New flexplate/ can changes ?

On a blown deal is cranking with a 139 tooth that much different then with a 168? I know directionally it would not be as good, but in the real world is it that big an issue?....

 

Thanks Mike. Seems to me that there is lot's of incentive for the can company's to come up with a 168 tooth solution. Hopefully they will. Weird how this has flown under the radar for so long......

 

i think the 139 tooth deal is a flexplate solution only, which since i dumped the clutch and went to a rossler on my turbo car will fix my problem ( at a decent cost) but the clutch guys have limited options
Mike did you ask trick about their redesigned liner which will let 168 fit??

martin Lundkvist is sending me pics sometime today ill forward them if you like

 

probell is making a billet steel 139 and a 166 tooth wheel that will fit in the new liner. the wheel was debuted at PRI.

 

So how about we all work together and fix this problem . If you have the fix let us know. If you machine something to make work and it's a good fix keep us in the loop. To be blindsided like this is just uncalled for by those in charge.

 

blindsided...yes i just found out about this by accident ....no one is saying anything,
could be down to embaressment that they have been messing with the rules and then got caught out to the racers cost........

 

Ok heres the deal

from 15/11/ 2012 no can wil recert without the liner being right up to the midplate,

this concernes trick cans only

if the can was built befour 15/6/ 2010 the the 168 tooth ring wont fit
if the can was built post 15/6/2010 then it will fit ...
thats from trick themselves

 

Mike, smaller OD flywheel and ring gear means it should turn faster with the starter. The problem might be the starter's ability to crank with less gear reduction from the flywheel. Figure that if you have an 11" clutch, the smallest I.D. of a ring gear you can most likely run safely would be in the 13" range. 11" Friction diameter, add at least another 1-1.5" or so for stud head clearance, and at least another inch in total diameter for meat around stud heads/pockets and stability.

They may have created a bit of a monster with this deal.. Last year or two years ago, the clutch manufacturers of SFI voted on even keeping a 168 tooth flywheel certifiable, being as there have been numerous failures of the ring gears themselves, not the flywheels. We voted the deal down to keep allowing them, but it was an ultimatum that we needed to do a better job fastening the ring gears to the flywheels. That's 14" diameter piece of steel spinning 10,000+ at times. Something sitting on a clutch 13.25" in diameter spinning 10,000 RPM is moving almost 400mph.

 

Hey Justin, what do you think about the segmented ring gear approach like this one for example?....... http://www.dmpeinc.com/supercharger...tern-flex-plate-with-168-tooth-ring-gear.html

 

As long as the fastening is adequate, I don't see why it wouldn't work. Most of us rely on the burst strength of the ring gear itself as well as the friction/sweat fit of the ring gear to aid in turning the flywheel to keep the stresses off the tabs and fasteners. The welded tabs we use just primarily serve as an aid to the burst strength of the ring gear at high RPM. Looks like he spread the contact surface area out more to aid in the starting stresses. It's a neat design. Would we change to such a thing? Probably not. Besides being Patent Pending, I don't want any more fastener supported mass or just mass in general on the OD than I absolutely have to have.

 

I thought it was kind of neat in one aspect. If a conventional one piece ring does fail, then huge chunks of it are going to try to wreak havoc all of a sudden all at once. With the segmented approach a failure in one segment would not necessarily cause a sympathetic failure in the other segments. I hear your point about spinning all of those fasteners at the OD though.

On a different note, what's actually required to SFI cert a clutch and or can these days? Does a person have to actually drive a clutch to failure to proof either the can design or the clutch design? If so that would be a pretty neat video to see . Got any footage or links you can share?

 

trick Can

Want to get this correct. Having a can being built by trick right now so I called and asked last week if the 168 tooth ring gear will work. They told me yes but it sounds like you guys are saying they are going to put in a special liner that I will have to replace next year at recert time. I have to buy a new flexplate now to replace my reactor now so I don't want to waste money buying a 168 that will need to be replaced next year. Going to call meizer tomorrow cause the csr that I bought a month ago is off by .25" from the back of the flange. Starter only engages 20% into the ring ring.

CN wide pan rail block hemi with a bruno

 

FLYING DEBRIS (ie instant hole in hood)

even though this all sounds like kaka now, we did have a ring gear that flew off a flexplate, went through the trans (auto) through the dash and windshield and landed on the track. after about 30 cars ran, somebody brought us the piece of the ring gear that came off. the engine had a slight vibration that wasnt normal, that was it. sfi said they only certify the flexplate, not the ring gear and when we showed them that was it. now that thing could have came out anywhere, and luckily not at the drivers foot! (door car). i can only think what could have happened, and im surprised with all these stupid self starting rules,it hasnt happend more. considering the proximety of these flying bits, i wouldnt make light of the rules after having this go wrong. i would put 2 cans on if i had to!!!!!!!!!!

 

As Nitrobandit experienced, usually ring gear failures occur in segments anyway. I've seen ring gears spun off before, never had one fail on us that I know of, have seen the welds crack on the tabs over time. But the failures I have seen, it usually breaks somewhere between weld points creating a 3-6" piece of flying ring gear. I've never seen one completely thrown off, but that doesn't mean it can't happen.

I couldn't tell you about what it takes to cert a can, but with clutches and presumably flexplates, we have to send it to an SFI approved lab for material certification and then typically send a unit or part off for destructive testing. It has to be able to withstand extended periods of forces typical of 150% of the maximum RPM it should see in normal use.

Now, to get back more to the topic of the thread, let's say a 30 gram piece of ring gear does break off at 10,000RPM. That 30 gram piece of metal has a little more kinetic energy than a 124 Gr. 9mm bullet at 1150fps. And because of the mass, it will have almost twice the destructive power.

 

and have for a couple of years.

 

september 2006 here in england we had a spectator killed when a piece of pro mod ring gear entered his chest, on its way to its victim it severed both shroud lines of the car next to it as it was at the finishline leaving the chutes hanging in the air .....nasty things flying ring gears