Here's the deal. I have an 88 SE. I am beginning to start my upgrade process by picking up a K&N cone filter, building a cold air intake, and installing a custom dual exhaust system using the RB dual header.

I went to my local junkyard, and low and behold, they have an 86 RX-7 there. The car has no markings to let me know the model, so I will have to start looking closer at the options on it. It does have the U-shaped spoiler (GTU spoiler, I think.) installed and is in mint condition. Looks like a possible engine fire or front end collision. The entire rear of the car looks great. They told me I can have the spoiler for $50 if I yank it and $65 if they yank it.

This got me thinking. Might this car also have an LSD rear-end? Everything is present up to the lugs. The rims are removed and the car is set up on some blocks to keep it off the ground. How much of the rear-end do I have to remove to get the differential out and able to install in my RX? Do I need to convert to 5-lug or can I stick with the 4-lug? All the break components appear to be there, but I wasn't looking at that and didn't take a good look. What do you think the brakes condition would be after sitting in the weather like this?

Basically, my questions:

How to tell if it is a LSD rear-end? (Spin it and watch both tires spin in the same direction?)
Can I leave my 4-lug setup alone?
Would it be worth upgrading to the 5-lug if I have to sink alot of money into rebuilding my brakes again?

 

Marajuana, marajuana, lsd, lsd;

Jimmy carter makes it,
Ronald Regan takes it,

why cant we,
WHY CANT WE!

 

LOL

(oops........I almost got in trouble in my class. Laughing out loud during lectures draws attention.)

 

If the whole rear end is cheap, grab it.

Without knowing the model and year its pretty hard to know you have found a LSD without testing.

But the 5 lug hubs/brakes are considerably better than the 4 lugs for stopping power and overheating plus there are a lot more options for wheels then.

 

Do any of the five lug setups use the same calipers as the 4 lug? I thought I read somewhere where there is three styles of brakes.

1. 4 lug, small brakes
2. 5 lug, small brakes
3. 5 lug, large brakes (e.g. TII etc.)

I am currently 110 miles from my home and the junkyard there, I will be going home tonight and will go to the junkyard tomorrow and check it out.

The main reason I ask is this:

I just bought new, non-returnable front brake pads for my RX. I would like to be able to use them. Also, the rear right caliper was just replaced and has less than 5k miles on it. I would feel a little cheated if I had to go through and rebuild the whole brake system again and be out that $100 I spent as well as have to buy new wheels. Can't really swing it all at once. I will probably purchase the rear end and just wait to install it until I can afford some new wheels and tires as well as a couple hundred dollars worth of brake components (e.g. calipers as needed, new rotors, and brake pad). Don't get me wrong, I will definitely put new pads all around on the setup as well as turning the rotors or replacing them as well. I just am worried about getting stuck with two or three frozen calipers.

Thanks so far guys. Keep the suggestions coming.