Go Fast Bits GFB 04-05 Miata / 93-98 Supra (w/ modification of factory hoses) TMS Respons Blow Off Valve Kit - T9020 $342.00 $307.80 If cars like yours typically suffer issues such as backfiring and stalling when using a fixed-ratio atmosphere-venting BOV, the Respons can help. By adjusting the venting bias to suit the car you can achieve a blow-off sound without having to put up with... Add to Cart