I picked up a used Diff last sunday. guys says it has a Comptech reinforced housing with a richmond 4.56 with 10000 miles on the build. i installed it on my ap1 couple days ago and put Amsoil severegear 75-110 fluid on it. i cant feel a huge diffrence in it but have only driven it about twenty miles or so right now. one thing i did notice is that it has alittle whine to it, is this normal? made me double guess myself as if it even does has a 4.56 in it but i turned my gps on and the speedometer is reading about 5 miles faster than the gps? so for the long extensive type. what do you guys think.

 

those gears are suppose to whine. as for the speed on. you are suppose to be going slower than what your speedometer is saying. you need to get a yellow jacket. it fixes the speedo reeding. modifry has one and rick used to sell one. the modifry can only be calibrated for shorter gears while ricks can be calibrated from longer and shorter gears. you really only need to calibrate to your shorter 4.56 gears. but if you happened to come across a ricks for a good deal then get it. i have 4.44 gears and i used the modifry one. i personally think it is a little easier to calibrate. the modifry has 2 dials and numbers that allow you to choose the percent change, while ricks is a series of switches.

you can do a search or go on modify and you can see the common percent change of 4.56 gears.

 

How much of a butt dyno could you tell when you switched to 4.44

 

??? there is no horse power increase. but it does feel faster. gears only allow the car to feel more torque-y.

 

I realize that but i was talking about how much torquier does it feel, because i didnt build this diff so i really dont know what all is done to it unless i would open it up and i didnt feel that great of diffrence the twenty or so miles that i drove it.

 

there is a difference. but it isnt going to be a turbo difference. if you look at my mod list and i have tuned it since. i can keep up with a super charged s2k till about 3rd gear and he is gone. so first and second gear should have a strong pull to it.