Safety Reminder: What flywheel/bellhousing?
 

I ran across this thread over on Chevelles.com. It's a reminder of how important a quality SFI billet flywheel AND SFI bellhousing are for any type of performance application.
http://www.chevelles.com/forums/showthread.php?t=360588
http://www.flickr.com/photos/65538622@N05/6005887929/

Amen! Doesn't look like there was a block saver plate........

Steel plate that goes behind the fly wheel to "save the block" :cheers:

Looks like this:

http://www.summitracing.com/parts/MCL-8630/

Absolutely. An sfi scattershield and block plate were must haves for my build. I've seen too many examples of disasters from not having them.

The comment about billet flywheel's, are these aluminum or steel? I can get a chromoly or billet aluminum flywheel for my application. Which one would be the better way to go? I'm checking if either are SFI rated. Thanks.

The SFI flywheel is just one part of the "system" you should have in place. You also need top quality (arp) flywheel bolts, clutch mount bolts, SFI bellhousing, or scatter shield, and a high quality clutch disc and pressure plate.
Any of those parts can grenade on you and destroy your feet/legs.

I think your questions is really about how heavy a flywheel is most appropriate, and you'll probably find differences of opinion in that regard. Personally, I'm not a fan of aluminum/lightweight flywheels on street cars. But I know others who find them far more favorable than I do.

I'll probably go the chromoly. It's sfi certified and only 1.5 lbs heavier than the aluminum. However, the billet aluminum is sfi as well. I'll be picking up a schattershield and ARP bolts as well. Not sure what I'm doing for the clutch yet but I'll be keeping all of this in mind as I make the selection. I just changed engines and it came with an aluminum bell but this thread reminded me that I need to get the scattershield despite the $600 price tag.

I think you might have misunderstood what I was saying. A lighter flywheel is not necessarily better. It may be (and often is) worse for anything other than pure track driving. In fact, even on a track car too light a flywheel can be a problem.

Would you guys say the upgrades are necessary if your not drag racing or doing track days?

It has nothing to do with racing , although to be legal in many events I believe SFI rating is required.
It has to do with horsepower, rpm, driving and your safety. With a high hp motor on the street parts can still break.
What happens if you get on the throttle on your favorite back road, miss a shift and over rev your intended RPM?
Or you decide on a whim to show some kid how fast your "old" car really is to the next stop light? (not suggested)
The reality is that these cars get driven. And if driven hard, even not very often things can go wrong.
To me it comes down to chance. I want to be safe, along with anyone else in or around my car. Why take the risk and skimp on safety?

Clutches explode ALL the time at the drag strip. Even an automatic should have a scatter shield. This is a requirement in a lot of racing classes. I used to run a transmission blanket, the fact that it absorbs the impact damage over a longer period of time, and thus lowers the force at any point in time was the deciding factor for me.

My car is a family convertible cruiser that will never see the track. I was just curious if its necessary to upgrade.

Thanks

If you are using parts in excess of what they were engineered for, then I think the answer is yes. For example, exceeding factory hp ratings while using stock components.

Billet means it is machined from raw stock as delivered from the mill. The part is machined from this chunk of metal into the part. Alternatively, a part is cast into the design and then finished machined into tolerance. It's the process not the material really. So you can have billet steel or billet aluminum.

As for aluminum or not flywheels I can only speak from experience with my car. I put an aluminum flywheel in my formula. It revved more easily and would respond well after already moving. From a stop, the cast steel flywheel hit harder and would get the car up and moving more quickly. The cast flywheel had more inertia to transfer to the rear wheels and get the car moving from a stop. I didn't regret putting the Fidanza flywheel in the car even though I would randomly stall out at a stop light after many thousands of miles of driving the car. However, if I were to do it again, I'd go billet steel. Lighter than cast, heavier than aluminum, and stronger than both.

i have an alu flywheel in my Nova with a Dual Disk clutch, i like it, makes it rev alot faster, but if i was drag racing i would be using a steel one to keep the inertia up

what is it you don't like about them for a street car.

can you imagine what that Chevelle would have looked like if it had an aluminum bell housing??????:wow:

Effective loss of torque, too little benefit for the cost, reduced strength (debatable).

Bottom line, on the street and the track, every time I or a friend has used a lightweight flywheel, there has been no real measured improvement at the cost of some amount of drivability. At the 1/4 mile, typically have found them to even sometimes slow the car down. It all depends, but why bother for a street car?

Circle track guys like the aluminum because when they lift getting into the corner, the inertia in the flywheel is less and it won't carry the car as deep into the corner. This requires less brake. It can be debated as to whether you should be letting the engine brake the car or not, but that is the justification in some cases. There is also less parasitic loss. With the restricted engines in NASCAR sanctioned events, the lighter the rotating assembly the better. I can confirm that from experience. Now a days though, the aluminum flywheels are mostly illegal in NASCAR weekly racing series competition. They claim safety issue. Must be something to that! I would go forged steel in my opinion. If you really want a more track only setup, use a Tilton Triple disk, it has built in plates and mounts to a flex plate. Great for the track, but do not like starting out. :thumbsup: