2015+ Super 8.8 Non Performance Pack vs Performance Pack Rear Ends

[T6Ted]

Thanks guys!

Ya I am leaning towards a low miles savage Performance pack rear end. How much can the Trac-loks handle as far as power?

[edwardb]

Thanks guys!

Ya I am leaning towards a low miles savage Performance pack rear end. How much can the Trac-loks handle as far as power?

Unless you're talking about high horsepower (and I'm talking about ridiculous numbers) and drag slicks really nothing to be worried about IMO. The Mustang crowd is running this diff with big power adders and sticky tires basically unchanged other than stiffer mounts. A much heavier car of course. And the Factory Five mounts are poly and already pretty stiff. Axles are what the Mustang guys are breaking. But again, unless you're talking crazy numbers, the ones Factory Five provides are very strong for these builds.

[T6Ted]

Unless you're talking about high horsepower (and I'm talking about ridiculous numbers) and drag slicks really nothing to be worried about IMO. The Mustang crowd is running this diff with big power adders and sticky tires basically unchanged other than stiffer mounts. A much heavier car of course. And the Factory Five mounts are poly and already pretty stiff. Axles are what the Mustang guys are breaking. But again, unless you're talking crazy numbers, the ones Factory Five provides are very strong for these builds.

I suspected that was the case with the Trak-Loc. I am putting a 427W in my coupe so 500-600hp. From my initial search of complete rear ends its only a couple hundred difference between Perf pack and non so likely just focus on finding a 3.73 rear end.

[edwardb]

I suspected that was the case with the Trak-Loc. I am putting a 427W in my coupe so 500-600hp. From my initial search of complete rear ends its only a couple hundred difference between Perf pack and non so likely just focus on finding a 3.73 rear end.

Just make sure you look at the whole picture when deciding about the diff ratio. Engine, trans, diff, wheel size, how you're planning to use the car. Depending on the trans you're planning, along with everything else, with power like that 3.73 might be on the high side. Play with the numbers using a calculator like this one http://www.tremec.com/calculadora.php. Understand you may want to use the Torsen setup. But that's where guys are swapping out the clutch packs for the Torsen in the 3.31 or 3.55 diffs where it makes sense. Or swapping the gears in a 3.73 Torsen. Either works.

[T6Ted]

Yea make sense. But being an auto engineer I do love Excel! But you were not far off. Looking like 3.73 gearing will work. For starters 4.11 with the 2.66 1st gear in the close ratio T56 is 10.93. Making for a bit of a rough cruiser. With the 3.73 dropping it down to 9.93 that is a little bit more livable as my goal is a hybrid track/cruiser. Leaning towards track/race car really.



Gearing.PNG

[edwardb]

Yea make sense. But being an auto engineer I do love Excel! Looking like 3.73 gearing will work. For starters 4.11 with the 2.66 1st gear in the close ratio T56 is 10.93. Making for a bit of a rough cruiser. With the 3.73 dropping it down to 9.93 that is a little bit more livable as my goal is a hybrid track/cruiser. Leaning towards track/race car really.

I'm not quite getting your reference to 4.11, since that's not an available diff ratio. If that's what you meant. But the 3.73 and T-56 Magnum with the 2.66 first (Tremec TUET11010) matches up quite nicely. Happens to be the combination I'm using in my Gen 3 Coupe build. Very similar in a lot of ways with a TKO600 and 3.55, which is a very popular combination and I have in my Roadster.

But you were not far off.

Thanks. I think.