Strange 12 bolt center for ford 9" housing
11-22-2007, 10:20 PM
#1
Strange 12 bolt center for ford 9" housing Has anyone had experience with this? I saw it listed on the Strange website. Has the benefit of removable center section and the added efficiency of the 12 bolt ring and pinion.
http://www.strangeengineering.net/catalog/index.html
listed in 9" components # 75
http://www.strangeengineering.net/catalog/index.html
listed in 9" components # 75
11-23-2007, 01:06 PM
#2
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I've thought about this housing. It certainly looks as if they intend it to be for a drag race only setup..but ten again they list it as accepting posi units so I dunno. Perhaps someone out there has used it.
It seems to me the positives are:
Removable center section making gear swaps quicker
Lower power consumption of the 12 bolt design.
Larger differential side bearings.
The (slightly) smaller, more efficient 12 bolt r & p setup without the case spreading tendencies of a rear-loading housing.
The negatives are of debatable relevance as far as most F-bodes go. The higher your power level, the higher the relevance:
Requires a 12 bolt differential, smaller and weaker than a 9". A few less options too.
Giving up the increased strength of the 9" pinion setup.
Aluminum version of a 12 bolt housing would tend to be less rigid than iron.
Aluminum center section providing a somewhat less consistent gear mesh over the temperature range.
I could forsee some of these negatives and positives countering each other. For example, the decreased rigidity of the aluminum countering the lack of case spreading as would be seen in a normal 12 bolt.
It seems to me the positives are:
Removable center section making gear swaps quicker
Lower power consumption of the 12 bolt design.
Larger differential side bearings.
The (slightly) smaller, more efficient 12 bolt r & p setup without the case spreading tendencies of a rear-loading housing.
The negatives are of debatable relevance as far as most F-bodes go. The higher your power level, the higher the relevance:
Requires a 12 bolt differential, smaller and weaker than a 9". A few less options too.
Giving up the increased strength of the 9" pinion setup.
Aluminum version of a 12 bolt housing would tend to be less rigid than iron.
Aluminum center section providing a somewhat less consistent gear mesh over the temperature range.
I could forsee some of these negatives and positives countering each other. For example, the decreased rigidity of the aluminum countering the lack of case spreading as would be seen in a normal 12 bolt.
Last edited by Awake455; 11-23-2007 at 01:17 PM. Reason: I'm a non-typing goober
11-23-2007, 04:24 PM
#3
The 12-bolt drop-out was created by Strange in 1994 and has been relied on by leading Competition Eliminator cars.
The 12-bolt drop-out is offered in two case bore sizes- 3.0625” and 3.250”- both cases fit 9” housings (Some factory
housings require modification). Strange’s 3.0625” bore case accepts factory posi-units and Strange 30 and 33-spline
12-bolt spools. The 3.250” case accepts specially designed 35 & 40-spline ultra light spools.
The 12-bolt drop-out case is designed for the racer seeking the least amount of weight and where lower E.T. is
crucial. The 12-bolt pinion is closer to the the center of the ring gear, in comparison to a 9”gear, making the 12-bolt
3% more efficient than a 9” rear ( 9” pinion is 2.250” below the center of the ring gear; compared to a 1.50” drop for
our 12-bolt). Besides being more efficient, the fully assembled unit is 8-9 pounds lighter than a comparable
aluminum 9”assembly.
For years, racers have spent small fortunes in acquiring aluminum, titanium, and magnesium components. The 12-
bolt drop-out recovers horsepower, as well as being extremely light and at the same cost as conventional Strange 9”
components.
The 12-bolt drop-out is offered in two case bore sizes- 3.0625” and 3.250”- both cases fit 9” housings (Some factory
housings require modification). Strange’s 3.0625” bore case accepts factory posi-units and Strange 30 and 33-spline
12-bolt spools. The 3.250” case accepts specially designed 35 & 40-spline ultra light spools.
The 12-bolt drop-out case is designed for the racer seeking the least amount of weight and where lower E.T. is
crucial. The 12-bolt pinion is closer to the the center of the ring gear, in comparison to a 9”gear, making the 12-bolt
3% more efficient than a 9” rear ( 9” pinion is 2.250” below the center of the ring gear; compared to a 1.50” drop for
our 12-bolt). Besides being more efficient, the fully assembled unit is 8-9 pounds lighter than a comparable
aluminum 9”assembly.
For years, racers have spent small fortunes in acquiring aluminum, titanium, and magnesium components. The 12-
bolt drop-out recovers horsepower, as well as being extremely light and at the same cost as conventional Strange 9”
components.
interesting...
