I have two questions. I am new to Evos and recently picked up a 03' Evo. I changed all the fluids for the motor, tranny, tc, and diff on time. But some things I noticed, if I drive in 5th under 3 RPM, the car rumbles while driving. But once I am over 3 RPM, car drives normally. My other problem is when I use the ac, the car feels weak. The turbo goes off, but the car doesn't gain any speed? Can someone help?

 

The 2003 Evo VIII's and maybe other years have an NVH problem in 5th gear at the rpm you mention. People say it is the transmission, transfer, clutch or other parts. I notice what tire I am running makes a difference. I dunno the real answer or fix.

The Evo 4 cylinder is tiny with little torque until boost comes on. The AC soaks up about 25 hp. Add in hot weather meaning thin air and the car is doggy on a hot day.

 

My '04 doesn't get too shaky 'till down around 1500. There's no real power down there but if you're just putting around town it's fine.

Has anyone improved this with tuning? It seems like this could be improved with timing map changes thru reduced timing and therefore softer torque pulses...