Topillogic

Right on, that'll teach me to try math at 3am. Found a better calc that lets me mess with the reduction gear.
I really need someone smarter than me to do the real math with an approximation of the torque curve we're going to end up with.

Appreciate the detailed reply on the diff I was considering the Quaife, although it's more spendy it seems like a good fit for the way I'm going to use the car.

tunedbycft

If you are looking to have fun in the street & 1/4 track, you should go with the 3.90 ratio.

That's what I'm running!

Fernando @ Kings Performance

Topillogic

Right on, I'm going for the 3.90. Gearing felt too short already with the old setup, going bigger for round 2 (w/4.10) would just make that worse.

passmans2kny

same here, running a richmond gear 3.90

B3AN

For those of us who don't enjoy shifting every half second and would prefer to not need 6th gear to reach 150mph, would the 3.55 rear or something in that range for the 8.8 be a good idea?

Note: this is for a theoretical 500whp AP2

passmans2kny

no go with the 3.9, the 3.55 would make the gears too long

Ilike2DRIFT

If the 03 cobra uses a aluminum housing don't you think it can handle the abuse? Or are the 03 cobra's built different?

wadzii

the 03 cobra diff's hold up to around 600 in those cars with no problems, after that they need a reinforced cover that usually runs about 200bux.

some of those used the 31spline axles vs the 28 spline so make sure you get the right axles for which ever one you have.

passmans2kny

u cant run a reinforced cover on these since no after market covers have the mounting holes in them which holds up the diff on this kit

passmans2kny

jesus christ