I bought a 94 RX-7 3 months ago. With these mods, 13B-REW (less than 10000 mi. on engine) w/3mm Apex seals, port & prep. Apex SuperIntake. Bonez stainless downpipe and converter, RP type-C stainless catback.

I've got a steady hum around the 2800 -3400 RPM range. Anyone got any ideas what it could be.

thanks
Carl

 

I bought a 94 RX-7 a few months ago. Here is some of the mods on it. 13B-REW (less than 10000 mi. on engine) w/3mm Apex seals, port & prep. Apex SuperIntake. Bonez stainless downpipe and converter, RP type-C stainless catback. This started about a month ago. under Light acc or crusing a have a constant hum in between 2800 - 3300 RPM. But when i'm ACC heavly there is no hum. Anyone got any ideas?


Thanks
Carl

 

It may be vibration coming from some place in the Exhaust piping or actual Muff. Muff Shops sometimes have to weld additional hanger braces on Muffler to chassis....and the vibration transmits to chassis/frame of vehicle. Sound/hum can be pretty annoying!! If not a hanger/brace problem, hope it's not serious. Or maybe just a bad/clogged back-cat?