Scattershield

Clark Lincoln

Clark Lincoln

Well-known member
What method are you guys using (metal or kevlar blanket)? And when was the last time anyone experienced (or knows about one) an exploding clutch or flywheel?

Thanks,Clark
 
Not sure of the best current protection but last year at Mid Ohio I know of a flywheel failure that happened.

Bryan Floyd
 
Car if front of me at Daytona sheered the bolts on flywheel and lost entire assembly. Pretty sure I wouldn't want that to hit my leg. His went down and out from under car.
 
Mine is steel and bolted to the tranny side of the footwell wall. It's a scary thing to have a failure with that much angular momentum spinning that fast. I've not seen one in person but I've seen the results.

Dayle
 
I saw one happen to a Sprite guy at an autocross years back. He had a steel plate.
Pieces exited through the battery tray and the hood!! No one was hurt.
 
Clark,

Ours is a fabbed steel plate bolted to the frame under the trans tunnel. I think it's even more important than most cars on a Spit/GT6 because of the non-metallic trans tunnel.
 
I have known 4 failures.

Everyone was a lightened, cast iron flywheel. One cut straight though a Morgan steel chassis (approx. 2"X3"). One was a front drive car that cut thought the bulkhead and missed the driver (just), cut through all the brake lines. The car rolled 1/2 mile before it stopped!

One was a Mk1 Ford Escort and the other one was more recent - an X-19.

None of the results were pretty.....

Bottom line. Use a steel flywheel, have it crack test frequently and use a scatter shield!
 
Something to think about... the NHRA requires all fuel line passing in the area near the bellhousing to be installed inside a 16" length x 1/8" (minimum) thick tubing and be securely fastened.
 
Clark, my Spit came with a kevlar layer fastened inside of the removable fiberglass trans cover. Mine is really a stiff layer of rubber with kevlar weave as reinforcement, possibly from a conveyor belt. The layer is stiff enough that it actually makes the fiberglass tunnel alot stonger.
If I was going to start from scratch, I probably would put some fittings on the floor on both sides of the trans tunnel and secure an off the shelf kevlar blanket over the top of the fiberglass tunnel. Having any type of fabric under the trans tunnel would likely get oil soaked and may prevent the trans from shedding heat.
And yes I did have a Tilton clutch disk split and blow a hole through the aluminum bellhousing.
 
I think the blanket type is used more in drag racing, where heat build-up won't be a concern.

Typically a steel plate is used with a air gap, that way the transmission won't build up heat from the scatter shield.
 
Thanks to all - I will fabricate a steel "Hoop" to cover the clutch/flywheel portion of the trans. It will be bolted to the frame and offset from the trans while still fitting under the trans tunnel.
 
I have used the Kevlar trans blankets, draped over the interior side of the trans tunnel. If heat is a problem inside the car, that can mitigate some of the heat.

If you are fabricationing your own, insure you have enough width, front to rear, to allow for bouncing/ricocheting shrapnel protection. Allow more width protection than just covering immediately over the revolving assembly. Possibly including more than a 2" inward angle bend at the rear.

Design it for a hand grenade level of protection. They usually blow at high RPM's. One of the engineer types can compute the explosive power, something like mass X RPM X diameter with something squared for affect.

I had to dodge a transmission bouncing right front of me. It dropped out of a small car when everthing went bang in the bellhousing. I avoided both the car and big parts.... The bell housing went away, and the drive shaft continued to add top gear speed and torque motion to the rear mounting pad of the trans. It will take your breath away, watching an ungodly amount of activity that close!
 
Few and far between and hopefully so. Haven't seen clutch/flywheel disaster in a few years......and it is a disaster....f. wheel letting go is like a radial saw amok. Reminds me of the one I used to use .....no use for it now as the motor is in back...I'll put it up for sale.
 
So how many of you with FWD cars have a scattershield? Any pictures you can share with they type you are using or designed?
 
You must log in or register to reply here.
Back
Top