I use an Excedy ceramic 4-button clutch in my race car and I love it. All A-series clutches are 180mm diameter. The E-series motors use 190mm. I purchased an E-series 190mm clutch and my clutch guy used my original a-series housing so it would attach to my flywheel. my car will spin both back wheels (its locked) in any gear possible without the clutch slipping, but the pedal isn't hard at all.