Mazda Talk Forums

Hey guys! I have a 2008 MX5 with the 6 speed and im running 17x9 cobra wheels from the 03/04 mustang cobra. I have 225/45's up front and 245/40's in the back... now these wheels are MUCH heavier than OEM, but I don't plan on using them for racing...I got an alignment this morning, but my steering wheel STILL shakes a lot at highway speeds... Im guessing the RX8 front hubs might help, but I was wondering if you guys had any other suggestions(other than getting new wheels, LOL), like maybe better bushings, or ball joints?

Unsprung weight will make the car ride poorly but the poor ride is consistent at all speeds. If the shakes are coming and going depending on speed, like worst at 60mph, it is most likely balance issues on the wheel and tire combo. Google Hunter Road Force Balance and from their website enter you zip and find nearest place near you with Road Force Balance setup and have those wheels/tires rebalanced.

Note 225/45's up front and 245/40's rear is a terrible setup for a 50/50 balance Miata, in emergency the car understeers so severely that you plow right into the guard rail, tree, cliff edge, etc. So I need to just underline we do NOT recommend staggered setups.

Thanks Brian! Last night I had a flat so I will be going back to my OEM wheels here soon. After three months of driving on the mustang wheels, I'm getting tired of the terrible ride quality. I will probably keep them though because I want to go for the whole "stanced" look once I get some BC Racing coilovers and the rx8 Megan Racing control/lateral/toe arms. Talk about un-recommended suspension set-ups! LOL. but I plan on gathering a collection of adjustable suspension arms and different wheel/tire combos because I already know I will change my mind in the future.