Best differential for the street?

steel1212

Active Member
Jun 24, 2004
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Frankfort, Ky
What is the best limited slip/posi for the strip? I don't want something thats going to be making a lot of noise going around the corners but I want to hook up also...I'll be putting cal-tracs on there as well as subframe connectors. I know everybody has their opinions but give me the reason why you picked what you did and why:

PRICE
NOISE
QUALITY

Also anybody tried the newer one that doesn't use clutchs?
 
Powertrax No-Slip

I bought a powertrax no slip and I really like it. The only noise it makes (after the 50 mile break in) is when I am turning hard in a parking lot at 3mph or less. And once you have it for a while you get used to it and you can even make that very minimal. As far as on the road, this thing hooks up great. It is supposed to last longer than the clutch style diffs. I would highly recommend it. Get ready to go sideways....
 
DPI Black gold street differential. Works like a posi when you accelerate, but rolls freely through turns like an open differential. If one wheel brakes loose it puts power where you have traction. It can take up to 750hp/tq reliably, doesn't make any noise, doesn't use springs or clutches like a limited slip so it hits much harder, etc etc.
 
I have auburn pro unit and love it. It was suggested to me by PEARSON'S AUTO, a highly recommended local guy. Love it and the launch is far superior. I also went from 3:00's to 3:70's. Again FAR SUPERIOR
 
Of the three listed, there are mechanical and clutch style differentials; each are best suited on the type of driving you are doing. Generally speaking, mechanical are best suited for 1/4 mi. These include Powertrax, Detroit Locker, and others. Clutch styles are best suited for Autocross and Open Track. These include Ford traction-loc, Auburns, and other limited slip type differentials.

Of the three listed I'd choose the Auburn. Griggs racing uses Auburn's in all of their track beasts and are proven performers under extreme conditions.

I personally chose a 4-Spider Traction-Loc for my 8". If I ever have the need for a 9", I'd choose the Auburn. If you plan on using the 8", your choices will be fewer.

Cost wise, they are all relatively the same and are in the $350 - $500 range.
 
66P51GT said:
Of the three listed, there are mechanical and clutch style differentials; each are best suited on the type of driving you are doing. Generally speaking, mechanical are best suited for 1/4 mi. These include Powertrax, Detroit Locker, and others. Clutch styles are best suited for Autocross and Open Track. These include Ford traction-loc, Auburns, and other limited slip type differentials.

Of the three listed I'd choose the Auburn. Griggs racing uses Auburn's in all of their track beasts and are proven performers under extreme conditions.

I personally chose a 4-Spider Traction-Loc for my 8". If I ever have the need for a 9", I'd choose the Auburn. If you plan on using the 8", your choices will be fewer.

Cost wise, they are all relatively the same and are in the $350 - $500 range.

The DPI is mechanical but is better for drag/street/autocross than all of those. It works like all of them in the same package. It basically changes it's operation because it reacts to driving conditions. Top road racers and circle track drivers use them and they are completely gear driven. They are also good like a Posi or locker because they bind on their own and work like a posi under acceleration until one wheel brakes traction and then it acts like an LSD and puts power to the wheel with traction.

None of the other differentials are even worthy of comparison, the only thing that the Black Gold lacks is price because it costs $650 But none of those other differentials can hold a candle to it in any way shape or form. It drives like a whole new car upgrading from an Auburn or Posi to a Black gold. They are better around town, and better for performance driving hands down.
 
eric n said:
I have auburn pro unit and love it. It was suggested to me by PEARSON'S AUTO, a highly recommended local guy. Love it and the launch is far superior. I also went from 3:00's to 3:70's. Again FAR SUPERIOR
I have that one too with 3:25 gears.I love it a lil bit noisy around the turns at slow speed definitly good though :nice: :nice:
 
Paul619 said:
I have that one too with 3:25 gears.I love it a lil bit noisy around the turns at slow speed definitly good though :nice: :nice:

I guess I got lucky, I have no audible noise around corners. Then again maybe I can't hear it over my noisy arse flowmasters or maybe I never actually slow down. Anyway, without a lot of knowlege I can say an auburn in a 9" rear (mine is a 28 spline ) running 280 hp 292# at the rear wheels, is much good fun.
 
I have an 8 inch rear with stock gears and I'm trying to decide on that one to if I want to get a currie 9" or just build my 8. I'm thinking my engine will be around 360ish hp with afr 165s and I'm pretty sure the 8 can handle that especially if I upgrade the diff and gears. Now later on when I get a stroker..... :D

As for makeing noise I don't want something thats going to sound like my rearend is trying to ratchet itself out from under my car. I mean I have flow master 40s and they aren't exactly the quietest.

2bav8 you do make a point I guess when I get my cals they are going to be noisy as well but I didn't figue they would be real loud.

The only posi I'm around on a regular basis is my buddy's 70 chevelle and it still has the factor posi and you can't hear it or the traction bars but then again his exahust ends under the seats right now :D
 
steel1212 said:
I have an 8 inch rear with stock gears and I'm trying to decide on that one to if I want to get a currie 9" or just build my 8. I'm thinking my engine will be around 360ish hp with afr 165s and I'm pretty sure the 8 can handle that especially if I upgrade the diff and gears. Now later on when I get a stroker...
I will have ~380HP at the crank and chose to use an 8" 4-Spider Traction-Loc with 3:80 gears. Currie sells these but I picked up an entire rebuilt 3rd member with new gears for $550 shipped from [email protected]. He also sells on ebay. His ID is fast500xl1.

If I end up doing the Summit series next spring (assuming the car is done by then!!!), I will upgrade to Currie's new 8" aluminum pinion support. It is only $100 and would not be too expensive to install. It houses a larger/stronger bearing and will shave a few pounds off the RR as well.

View attachment 521436
 
I talked to a guy here in Kentucky that builds rears and he suggested auburn pro, 4pinion that they build or true trax. The true trax he says is quite but is gear driven. Anybody use the true trax? The true trax is around 700 with gears and ready to drop in the other 2 are around 500ish.
 
True Trax is similar to the DPI black gold.

steel1212 said:
I talked to a guy here in Kentucky that builds rears and he suggested auburn pro, 4pinion that they build or true trax. The true trax he says is quite but is gear driven. Anybody use the true trax? The true trax is around 700 with gears and ready to drop in the other 2 are around 500ish.
 
I just got an 8 inch with 3:80 from fast500kl1. took out the old center today, putting in new one tomorow

be prepared to wait. he told me it would take 3 weeks, but it took 4
 
bmcelhinn said:
DPI Black gold street differential. Works like a posi when you accelerate, but rolls freely through turns like an open differential. If one wheel brakes loose it puts power where you have traction. It can take up to 750hp/tq reliably, doesn't make any noise, doesn't use springs or clutches like a limited slip so it hits much harder, etc etc.

So this is a torque-sensing differential ? Like the ones you find in Audi's Quattro system?
 
fvike said:
So this is a torque-sensing differential ? Like the ones you find in Audi's Quattro system?


Just reading DPI's website real quick, the Black Gold is a torque sensing differential, not exactly like the Audi system though because I believe their's has an electronic element to it too.