I currently run a DX tranny with my boosted z6, I own a EX tranny with a bad 3-4 syncro that i'll be rebuilding at school and also putting in an OBX LSD. I had the thought of putting in the taller DX 1st gear in the EX tranny as I feel this would help with my 60ft times.

My first question is, are these gears even interchangeable? and my second question is will this additional work be worth the payoff or even make sense? Lastly, should I just STFU and run the LSD EX tranny and leave the gear alone?

 

First gear is the same.

I suggest using something better than the OBX LSD, they have quite a few problems.

 

Ditto that!

 

there's an *** ton of folks that run the OBX LSD with no problems, and they've fixed the passenger side axle issue.

 

It is more than a passenger side axle issue. Ever check the runout on an OBX?? I know there are some adjustments that can be made but, still not satisfied. I have seen them apart and would rather use a more quality LSD. Just my .02

 

All of the S20 and S40 D series transmissions use the same 3.25 ratio 1st gear. You can get an aftermarket MFactory 3.083 1st if you want the longer ratio. I would also suggest spending a little more and getting the MFactory LSD - it is worth it for a better quality part.

 

christ, i wasn't trying to go ape ****..i have a 4,000 bill i'm about to ring up for myself on the car. I only thought of running an LSD this morning, because I started my manual transmission class at school and thought it would be fun to do. Not to be a pain in the ***, but what about all the success stories?? there's peeps on here running 600hp with this OBX piece. Is there anything i can do to ensure its durability? I have a teaching professional assisting me with the install.

 

Not really, OBX is just flat out junk, the basic materials are crap, the QA is crap and fitment is crap. There's a lot of guys that talk about replacing the belville washers in them, but all they do is provide noise suppression. They wont do anything for the runout and poor materials and machining. Mfactory LSDs aren't exactly cheap, but they're very worthwhile.

 

Honestly, i'd rather save my money than buy an obx lsd. If you can't afford to buy a mfactory unit just save your money, you will have less headaches down the road.