dont know weather to put on a 2 inch exaust piping or 2 1/2 piping non turbo 88 seven

 

I used to have a non-turbo 1988 Mazda RX-7 GTU, and I went with a custom made 2" downpipe. I think that if you're naturally aspirated, anything larger would just cause you to lose back-pressure and be pointless. The whole job cost me under $100 and I saved a lot of money.

 

thanks .