Ok, I've read all the posts on the bellhousing protection issue and I'm trying to pick a plan.

I know the blankets are SFI 4.1 approved, but what exactly does that mean? Tested to contain shrapnel? Has anybody ever seen one contain a clutch/flywheel destruction? Is the $180 version from Exoctic Muscle worth the extra money over the $90 TCI universal fit version from Summit?

I know the Mcleod steel bellhousing conversion would be ideal, but I believe they require a new clutch/flywheel as well as the hydraulic throwout bearing, so it's a bit past my budget right now. I'm hoping for some feedback that an SFI steel flywheel & blanket is a reasonable compromise with my new CF DF clutch. But if it's a waste of time I'll just skip it until I need a clutch again, then do the steel Mcleod unit.

Again, I know steel is better, and a some guys (LR ) have said only steel is acceptable. Nobody likes to make safety tradeoffs, but not many drive around in full cages with firesuits and suppression systems in 11 -12 sec cars, either.

 

If you have a 11-12 second car you probly don't need it anyway
I thought the blanket was for the trans....not the bellhousing

I have seen a flywheel come apart and it will take you foot off.......weld a pc of plate steel on your side floor under the carpet.

Don't know what trans you have but it is a tight fit in the 4th gens....so I'm going to an ultra bell next time I have mine down for a refresh

 

a blanket is really desgined for an auto to cover the body. I just bought one and there are no holes on top to allow for a shifter. In an auto the internals can come flying out thru the case but the converter is pretty much a solid piece. If it breaks its not throwing metal. It fails internally and just stops working. But the drum and planetary gears are spinning in an auto and can come outside of the box in a major failure.

In a manual the gears ride on different steel shafts. If one break no parts come flying out since they are still held in place. The gears just loose teeth and take out the teeth one other gears. Now the clutch can come apart and throw parts. This is where a bellhousing shield is needed. The aluminum stock piece will break instantly and very easily. The only thing stopping your leg from being hit is the floor pan.

This is not meant to be perfect here because we all know that a general assumption is not always right. These are just my general assumptions.

Nobody makes a flexplate shield for a 4L60E/700R4 that I have found. But its been a little while since I looked. Somone may be amking one now. Your best option is a universal blanket, but it will only cover the trans body.


If you conver to a th350/400 there are complete shields available but I have no idea about fitment. As already stated a 4th gen is tight. I'm sure someone out there is using one.

 

I would be nice to think I don't need it. But it seems like the level of risk would be RPM rated, not ET related. 7k RPM seems equally risky in a rock crawler as a drag car, unless the risk is more related to torque shearing the bolts.

I'm pretty sure these are for the bellhousing, based on Exotic Muscle's description of their Corvette blanket. But, I just found that SFI 4.1 is only rated for automatic trans applications so I'm not sure it would do much.

That is a really good suggestion! I was thinking in terms of not having room to add steel on the underbody side, but under the carpet is a workable solution. Thanks.

 

check out some off madmans stuff...he has alot of pics of his work floating around...it may be required on a 25.5 car...not sure

The 7k rpm....I can see but it the h.p. when it clamps....2200h.p. and 300 h.p. are going to do very different things when they bite



Brian...I think frank from cpt made a post where the CSR 4l60 trans shield was now available, but not sure if anyone has used one yet

 

I've seen pics of it... still not out yet from what I know. If it is I should return the blanket I just bought and get one.

 

not out yet, but soon...

http://store.summitracing.com/partde...5&autoview=sku

I think TCI makes a flexplate shield that might fit the trans but it wont fit in the f-body. I've seen pics of one on a 700r4 before. Not sure if it was modified or not to fit. But if it was modified then it technically will no longer have a valid SFI rating.

 

I think he specifically asked is if a blanket was good for a bellhousing, and he has an M6. Long before anyone even thought of an explosion-proof bell housing for an LT1 T56/clutch, I was running a ballistic blanket on my Street Twin. Not sure if it was going to contain the clutch, but it had to be better than nothing at all. Also not sure where it even came from, because is was included with the used Street Twin. It was the correct shape for the bell housing, a long, circluar band with rings that went under the bell housing bolts, and straps to hold the ends together.

SFI 4.1 applies to tranny shields, not to flexplates or to clutch/bellhousing. An auto trans flexplate shield has to meet SFI 29.1, and a clutch/bellhousing shield has to meet SFI 1.1 or 1.2. The bellhousing shield is required by NHRA under 11.49 seconds.

 

Thanks Injuneer. Yes, I am specifically concerned with protection on M6 bellhousing. I'm not too worried about tech aspects, just protection. If I ever break 11.49 I'll guess I'll just have to celebrate with the Mcleod conversion. There are enough frag stories that I feel some protection is worthwhile. Seatbelts, helmets, & fire extinguishers have all saved me in one way or another, so I'm sticking with my safety equipment trend.

I think the steel plate idea is workable PROVIDED there is adequate weld to the floor, and that could be tricky. I would patch several 3/8 thick pieces of plate to the floor for a good fit and lots of weld area, and then weld the pieces together for rigidity. Maybe some plug welds to backer plates where there is room. But that approach will be impossible to properly coat, and will thus lead to rust someday.

I've done some reading on ballistic protection today, and I'm now considering making a multilayer (4-5 layers of 14.7 oz Kevlar 29 Ballistic Fabric) blanket over the tunnel (under carpet) instead, with wrapped, through bolted bars at the perimeter for attachment and some straps over the top. That plus a blanket should stop a lot of shrapnel. Based on methods of increasing bomb resistance of vehicle floorpans. Would cost about $100 for 5 layers over the bellhousing area.

 

I bought the Exoctic Muscle bell housing blanket years ago for my M6. It's a nice piece and gives me piece of mind. It mounts as described by Injuneer, the correct shape for the bell housing, a long, circular band with rings that went under the bell housing bolts, and straps to hold the ends together. It's made of Kevlar.

 

Good feedback OBE1, I'll go with the Exotic version then, rather than the Summit 'universal' one. Nice to know it fits well.