

[Randy67]

I would think your camshaft rpm band is too high. It is definitely not your gearing! What's your vehicle and weight?

It's a 67 El Camino that weights 3350 lbs. The cam rpm range is a bit high, no doubt. It's a Comp Cams TL with 266/274 dur @ 050 on 106 centerline, RPM range 3500-7500. The engine is a 377 with lightweight crank & pistons with Victor jr heads and a Chevy Z/28 crossram intake. I never kidded myself that this was a "street" engine, just a darn fun one.

[70camaro406]

It's a 67 El Camino that weights 3350 lbs. The cam rpm range is a bit high, no doubt. It's a Comp Cams TL with 266/274 dur @ 050 on 106 centerline, RPM range 3500-7500. The engine is a 377 with lightweight crank & pistons with Victor jr heads and a Chevy Z/28 crossram intake. I never kidded myself that this was a "street" engine, just a darn fun one.

WOW, I bet that thing is a screamer!!

[shortrack]

was going to post a thread on this subject but all my questions were pretty much answered here.....thanks Jody!