At what point is it necessary or recommended to install an "ultimate" or "super sprag" over 12 roller bolt in sprag?

IMHO when your sprag is bad or showing lots off wear. If you have low band apply sprag importance drops quite a bit

I ran the stock 65 sprag for 200 passes with a non LBA apply valve body running high 1.2 low 1.3 60ft foot braking. When it was pulled it looked like new. I stepped up to the good one, still no issues at 425 passes. Dizusters turbo car killed the stock at less than 100 passes with a LBA valve body using a brake, high 1.3 low 1.4 60ft.
Doug

Not sure myself, but if you need a oem one, this is as cheap as it gets.

http://www.ebay.com/itm/NOS-Mopar-A727-A904-OVERRUN-CLUTCH-SPRING-ROLLER-KIT-REAR-SPRAG-KIT/152511409425?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649

If you're worried about safety, you money would be better spent by applying it to a billet front drum.

saved me from typing the same thing....

The trans already has a billet steel front drum and I have a nearly new bolt in sprag. I was just curious as to when a better one was needed.

When you decided to put in the current 12 bolt. Rarely does the outer race's press fail , its the 12 rollers that fail. Your current unit still can fail, it takes more to make a 16 roller fail.

Yep, here's a 16-element SuperSprag failure with the cam ring in place.

Thanks guys, I'll use the sprag I have.

What causes that?

I have lots of miles, strip passes and even a few u-joints that broke. I always pull apart the trans to check the sprag after a failure and never had an issue.

I do have a LBA forward pattern manual valvebody and always shift to second on the burnout.

Something seriously wrong happened there , downshift into low at about 100mph with no LBA ???

Saw one just like it in a 10.0 foot brake car that broke a ring gear.
Doug

That is my photo, its from my friends valiant. +900hp 1080nm big block. It broke the rear end (8 3/4) and after about 10passes it grenaded the sprag.

The case got a small crack but we didnt have spare one at the time, installed new super sprag and after around 25-35 passes it broke again. Picture attached.

It has aluminum drum and in both cases the springs were all over the place, retainer still in place. Drum had spinned very fast.

I fixed it again few weeks ago with new good case and new super sprag and few other items. Week ago it went 8.88s at 1/4 with zero problems so far, fingers crossed.

I did the Billet steel drum complete from CRT as well as the Ultimate sprag also from CRT.

Not because of power as much as the 3,950 weight.

Fairly heavy car on a radial slick that hit's high 1.5's in the sixty in the spring and fall.

Piece of mind.

If the sprag does fail I'm hoping to not wear the drum.

Do have a new Dana, 1350 yoke front and rear and a 3-1/2 driveshaft.

I put a better bolt in rear overrunning clutch (sprag) in my trans but still have the stock front drum. I dont race much as the past few years I only get to the track about once a year and put from 4 to 8 passes a year on it. I have never had a problem in any of my cars but I did put a trans blanket on my 63 about 4 years ago. Dont know how good a blanket really works but it helps give me a little piece of mind until I update the drum. I hope I never have to test the blanket. Ron

"The case got a small crack but we didnt have spare one at the time, installed new super sprag and after around 25-35 passes it broke again."

When the facts are revealed, the correct information is applicable.