bewbzout

For those that have done it any better 1/4 MI tkmes? Also with the diff swap will I need new axles? I read somewhere that the early e55's had different diffs so new axles were needed. I have a 06 e55 and the sl55 diff I'm looking at is a 05.

JoeNobody

You have the later axle design. The SL65 diff probably has them as well, but if you need new axles you can find salvage axles pretty cheap off eBay.

Does the SL65 also have the factory LSD? It's not as good as an aftermarket LSD, but getting a diff with an LSD already installed is zero extra work and usually cheap too.

I swapped an E63 LSD diff into my E55 and it was one of the best mods I did. Not sure on quarter mile times, but I think others have reported better times. My highly accurate butt dyno says it's faster, and second gear now pulls really hard.

As you already know, you'll need your TCU reprogrammed for the different axle ratio. There's also a developer menu in the ECU you should change to reflect be updated ratio (search posts and you'll find the info).

The only thing I haven't figured out is how to make the changes that cars with factory LSD have. It's subtle changes for the ESP, and it could be done by adding the LSD option to the datacard, but I don't have access to online coding. A tuner reported there is a way to make the changes without using online coding, but how to do that remains elusive.

bewbzout

Thanks man that is some good info. So damn now I have to try and source a sl65 diff? I think that will be much harder then the sl55. Can anyone confirm this?

JoeNobody

You can source the diff from many different models. An SL55 will work, and it'll have lower gearing. Search and you'll find what cars are compatible along with their gear ratio.

99lightning

I would got 3.06 if you are going to go through the hassle. Its a perfect balance. It will pull like a maniac. for quartermile times all I can say is I have not had a true test since I have battle wot shifting issues which I think is fixed now and traction that being said. My car would trap 121 before gears with 94 or 95 in the eighth. with the gears blowing the tires off and cutting out on the shifts trapping 92mph in the eighth I would still trap 121mph. so that tells me the gears are doing something. now when I get traction and solid shifts I should see a nice gain.

bewbzout

That's actually what I would like to do. Where are you getting 3.06 gears? I have never heard of that

99lightning

mine were out of a challenger 215mm I believe go on the lx challenger boards got mine cheap contact eurocharge let them know exactly what vehicle they came out of he can do the tcu tune. I will do more stock shift point testing but that's where I think they need to be.

JoeNobody

If you're going to swap the ring gear in your original diff, might as well put an aftermarket LSD in there as well.

The main benefit of sourcing an OEM diff is the ease of install since you don't pay the labor of opening up the pumpkin.

bewbzout

Yea I definitely would install a wavetrac or quaif when doing the gears. The nice thing is I can do it myself :-)