NHRA rules for SFI Bellhousing

[PeteyDaMan]

Hi All,
So I took The Beast down the 1/4 this past weekend at Island Dragway in NJ. I had a ton of fun.
During tech inspection the inspector asked if I had an SFI bellhousing. I do not. (I have a 4 speed and twin disc setup)
I thought it wasn't required unless you ran faster than an 11.5 as per the 2023 rules.

I'm not asking if it's a good idea or not (I agree, it is), I'm asking what the NHRA rule book says.

I looked though the 2024 rules online but good God, they're impossible to decipher.

I ran in the mid 12's but I could easily get her down into the high 11's with some launch practice.

 

[GTX JOHN]

I am thinking it is not mandatory at that ET.

It however is a very good idea especially with Slicks or
drag Radials. In 1969 we blew the flywheel out of a Hemi
Roadrunner running High 11's. It took out the Drivers floorboard
and the petals clean out of the car. We had a blanket over the bell
and transmission and it still racked up everything and just missed
the drivers legs.

 

[dvw]

From the 2024 NHRA rule book
Doug

 

[70bigblockdodge]

From the 2024 NHRA rule book
Doug


View attachment 1655371

So you need a minimum of 15, 3/8" bolts holding the bell housing on? On a BB Mopar you fail before you start, there are only 6 bolts on bell housing and 2 are below the crankshaft therefore bottom half. Typical NHRA jibberish. Worse than dealing with the government.
You also get a pass if you have a factory 6 speed Hellcat that should run 11.49 with factory everything (aluminum bell housing, no driveshaft loop, no roll bar)

 

[dvw]

So you need a minimum of 15, 3/8" bolts holding the bell housing on? On a BB Mopar you fail before you start, there are only 6 bolts on bell housing and 2 are below the crankshaft therefore bottom half. Typical NHRA jibberish. Worse than dealing with the government.
You also get a pass if you have a factory 6 speed Hellcat that should run 11.49 with factory everything (aluminum bell housing, no driveshaft loop, no roll bar)

Thats only below 11.49. When required those extra bolts do not go into the block. They go into a mid plate between the block and bell housing.
Doug

 

[DPeltz]

You must be running some sticky tires to be flirting with 11’s? Would highly recommend a SFI bell.

AND always use proper hardware on your your flywheel and pressure plate.

Are you running an SFI spec flywheel?

 

[6PKRTSE]

I have an SFI bellhousing and flexplate (now expired) on my torque flight. Never had any tech question it or even look for it before.

 

[PeteyDaMan]

You must be running some sticky tires to be flirting with 11’s? Would highly recommend a SFI bell.

AND always use proper hardware on your your flywheel and pressure plate.

Are you running an SFI spec flywheel?

It's an 8 bolt billet flywheel from 440 Source (when they used to sell them)

 

[70bigblockdodge]

Thats only below 11.49. When required those extra bolts do not go into the block. They go into a mid plate between the block and bell housing.
Doug

Understood, but the lawyer speak is annoying. Then you get a free pass with new stuff, because safety be damned we need newer cars in staging lanes. I'm all for keeping my pieces attached, but wordy indirect sentences leave dumb people behind and their only defense is to fail you and then you have to prove your legality.
Sound familiar? Cops will lay the paper on you and you have to get it unstuck.