??? About 9" vs. 12 bolt
??? About 9" vs. 12 bolt I am seriously considering saving up and buying a rearend this spring. I have been doing a little reading, and not much pricing so far. I have a couple questions:
1. As far as the 12 bolts, I keep reading how most Mosers aren't set up correctly when you get them. I also read about the TQ arm mount situation with the Moser. Does this mean the Strange 12 bolt is better? I haven't seen it talked about as much...
2. I read how 9" loses some more HP than a 12 bolt. How much HP loss are we talking here? (If it matters I had in mind the 9" with 31 splined axels and true-trac)
3. What is the price comparison? Can you get them for the same prices, or is one cheaper than the other??
1. As far as the 12 bolts, I keep reading how most Mosers aren't set up correctly when you get them. I also read about the TQ arm mount situation with the Moser. Does this mean the Strange 12 bolt is better? I haven't seen it talked about as much...
2. I read how 9" loses some more HP than a 12 bolt. How much HP loss are we talking here? (If it matters I had in mind the 9" with 31 splined axels and true-trac)
3. What is the price comparison? Can you get them for the same prices, or is one cheaper than the other??
I been checking on rears a bit latly, hanvt heard anything about T/A mount problems with mosers, The 9' weighs more and is beefier than the 12 bolt, hence the power lose, I wouldnt think it would be too much, I found that the 9" cost a little bit more, but for a m6 is worth the extra dough, me having an a4 Im goin with a moser 12 bolt !
........ 
IMHO, the strange 12 bolt housing is better than the Moser. The strange housing uses through bolts to connect the TA to the housing, instead of threaded holes. Quite a few people have stripped the bolt holes on their Moser. I don't know why, and it probably should not have happened, but I have seen people post about it. Even with one stripped, three bolts should hold, but I see no advantage to a threaded hole vs through bolts. Also, with through bolts, you can put the bolts in from the top, so even if the nuts/bolts loosen, they most probably will not come out. If the Moser bolts get loose, they will fall out.
I've see the numbers somewhere and don't remember where, but the efficiency loss is something like 3% for 10 bolt and 8.8, 5% for 12 bolt, and 7-9% for 9". Maybe one of the other guys can provide a link or data.
As far as strength, the 31 spline axles are going to have the same strength in both setups, however the 9" has a stronger pinion bearing setup and ring gear. Usually only an issue if you are running in excess of 600-750 hp from what I remember.
Unless you are making more than 500 rwhp, I wouldn't even consider a 9" due to the weight and efficiency loss. However, it does allow pretty quick gear swaps, which is a nice feature.
Good luck !
I've see the numbers somewhere and don't remember where, but the efficiency loss is something like 3% for 10 bolt and 8.8, 5% for 12 bolt, and 7-9% for 9". Maybe one of the other guys can provide a link or data.
As far as strength, the 31 spline axles are going to have the same strength in both setups, however the 9" has a stronger pinion bearing setup and ring gear. Usually only an issue if you are running in excess of 600-750 hp from what I remember.
Unless you are making more than 500 rwhp, I wouldn't even consider a 9" due to the weight and efficiency loss. However, it does allow pretty quick gear swaps, which is a nice feature.
Good luck !
