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Re: Street/strip diff upgrade: D60 vs 9" pros & cons
[Re: maximum entropy]
#1752507
02/20/15 08:57 PM
02/20/15 08:57 PM
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Joined: Jan 2008
Posts: 1,211
Minn
SportF
pro stock
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pro stock
Joined: Jan 2008
Posts: 1,211
Minn
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Quote:
i run a dana for a number of reasons. the dana may weigh slightly more, but has less rotating drag due to the fact that the pinion centerline is closer to the ring gear centerline (vertically). granted there is tons of aftermarket support for the 9", but i just didn't want a ford based rear in my car. that and i've broken a 9". and an 8 3/4. and an 8 1/4. i also agonized over which posi to use. i have a full spool. it was the right decision for me.
This rotating effort/efficiency of rear ends I find exceptionally interesting. I have NEVER seen an actual test, figures, or calculations. As such, I believe that it really doesn't make a difference, a measurable difference. NASCAR guys do everything to extract every bit of power, yet they run a 9". Show me facts, otherwise, I say this is 50 years of bull.....
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Re: Street/strip diff upgrade: D60 vs 9" pros & cons
[Re: fourgearsavoy]
#1752508
02/20/15 09:30 PM
02/20/15 09:30 PM
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Joined: Aug 2003
Posts: 1,574
KOS
pro stock
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pro stock
Joined: Aug 2003
Posts: 1,574
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Re: Street/strip diff upgrade: D60 vs 9" pros & cons
[Re: pittsburghracer]
#1752511
02/20/15 09:54 PM
02/20/15 09:54 PM
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Joined: Feb 2007
Posts: 6,295
U.S.
moparniac
master
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master
Joined: Feb 2007
Posts: 6,295
U.S.
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Works for me... 550" HEMI with f2 procharger
Mopar Performance
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Re: Street/strip diff upgrade: D60 vs 9" pros & cons
[Re: KOS]
#1752513
02/20/15 10:12 PM
02/20/15 10:12 PM
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Joined: Jan 2008
Posts: 1,211
Minn
SportF
pro stock
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pro stock
Joined: Jan 2008
Posts: 1,211
Minn
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Quote:
Quote:
Interesting read here Brad 
http://www.hotrod.com/how-to/transmission-drivetrain/ccrp-0806-chevy-chevelle-rear-axle-swap/
Gus
read this heres your proof
Well, I stand corrected. What a great test! Man, that took some time and effort.
It stated at the end that the ET would be measured in hundred's of a second. Um, the Ford was 17 pounds lighter (balancing the brake weights). With an aluminum center you could drop enough weight to make the ET's the same????
This thread really hashed out some opinions and ideas here, so I will put mine here as well. I think the ford rear (with aluminum center) looks better than the Dana. Thanks to all for the inputs!
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Re: Street/strip diff upgrade: D60 vs 9" pros & cons
[Re: SportF]
#1752514
02/21/15 12:03 AM
02/21/15 12:03 AM
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Joined: Apr 2013
Posts: 345
Nebraska
451Cuda
enthusiast
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enthusiast
Joined: Apr 2013
Posts: 345
Nebraska
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Quote:
Quote:
Quote:
Interesting read here Brad
http://www.hotrod.com/how-to/transmission-drivetrain/ccrp-0806-chevy-chevelle-rear-axle-swap/
Gus
read this heres your proof
Well, I stand corrected. What a great test! Man, that took some time and effort.
It stated at the end that the ET would be measured in hundred's of a second. Um, the Ford was 17 pounds lighter (balancing the brake weights). With an aluminum center you could drop enough weight to make the ET's the same????
This thread really hashed out some opinions and ideas here, so I will put mine here as well. I think the ford rear (with aluminum center) looks better than the Dana. Thanks to all for the inputs!
And get the aluminum 9 inch center that runs 12 bolt gears, there's the winner
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Re: Street/strip diff upgrade: D60 vs 9" pros & cons
[Re: WO23Coronet]
#1752521
02/23/15 06:48 PM
02/23/15 06:48 PM
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Joined: Jan 2008
Posts: 1,211
Minn
SportF
pro stock
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pro stock
Joined: Jan 2008
Posts: 1,211
Minn
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Well, they are saying 12 bolt gears, and with the pinion higher, I doubt the support bearing is possible.
I don't exactly agree with someone calling the 9" a power robber, there was a 1.5% difference in power output, which could be caused by a simple temperature or barometric change. Maybe they accounted for that, don't remember reading that though. Did anybody see if they accounted for "weather/altitude" change?
Overall it was a really interesting test of rears, but what if bearing pre-load is on the high side of one rear, and low on the other.
I no doubt learned something there, but it wouldn't change my mind as to which rear I would choose.
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Re: Street/strip diff upgrade: D60 vs 9" pros & cons
[Re: SportF]
#1752524
02/23/15 07:40 PM
02/23/15 07:40 PM
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Joined: Jun 2003
Posts: 52,972
Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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Quote:
Well, they are saying 12 bolt gears, and with the pinion higher, I doubt the support bearing is possible.
I don't exactly agree with someone calling the 9" a power robber, there was a 1.5% difference in power output, which could be caused by a simple temperature or barometric change. Maybe they accounted for that, don't remember reading that though. Did anybody see if they accounted for "weather/altitude" change?
Overall it was a really interesting test of rears, but what if bearing pre-load is on the high side of one rear, and low on the other.
I no doubt learned something there, but it wouldn't change my mind as to which rear I would choose.
The heavy brakes would account for most of the difference
they showed.. and they made note of the brakes being
heavy
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Re: Street/strip diff upgrade: D60 vs 9" pros & cons
[Re: Monte_Smith]
#1752525
02/23/15 08:04 PM
02/23/15 08:04 PM
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Joined: Oct 2003
Posts: 11,684
W. Kentucky
justinp61
I Live Here
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I Live Here
Joined: Oct 2003
Posts: 11,684
W. Kentucky
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Quote:
As somebody already stated, if there was shred of evidence that a Ford COST you ANY power or performance over the entire range, they would NOT be under CUP cars.....period. Instead of center sections for every track, they would just have complete assys. Could change them just as fast, probably faster.
I'd be curious to see if the rear end was like everything else in nascar. It's probably the only one approved to run in their major series.
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