How Imprtant is a back brace on a 9 inch rear?

**1slowbusa** · 04-22-2012, 03:54 PM

Just like the title says. How important is the back brace and why is it there or not there?

**35th-ANV-SS** · 04-22-2012, 05:15 PM

To strengthen it in HIGH HP applications. I don't have one and I'm at 500rwhp and have been fine. If you plan on going real big, it's added insurance.

**1slowbusa** · 04-23-2012, 07:52 AM

Would you need one at 600 HP?

**Knight** · 04-23-2012, 08:08 AM

I would contact the manufacturer of the rear, and ask them. Every brand has a different hp and tq rating, I would guess.

**Supershafts** · 04-23-2012, 10:03 AM

From my experience i find it's more a issue of 3 things, weight, power and location of the links, springs, ladder bars in relation to the ends...

If the car has a ladder or link close to the ends of the axle (bearing housing/tire, like it should be) the tendency to bend the housing with big power doesn't usually happen, but move the bars, links, leaf springs in and now you created a leverage effect.

So it kinda depends on a few things, very wide tires massive off set wheels and power and the attachment points are 14" in, brace it

Oh, and don't you brace it unless you have the tooling for it, the housing can and will move and sometimes you will need to reset the ends true to the carrier center line

**Blue28** · 04-25-2012, 12:55 AM

MWC suggests a back brace starting at 550-600 rwhp for their FAB 9.

**Supershafts** · 04-25-2012, 07:17 AM

The housings of some companies are LIGHT gauge material to make them weigh less the dana and the 12 bolt

**xssv** · 04-27-2012, 06:06 PM

Originally Posted by Blue28

MWC suggests a back brace starting at 550-600 rwhp for their FAB 9.

If you spend as much time at the track as on the street.....

I'll be past that, street car, they said no problem without a brace.

OP, be honest with intent and use. Make a decision from there.

**bberretta** · 04-27-2012, 09:58 PM

When I went with the MWC Fab 9 I chose to go ahead with the brace simply because the way the Fab 9 is built, the brace is welded in during assembly. Sure, I'm nowhere near 600hp but the brace is a minimal weight addition for additional room for growth. At some point it becomes a personal preference, really.

**35th-ANV-SS** · 04-28-2012, 03:20 AM

I don't recall off-hand...what's the added cost?

**1slowbusa** · 04-28-2012, 05:22 AM

The back brac is an extra 150. I got a quote from them and for them to ship me everything so I can assemble due to reusing the ABS and traction control they want 4600 dollars. Of course that is with the s track upgrade with35 spline axels.
What did you guys pay?

**35th-ANV-SS** · 04-29-2012, 09:03 PM

I paid $2500 for my Moser 9" which included new reluctor rings, drain plug, 31 spline axles, housing, third member with 4.11 gears, relocation brackets for the LCA's welded on, and ABS/traction control. It was also painted.

**1slowbusa** · 04-30-2012, 05:21 AM

Originally Posted by 35th-ANV-SS

I paid $2500 for my Moser 9" which included new reluctor rings, drain plug, 31 spline axles, housing, third member with 4.11 gears, relocation brackets for the LCA's welded on, and ABS/traction control. It was also painted.

What drive shaft did you go with? How much horsepower are you running? What torque arm did you use? I have only really looked at the Midwest and havent considered a moser. How happy are you with your moser and have you had any issues?

**35th-ANV-SS** · 04-30-2012, 09:12 AM

Running a PST 3.5" AL drive shaft and a BMR Trak Pak torque arm. Installed the set-up in 2009. Other than an initial axle seal leak I've had zero issues.

Car puts down 500rwhp as of last summer.

Forgot to add, I have the Trutrac center section. Not Mosers strongest set-up.

Some people don't like the torque arm mount on the 9". I haven't had any issues to date though.

Have you looked into the S60?

**1slowbusa** · 04-30-2012, 03:52 PM

I receved a quotation for the S60 from Midwest at the same time i recieved the quote for the 9MW and it was only 200 dollars cheaper.

**35th-ANV-SS** · 04-30-2012, 04:00 PM

Does your price include the drive shaft and torque arm? My DS was $400 and I believe my torque arm set-up was about the same, if not a little more since it's BMR's drag racing torque arm and one of their better units.

**1slowbusa** · 04-30-2012, 04:08 PM

Yes it did, it included everything to bolt into the car.

**35th-ANV-SS** · 04-30-2012, 05:07 PM

Well then that makes the price somewhat more manageable. That would have brought my total up to somewhere in the ballpark of $3400. I'm sure you're being charged a good piece for shipping also.

The MWC fab'd 9" is a stronger unit than the Moser, so you're going to pay more for it.

If I had to do it all over again, I might have got the Wavetrac (lifetime warranty) instead of the TruTrac. Hindsight is always 20/20 though. Hopefully this rear end will hold up. Putting slicks on the car hopefully before year's end to really see what it's capable of at the track. For the more part though, mine is strictly a street car so I feel pretty comfortable with my set-up.