MBRP 4" Armor Lite Performance Turbo Back Exhaust 89-93 Dodge 5.9L Cummins 4WD MBRP-FALCA460 Testing has shown that the

Testing has shown that the hole diameter is too small

if you installed a 3K governor spring kit

A temporary "stall" of the intake airflow occurs until the pressure in the discharge side drops and airflow continues in the "forward" direction again

5-75 PSI Normal Operating Range

If you had a CP4 failure

MBRP 4" Armor Lite Performance Turbo Back Exhaust 89-93 Dodge 5.9L Cummins 4WD MBRP-FALCA460 Testing has shown that theIs it time to give your 1st Gen Cummins some added power and sound? Or is your factory exhaust hanging on by a thread? MBRP has the solution with their aluminized 4" Armor Lite performance turbo back exhaust systems for the 1989 1993 Cummins.