SFI flexplate mandatory in all v8s Jan 2024
 

Here we go , didn’t take long for this to happen after unfortunate incident in D-4. I personally would only use an SFI flex plate as I really like my two feet. This rule just insures that the V8 in the other lane has one also. :)

Re: SFI flexplate mandatory in all v8s Jan 2024
 

It looks like I won't be putting my 301 Pontiac back together any time soon.

Re: SFI flexplate mandatory in all v8s Jan 2024
 

I assume one came apart? I hadn't heard of the incident in D-4.

Re: SFI flexplate mandatory in all v8s Jan 2024
 

I would actually have more faith in an older flex plate. Most of the newer ones are probably Chinese made. I bought a summit brand for my car last and it was a Pioneer brand stamped into it. It is SFI approved. Next time I have it out I will look for a better wheel. I have an ATI safety bell housing too.
That was a fluke happening. I can’t remember the last time I heard of a flywheel breaking. Think of how many runs are made each weekend at drag races across the country.

Re: SFI flexplate mandatory in all v8s Jan 2024
 

I’m glad that this rule is being adopted! Lots of difference between stock one and a certified one. Mike McMahan 2543 H/SA

Re: SFI flexplate mandatory in all v8s Jan 2024
 

I have been using a SFI flexplate but it has expired. Do they have a 3 year certified life? I can not remember. Ray

Re: SFI flexplate mandatory in all v8s Jan 2024
 

Like to know how they will be checking that-they don’t check anything these days

Re: SFI flexplate mandatory in all v8s Jan 2024
 

Both Jegs and Summit sell a stock appearing flexplate that is SFI approved.If you have one of these,I suggest that you replace it with a quality piece.I don't know which flexplate was involved in the last D4 race,but we had one of the inexpensive ones a few years back on our B/ED and a section of the ring come off.How can that part pass SFI specs? There are more of these incidents than you would think.We replaced ours with a billet Meziere.Quality part.

Re: SFI flexplate mandatory in all v8s Jan 2024
 

There's a lot of difference between a Mopar flex plate and a GM flex plate. The Mopar is much smaller and lighter, one piece and has no ring gear welded on. I don't think its possible for a Mopar stocker to break a flex plate. They do fatigue and crack around the bolt holes but still don't come apart.

Re: SFI flexplate mandatory in all v8s Jan 2024
 

I just bought a couple different Chrysler flexplates. I bought an eBay special that had "Meets SFI standards" or something thereabout engraved/punched into it, and then I bought a PRW from Summit. The latter is about an 1/8th inch thicker, and actually has an SFI sticker on it. The PRW unfortunately does not say anywhere on it or in the instructions of where it is made, but I am assuming overseas.

I'll have to take a pic of the other one and post it tonight, but something about it just made me uneasy, so I bought the PRW. I've never had any issues with a Chrysler flexplate of any kind, and don't intend to start.

Re: SFI flexplate mandatory in all v8s Jan 2024
 

My last round in 2019 the flex plate in the Coronet broke completely. Right around where all the bolts were attached. It was a Mopar performance plate that looked like a star. I couldn’t have made another round. Replaced it with a B&M piece. Much nicer and more robust. It definitely broke, probably a few years old and was through a few recerts.

Re: SFI flexplate mandatory in all v8s Jan 2024
 

Does any body have a brand name/part number, et al for the 14" replacement unit for my 327? I don't mind replacing it while I'm apart right now, just want to be sure I have the right brand and part number.

Re: SFI flexplate mandatory in all v8s Jan 2024
 

Lil’ Jimmy Hildago was staged when a competitors flexplate broke and attacked his GTO . Pictures are floating around the internet . Thank God young Hildago was not injured

Re: SFI flexplate mandatory in all v8s Jan 2024
 

Probably 20 years ago a dragster destroyed one during the burnout at Indy and pieces went over the spectator side stands and one stuck in the side of our trailer. Rare but happens.

Re: SFI flexplate mandatory in all v8s Jan 2024
 

Glad Jimmy is o.k. Any chance of getting the picture of the car posted here.

Re: SFI flexplate mandatory in all v8s Jan 2024
 

Here's the thread that was on here:https://classracer.com/classforum/sh...ad.php?t=84937

Re: SFI flexplate mandatory in all v8s Jan 2024
 

I have been very busy and had not seen that thread. Thanks Dave. So glad that it wasn't worse. Thank God Jimmy is o.k!!!!!!!!

Re: SFI flexplate mandatory in all v8s Jan 2024
 

I had that happen on my Cuda back in the mid 70s but it was never a dangerous situation, there's not enough mass, circumference or welded on parts to enable it to come near the danger and damage that a GM flex plate can do.

Re: SFI flexplate mandatory in all v8s Jan 2024
 

In the early 2000s in a modified super stock car I had the ring come off of a SFI fleplate just as the car shifted into 2nd gear, it came out from under the car, hit the right wall and then back through my passenger window and into the side of my helmet! It happens really fast to say the least.

Re: SFI flexplate mandatory in all v8s Jan 2024
 

Now that’s funny

Re: SFI flexplate mandatory in all v8s Jan 2024
 

It's a good thing nobody was injured period.

Re: SFI flexplate mandatory in all v8s Jan 2024
 

Yes, the driver of the Chevy11, the starting line crew, and spectators were all very fortunate.

Re: SFI flexplate mandatory in all v8s Jan 2024
 

Let's look a few things here:

Mopar ring gear is attached to the converter. I can buy them from a number of sources. Not SFI certified, in any case.

Fords have 4 bolts on the converter..Possible a stronger deal.

You cannot modify an SFI part i.e. cutting a window or a door in a bell housing. How do balance an approved flex plate then?

Turbo Grand National Buicks run way run way down in the 11's., as a V6 combo.
Same for Saturn Sky and Pontiac Solstice Eco-Tec 4 cylinder combos in Stock.

Seems to me that this should be done by ET, rather than singling out a particular brand or two..Maybe 12 flat ET..Not by class or eliminator like the stupid roll bar rule.

Just a thought or two, but whatever anybody does , don't show this post to the NHRA lawyers or insurance company..They're all pacified now.

Re: SFI flexplate mandatory in all v8s Jan 2024
 

Yac. Get back over to the Hamb and keep us all straight on the Jr. Stock thread.�� That'll run off the rails if you stay away too long.

Re: SFI flexplate mandatory in all v8s Jan 2024
 

Tommy, I just call 'em like I see 'em...
The Tokyo Rose deal? Easy peasy ;-)

Re: SFI flexplate mandatory in all v8s Jan 2024
 

I used The Wheel from JW transmissions on my powerglide for years. I guess some people like a lighter weight but it was consistent and heavy duty, I trusted it 100%.

Re: SFI flexplate mandatory in all v8s Jan 2024
 

Mark, you don't think it might have more to do with RPM rather than E.T.

Re: SFI flexplate mandatory in all v8s Jan 2024
 

It might but would be hard to regulate that in an equitable manor...Re: Eco-Tec 4

Re: SFI flexplate mandatory in all v8s Jan 2024
 

I don’t think the ring gear knows any difference if it’s being spun to 7000rpm by a BBC, SB2, SBC, V6, or a 151.

Re: SFI flexplate mandatory in all v8s Jan 2024
 

They'll check it when it's laying on track or out from under the car. Then you will get a nice letter and a fine.

Re: SFI flexplate mandatory in all v8s Jan 2024
 

Never had any problems with any SFI certified Mopar Flex Plates "UNTIL" I started to two step. We're our own worst enemy. If you two step, the flex plate must become a part of your service routine. Just saying .........

Re: SFI flexplate mandatory in all v8s Jan 2024
 

Did it crack or explode.

Re: SFI flexplate mandatory in all v8s Jan 2024
 

I’m not sure if it’s the 7000 rpm or the converter hitting at 5800 instead of the 4400 people used to use! I think the converter hit stresses the flex plate more than going down the track but it could crack at the hit and come apart down track. The stock GM flex plate that I saw has the ring gear only welded on one side. The certified appears to be welded on both sides of the ring gear and possibly more welds. Both of mine are certified but have been in my cards for years. I’m thinking I’m going to replace them. Mike McMahan 2543 H/SA

Re: SFI flexplate mandatory in all v8s Jan 2024
 

Now just to be "fair", this ruling is going to apply to all V8 bracket cars also right?

Re: SFI flexplate mandatory in all v8s Jan 2024
 

Paul, never had one come apart. Had several crack near the convertor bolt holes, but caught it.

Re: SFI flexplate mandatory in all v8s Jan 2024
 

Better be careful Mike, Old Chinese philosopher Confucius sez older flexplates made in USA might be stronger than newer flex plates made in CHINA ….

Re: SFI flexplate mandatory in all v8s Jan 2024
 

Thats why I buy a Meziere flex plate. I go thru between 8200-8300 rpm on the big end..... Not saying I will never have an issue, but I haven't as of yet. Been running one for quite some time now.

Re: SFI flexplate mandatory in all v8s Jan 2024
 

2023 NHRA RULE AMENDMENTS

Beginning January 1, 2024, SFI 29.1 flexplate mandatory on all V-8 vehicles. Any car running quicker than 9.99, SFI 29.1 automatic transmission flexplate and SFI 30.1 flexplate shield mandatory. See General Regulations 2:12, 2:14.

Re: SFI flexplate mandatory in all v8s Jan 2024
 

Having repaired several racers cars after a flexplate explosion I cannot understand why anyone would be against this rule which should have been in place years ago.
I've seen headers sliced off, frame rails cut in half and floors with shrapnel sticking thru within inches of the drivers feet. . Not to mention the possibility of severe injury to track personell or even your crew menbers.
Jim Bailey is correct . the 2 step is well known for causing other issues like broken oil pumps and pickups..

Re: SFI flexplate mandatory in all v8s Jan 2024
 

Yes..Okay.
So how does that apply to U/SA 273 Mopars?