need type r specs 1240d

Ok so i had a type R fall in my lap at work and so i figured id make a ported box for it to fit in my camaro,i looked up the specs for the type-r's at work and it said i needed 1.9cu ft of volume for a ported box, now heres my issue im pretty sure the type R ive got is older, and so im thinking the needed volume is different, i searched the net and found nothing on it, the newer manuals show the "optimum volume" but the other one i found on here didnt have anything like that

anyone know the specs on this sub? If its a different volume im gonna have to re work my box design

any info would be great TIA

oh yeah box is going into an 89 camaro in the rear well, just big enough for the needed volume and then im putting a carpeted trim plate over it to give a flushed look for the sub, cant really tell the year of the type R but i know its older lol