mw66nova

iTrader: (13)

i am looking to buy a new rearend for the car sometime at the end of this year. i am looking for pro's and con's of both the ford 9" and the GM 12bolt. i know that the 9" is STONG, my father has one in his car, but the 12 bolt is lighter and takes less to spin. this car will probably never see anything faster than low 11's.

How much lighter is the 12 bolt than the 9"?

what kind of posi/lockers are available for the 12bolt?

on average, how much less does the 12bolt cost?

hope these aren't too vague of questions and you can answer me.

383backinblack

the 9" isn't overwhelmingly stronger than a 12 bolt, and the 12 bolt is MUCH more efficient

pasky

I disagree, I hear of many people breaking 12 bolts with aftermarket parts (high spline count axles, etc...), I have yet to hear a 9" getting broken on a street car that had aftermarket parts.

mw66nova

iTrader: (13)

how much power were those 12bolt guys putting down that broke them??

KagA152

iTrader: (5)

if youre going to stay auto, then do the 12 bolt. shock kills rear ends, so if its a stick, do a 9

mw66nova

iTrader: (13)

stick would be fun, but in no way consistant, which is the name of the game in index racing, so, auto it is. think the 12 bolt will be ok in a car never seeing anything faster than low 11's/ high 10's?

383backinblack

lol you haven't been around long enough then



my rear has like 200 or so passes on slicks with almost 470hp to the tires and a manual trans........hasn't made a peep

it probably has about 10,000 street miles on it too.

its all got to do with using good parts and setting up the rear right.

IHI

iTrader: (1)

Your not going to lose alot of HP using the 9" over the 12 bolt IMO to even take that into consideration when deciding between the two.

I like the 9" because soo many guys run them, they are proven, and parts are readily available if you ever want/need to change something.

With the 9", it's easier to remove the axles since they have a built in axle retension device by using the horeshoes on the end of the axle tubes. You take the horse shoes off and the axle slides out, none of this disassembling the carrier to get the C clips out. That is another issue, if you plan on going fast you are required to have some sort of axle retension device-9" as already mentioned has them built in, a 12 bolt you need to buy C lip eliminators to bolt onto the end of the axle tubes and they are not street miles freindly. It is very common to tear up axle seals using the c clip eliminators.

Say you want to change gearing for what ever reason, or spool, posi, etc...the 9" you take out the center section only and take to your shop of choice. With the 12 bolt you either take the entire car in or have to remove the entire rear end and take it in-I ask you, honestly, which scenario sounds better?.

As long as axle splines match to what you got, many mud packers or hot rodders have at least 2 or 3 3rd members laying around ready for install, so it's a matter of borrowing a 3rd member, setting aside 30minutes of your day to swap them. Try that with a 12 bolt.

You said this is mostly a street car, but for anybody else that drag races, have you ever seen 12 bolts behind anything real fast? No, either built up 9" or fab 9 housings.

You can argue weight savings of one over the other, hp loss from one over the other, but fact is there is just not enough to really use that as a valid arguement when your looking to get a rear end for strength/reliability and the big picture.

mw66nova

iTrader: (13)

is picking up a center section from the junk yard and rebuilding it with all the right peices a good/econoical idea? the nodular iron peices that i see from moser are AT LEAST $1100. i do like the idea of the 9" though. remember, i have experience with these, my father has one in his car and helped put it together and put it in the car.

pasky

450rwhp and that range.

pasky

And im not saying the 12 bolt isn't a good option, what im saying is the 9" is superior.

IHI

iTrader: (1)

For the average joe that doesn't race every weekend, or just foot braking then a properly built junkyard 3rd member will last a long time. Naturally you'd want to find a Nodular case if you were hunting, but "the average joe" could get by just fine with a stock peice and good internals.

I opted to buy the Strange center section when I ordered my rear end up, only $230. It's supposed to be stronger than stock and worked well all last year using my transbrake and heavy car.

I'm also running a full spool on the street and after the first drive I got used to the front end wanting to push, that now I dont even notice it. Definately not bad at all on the street, especailly since I have the slicks mounted at all times.

383backinblack

12 bolt parts are every bit as common as 9" parts are

also, if you buy a new 12 bolt these days it does not have c-clips....my rear end has bolt in axle retention, it uses big ford bearing housing ends......and thats standard on all moser rears now i believe......NO C-CLIP ELIMINATORS

and the whole center section thing......everyone always trys to play that card.....unless your a pro, or someone that travels on a race circuit....NO ONE SWAPS PUMPKINS......thats ridiculous....no one every changes gears for conditions, if they do ITS NOT a street car.

many tests have been done on the 9" vs 12 bolt......and ya know what they came up with?

not one of them has ever shown a definitive strength advantage over the 12 bolt......its marginal at best.

the percentage of power loss is measurably i believe its a 2-3% difference in efficiency, which is caused by the longer pinion spread in the 9"


all this argument is, everytime it happens, and it does happen often is a "my part is better than your part" argument with no facts backing anything up

the only real difference is personal preference

KagA152

iTrader: (5)

pretty good deal:
http://cgi.ebay.com/ebaymotors/ws/eB...sPageName=WDVW

IHI

iTrader: (1)

That's the same guy most all of us in this area buy are rear end stuff from. I like Doug, good guy, but the monkeys he has working the phones can screw up a bad dream....I had a bad expereince when I placed the order for my 9". He kinda made it right, but I was still PO'd.

383...my 9" is bigger than your 12 bolt

I agree totally with...BUT....I funlly intend to take a leg on the pwr tour this year. I will pull my 3rd member with spooled 4.11 and install the 3rd member under the bench with open diff 3.00, I will have 30 minutes time going from race set-up to hwy crusier....can you do that with your 12 bolt??!!!! LOL

For the average joe they will not swap gear sets....just like how many people acutually NEED a camera phone, video phone, DVD/radio in the car, pwr windows/locks, off road package, etc...you see where I'm going. It's there and that option that probably is not practical or utilized, but it's still there to brag about to the buddies

mw66nova

iTrader: (13)

i was looking at Currie's website. is TractionLock a locker of sorts? is it strong? $2200 for a complete, ready to bolt in rear is pretty damn good in my book.

IHI

iTrader: (1)

Neer heard of it myself, but would assume it along the lines of a Detroit locker, but that's just a guess on my part right now.

$2200 installed is a great price! Does that include brakes/brake lines to hook back into car and shipping?

Mine complete from the above mentioned company selling the Strange section on e-bay was $2300 with the cheap disc brake option that I had to install. Doug said he would'nt install the brake set-up becasue of liability issues, other I've talked to said they install them all the time, just dont know if they made it known to Doug they were strip only cars where I told him mine was a street/strip car. On top of that $2300 I still had to buy the braided brake lines and fittings to hook it all up, another $115.

mw66nova

iTrader: (13)

comes with drum brakes, they didn't say if i was going to need aftermarket lines. it looks like i can reuse my exsisting brake lines.

383backinblack

i know what your saying......but see, i don't need to do that even with 4.10's cause i have a .64 overdrive

so it takes me 0 minutes to get ready to go on the highway

IHI

iTrader: (1)

LOL, you guys and your OD

White91GTA

9" is the way to go. Look at NASCAR, do you see them using a 12 bolt in any of the GM cars out there...the answer is NO. Reason being that they are stronger than a 12 bolt. NASCAR only uses the strongest parts they can and that is why they also use rods from Honda in all of their motors.

383backinblack

lol......wow.....are you ok man?

the use honda rods for 2 reasons.....they are very light, and they the big end is narrower, so there is NO contact between adjoining rods on the crank to greatly reduce friction....they are about as strong as a regular steel rod.

they use 9 inch rears because in nascar they DO change gear ratio's every day.....they have whole racks of center sections so they can swap in the ideal gear ratio for the track/conditions.

ya its strong......but so is a dana 60.....thats not why they use them

stop humping nascar you *******

pasky

Oh yes, if you can't come up with a logical argument, let the name calling begin. Seriously, you sounded like you knew something until that happened....

Rembrandt

NASCAR isn't a relevant example for what we are talking about; they never do drag launches with wrinkle-wall slicks.

Don't the rules require them ALL to run the same type of rear end?

The rods aren't from Honda. They use a big end journal diameter the same as a Honda. Like 383 said, it is lighter. But there isn't a strength sacrifice.

Rembrandt

I'd like to read some of those tests.

Got any links?

mw66nova

iTrader: (13)

honestly, i could care less about NASCAR, they aren't at all like what i am doing here. driving my racecar on the street most days i want it to hold up. actually, as long as i have the 305 in it, i plan to drive it everyday. 13.75@100.5 is the fastest it's been so far, and i am putting in a beefed up 700r4 with a high stall converter (around 3000) and i have already put in a set of 4.10's and a locker since those times. the possibility of low 13's with my 305 is there, and i don't want to grenade the rear.

pasky

Once again, I vote for the 9". Like I said, I have yet hear of one break on a street car with aftermarket parts. I've heard of stock ones breaking but not mosers. I've heard of plenty of moser 12 bolts fall apart in high performance street cars. They weigh more, and yes, the 2-3% powerloss over a 12 bolt is true, but to me its worth it for that extra security and the ability to get better 60's at the track.

383backinblack

\


nope......just poke around for back issues of car craft, super chevy, chevy high performance etc etc etc......thats where they usually take place.

brutalform

The Currie charges break down as follows:

Yellow Freight...................................................$230.00
Palletizing and boxing.......................................$27.50
assemble (install third member and axles)........$29.95
upgrade stock case to 9+ case..........................$120.00
gears, 31 spline Detroit Locker &
9+ big bearing support.......................................$999.95
Labor to modify disc brake brackets for
use on 9 in...........................................................$64.95
Currie performance axles.....................................$389.95
housing w/ torque arm bracket............................$549.95
-------------
$2412.25
Then I added the powdercoating for an additional $139.95. Now it can be more or less, depending what you order.

These prices were in 2002.

By the way, parts is parts, and anything can break. A 12 bolt, or 9 in. I was going to buy a 12 bolt, and a friend had great dealings with Currie, so I bought my rear from them. Glad I did, best $2500.00 I ever spent.

383backinblack

way to swipe my back in black theme by the way

in any case......i don't buy it....my car is making close to 470hp at the wheel and gets its *** kicked with a manual trans and sticky tires 2-3 days at the track a week during the season........plus 4-5 thousand street miles during the summer AT LEAST

this thing is bullet proof.....alot of people that claim to break them, are either being idiots, or they didn't order them with good parts....you can get just about anything in these things.....i would venture a guess that most of those people didn't have the support cover either......the only thing thats gonna break the rear is deflection, and with the cover, there really isnt any.....especially when your talking about under 800hp

mine has 33 spline alloy axles, eaton 33 spline posi unit, richmond gears, big bearing ford housing ends, the moser support cover etc.

383backinblack

really exactly what part of that isn't logical?

you think that the "durrrerrrr nascar duz dis wit theer race kahhs....so its rite fo drag racin too"

is a logical argument?

pasky

No, but I don't see it as a reason to name call either, people like yourself get threads locked for being immature rather than handling the situation better.

pasky

Not even aware of who you are until this thread, reason I have that in the signature is my vehicle's factory color was black, the car was painted white when I bought it, I restored its original color after doing my performance upgrade.

brutalform

Yes, but some people do though.

Bottom line is, both rears are super strong, I would even consider them equal. But, with almost endless gear choices, and array of differential choices, the 9 in. is more versitile. Throw in the fact that you dont have to drop the entire housing out of the car, makes it even more of a good thing.

Then there are the "keep my GM car all GM' guys. The 12 bolt is for you. To each his own.....

383backinblack

if people that are genetically unable to function mentally wouldn't post retarded things there wouldn't be a problem

but it does happen, and i feel ignoring it is only making the problem bigger.