What type of transmission did you choose and why?

[RJacobsen]

The "clunking" that you have heard about is more of a problem with certain types of carriers than others. Some units transfer power to the wheel that has the most traction, some have a mechanical method of locking up, and some simply have clutch packs inside that lock both wheels to a point and then allow them to "slip" as nessasary. The clutch pack type is probably the most common and needs to have a friction additive included in the gear lube to keep the plates from sticking and creating the clunking noise.

[Slither]

I have heard lots of different names for these "posi" rear-ends... Detroit Locker, Power Lock (Auburn??), limited slip, Auburn, etc.

I recall hearing about the differences in bench-racing conversation, but I am not able to recall all the nuances at will.

Could someone with some expertise/knowledge post here about the differences so that we could have a reference point for future, and old, users? It might be a help for those looking to make this decision.

EDIT:

I guess this info would be better placed in this thread...

http://www.uniquecobra.com/forums/showthread.php?t=7967

Thanks!

END EDIT

[pbrown]

I have heard lots of different names for these "posi" rear-ends... Detroit Locker, Power Lock (Auburn??), limited slip, Auburn, etc.

Those are all brand names. In fact, Positraction is a GM name. I know some Ford guys that would pounce on anyone that used the word Posi in relation to a Ford.

There are open, limited slip, locking, and spool setups.

Open is the old peg leg setup. One wheel spins and the other does nothin' as said in one of my favorite movies.

Limited slip is what most people get. It used cluch material and is great on the street and track. This is what people often call a Posi. The Ford variation is the Trak-Lock.

Locking units (aka Detroit Locker) is popular with the drag race croud that still wants something that can be used on the street. They tend to make a clunk sound around corners. They handle a lot more power than the limited slip solutions.

Spool setups are solid axles are are best kept on the drag strip. I do know of people that use them on the street. There is tire scrubbing and axle binding on sharp corners. Probably best kept out of the mall parking lot.

[RJacobsen]

Limited slip is what most people get. It used cluch material and is great on the street and track. This is what people often call a Posi. The Ford variation is the Trak-Lock.

Ford also had an earlier version called the Equi-Lock, it had a slightly different and less effective clutch setup as the Traction-lock

[Slither]

Thanks for the good info Patrick.

I was lucky enough to have had lunch with Butch Capps and Ralph Scott last Monday, up in Knoxville, TN, as I was traveling to a conference. I very much enjoyed seeing Butch again, as well as meeting Ralph. They are both first-class individuals. It was a treat! Thanks for coming on such short notice Ralph.

Butch explained the "posi" stuff well, though we did not go into the obscure stuff. Interestingly, he mentioned that the Auburn Power Lock unit, the limited-slip with clutch packs found in the Jag center sections, has not been made for about 25years... Auburn now makes the cone-style clutch setup that Rick has.

Butch mentioned that he has a Detroit Locker in his 289 car, and the Power Lock in his 427 car.

[ralphscott]

DRBB I currently have an edelbrock Performer RPM #7106 in Lil Cobra the specs:

Ford FE 390-428

Operating Range 1500-6500 RPM
Duration Advertised 296° Intake/296° Exhaust
Duration @ .050'' 236° Intake/236° Exhaust
Lift @ Valve .572'' Intake/.572'' Exhaust
Lift @ Cam .325'' Intake/.325'' Exhaust
Lobe Separation Angle 108°
Intake Centerline 103°
Intake Timing @ .050" Open 15° BTDC
Close 41° ABDC
Exhaust Timing @ .050" Open 51° BBDC
Close 5° ATDC


I plan on going to a Comp Cam Dual Pattern CCA AL33-207-3
It's specs are:
Basic Operating RPM Range: 1,500-5,750
Intake Duration at 050 inch Lift: 211
Exhaust Duration at 050 inch Lift: 223
Duration at 050 inch Lift: 211 int./223 exh.
Advertised Intake Duration: 265
Advertised Exhaust Duration: 275
Advertised Duration: 265 int./275 exh.
Intake Valve Lift with Factory Rocker Arm Ratio: 0.484 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.510 in.
Valve Lift with Factory Rocker Arm Ratio: 0.484 int./0.510 exh. lift
Lobe Separation (degrees): 110

I have also changed out my carb from a 780 to a 650 I have much better thottle response from a stop and go situation.

Had a great time meeting Paul. We ate at a Mexican restaurant and Butch brought one of the twins, Will. Great meeting you Paul.

Ralph

[drbb]

Has anyone used a tremec t56? and if so what gearing ratios? If so anything you would change?