SPOOL and LOCKER...

Also, can someone explain the difference between mini-spools and full spools.

BTW. This is a TRACK car. It will only bei seeing the street to drive TO the track and back home. Streetabitliy is not an issue.

Why are spools so cheap and lockers so expensive? And mini-spools are like $30??? Is this right???
 
A mini spool is piece together to go in a open carrier. It uses a cross pin like what's in a stock carrier which can break and they can't be installed in a locker carrier so you need to find an open carrier to use a mini spool. A spool replace the carrier and is solid you can't break it. Locker has more engineering and technology then a spool. I run a spool in my Daily Driver and my Track car. If it's mostly track driven then go with a spool.
 
a spool permenantly locks both axles together so that both wheels get exactly the same power at all times. when turning, a spool will cause one wheel to drag on the ground a bit and make scraping sounds.
a locker gives equal power to both wheels just like a spool but when on the street, it disengages when not on the throttle so you can turn without the tire wear and noise.

i believe the mini spools arent for drag racing. the poor man's way of making a spool is just welding the differencial gears in the trac loc you already have so that they cant spin.