Shield or blanket

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I think a blanket is sufficient, but i may be wrong. I dont have a current rulebook.
Mine had a sfi flexplate, a csr flexplate shield, and a tci aluminum trans shield.
Ive got a blanket for my 727, not installed yet, but that car is only mid elevens at the moment.
 
According to the NHRA rulebook (2021), cars running 9.99 or 135 mph or faster w/ an auto trans, must use a flexplate shield that meets SFI spec 30.1.

I don't imagine blanket meet 30.1 since they're covered by SFI spec 4.1. Here's a link to the two SFI specs:

https://www.sfifoundation.com/wp-content/pdfs/specs/Spec_30.1_061799.pdf
https://www.sfifoundation.com/wp-content/pdfs/specs/Spec_4.1_032713.pdf

upload_2021-6-16_17-25-10.png
 
The rules and lack of sfi cases (torqueflight) is the reason 99% look to the CSR sheild. It covers the trans shield ruling as well as the required flex plate shield requirements.
 
I have not had my blanket tested for 30.1, But it would most likely pass SFI testing. SFI testing involves bolting a mopar flexplate to a simulated crankshaft. They spin this flexplate at high RPM until syintrifical force makes it explode. They can also ad cuts to the flexplate to lower the rpm level at which it explodes. Beside paying $$$ for the test you also have to supply them with a transmission case to blow up!!!! SFI requires that the protection device has to remain attached to the transmission bolts or stlll attached at it's attachment points to the engine. And it has to contain or deflect the explosion. The problem with the one I had (name brand) if it were to explode it can deflect all the flying parts to the rear towards the transmission tunnel of the car. This does not make it very safe IMO. Did you know in order to pass the "SFI Blanket Test" It only has to pass 50% of the test to be certified? All SFI certification testing information can be found on the SFI Foundation web site
 
I use a trans shield and a flex plate shield on my 904. I'm not a fan of blankets as they hold heat and oil. Plus they're hard to clean.
 
If you have not modified the shield IN ANY WAY, they should give you another 2 year certification. To those oil soaked blankets, FIX YOUR LEAKS! Trans blankets are not supposed to be used as diapers... To get the oils out dip it in Dawn dish washing liquid. Gently work the suds into the blanket. Dip in and out of warm clean water to rinse. Let drip dry. Kevlar is not affected by a little soap and water. Heat issues are always a problem. Insulating your header pipes is a huge help. Especially under the chassis headers. External fan driven coolers. My blanket addresses heat issues in it's design, others do not.
 
Perhaps a few still remember the blanket Chuck Lofgren had made that covered the critical areas of the torqueflight. He had them SFI and non approved…. I still have one on the shelf. They were a nice fitting piece.
 
do you need to do any mods to the floor boards to get a CRT shield to fit?
 
A body said:
Perhaps a few still remember the blanket Chuck Lofgren had made that covered the critical areas of the torqueflight. He had them SFI and non approved…. I still have one on the shelf. They were a nice fitting piece.
Click to expand...

Is no one making them anymore? I was lucky enough to pick one up for my 66 BB project. It's still one my shell as well. I do know it fits VERY well.
 
from what i understand you might need both i know guys that are into the low 9s and are running both
 
Duane said:
Trans blanket only at 10.99 not a flex plate shield.
9.99 needs both.afaik
Click to expand...

SFI 4.1 transmission shield required at 10.99 and faster

NHRA…
10.99 seconds (6.99 1/8th) or Super Street
SFI 4.1 Transmission Shield, or at 135 mph Locking transmission dipstick tube Aftermarket axles and axle retainers
SFI Harmonic Balancer
Roll Cage with altered floor pans, or 135 mph - Window net required Ignition cut-off on all bikes / snowmobiles that exceed 135 mph


IHRA
TRANSMISSION SHIELD: SFI 4.1 mandatory on all automatic transmissions equipped entries running 10.99 and quicker 1/4 mile or 6.99 and quicker 1/8 mile.
 
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