ren987

iTrader: (4)

I have a detroit locker in my 9 inch, my set up is a 6 speed not sure if you are an auto or not but if I had it to do over again I would go spool with out a doubt. The locker is so loud and clunky @ low speeds its almost embarassing.

Sarg

iTrader: (6)

Has anyone here run the Powertrax No-slip? What about the Currie platinum?

3rdgentug

iTrader: (23)

sarg im at the same point you seem to be

i did a lot of research and talked to quite a few people that all tried to sell me things

took all the advise i got and made my decision

i ended up going with a currie 9in with a true trac and a 3.25 gear
of all the advise i was given that option seemed to come up more then any other
ofcourse mines not a drag setup either but more for road warrior n maybe some auto x

Sarg

iTrader: (6)

The 9" does seem to come up a lot, but that seems like it is going to be stupid expensive. Currently I can buy for the 8.8:

-Differential $300-$1000
-Axles: $300
-Brakes: $0
-Housing $0

Or 9":
-9" housing with axles set up for a fox $1000
-Carrier and diff $1000
-Brake set up ? maybe another $300-$1000

While I agree that would be the best way to go I just can't justify at this point the massive expense. If it comes down to it I can always get an open diff from a junk yard for the 8.8 with 31 spline axles and do this for $400 and see how it works. At that point I already have my disc brakes and if I hate it I am not out a metric crap ton of money.

Gonoma

iTrader: (15)

I think you can get 9" housing ends that will let you use the brakes you already have. You could put them on the 8.8 housing to eliminate the c clips or just have them put on the custom 9"

65panel5.3

im running a detroit locker in my 65 panel with twin turbo lq4 th350 trans,12 bolt gm, 28 inch tall m/t et street. hooks up great and turns nice still with no shuddering, i think ive heard it unlock about 3 times ever, yes its a little loud when it does but the sound doesnt bother me at all.

Tjabo

Do those clutch packs actually hold up, and really grip when you apply power in a right hand turn? With the old school traction lock diffs you might as well have had an open diff when trying to power out of a tight right hand turn unless you added clutches until you preloaded them against the pinion, so I don't think they would be worth a damn for trying to run 9s. These must grip a lot better I guess...

Sarg

iTrader: (6)

I was kinda thinking the same. I would think a car in the 9's would have the traclok doing one wheel peels in short order. I have been wrong before though.

stmz28

iTrader: (9)

I had a detroit locker in my 9 inch then it broke so I switched to a spool

zapp109

iTrader: (13)

Im going to run a wavtrac in my fox with moser 31 spline axles and c clip eliminators. Just waiting on my tax refund to make the order. The person i talked to about the wavtrac told me to call moser and they would do a better deal for me since im getting everything... And i run street to much to run spool.

usdmholden

They are better than the OEM Mustang diffs, but they aren't going to compare to a good road race torsen. They seem about the equivalent to the old school OEM trac lok with an extra clutch pack and an F150 spring, if you are familiar with Fox Mustangs circa 10-15 years ago for trac lok action, but they turn better than the old school stuff. The biggest benefit is you can now just go buy one brand new with 31 splines which works pretty well, and install it, instead of screwing around with the clutch pack thicknesses, F150 spring insertion, truck 31 spline sourcing, etc.

Also, my choice was based purely on driveability, not running 9's. I believe the Cobra diff could do it in a light car, but is it optimal? No.

Tjabo

Cool, thanks! I hope to be able to give one a shot in something at some point then!

Are there any options to try to jam a little more spring pressure in there, or not? Seems like I read that there was a stiffer S-spring that people were unable to squeeze into the diff, so that sounded hopeful assuming a person could figure out a way to get it jammed in there...

Sarg

iTrader: (6)

Well it is looking like a spool with 33 spline axles unless someone has had good experience with the platinum or powertrax no-slip.

usdmholden

If you are worried about a Cobra diff, then automatically rule out any of the inserts which install the OEM diff carriers. My opinion is those products are low budget gimmicks which offer the buyer a sense of security rather than actual security.

I don't mean to offend, but I don't really understand the goal of your car, because the drivetrain is kind of drag, the suspension is kind of drag, the brakes are sort of street, and the wheels/tires are sort of road course. I think pretty much any 31 spline (or more) diff/spool will work in your application. Spool will be the cheapest, you can buy one for $150 brand new from Summit.

usdmholden

That sounds like the F150 spring. I can tell you from my experience, it's nearly impossible to jam in an F150 spring while lying on your back under a car with the gas tank in the way. Yes, people have done it that way, just not me. Pulling the diff and doing it on a bench or an H frame press is much easier.

I didn't try to modify the Cobra diff at all, I don't ever want another dedicated drag car, 99% street daily driver is fine for me.

Sarg

iTrader: (6)

None taken. Drivetrain is drag/highway. Brakes are street. Rear wheels will come off and go to slicks for the drag strip. The goal is a low 9 second drag car that can still be driven weekends on the street or down the highway, mountain cruise, whatever. That may not be 100% realistic from what I am hearing, but I was trying to explore some of the lockers on the market as they seemed like they could have the best of both worlds.

usdmholden

A locker will work fine on the street. I've never had one in any of my Mustangs but I have ridden in and driven many Mustangs with lockers. When I say locker, I mean an actual FMS detroit locker type diff, not an insert.

Sometimes, and possibly often, people don't like the "jerk" which occurs in a locker, when the driver punches the gas while going around a turn and the inside tire instantly starts turning the same speed as the outside tire. As long as you expect it to happen, it should not come as a surprise. Some people hate it, some people never notice it at all, it only depends on personality. Honestly, punching it around corners is probably not something you would want to do with a big turbo anyway.

Monzsta

The way a locker works is both beautiful at the strip and tiresome on the street. The locker will unlock the faster moving tire and power the slower moving one always. So in a turn, you step on the gas, ALL the power goes to the inside tire which will make you push through the turn in an ungodly fashion, and/or if traction is lost on that tire you end up with a vicious snap oversteer. If you lift in the same turn, the same inside tire now exerts all the engine braking to the chassis making the car suddenly VERY hungry for the inside of the turn.

Going straight down the highway with traffic, it will randomly lock and unlock whichever goddamn wheel it feels like as you are on and off the throttle staying with traffic, gently tugging the car side to side like you're riding in ruts.

I'm ditching my locker for a Quaife Helical diff and never looking back.

usdmholden

I've seen this before in a Mustang and we minimized it by adjusting the rear control arms to effectively square the axle relative to the front wheels.

First we had the front end aligned relative to itself, and then we put the car up on blocks so it's weight was supported by the axle and front control arms, IE it was at it's ride height. The we dropped carpentry bob weights from the axle/hub centers to the floor and aligned the rear relative to the front by matching the X dimension measurements from RR/FL and RL/FR.

Basically a combination of a slight front toe out condition and an invisible rear crab walk was sensed by the differential even though we could not see it with our naked eyes. Add that to a huge pneumatic trail on the front tires, and well, it was obvious while driving the car.

After our "fix" it was virtually unnoticeable.

Monzsta

The thrust angle was around 1 degree when I last had the car on the rack. Not perfect, but well within tolerances and at the time it didn't seem necessary to get it closer. I was pretty pleased as it was a 9" I had cut down and welded the brackets on salvaged from the old 7.5"

Also with a brand new set of tires on the car it was almost perfect in regards to highway driving, but after a few weeks and burnouts, the throttle wander seemed to get worse.