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9" too much for A4?

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Old 03-16-2005, 06:47 PM
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Default 9" too much for A4?

I am considering getting a 9" for my A4 w/a Vig3200 in it.. i'll probabaly get either a carbon fiber or chrome moly driveshaft.. I am just worried about all of the drivetrain loss.. Does anybody have numbers before and after with an A4?

Also i am going to be running weld draglites.. I don't know whether to go with a 15x8 rim with a 10" tire or get 15x10's with a 10 inch or bigger tire.. with a 9" would the 15x10's be an overkill with a 3200 stall? Any opinions?

Thanks to anyone with any kind of helpful advice!
Old 03-16-2005, 10:32 PM
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Not from experience, but from a lot of reading....I know you will not need a 9" with an A4. The A4 will explode before it breaks a 12bolt in most cases...

I think it is extremely rare for a 12boly yo break behind a 4L60. Now a TH400 is a different story, but even with them I think it is still rare...
Old 03-17-2005, 08:46 AM
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anybody else hav some opinions? should i really get a 12 bolt or just get the 9"? and what about the rim and tire question? any help would be great!
Old 03-17-2005, 10:14 AM
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Strictly my opinion:
I would get the 9". Mainly because of the strength and gear swap capability. Also because I've been involved with stock cars for a long time and most all teams in all divisions use the 9". The 9" must be doing something right.

Exotic Performance Plus sells them both for about the same price, so that negates any price issue.

The biggest factor with a 9" is that you can swap gear pumpkins very easily. Not as easy as a quick change rearend but you can run hiway gears for normal driving then pop in qtr mile gears for the track. Check with some local late model stock NASCAR guys for getting cheaper deals on pumpkins. But additional pumpkins will be another cost factor.

There is certainly nothing wrong with a 12 bolt rearend, it will serve greatly. It's really a coin flip for which one you want. I just lean on the 9" side a little more.
Old 03-17-2005, 09:38 PM
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What am I missing here?
You have a mild bolt-on car and you're ready to invest in a 9" and big slicks. The CF or chromo DS aren't going to make you much faster either. Pretty rare for an A4 to tear up a DS unless there is really big power flowing through it.
Your car should run nicely on nittos drag radials and stock rear and stock Aluminium DS.

If your future plans call for a big shot of spray or max effort NA set-up then you're heading in the right direction. Otherwise, you may never need either.

FWIW, I think a 12 bolt is fine for an A4. Less hassles keeping ABS and ASR and I think they weigh a bit less too.
Old 03-17-2005, 09:51 PM
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well my car is pushing around 400 RWHP.. and i have a NX 125 shot going through it soon.. Also i'm adding a pulling, QA1 suspension, and getting Weld draglites..

Haha your making my car sound almost stock! Am i really in need of some heads or a supercharger? haha
Old 03-17-2005, 10:14 PM
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Originally Posted by Ragtop 99
What am I missing here?
You have a mild bolt-on car and you're ready to invest in a 9" and big slicks. The CF or chromo DS aren't going to make you much faster either. Pretty rare for an A4 to tear up a DS unless there is really big power flowing through it.
Your car should run nicely on nittos drag radials and stock rear and stock Aluminium DS.

If your future plans call for a big shot of spray or max effort NA set-up then you're heading in the right direction. Otherwise, you may never need either.

FWIW, I think a 12 bolt is fine for an A4. Less hassles keeping ABS and ASR and I think they weigh a bit less too.
Old 03-18-2005, 07:55 AM
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I must have missed your sig saying you have a cam. I looked briefly at your website and stopped reading the list of mods when I saw spark plugs listed.

Wet shot hits harder than dry. If you are going to spray regularly a 9" might be a good choice.

FWIW, drag lites and anything that reduces weight actually contributes to your stock rear lasting longer.
Old 03-18-2005, 11:12 AM
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Originally Posted by Ragtop 99
I must have missed your sig saying you have a cam. I looked briefly at your website and stopped reading the list of mods when I saw spark plugs listed.

Wet shot hits harder than dry. If you are going to spray regularly a 9" might be a good choice.

FWIW, drag lites and anything that reduces weight actually contributes to your stock rear lasting longer.
u sir are wrong dry shots hit alot harder then wet shots.
Old 03-18-2005, 10:18 PM
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Personally the price diff is minimal, but the breakage factor is way different. It is posted time and time again on here and every other board, 12bolts still break! I would go with a 9" and call it done, why take unnecessary risks.
Old 03-18-2005, 11:55 PM
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9" 35 spline lightened, spool.

Done.
Old 03-19-2005, 12:29 AM
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Haha yea.. my mods list on my site is pretty broke down.. pretty much everything i've touched on my car going from spark plugs and smooth bellows to Cams, stalls, headers, and so on..

Thats the only reason why i think a 9" would be better.. because so many people complain that their 12 bolts whine after a couple hard launches.. i have never heard anyone complain about 9" rears.. and with the 9" i could also spray out of the hole a little and not worry about it breaking! =) Thanks for the replies!!
Old 03-19-2005, 07:55 AM
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Everyone has a different view of this topic. Personnaly, I've owned both and I believe that 12 bolt are fine for 99% of these cars. Nine inch Fords are more expensive, heavier and consume more power and are intended for high hp setups. As a rough rule of thumb, 10s and slower should run 12 bolts, 9s and faster = 9-inch Fords. JMHO.
Old 03-19-2005, 09:13 AM
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Originally Posted by bickelfirebird
As a rough rule of thumb, 10s and slower should run 12 bolts, 9s and faster = 9-inch Fords. JMHO.
That's a good rule!
Old 03-20-2005, 12:12 AM
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yea see thats what i was thinking too.. but what about all of the people that complain of their 12 bolts whining after a couple hard launches? Would it really be that bad of a move for me to get the more dependable one and not have to worry about any problems.. even if it drains a little more HP?
Old 03-21-2005, 01:31 AM
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Originally Posted by RollinSScamaro
yea see thats what i was thinking too.. but what about all of the people that complain of their 12 bolts whining after a couple hard launches? Would it really be that bad of a move for me to get the more dependable one and not have to worry about any problems.. even if it drains a little more HP?
that was my dilemma, but i was hurting for transportation and a few other factors (abs/resale/etc.) pushed me toward 12 bolt.

if your car isnt down for the count, and you have plenty-o-time, go with the 9", security

i would call up billingsly racing and have them build you a badass 9", 35 spline with a detroit locker. when you start making enough power to blow out the locker, swap it for a spool and you're ready for 1.00 60's
Old 03-21-2005, 08:55 AM
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haha yea.. i am actually going picking up a 9" used from a guy i know for $1000.. i can't turn it down.. it has ABS but no traction control.. it has a posi in it too.. the gear size i'm not sure about.. but it comes with cross drilled rotors and everything.. pretty damn good deal! i can't wait to see how hard my car hooks with draglites, QA1, and the 9"! thanks for the responses
Old 03-21-2005, 01:45 PM
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i have a cam,150 wet, 3600 stall,shift kit,10 bolt with eaton posi, 3.73s, and 15x10 bogarts, and on spray my car cut a 1.52 60. with 28" MT drags.
so depending on ur gears id say either a 26 or 28" slick will hook nicely.
Old 03-21-2005, 03:23 PM
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so are you running 10's on a built 10 bolt i take it? and everyone told me not to do it haha.. maybe its hit and miss?
Old 03-22-2005, 01:53 AM
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Originally Posted by RollinSScamaro
it has ABS but no traction control..
jigga whaa?



how is this animal working? you better do some more research before buying this. i've seen ONE 9" rear end w/ working ABS/noTCS. it had a ghetto *** reluctor ring on the pinion (but it worked )

send us some pics or a link or somthing, you need to verify the legitamicy of this before you drop a grand on it.



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