what the difference ?

theres a classic and a race version , classic is the most popular one its got a bigger core and produces a little more power, then u got the race version which is a longer canister and a smaller core, it is quieter for racing etc,

the higher hp your bike is, its been proven the bigger losses with the race canister.

the race is a 99 db canister, about 2-3 inches longer, with a smaller core.

the classic is 2-3 inch shorter, larger core and loud as balls. i love mine

I have a classic dasa and race dasa and a 4" cut classic dasa and the 4" cut dasa makes the best power but oh my is it loud, the classic dasa sounds realy good and runs great but it is also a bit loud i think like 102db, the race dasa sounds great realy low on my bike and makes realy good bottom but flattens out on top but is lots better on the ears, the classic is the most popular thats for sure