Re: Strange S-60 more efficient than 8.75"?
[Re: BradH]
#2708839
10/21/19 12:24 PM
10/21/19 12:24 PM
|
Joined: Sep 2014
Posts: 4,457 Washington
madscientist
master
|
master
Joined: Sep 2014
Posts: 4,457
Washington
|
Is a Strange S-60 more efficient than an 8.75", as in enough to help offset (some of?) the weight difference?
I'm trying to calc some target ET & MPH #s for my new combination. I know the Strange S-60 conversion has added some weight (not sure exactly now much; estimating 50#s) compared to my old 8.75". Neither old or new diff use spools; 8.75" had Power-Lok and S-60 and Strange has S-Track.
However, I've read here that a Dana 60 is more efficient than an 8.75" and the ETs are usually very close, despite the weight increase. True? The weight is a push at best. When you get the 8.75 braced, used a NI case and all that, what weight you gain with the S60 is almost nothing. Also, the weight is low and far enough back to almost not matter. Also, the S60 is only more efficient when the gear ratios are lower (numerically higher) than ~3.90 otherwise that's a push. If I'm wrong, Dr. Diff can come along and fix it, but I think I'm correct.
Just because you think it won't make it true. Horsepower is KING. To dispute this is stupid. C. Alston
|
|
|
Re: Strange S-60 more efficient than 8.75"?
[Re: BradH]
#2708840
10/21/19 12:24 PM
10/21/19 12:24 PM
|
Joined: Jan 2003
Posts: 5,894 Florida
Locomotion
master
|
master
Joined: Jan 2003
Posts: 5,894
Florida
|
I specifically remember an old magazine article that showed a Dana 60 to be more efficient than an 8 3/4 mainly because of the ring & pinion orientation. Dana 60 is more centered. It also pointed out that a Ford 9" is the least efficient not only because of the R&P, but also because of the extra bearings. A GM 12 bolt was the most efficient of the "common" rears tested and I would guess that a 10 bolt would have been a bit better. In fact, I believe some rear end manufacturer had/has a 12 bolt gear drop-out made for Ford 9" rears with improved efficiency.
Granted, these differences were pretty small, but it apparently was worth the effort by several class racers who noted that they didn't see any loss of ET, especially after their cars had the weight adjusted back after the swap. Also worth noting, there would be less difference in weight if both were using a spool as opposed to a Sure-Grip or other such part. Added bonus is the durability.
I believed in it enough to replace the 8 3/4" in my Stock class Aspen Wagon with a Dana 60. I believe the weight difference was between 35-40 lbs,.Both had spools and star-flanged axles with the 8 3/4 being braced. The Dana had a thick, aluminum girdle cover. But I was mainly interested in durability as I doubt I'll ever have any breakage problems in a high-11 to mid-12 second car, despite it's 3,927 lb weight in K/SA. Unfortunately, with the problems I had, I was never able to establish a baseline to compare from and am currently trying to get an engine for it again.
I
Last edited by Locomotion; 10/21/19 12:27 PM.
|
|
|
Re: Strange S-60 more efficient than 8.75"?
[Re: BradH]
#2708849
10/21/19 12:41 PM
10/21/19 12:41 PM
|
Joined: Aug 2011
Posts: 2,857 Pattison Texas
CSK
master
|
master
Joined: Aug 2011
Posts: 2,857
Pattison Texas
|
FWIW, 4.10s in both and the 8.75" had a back brace (I don't recall the weight increase for that alone). Jacking around w/ the latest dyno #s, old dyno #s, old track results, and the other stuff that's changed... I THINK the MoPig "should" be capable of squeaking into the 10.1s at 129+ MPH. But reality has a funny way of changing hopeful expectations... Now that I've put it out there publically, the laughter may begin. No laughter here, just waiting with GREAT anticipation for you getting the car running & at the track
1968 Charger COLD A/C Hilborn EFI 512ci 9.7 compression, Stealth heads, 4.10 gear A518 ODtrans 4100lb,10.93 full street car trim 2020 T/A 392 Stock 11.79 @ 114.5
|
|
|
Re: Strange S-60 more efficient than 8.75"?
[Re: Cab_Burge]
#2708917
10/21/19 04:02 PM
10/21/19 04:02 PM
|
Joined: Dec 2013
Posts: 4,672 Wichita
GY3
master
|
master
Joined: Dec 2013
Posts: 4,672
Wichita
|
We ran back to back weekends with 8 3/4 and then with Dana 60. With 3.55 and 3.54 gears, the car ran identical to the hundredth. 11.41's as I recall.
'63 Dodge 330 11.19 @ 121 mph Pump gas, n/a, through the mufflers on street tires with 3.54's. 3,600 lbs. 10.01 @ 133mph with a 250 shot of nitrous an a splash of race gas. 1.36 60 ft. 3,700 lbs.
|
|
|
Re: Strange S-60 more efficient than 8.75"?
[Re: GY3]
#2708918
10/21/19 04:06 PM
10/21/19 04:06 PM
|
Joined: Jan 2003
Posts: 9,826 las vegas
70AARcuda
master
|
master
Joined: Jan 2003
Posts: 9,826
las vegas
|
Our 71 Dart 360 ran best of 10.35 with the 8 3/4....after twisting axle housing. A Strange D60 was installed with same gear ratio and spool.....35 spline axles compared to the 83/4 30 spline...the Dart ran 10.31...with pretty much the same mph...
Last edited by 70AARcuda; 10/21/19 04:07 PM.
Tony
70 AARCuda Vitamin C 71 Dart Swinger 360 10.318 @ 128.22(10-04-14 Bakersfield) 71 Demon 360 10.666 @122.41 (01-29-17 @ Las Vegas) 71 Duster 408 (10.29 @ 127.86 3/16/19 Las Vegas)
|
|
|
Re: Strange S-60 more efficient than 8.75"?
[Re: BradH]
#2708987
10/21/19 07:45 PM
10/21/19 07:45 PM
|
Joined: Oct 2007
Posts: 4,206 New York
polyspheric
master
|
master
Joined: Oct 2007
Posts: 4,206
New York
|
The lighter axle is easier for the shock to control: unsprung weight.
Boffin Emeritus
|
|
|
Re: Strange S-60 more efficient than 8.75"?
[Re: J_BODY]
#2709015
10/21/19 09:04 PM
10/21/19 09:04 PM
|
Joined: Dec 2013
Posts: 4,672 Wichita
GY3
master
|
master
Joined: Dec 2013
Posts: 4,672
Wichita
|
S60 is way more efficient in keeping money in my wallet over my past 8.75 experiences.... This! Under pressure, pushin' down on me...
'63 Dodge 330 11.19 @ 121 mph Pump gas, n/a, through the mufflers on street tires with 3.54's. 3,600 lbs. 10.01 @ 133mph with a 250 shot of nitrous an a splash of race gas. 1.36 60 ft. 3,700 lbs.
|
|
|
Re: Strange S-60 more efficient than 8.75"?
[Re: BradH]
#2709016
10/21/19 09:14 PM
10/21/19 09:14 PM
|
Joined: Jan 2003
Posts: 11,711 Portage,michigan
B3422W5
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 11,711
Portage,michigan
|
Is a Strange S-60 more efficient than an 8.75", as in enough to help offset (some of?) the weight difference?
I'm trying to calc some target ET & MPH #s for my new combination. I know the Strange S-60 conversion has added some weight (not sure exactly now much; estimating 50#s) compared to my old 8.75". Neither old or new diff use spools; 8.75" had Power-Lok and S-60 and Strange has S-Track.
However, I've read here that a Dana 60 is more efficient than an 8.75" and the ETs are usually very close, despite the weight increase. True? Ran an 8.75 forever( well sorted car) broke it. By the following race weekend a Dana was installed. Despite being heavier, i saw absolutely zero difference in time slips. As if i never made the swap regards, incrementals, MPH, ET, you name it. So it must be more effecient to weigh 60-70 pounds more and have zero impact on my slips This was running 10.40’s at the time
Last edited by B3422W5; 10/21/19 09:14 PM.
69 Dart GTS A4 Silver All steel, flat factory hood, 3360race weight 418 BPE factory replacement headed stroker, 565 lift solid cam Best so far, 10.40 @127 1/4 1.41 best 60 foot 6.60 at 103.90 1/8
|
|
|
Re: Strange S-60 more efficient than 8.75"?
[Re: B3422W5]
#2709018
10/21/19 09:22 PM
10/21/19 09:22 PM
|
Joined: Dec 2005
Posts: 11,551 Fulton County, PA
CMcAllister
Mr. Helpful
|
Mr. Helpful
Joined: Dec 2005
Posts: 11,551
Fulton County, PA
|
There are things besides the pinion to ring gear centerline aspect that effect how much power a rear end assembly absorbs. Tooth design, gear treatments, weight of internal components, bearings used (ceramics), how it is assembled (turning torque/preload), oil viscosity and amount in the housing, housing fabrication (nice true centerline from axle bearing to axle bearing), etc...
If the results don't match the theory, change the theory.
|
|
|
Re: Strange S-60 more efficient than 8.75"?
[Re: CMcAllister]
#2709055
10/22/19 12:07 AM
10/22/19 12:07 AM
|
Joined: Jan 2003
Posts: 8,022 Tulsa OK
Bad340fish
master
|
master
Joined: Jan 2003
Posts: 8,022
Tulsa OK
|
Instead of sweating the efficiency enjoy the comfort of being able to drive home after ripping some new best ETs because your Dana didn't even realize it was at work. I like the "set it and forget it" feeling the Dana swap gave me.
68 Barracuda Formula S 340
|
|
|
Re: Strange S-60 more efficient than 8.75"?
[Re: Bad340fish]
#2709059
10/22/19 12:25 AM
10/22/19 12:25 AM
|
Joined: Jan 2003
Posts: 9,826 las vegas
70AARcuda
master
|
master
Joined: Jan 2003
Posts: 9,826
las vegas
|
One other thing about the Strange D60 is it uses spanner adjuster to remove the carrier....no shims....make changing the ring and pinion easier...
Tony
70 AARCuda Vitamin C 71 Dart Swinger 360 10.318 @ 128.22(10-04-14 Bakersfield) 71 Demon 360 10.666 @122.41 (01-29-17 @ Las Vegas) 71 Duster 408 (10.29 @ 127.86 3/16/19 Las Vegas)
|
|
|
Re: Strange S-60 more efficient than 8.75"?
[Re: Bad340fish]
#2709079
10/22/19 06:31 AM
10/22/19 06:31 AM
|
Joined: Jan 2003
Posts: 15,439 Val-haul-ass... eventually
BradH
OP
Taking time off to work on my car
|
OP
Taking time off to work on my car
Joined: Jan 2003
Posts: 15,439
Val-haul-ass... eventually
|
Instead of sweating the efficiency enjoy the comfort of being able to drive home after ripping some new best ETs because your Dana didn't even realize it was at work. I like the "set it and forget it" feeling the Dana swap gave me. I definitely made the switch out of concern the fuse was lit on my 8.75". My question was more out of curiosity as to how much I should factor in the weight gain on the performance.
|
|
|
Re: Strange S-60 more efficient than 8.75"?
[Re: BradH]
#2709080
10/22/19 06:37 AM
10/22/19 06:37 AM
|
Joined: Aug 2004
Posts: 214 Hamburg / Germany
Den300
enthusiast
|
enthusiast
Joined: Aug 2004
Posts: 214
Hamburg / Germany
|
Changed from a 8.75 with 3.91 gears to a S60 with 3.73. No difference at all. Just more relaxed as it is under a Fuselage.
Hamburg/Germany
69 Chrysler 300 446cui Dual Quad 12.64 @ 110.7
|
|
|
|
|